Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Electronic Resource  (252)
  • 2020-2023
  • 1995-1999
  • 1980-1984  (153)
  • 1965-1969  (99)
  • 1950-1954
  • 1860-1869
  • 2022
  • 1981  (153)
  • 1969  (84)
  • 1968  (15)
  • 1953
  • 1866
  • Physical Chemistry  (179)
  • Cat
Source
Material
  • Electronic Resource  (252)
Years
  • 2020-2023
  • 1995-1999
  • 1980-1984  (153)
  • 1965-1969  (99)
  • 1950-1954
    • +
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Effects of early monocular deprivation on development of cortico-geniculate projections in the cat (1981)
    Springer
    Experimental brain research 43 (1981), S. 451-454 
    Details
    ISSN: 1432-1106
    Keywords: Monocular deprivation ; Cortico-geniculate projections ; Visual cortex ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In 16 cats monocularly deprived from 2 to 3 weeks of age, we studied 53 striate cortical cells which were identified as projecting to the dorsal lateral geniculate nucleus (LGN) on the basis of antidromic activation from LGN and of histological localization within cortical layer VI. As in the normal cat, these cortico-geniculate cells could be classified as slow, intermediate or fast, according to their axonal conduction velocities. The sampling ratio of the slow cells (mostly unresponsive to visual stimuli) was much higher than normal. On the other hand, the ratio of the intermediate (one half were simple cells) and fast cells (all except one were complex cells) was significantly lower than the norm. Also, the average axonal conduction velocities of the complex and simple cells were significantly slower than normal. These results suggest that normal maturation of cortico-geniculate cells, particularly fast and intermediate ones, is retarded or arrested by monocular visual deprivation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238390
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The eye movements of the dark-reared cat (1981)
    Springer
    Experimental brain research 44 (1981), S. 41-56 
    Details
    ISSN: 1432-1106
    Keywords: Eye movements ; Dark-rearing ; Cat ; Vestibulo-ocular reflex ; Optokinetic nystagmus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cats reared in total darkness to adulthood have abnormal eye movements. A spontaneous nystagmus is found in the dark before any visual experience. The eye movements evoked by vestibular or optokinetic stimulation are less effective at compensation than for a normal cat. The vestibuloocular reflex (VOR) has a low gain (around 0.3) and a frequency dependent phase relation. The efficiency of optokinetic nystagmus (OKN) is poorer than for a normal cat, except for downwards stimulus movement which is followed better than normal. OKN is poorest in response to a stimulus viewed monocularly moving in the nasal to temporal direction. Neither VOR nor OKN of a dark-reared cat recover in efficiency within 5 months of the animal being brought into the light. A normal cat put into the dark for 135 days shows none of these abnormalities except an occasional spontaneous nystagmus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238748
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Effects of unilateral superior colliculus ablation on oculomotor and vestibulo-ocular responses in the cat (1981)
    Springer
    Experimental brain research 42 (1981), S. 73-80 
    Details
    ISSN: 1432-1106
    Keywords: Superior colliculus ; Vestibulo-ocular responses ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Unilateral lesions of the superior colliculus were made in normal cats. Following the operation, animals exhibited a typical neglect for contralateral visual space and forced circling toward the ipsilateral side. Optokinetic nystagmus was decreased for a stimulus moving toward the ipsilateral side, particularly in the temporal-to-nasal direction when the eye contralateral to the lesion was stimulated alone. — 2. When tested in the dark, animals exhibited a strong imbalance of their vestibulo-ocular responses (VOR) to velocity steps or to sinusoidal oscillations. Rotation of the animal toward the ipsilateral side produced a VOR with a higher gain, and a shorter phase-lead than in pre-operative controls. VOR was decreased in the opposite direction to a smaller extent, however. The overall asymmetry between the two sides at the post-operative stage was about 40%. — 3. In two animals, spontaneous nystagmus was present in the dark with the fast phase toward the ipsilateral side. — 4. Visual suppression of VOR was abolished during ipsiversive rotation and was still present during contraversive rotation. — 5. The effects of unilateral colliculectomy on VOR were transient. Spontaneous nystagmus disappeared in 3 days. VOR asymmetry in the dark was no longer present after 2–3 weeks. Loss of visual VOR suppression persisted for a few more days. — 6. Superior colliculus exerts a tonic control on static and dynamic components of VOR. This control may mediate part of VOR visual modulation and provide a substitutive input for compensation of pathological VOR asymmetry.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235731
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Some comparative quantitative data on the different (Relay and associative) thalamic nuclei in the cat (1981)
    Springer
    Anatomy and embryology 162 (1981), S. 363-378 
    Details
    ISSN: 1432-0568
    Keywords: Thalamus ; Ultrastructure ; Cat ; Quantitative analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of the ventrobasal complex (VB) of the cat thalamus was investigated in order to compare the data with those obtained in other thalamic nuclei. New data are described regarding the identification of Golgi II type neurons and several forms of axo-somatic synapses. By means of a quantitative analysis the number of different profiles, distribution of interprofile contacts, synaptic densities and degree of synaptic input of the two main cell-types were defined. The quantitative data obtained in the VB complex were compared with values for the lateral geniculate body (CGL), nucleus anterior ventralis (AV-non-sensory relay thalamic nucleus) and nucleus lateralis posterior-pulvinar complex (LP-PU-associative thalamic nucleus). The quantitative data reveal that: 1. The occurrence of RL terminals is equal in the two relay nuclei (VB and AV) and three-fold higher than in the LP-PU. 2. The percentage ratio of specific terminals (RL) in the total surface area in the relay nuclei is three-fold higher than in the LP-PU. 3. The RL→D synapses are twice as numerous in the relay nuclei as in the associative nucleus. 4. The density of synaptic RS profiles in VB is half of that found in LP-Pu. 5. In the thalamic relay nuclei the number of synaptic contacts on Golgi II type neurons is one-third of the synaptic supply of relay neurons; in the LP-Pu the amount of synaptic contacts on Golgi II type neuron approaches the synaptic supply of projective neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00299979
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Widespread cortical projections of the ventral tegmental area and of other brain stem structures in the cat (1981)
    Springer
    Experimental brain research 41 (1981), S. 233-246 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Ventral tegmental area ; Locus ceruleus ; Parabrachial nuclei ; Horseradish peroxidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Thirty-three cat brains with injections of horseradish peroxidase in various regions of the cerebral cortex were screened for afferent projections from the ventral tegmental area, the locus ceruleus, and the parabrachial nuclei. All three structures were found to project to rather divergent parts of the cortex, including regions in the posterior half of the hemisphere. These results, especially for the ventral tegmental area and, to a lesser degree, for the parabrachial neurons, disagree with most of the target loci of established cortical afferents in the rat. Though our results might be attributed to species differences in the cortical innervation of brain stem structures, we prefer explanations which emphasize different densities in the distribution of brain stem afferents to the cortex, and/or which suggest different cortical targets of catecholaminergic and noncatecholaminergic neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238880
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Unidirectional habituation of vestibulo-ocular responses by repeated rotational or optokinetic stimulations in the cat (1981)
    Springer
    Experimental brain research 42 (1981), S. 34-42 
    Details
    ISSN: 1432-1106
    Keywords: Vestibulo-ocular reflex ; Optokinetic nystagmus ; Vestibular habituation ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1.Unilateral habituation of the vestibuloocular reflex was produced in adult cats stimulated by repeated unidirectional velocity steps (vestibular training) or by a continuously moving visual surround (optokinetic training). — 2. Unidirectional vestibular training produced a strong asymmetry of vestibuloocular responses (VOR). Responses to velocity steps applied to the “trained” labyrinth were decreased both in gain and in time-constant. This effect generalized to responses to sinusoidal oscillations (0.03 Hz to 0.1 Hz), i.e. to a stimulus not used during training. — No spontaneous nystagmus was ever observed in spite of the dynamic VOR asymmetry. — 3. Unilateral vestibular habituation produced by vestibular training appeared to be a long-lasting phenomenon. It was still present 10 days after the end of training. — 4. Optokinetic responses were not affected by vestibular training. — 5. Unidirectional optokinetic training produced an increase in the slow phase velocity of optokinetic nystagmus (OKN) by about 25% in both directions. This effect did not persist for more than a few minutes. A marked spontaneous nystagmus was recorded in the dark after each session of optokinetic training, with a slow phase in the direction opposite to the previous OKN. — 6. VOR in response to velocity steps and to sinusoidal oscillations were decreased unilaterally after optokinetic training. This effect was of short duration, however, and disappeared within the interval between training sessions. This lack of retention contrasted with the prolonged effect of vestibular training.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235726
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Acido- et glucorecepteurs vagaux de la région gastro-duodénale (1981)
    Springer
    Experimental brain research 42 (1981), S. 442-452 
    Details
    ISSN: 1432-1106
    Keywords: Chemoreceptors ; C Fibers ; Vagal nerves ; Gastro-duodenal Region ; Microelectrode technique ; Cat ; Chémorécepteurs ; Fibres C ; Nerfs vagues ; Région Gastro-duodénale ; Technique des ; Microélectrodes ; Chat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé La sensibilité vagale aux hydrates de carbone (glucose en particulier) et aux acides (acide chlorhydrique et acide acétique) a été étudiée dans la région gastro-duodénale chez des chats anesthésiés. Les potentiels d'action ont été enregistrés dans le ganglion plexiforme droit au moyen de microélectrodes extracellulaires. Des récepteurs, sélectivement sensibles soit aux hydrates de carbone, soit aux acides, ont été ainsi mis en évidence. Ces récepteurs doivent donc être considérés comme de véritables glucorécepteurs et acidorécepteurs. Les deux types de chémorécepteurs, silencieux au départ, présentent une fréquence de décharge basse qui varie entre 2 et 14 imp/s pour les acido-récepteurs et entre 2 et 30 imp/s pour les glucorécepteurs. Les réponses peuvent être irrégulières ou régulières et durer plusieurs minutes; leur latence est faible (entre 1 et 20 s) pour les deux types de chémorécepteurs, ce qui suggère une localisation dans la muqueuse ou au voisinage de celleci. Les fibres connectées aux glucorécepteurs et aux acido-récepteurs ont une vitesse de conduction qui varie entre 0,8 et 1,2 m/s: elles sont donc amyéliniques. L'enregistrement de l'activité électromyographique de la région gastro-duodénale a permis de montrer que les acido-récepteurs et les glucorécepteurs interviennent dans la régulation de la motilité gastrique et duodénale, l'effet le plus marqué étant une diminution du rythme électrique de base de l'estomac.
    Notes: Summary Vagal sensitivity to carbohydrates (mainly glucose) and to acids (hydrochloric and acetic acids) was studied in the gastro-duodenal region of anesthetized cats. Action potentials were recorded extracellularly from the nodose ganglion by means of glass microelectrodes. Receptors responding to glucose perfusion were found at this level as well as receptors stimulated by acid perfusion. It is shown that each type of receptor was activated by only one kind of stimulus (carbohydrates and acids, respectively). These receptors must thus be considered as true glucoreceptors or acido-receptors. Being silent before activation, these two types of chemoreceptors discharged at a frequency that varied from 2 to 14 imp/s for the acido-receptors, and from 2 to 30 imp/s for the glucoreceptors. The response could be irregular or regular and might last several minutes. Its latency was short (between 1 and 20 s for both types of chemoreceptors. It was therefore supposed that they were located in the mucosa or neighboring structures. From the conduction velocities (0.8–1.2 m/s), it was concluded that fibers originating from the acidoand glucoreceptors belonged to the C type. Recording of the electromyographic activity from the gastro-duodenal region demonstrated that the gluco- and acido-receptors are involved in the regulation of motility of the gastric and duodenal regions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237509
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Differential responsiveness of cells in the visual zones of the cat's LP-pulvinar complex to visual stimuli (1981)
    Springer
    Experimental brain research 43 (1981), S. 25-33 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; LP-pulvinar complex ; MIN ; Visual texture ; Receptive field properties
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Multiple visual field representations are contained within the feline LP-pulvinar complex; regions differentiated by their afferent and efferent connectivity patterns as the striate-, tecto- and retino-recipient zones. Cell responses from these visuotopic zones were investigated in immobilized cats under N2O/O2 supplemented with pentobarbitone or Althesin, using spot, bar and textured stimuli. Response fields recorded within the LP-pulvinar complex were classified as diffuse, concentric, movement-, direction- or orientation-sensitive. Concentric receptive fields were further classified as sustained (X), transient (Y) or tonic/phasic W-cells. Direction-and movement-sensitive cells predominated in the striate- and tecto-recipient zones, respectively. Motion of noise fields, or noise bars against an identical stationary noise background elicited vigorous responses from cells in the striate zone, many showing a preference for noise stimuli. In contrast, cells from the tectal zone and other divisions of the LP-pulvinar complex were insensitive to noise. The retino-recipient zone at the lateral margin of the pulvinar nucleus was characterized by cells with concentric receptive fields, the majority exhibiting properties similar to W-cells in the LGNd. The evidence supports the notion of functional subdivision within the LP-pulvinar complex corresponding to the visuotopically organized regions defined by their connectivity patterns. Consideration of the retino-recipient zone as an extension of the LGNd-MIN complex is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238806
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Effects of corticospinal lesions upon treadmill locomotion by cats (1981)
    Springer
    Experimental brain research 43 (1981), S. 101-103 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Pyramidal tract ; Corticospinal system ; Locomotion ; Stepping
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We studied the pattern of stepping in cats, before and after the placement of lesions in the corticospinal system. We found a deficit after the lesions, which was characterized by increased extension of the involved hindlimbs during the stance (E2–E3) phase of the step cycle. This deficit lasted two weeks or less. It may reflect loss of inhibitory influences upon extensor motoneuron pools.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238815
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    The somatotopy of the gracile nucleus in cats with agenesis of a hindfoot (1981)
    Springer
    Experimental brain research 43 (1981), S. 413-418 
    Details
    ISSN: 1432-1106
    Keywords: Gracile nucleus ; Plasticity ; Somatotopy ; Agenetic defect ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The somatotopic representation of the hindlimb in the gracile nucleus was studied in two cats who had a congenital defect of one hindfoot. The defect comprised all of the foot downward from and including the heel, and the distal third of tibia and fibula. The part of the sciatic nerve normally supplying the lower hindlimb and the hindfoot was reduced in diameter by one third. The motoneurones corresponding to the absent muscles were lacking and replaced by glial elements. The cross-sectional area of the dorsal columns at segment S2 was reduced by more than 20%. The gracile nuclei, in contrast, were not reduced in size. Only the diameter of its neurones was significantly smaller. Electrophysiological single and multi-neurone recordings revealed an altered somatotopic representation in the gracile nucleus on the defective side. The nuclear area normally representing the missing parts of the body surface now received input from the stump. There was no nuclear area devoid of afferent input, and there was no input in the gracile from the forelimb or from the contralateral side. It is concluded that the remaining parts of the leg project onto the gracile nucleus in an ordered fashion, sharing the entire nucleus according to their present afferent fibres.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238384
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    The size and shape of rod and cone centres of cat retinal ganglion cells (1981)
    Springer
    Experimental brain research 43 (1981), S. 422-428 
    Details
    ISSN: 1432-1106
    Keywords: Retinal ganglion cells ; Cat ; Rod and cone mediated receptive fields ; Receptive field size/shape
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Receptive field centres of cat retinal ganglion cells, as mediated by rod and by cone inputs, were mapped as contours of iso-sensitivity at a mid-mesopic adapting luminance using, respec-tively, 452 nm-blue and 578 nm-yellow narrow-band lights at an intensity 1 log unit above threshold for the most sensitive locus. Based on the sizes and shapes of mapped rod and cone centres for 74 ganglion cells, four receptive field centre categories were distinguished. Cone and rod centres were usually elliptical, and in almost 60% of cells the major axis through the receptive field centre was oriented within ±20 ° of horizontal. In 69%, rod and cone centres were non-concentric, 66% had larger rod than cone centres — area ratios ranging from 0.6 ∶ 1 to 2.9 ∶ 1, and in only two cases was the rod centre actually smaller than the cone centre.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238386
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Development of responses to acoustic interaural intensity differences in the cat inferior colliculus (1981)
    Springer
    Experimental brain research 41 (1981), S. 301-309 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Auditory ; Localization ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Responses of single neurones in the inferior colliculus of anaesthetized adult cats and kittens were studied using best-frequency stimuli of varying interaural intensity difference (IID). Two broad classes of neurone, distinguished by the predominant type of input from each ear, were examined. One class of cells received predominantly excitatory input from each ear (EE cells). The other class were excited by monaural stimulation of the contralateral ear and showed no response to monaural stimulation of the ipsilateral ear, but inhibition of the excitatory response by simultaneous ipsilateral stimulation (EI cells). Fourteen of the 18 adult EI cells showed marked changes in discharge rate with variation in IID. Adult EI cells showed low response variability and were insensitive to changes in average binaural intensity. In all cases of IID sensitivity, the onset component of the response was less sensitive to IID than the sustained component. Eight out of ten EE cells were insensitive to IID over the range tested. Cells of high best-frequency in kittens younger than 28 days showed irregular changes in discharge rate with variation in IID and wide response variability. Some low-frequency EI cells in young kittens showed sensitivity to IID, but it is unlikely that these could be involved in sound localization as their frequency response was inappropriate. Many cells in kittens aged 31–40 days showed monotonic, adult-like IID functions, but the response variability of these cells remained higher than that of adult cat neurones. These data provide evidence for a developmental change of binaural interaction in the cat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238887
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Termination of cortical afferents on identified neurons in the caudate nucleus of the cat (1981)
    Springer
    Experimental brain research 41 (1981), S. 329-337 
    Details
    ISSN: 1432-1106
    Keywords: Caudate nucleus ; Golgi/EM ; Corticocaudate projection ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A combined Golgi/electron microscopic technique was used to investigate the fine structure and synaptology of Golgi-stained spiny neurons in the caudate nucleus of the cat. In order to study the termination sites of cortical afferents on Golgistained spiny neurons, cortical fibres were caused to degenerate by making extensive cortical lesions 3 days prior to fixation of the animals. When examined in the electron microscope, perikarya of labelled spiny neurons have a round nucleus, a few mitochondria and microtubules, and a poorly developed Golgi apparatus and rough endoplasmic reticulum. Only rarely are axo-somatic contacts seen. Labelled dendrites exhibit a moderate number of microtubules and sometimes elongated mitochondria. Numerous labelled spines are seen in the vicinity of their parent dendrites. They are contacted by smaller type I and type III boutons and larger type IV boutons (Hassler et al. 1978). Large boutons filled with clear round vesicles establish symmetric contacts with labelled dendritic shafts. Degenerating boutons of cortical afferents are seen in contact with spines and, more rarely, with dendritic shafts of Golgi-stained spiny neurons. All degenerating boutons synapsing with labelled structures are found some distance from the cell body. No contacts of degenerating cortical boutons with the soma or with stem dendrites of Golgi-stained spiny neurons are found.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238890
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Cat retina and the sampling theorem; the relation of transient and sustained brisk-unit cut-off frequency to α and β-mode cell density (1981)
    Springer
    Experimental brain research 42 (1981), S. 196-202 
    Details
    ISSN: 1432-1106
    Keywords: Retina ; Sampling theorem ; Brisk, X and Y, ganglion cells ; Cat ; Visual acuity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The relationship of brisk transient and brisk-sustained unit cut-off frequencies to their respective array cut-off frequencies has been calculated by means of sampling theory from the corresponding α and β-mode cell densities at various retinal eccentricities. Interpretation of the results depends on whether on and off cells of each class are functionally homogeneous or heterogeneous populations. In agreement with expectations from sampling theory for a system involved in resolution tasks, it is found that the brisk-sustained system has less potential for undersampling and spurious imagery than the brisk-transient system, which is thought to play a different role. The brisk-sustained array could avoid such aliasing altogether if it is functionally heterogeneous. The differences between the two systems are similar to those between insect eyes respectively optimised for high resolution vision or the detection of high velocity image motion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236906
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    The vibrissal pad as a source of sensory information for the oculomotor system of the cat (1981)
    Springer
    Experimental brain research 44 (1981), S. 409-418 
    Details
    ISSN: 1432-1106
    Keywords: Oculomotricity ; Lateral rectus and retractor bulbi motoneurones ; Infraorbital nerve ; Vibrissal pad ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Responses from lateral rectus, medial rectus and retractor bulbi nerves were obtained following electrical stimulation of the vibrissal pad of the cat. Discharges in afferent fibres dissected from the infraorbital nerve were recorded during movements of the vibrissae and following electrical stimulation of the vibrissal pad. Both stimuli activated the same population of Aα fibers. Intracellular records were obtained from lateral rectus motoneurones identified antidromically in the principal abducens nucleus and from retractor bulbi motoneurones similarly identified in the accessory abducens nucleus. EPSPs (3 mV) were recorded in lateral rectus motoneurones following electrical stimulation of the ipsilateral vibrissal pad at a latency of 3.5 ms. Large-amplitude disynaptic EPSPs (15 mV) were recorded in retractor bulbi motoneurones following the same vibrissal stimulation. The synaptic excitation evoked in both lateral rectus and retractor bulbi motoneurones through stimulation of the ipsilateral vibrissal pad induced an early retraction followed by an abduction of the eye ball. The hypothesis is that the vibrissal message might complement other sensory modalities in the generation of patterned eye movements.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238833
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Topographic organization of orientation columns in the cat visual cortex (1981)
    Springer
    Experimental brain research 44 (1981), S. 431-436 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Visual cortex ; Orientation columns ; Deoxyglucose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Three-dimensional reconstructions of the orientation column system were obtained from the visual cortex of four cats using the deoxyglucose technique. One cat had normal visual experience, one was monocularly deprived and two had selective experience with vertical and horizontal contours, respectively. In areas 17 and 18 orientation columns form a remarkably regular system of equally spaced parallel bands whose trajectory is orthogonal to the borderline between areas 17 and 18. This topographic organization is resistant to manipulations of early visual experience.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238836
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    The variability of discharge of simple cells in the cat striate cortex (1981)
    Springer
    Experimental brain research 44 (1981), S. 437-440 
    Details
    ISSN: 1432-1106
    Keywords: Response variability ; Visual cortex ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The relationship between the variance and mean rate of discharges of simple cells in the cat striate cortex has been examined when mean rate was varied by changing either stimulus spatial frequency or contrast. In both cases, the variance was related to the mean discharge rate by an exponent of about 1.15; the relation was thus roughly linear. The discharge variance was on average 1.7 times the mean rate for data obtained from measurements of the neurones' spatial frequency tuning curves, and 1.48 times the mean for data from the response-contrast determination. However, this difference was not statistically significant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238837
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Asymmetries of vertical vestibular nystagmus in the cat (1981)
    Springer
    Experimental brain research 41 (1981), S. 420-426 
    Details
    ISSN: 1432-1106
    Keywords: Vestibular nystagmus ; Cat ; Visual suppression ; Vertical asymmetries ; Nystagmus vestibulaire ; Chat ; Suppression visuelle ; Asymétries verticales
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Chez le chat, l'asymétrie des réponses nystagmiques verticales à une rotation autour d'un axe interaural a été caractérisée en mesurant la fréquence de battement et le gain du réflexe vestibulooculaire dans chaque sens vers le haut et vers le bas. Des variations sinusoïdales de la vitesse de la tête, ou des échelons de vitesse ont été exercés dans trois conditions visuelles: à l'obscurité (stimulation vestibulaire pure); à la lumière (stimulation mixte vestibulaire et optocinétique); et enfin, alors qu'un miroir placé devant l'animal et solidaire du mouvement de sa tête lui fournissait une référence visuelle stable (vision stabilisée). Dans les trois conditions, la fréquence de battement et le gain du nystagmus vers le bas (désigné par le sens des phases rapides) sont plus grands que ceux du nystagmus vers le haut. A l'obscurité, les caractéristiques des nystagmus postrotatoires suggèrent une constante de temps plus longue pour le réflexe vestibulo-oculaire vers le bas que vers le haut. A la lumière, les deux stimulations agissent synergiquement. En vision stabilisée, la suppression du nystagmus s'exerce préférentiellement sur le nystagmus haut, ce qui appuie l'hypothèse d'une addition algébrique des effets des deux stimulations.
    Notes: Summary In the cat, the asymmetry of vertical nystagmus in response to a rotation around the Yaxis has been characterized by measuring the beat frequency and gain of vestibulo-ocular reflexes in each direction (upward and downward). Sinusoidal variations of head velocity or velocity steps have been applied under three visual conditions (a) in darkness (pure vestibular stimulation); (b) in the light (mixed vestibular and optokinetic stimulation); (c) with a mirror placed in front of the animal; since the mirror image moved with the head, the animal was provided with a stable visual cue (stabilized vision). In all three conditions, beat frequency and gain were greater for downward than for upward nystagmus (the direction refers to that of the quick phase). In darkness, the characteristics of postrotatory nystagmus suggested a greater time constant for downward than for upward vestibulo-ocular reflexes. In the light, both stimuli acted synergistically. In stabilized vision, upward vestibular nystagmus was preferentially suppressed, suggesting an algebraic summation of the effects arising from both kinds of stimuli.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238901
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Receptive field organization of simple cells in cat striate cortex (1981)
    Springer
    Experimental brain research 42 (1981), S. 89-98 
    Details
    ISSN: 1432-1106
    Keywords: Receptive field ; Single unit ; Striate cortex ; Simple cell ; Cat ; Model stimulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The receptive field organization of simple cells was studied by analyzing interaction effects between two stationary flashing light stimuli. One stimulus was positioned in the most responsive part of the receptive field to produce activity against which the effects of the other stimulus in various positions of the visual field could be determined. The receptive field was subdivided into an elongated center and elongated antagonistic flanks. The effects on the flanks were always considerably stronger on one side. Powerful flank suppression could be elicited within a region which usually was only slightly wider than the receptive field center. The suppression was just as stimulus specific as the activation of the center and occurred only by light ON or OFF. The cells were classified into ON-dominant and OFF-dominant depending on the kind of response found in the center. In ON-dominant cells the strong flank suppression occurred only by light ON, and light OFF produced enhancement. Correspondingly, the strong flank suppression occurred only by light OFF in OFF-dominant cells. This is consistent with the interpretation that simple cells have excitatory and inhibitory input from the same type of cells in the lateral geniculate nucleus (LGN), i.e., only from ON-center or OFF-center cells. The small size of the area where strong flank suppression occurred shows that inhibition comes from a few LGN cells rather than from a large pool of cells. A model for simple cell receptive fields presuming overlapping but acentric excitatory and inhibitory fields with input to both fields from either ON- or OFF-center LGN cells was tested by computer simulation and shown to fit the experimental data.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235733
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Receptive field organization of complex cells in cat striate cortex (1981)
    Springer
    Experimental brain research 42 (1981), S. 99-107 
    Details
    ISSN: 1432-1106
    Keywords: Receptive field ; Single unit ; Striate cortex ; Complex cells ; Cat ; Model simulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The receptive field organization of complex cells was studied by analyzing interaction effects between two stationary flashing light stimuli. One was placed in the most responsive part of the receptive field to produce activity against which effects of the other in different visual field positions could be determined. The receptive field was spatially organized into antagonistic center and flanks just like the fields of simple cells. However, both center and flanks were found within the receptive field area where a single slit evoked discharge. Center and flanks were elongated along the optimal stimulus orientation. The flanks were displaced from the center normal to optimal stimulus orientation. In the center, ON- and OFF-responses were usually about equal in strength and the maximum ON- and OFF-responses occurred in about the same position. This shows that complex cells are activated by input from both ON- and OFF-center cells in the lateral geniculate nucleus (LGN) where the receptive field centers of the LGN cells overlap closely. This explains most of the specific features of complex cells, e.g., the spatially overlapping ON- and OFF-zones, the large response field, the repetitive firing when a slit moves over the receptive field, and the marked non-linear spatial summation. Strong flank suppression occurred with both ON and OFF. The effects were usually stronger on one side of the center. Maximal suppression occurred on the same side with both ON and OFF. This is consistent with the interpretation that complex cells are inhibited by input from both LGN ON- and OFF-center cells with overlapping receptive field centers. A model presuming that complex cells have overlapping but acentric excitatory and inhibitory fields was tested by computer simulation and shown to fit the experimental data. This is the same model as presented for simple cells in the preceding paper (Heggelund 1980), except that the excitatory and inhibitory fields of simple cells have input from either ON- or OFF-center LGN cells, whereas in complex cells they have input from both types.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235734
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    A quantitative analysis of the direction-specific response of neurons in the cat's nucleus of the optic tract (1981)
    Springer
    Experimental brain research 42 (1981), S. 146-157 
    Details
    ISSN: 1432-1106
    Keywords: Nucleus tractus opticus ; Visual response ; Direction specificity ; Optokinetic nystagmus ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary All cells in the nucleus of the optic tract (NOT) of the cat, that Bcould be activated antidromically from the inferior olive, were shown to be direction-specific, as influenced by horizontal movements of an extensive visual stimulus. Cells in the left NOT were activated by leftward and inhibited by rightward movement, while those in the right NOT were activated by rightward and inhibited by leftward movement. Vertical movements did not modulate the spontaneous activity of the cells. The mean spontaneous discharge rate in 50 NOT cells was 30 spikes/s. This direction-specific response was maintained over a broad velocity range (〈0.1 ° – 〉100 °/s). Velocities over 200 °/s could inhibit NOT cells regardless of stimulus direction. All cells in the NOT were driven by the contralateral eye, about half of them by the ipsilateral eye also. In addition, activation through the contralateral eye was stronger in most binocular units. Binocular cells preferred the same direction in the visual space through both eyes. An area approximately corresponding to the visual streak in the cat's retina projected most densely onto NOT cells. This included an extensive ipsilateral projection. No clear retinotopic order was seen. The most sensitive zone in the very large receptive fields (most diameters being 〉20 °) was along the horizontal zero meridian of the visual field. The retinal input to NOT cells was mediated by W-fibers. The striking similarities between the input characteristics of NOT-cells and optokinetic nystagmus are discussed. The direction selectivity and ocular dominance of the NOT system as a whole can provide a possible explanation for the directional asymmetry in the cat's optokinetic nystagmus when only one eye is stimulated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236901
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Influence of initial posture on posturo-kinetic co-ordination in the cat (1981)
    Springer
    Experimental brain research 44 (1981), S. 177-186 
    Details
    ISSN: 1432-1106
    Keywords: Posture ; Movement ; Motor cortex ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The influence of postural support on posturo-kinetic co-ordination has been studied with a model of movement consisting of limb flexion induced by stimulation of the motor cortex in chronically implanted cats. To more easily quantify the responses by measuring the vertical forces exerted at the level of the four limbs, only weak stimuli were used, mainly triggering isometric motor activity. The aim of the study was to analyse the influence on the motor responses of various postural supports leading to a weight distribution between the limbs which differs from the normal situation. Three kinds of initial posture were tested. The first was obtained by directing the head of the cat to the left or to the right. The second type consisted in raising one or two of the platforms supporting the limbs. The third was obtained by adding a load to one of the limbs. The main results established in these conditions were the following: The latencies of the beginning of the movement and its associated postural adjustment, as revealed by the onset of force changes, were independent of the initial postural situation. Whatever the initial weight distribution, the amplitudes of force variations induced by given intensities of cortical stimulation were generally constant, though small variations of amplitude were noted in some cases. When there were changes in the response amplitudes, all four limbs were generally affected. The effect was observed whatever the limb concerned by modification of the support. This not only means that the postural responses depend on the amplitude of the movement but also that the amplitude of the movement itself may be modified according to perturbations affecting the postural limbs. Comparison of the present data with previous results leads to the hypothesis that a postural reference is taken into account in the determination of amplitudes of responses to cortical stimulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237339
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Morphology of the medullary chemosensitive fields (1981)
    Springer
    Pflügers Archiv 391 (1981), S. 226-230 
    Details
    ISSN: 1432-2013
    Keywords: Central chemosensitivity ; Morphology ; HRP ; Labelling ; Mapping ; Medulla oblongata ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A modified horseradish peroxidase labelling technique was used to study the distribution pattern of neurons in the central chemosensitive fields of the medulla oblongata of cats. In several cryosectioned medullae a mapping of superficially located HRP-labelled neurons was achieved. The distribution and configuration of the labelled neurons indicate that most of them belong to the nucleus paragigantocellularis lateralis. However, by varying the time of incubation it was possible to identify different types of neurons. On the basis of certain aspects of the HRP incorporation mode and neuronal topography a specific type of small-sized neurons has been identified. Some functional implications of these small neurons with respect to their possible chemosensitive activity are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00596175
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Reflex control of the retractor bulbi muscle in the cat (1981)
    Springer
    Pflügers Archiv 389 (1981), S. 143-148 
    Details
    ISSN: 1432-2013
    Keywords: Retractor bulbi muscle ; Trigeminal afferents ; Oculomotricity ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of vestibular and trigeminal stimulation on reflex responses of each slip of the retractor bulbi muscle were tested by recording the electromyogram. 1. In “encéphale isolé” cat, phasic electrical stimulation of the horizontal canal induced no response in the RB slips. Repetitive vestibular stimulation did not produce nystagmus in the RB muscle while strong muscular discharges were observed in the nystagmus lateral rectus muscle. 2. In anaesthetized cats, three trigeminal inputs elicited strong reflex responses in each slip of the RB muscle. Electrical stimulation of the vibrissae or the infra-orbital nerve evoked a two component reflex response (latencies: 5ms±0.5 and 14ms±2). Electrical stimulation of the supraorbital nerve elicited a single component reflex response (latency: 6ms±0.5). Electrical stimulation of the long ciliary nerves evoked a complex response with four components (latencies: 7.5ms±0.5, 10ms±2,15ms±2,20ms±2) 3. Pentobarbital and morphine produced lasting depression of the reflex responses of the RB muscle. The depressive effect of morphine was reversed by naloxone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00582105
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Central effects of paraoxon on haemodynamics in the cat (1981)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 317 (1981), S. 168-172 
    Details
    ISSN: 1432-1912
    Keywords: Paraoxon ; Blood pressure ; Vertebral artery ; Central muscarinic receptors ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Application of paraoxon into the left vertebral artery (8–80 μg) or both the left and right vertebral artery (4–8 μg) of the anaesthetized cat evoked dose-dependent depressor effects, whereas heart rate was not influenced significantly. Also after systemic administration of paraoxon (150–825 μg·kg−1), while peripheral muscarinic receptors were blocked, depressor effects were still observed. Dose-response curves for the depressor response to paraoxon were established. Infusion of low doses of dexetimide via the vertebral artery prevented the hypotensive action of paraoxon. The distribution of this antimuscarinic drug in the brain was investigated. The depressor effect of paraoxon can be attributed to both a decrease in peripheral resistance and cardiac output. Decerebration and midcollicular transection were carried out in order to elucidate the site and mechanism of action. The depressor effect of paraoxon seems to be mediated by a central mechanism of action located within the lower brain stem. It is concluded that stimulation of muscarinic receptors in the pontomedullary region gives rise to the observed changes in haemodynamic parameters. Muscarinic receptors in the hypothalamus seem to be of minor importance for the hypotensive action of paraoxon.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00500075
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Morphological studies on neuroglia (1981)
    Springer
    Cell & tissue research 216 (1981), S. 557-568 
    Details
    ISSN: 1432-0878
    Keywords: Electron microscopy ; Neuroglia ; Silver impregnation ; Brain ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The silver-impregnation procedure of Tsujiyama is suitable for demonstration of all three classical types of neuroglial cells; in the present study it was used for electron microscopic identification of neuroglial cells in the brain of the cat. The aim of the present study was 1) to determine impregnated structural correlates of neuroglial cells at the light- and electron-microscopic levels, and 2) to determine whether the method of Tsujiyama is applicable for the electron microscopic identification of the single types of neuroglial cells. Silver deposits were observed over the cytoplasm and processes of astrocytes where numerous glial filaments were present. Oligodendrocytes and microglial cells may be precisely differentiated by use of Tsujiyama's silver impregnation method at the electron microscopic level due to the pattern of silver-deposition in these two basic types of cells. This silver-impregnation method combined with electron microscopy is thus suitable for a precise identification of neuroglial cells; the technique may prove to be very helpful in identification of such categories of neuroglial cells that encompass also the images of cells which cannot be classified by use of the standard methods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238651
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Development of surface-recorded cochlear and early neural potentials in the cat (1981)
    Springer
    European archives of oto-rhino-laryngology and head & neck 233 (1981), S. 1-12 
    Details
    ISSN: 1434-4726
    Keywords: CM ; SP ; Hirnstamm-Reaktion ; Katze ; Entwicklung ; CM ; SP ; Brainstem response ; Cat ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The development of the surface-recorded cochlear and early neural potentials has been studied in the cat from birth to the 8th post-natal week. CM, SP, and each of the neural waves has a characteristic temporal developmental pattern and mature threshold. Wave IV is the most resistant to reduction in stimulus intensity levels, while the thresholds of both cochlear potentials are high. Animals with hereditary unilateral deafness constitute a most convenient model for the study of functional maturation in the auditory pathways, particularly with regard to precise latency estimations.
    Notes: Zusammenfassung Die Entwicklung der an der Oberfläche registrierten cochlearen und frühen neuralen Potentiale wurde bei der Katze von der Geburt bis zur 8. Woche studiert. CM, SP und jeder der neuralen Wellen haben ein charakteristisches altersbedingtes Entwicklungsmuster und eine Responsschwelle. Welle IV wird am wenigsten von einer Reduktion in der Stimulusintensität beeinflußt. Die Schwelle der beiden cochlearen Potentiale sind dagegen erhöht. Tiere mit angeborener einseitiger Taubheit sind bestens geeignet für das Studium der funktionellen Reifung der Gehörbahnen, besonders in bezug auf die exakten Latenzzeitmessungen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00464268
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Scarpa's ganglion in the cat one year after labyrinthectomy (1981)
    Springer
    European archives of oto-rhino-laryngology and head & neck 230 (1981), S. 251-255 
    Details
    ISSN: 1434-4726
    Keywords: Ganglion Scarpae ; Katze ; Labyrinthektomie ; Scarpa's ganglion ; Cat ; Labyrinthectomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary One year after membraneous labyrinthectomy in three cats a quantitative analysis of neurons in Scarpa's ganglion was performed under the light microscope. Total numbers of neurons were found 30% lower than in the respective contralateral ears. Although remaining perikarya showed signs of degeneration, such as shrinkage and vacuoles the proportions of large and small neurons remained unchanged after this procedure.
    Notes: Zusammenfassung Ein Jahr nach Labyrinthektomie wurde eine quantitative Analyse der Neuronen im Ganglion Scarpae der Katze durchgeführt. Die Gesamtzahl der Perikarya war 30% niedriger als in den unoperiert belassenen kontralateralen Ohren. Obwohl die verbleibenden Neuronen degenerative Veränderungen wie Schrumpfung und Vakuolen aufwiesen, waren die Anteile an großen und kleinen Neuronen unverändert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00456326
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Structural alterations of tapetal cells in the retina of cats induced by prolonged treatment with chloroquine (1981)
    Springer
    Cell & tissue research 215 (1981), S. 263-269 
    Details
    ISSN: 1432-0878
    Keywords: Retina ; Tapetal cells ; Degeneration ; Chloroquine ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cats were treated with high doses of chloroquine for one year during which the ocular fundus was periodically examined. After completion of the treatment, the tapetal cells were investigated by light and electron microscopy. Prolonged treatment with the retinotoxic drug chloroquine reduced the light reflection of the fundus, and examination by light and electron microscopy revealed a destruction of the rod-like structures in the cytoplasm of the tapetal cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239113
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Cells capable of uptake of horseradish peroxidase in some circumventricular organs of the cat and rat (1981)
    Springer
    Cell & tissue research 219 (1981), S. 85-92 
    Details
    ISSN: 1432-0878
    Keywords: Circumventricular organs ; Reticuloendothelial system ; Phagocytic cells ; Horseradish peroxidase ; Cat ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The structure of mesenchymal cells distributed in some of the “hypendymal organs” of the circumventricular system in the cat and rat was demonstrated after intravenous injection of high doses of horseradish peroxidase. These cellular elements were observed in the vicinity of blood vessels of the organon vasculosum laminae terminalis, subfornical organ and area postrema. Electron-microscopically, these cells located between the basal laminae of the brain parenchyma and the blood capillaries show long cellular processes encircling fenestrated capillaries. Light and electron-microscopic examination revealed that this cell type is identical with the “horseradish peroxidase-uptake cells”, previously reported in the vicinity of the hypophysial portal system. Such phagocytic cells may be considered as a cellular component intervening between the brain parenchyma and the blood stream, playing a role in selective barrier functions in the above-mentioned circumventricular organs where a blood-brain barrier in the classical sense of the definition is lacking.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00210020
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Cerium (IV) oxidation rate of p-chloromandelic acid in perchlorate and sulfate media (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 135-148 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rate of the cerium (IV) oxidation of p-chloromandelic acid has been studied in perchlorate media at an ionic strength of 1.50 mol/dm3 by the stopped-flow technique and in H2SO4—MHSO4 (M+ = Li+, Na+, K+) and H2SO4—MClO4 (M+ = H+, Li+, Na+) mixtures at constant total electrolyte concentrations of 1.00 and 2.00 mol/dm3 using the conventional spectrophotometric method. In perchlorate media the kinetic data indicate the formation of two intermediate complexes between cerium (IV) and the organic substrate, but only one is significantly involved in the intramolecular electron-transfer process. The oxidation rate is markedly lower in sulfate media, where two reaction paths have been found to contribute to the overall redox reaction. The univalent cations examined exhibit negative specific effects upon the overall oxidation rate increasing in the order H+ 〈 Li+ 〈 Na+ 〈 K+. Activation parameters have been also estimated.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130205
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Masthead (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981) 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130301
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Studies of the photochemical reactions of sulfur dioxide with pentane in the presence of nitrogen oxide (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 231-243 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The spectrum of the intermediate product ascribed to nitrosopentane has been detected in the photolysis of the SO2-pentane (RH)-NO mixture. This result has been interpreted in terms of the radical mechanism by assuming the H-atom abstraction from RH by the excited SO2 molecules to be the primary act. The contribution of the singlet and triplet SO2 states to the product formation rate and the ratio of the singlet-to-triplet rate constants have been evaluated. At NO pressures above 5 torr, the product formation rate significantly deviates from the Stern-Volmer dependence.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130303
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    The infrared chemiluminescent reaction of Cl atoms with H2CO (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 325-332 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction Cl + H2CO → HCl + HCO has been studied at 295 K. Chlorine atoms were produced via the infrared laser induced dissociation of CCl3F, using a pulsed CO2 TEA laser. Using HCl infrared chemiluminescence as the diagnostic, we find the rate constant to be 7.4 ± 0.7 × 10-11 cm3/molecule sec, in good agreement with several recent studies. An evaluation of TEA laser photolysis as a technique for the generation of chlorine atoms is made, and the relationship of this experiment to recent theories of infrared laser induced chemistry is discussed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130402
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Kinetics of the oxidation of U (IV) by hydrogen peroxide in sulfuric acid medium (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 385-401 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of the reaction have been investigated in H2SO4 medium under different conditions. The observed bimolecular rate constant kobs, has been found to depend on [H+]-0.55 and to increase with the initial concentration ratio of the reactants R0 = [H2O2]0/[U (IV)]0 above 0.49. The activation energy of the overall reaction has been determined as 13.79 and 14.3 kcal/mol at R0 = 1 and 0.35, respectively. Consistent with experimental data, a detailed reaction mechanism has been proposed where the hydrolytic reaction (4) followed by the rate-controlling reaction (10) and subsequent fast reactions of U (V) and OH radicals are involved: A kinetic expression has been derived from which a graphical evaluation of (kK4)-1 and k-1 has been made at R0 = 1 as (12.30 ± 0.09) × 10-3 M min, (6.23 ± 2.19) × 10-4 M min; and at R0 = 0.35 as (12.63 ± 2.13) × 10-3 M min, (8.32 ± 6.62) × 10-4 M min, respectively. Indications of some participation of a chain reactionat R0 = 1 have been obtained without affecting thesecond-order kinetics as observed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130405
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Masthead (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981) 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130501
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    An indirect measurement of the absolute rate constant of the self-reaction of tert-butoxy radicalsPublication No. 251 from the Photochemistry Unit. (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 433-444 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No reliable rate constant is available for the self-reaction of tert-;butoxy radicals. We have set up a competition between hydrogen abstraction and self-reaction of tert-butoxy radicals in a flash photolysis electron spin resonance study to extract this information. Experimental values of hydrogen abstraction product radical concentrations under various hydrogen donor concentrations were then compared with theoretically calculated values with different values of 2k4 to obtain the best fit. Hydrogen donors such as cyclopentane, anisole, methyl tert-butyl ether, and methanol were chosen for the study. A value of (1.3 ± 0.5) × 109M-1 sec-1 for the rate constant of the self-reaction of tert-butoxy radicals has been determined at 293°K.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130502
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Consistency of theory and experiment in the ethane-methyl radical system (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 481-495 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The thermal decomposition of ethane has been reinvestigated using the single pulse, reflected shock technique. Reflected shock temperatures were corrected for boundary layer-induced nonidealities using the thermal decomposition of cyclohexene as a kinetic standard. The rate constant for the reaction was calculated from the rate of formation of methane under conditions of very low extent of reaction, over a temperature range of 1000-1241 K. Ethane compositions of 1% and 3% in argon at total reaction pressures of 3 and 9 atm were used, and a small pressure dependence of k1 was observed.An RRKM model is described which gives excellent agreement with this and other recent dissociation and recombination rate constant data in light of a recent revision to the thermochemistry of the methyl radical. In the range of 1000-1300 K an RRKM extrapolated k1∞ is given by the expression, log k1∞ = 17.2 - 91,000/2.3RT, while at 298 K the calculation gives log k-1∞ (l/mol sec) = 10.44, where k-1∞ is calculated from k1∞ and the equilibrium constant.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130506
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Kinetics of the gas-phase reaction between iodine and monosilane and the bond dissociation energy D(H3Si—H)A preliminary account of this work has appeared in Ref. [1]. (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 503-514 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The title reaction has been investigated in the temperature range of 494-545 K. During the early stages of reaction the only observed products were silyl iodide and hydrogen iodide. Initial rates were found to obey the rate law over a wide range of initial iodine and monosilane pressures. Secondary reactions, most probably of SiH3I with I2, became more important as the reaction progressed. However, provided [SiH4]0/[I2]0 〉 20, these secondary processes had a negligible effect on the kinetics, and an integrated rate expression could be used. These kinetics are consistent with an iodine atom abstraction chain mechanism, and for the step has been deduced. From this the bond dissociation energy D(SiH3—H) = 378 ± 5 kJ/mol (90 kcal/mol) is obtained. The kinetic and thermochemical implications of this value, especially to the pyrolysis of monosilane, are discussed.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130508
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    The estimation of a factors for atom fissions in polyatomics (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 591-601 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It is shown that A factors for atom fissions in polyatomics can be reliably estimated by an improved version of the restricted free rotor model (RFRM). No adjustable parameters are used in the evaluation of A factors for the dissociation of the RO—F bond (R: NO2, SF5, CF3, FSO2), and the authors' predictions are compared with high-pressure kinetic data for these reactions. In the case of O2NOF, for which full spectroscopic information is available, RFRM reproduces the observed value Am well within a factor of 2. Similar agreement is reached for F5SOF and FO2SOF, assigning reasonable limits to their —OF torsional frequencies. For F3COF, Am and the calculated back reaction rate constant, which is independent of the model, are both much too small to be plausible, suggesting falloff effects rather than a failure of RFRM.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130608
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Infrared photochemistry of bis(trifluoromethyl) peroxide (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 627-638 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Bis(trifluoromethyl) peroxide is readily dissociated by multiple infrared photon excitation at CO2 laser wavelengths. The primary dissociation product is CF3O; approximately 85% of the nascent radicals are further dissociated in the laser field to form CF2O and F. The F atoms then react with the remaining CF3O to produce CF3OF. The formation of CF3OF is strongly inhibited by addition of HI, which reacts preferentially with the F atoms.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130704
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Micellar catalyzed enolization of acetone (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 695-705 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The acid-catalyzed enolization of acetone in the presence of bromine is found to be catalyzed by the anionic micelles of sodium dodecyl sulfate. The rate acceleration expected on the basis of lowering of activation energy is largely nullified by the decrease in the entropy of activation, leading to a very small rate enhancement, i.e., kψ/k0 = 1.2 at 30°C. The binding constant for the micelle-substrate complex is determined. The micellar rate enhancement is the same, irrespective of the halogen used, chlorine, bromine, or iodine.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130802
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Minor products and initiation rate in the chain pyrolysis of propaneThis paper summarizes a part of the dissertation submitted by C. Juste for the degree of Docteur-Ingénieur, Nancy, France, 1980. (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 855-864 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: With a continuous jet-stirred tank reactor operating at small space time (0.05-1.2 s) the kinetics of the formation of six minor products (ethane, isobutane, butene-1, 2,3-dimethyl-butane, 4-methylpentene-1, and 1,5-hexadiene) are studied during the pyrolysis of propane, at small extents of reaction and over the temperature range of 600-780°C. The experimental results are in agreement with the free radical mechanism proposed by Jezequel, Baronnet, and Niclause for this reaction. They show that the two most important termination processes are The measured rates of formation of the minor products are consistent with the quasi-identical values estimated by Jezequel and co-workers (between 475 and 505°C) and by Allara and Edelson (between 510 and 560°C) for kinetic parameters (A1 ≃ 1016.65 s-1 and E1 ≃ 84.7 kcal/mole) of the chain initiation process
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130909
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    A study of the reactions of fluorine with hydrogen and methane in the initiation phase using a miniature tubular reactor (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 39-58 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A small tubular reactor having an inner diameter of 1-2 mm andused as the source in a molecular beam apparatus is described in detail. This arrangement allows the study of fast reactions with reaction times smaller than 1 msec. The preexplosive reaction phase between F2 and H2 and CH4, respectively, is investigated to find out the initiation reactions. In the F2/H2 reaction, initiation is brought about by heterogeneous generation of F atoms or some other surface reaction. Evidence is also obtained for chain branching reactions. In the F2/CH4 case the dominant initiation reaction is the homogeneous reaction CH4 + F2 → CH3 + HF + F. The rate constant for the reaction between 300 and 400 K is 1012.3±0.3 exp[-47 ± 8 kJ/mol/RT] cm3/mol sec. The analysis of the experimental data also yields the rate constant for the propagation reaction CH3 + F2 → CH3 F + F, which is 1012.3±0.3 exp[-4.6 ±2.1 kJ/mol/RT] cm3/mol sec.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130105
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    A novel type of chemical oscillator (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 321-322 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130311
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    The thermal decomposition of fluorinated esters (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 463-471 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of thermal decomposition of ethyl, isopropyl, and t-butyl trifluoroacetates have been studied in the gas phase. In each case initial decomposition follows the normal ester route to give an olefin and trifluoroacetic acid, and elimination of hydrogen fluoride does not occur. However, trifluoroacetic acid is thermally unstable at ethyl and isopropyl ester decomposition temperatures, and further products result, including those from the difluorocarbene produced by decomposing trifluoroacetic acid. Placing a CF3 group at an ester's γ carbon increases the polarity of its transition state and decreases its thermal stability. The activation energies of the ethyl and isopropyl esters are lowered by 3.8 and 4.7 kcal/mol compared to the corresponding acetates, and the primary decomposition kinetics, which are homogeneous and of the first order, are expressed by α-Methylation enhances the reactivity of the trifluoroacetates, and the t-butyl ester, the transition state for which is sufficiently polar for heterogeneous decomposition to occur, shows signs of thermal instability at room temperature. The equilibrium was also investigated and gave ΔH° = +13,580 cal/mol and ΔS° = +31.07 gibbs/mol in the forward direction. The results obtained extend and support the known structure-rate correlations in the gas-phase elimination of esters.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130504
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Very-low-pressure pyrolysis of ethylbenzene, isopropylbenzene, and tert-butylbenzene (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 445-462 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The thermal unimolecular decomposition of ethylbenzene, isopropylbenzene, and tert-butylbenzene was studied using the very-low-pressure pyrolysis (VLPP) technique. Each reactant decomposed by way of β C—C bond homolysis, producing methyl radicals and benzyl or benzylic-type radicals. RRKM calculations show that the observed rate constants, when combined with thermochemical estimates, are consistent with the following high-pressure rate expressions: \documentclass{article}\pagestyle{empty}\begin{document}$ \log k(\sec ^{ - 1}) = 15.3 - (72.7/{\rm \theta)} $\end{document} for ethylbenzene between 1053 and 1234 K, \documentclass{article}\pagestyle{empty}\begin{document}$ \log k(\sec ^{ - 1}) = 15.8 - (71.3/{\rm \theta)} $\end{document} for isopropylbenzene between 971 and 1151 K, and \documentclass{article}\pagestyle{empty}\begin{document}$ \log k(\sec ^{ - 1}) = 15.9 - (69.1/{\rm \theta)} $\end{document} for tert-butylbenzene between 929 and 1157 K, where θ (kcal/mol) = 2.303RT. Resulting activation energies combined with heat capacity and heat of formation data led to the following dissociation enthalpies and enthalpies of formation at 298 K: DH° (øCH(CH3)—CH3) = 73.8 kcal/mol, ΔHf° (øÇCH(CH3)) = 39.6 kcal/mol, DH° (øC(CH3)2—CH3) = 72.9 kcal/mol, and ΔHf° (øÇ(CH3)2) = 32.4 kcal/mol. Derived high-pressure rate constants are in good accord with results of lower temperature toluene- and aniline-carrier experiments.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130503
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Masthead (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981) 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130601
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    An overall and detailed kinetic study of the pyrolysis of propane (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 149-172 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Overall and detailed kinetic descriptions of the pyrolysis of C3H8 have been proposed as a result of a turbulent flow reactor investigation in the temperature range of 1110-1235 K and at atmospheric pressure. The overall reaction was described by a first-order rate expression with an activation energy of 58.65 kcal/mol and a preexponential factor of 3.2 × 1012 sec-1. This expression agrees with previously reported rate data. In addition, a kinetic mechanism involving 13 chemical species and 32 elementary reactions has been postulated to describe the kinetics. Experimental data from the present flow reactor experiments and from static vessel and shock tube experiments reported in the literature were used to verify the mechanism. Agreement over the temperature range of 800-1400 K and over the pressure range of 0.1-8.5 atm was obtained by adjusting three rate constants. Previously reported values for these rate constants appear to require reexamination. The reactions in question are the following: The sum of the rate constants for reactions (2a) and (2b) and the rate constant for reaction (23) are best represented by \documentclass{article}\pagestyle{empty}\begin{document}$$ k_{2a} + k_{2b} = 10^{- 0.1} T^4 \exp (-8300/{\rm RT}){\rm cm}^3 /{\rm mol}\;{\rm sec} $$\end{document} and \documentclass{article}\pagestyle{empty}\begin{document}$$ k_{23} = 10^{14.55} \exp (-14,340/{\rm RT}){\rm cm}^3 /{\rm mol}\;{\rm sec} $$\end{document} which differ with the expressions in the literature.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130206
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Rate constants for ozone-alkene reactions under atmospheric conditions (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 209-217 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: By measuring the rates of decay of ozone in a large excess of reactant, second-order rate constants have been obtained for the reactions of ozone with ethene, propene, but-1-ene, trans-but-2-ene, isobutene, hex-1-ene, cyclopentene, cyclohexene, isoprene, vinyl fluoride, 1,1-difluoroethene, cis-1,2-difluoroethene, trans-1,2-difluoroethene, trifluoroethene, tetrafluoroethene, and 2,5—dihydrofuran. The reactions have been studied in synthetic air at atmospheric pressure and at temperatures of 294 and 260 K. The rate constants and Arrhenius parameters are discussed in relation to existing kinetic data on ozone-alkene reactions.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130210
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Very low-pressure pyrolysis (VLPP) of pentynes. II. 4-methylpent-2-yne and 4,4-dimethylpent-2-yne. Heats of formation and resonance stabilization energies of methyl-substituted propargyl radicals (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 255-272 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Studies of the unimolecular decomposition of 4-methylpent-2-yne (M2P) and 4,4-dimethylpent-2-yne (DM2P) have been carried out over the temperature range of 903-1246 K using the technique of very-low pressure pyrolysis (VLPP). The primary reaction for both compounds is fission of the C—C bond adjacent to the acetylenic group producing the resonance-stabilized methyl-substituted propargyl radicals, CH3C≡ĊH(CH3) from M2P and CH3C≡CĊ(CH3)2 from DM2P. RRKM calculations were performed in conjunction with both vibrational and hindered rotational models for the transition state. Employing the usual assumption of unit efficiency for gas-wall collisions, the results show that only the rotational model with a temperature-dependent hindrance parameter gives a proper fit to the VLPP data over the entire experimental temperature range. The high-pressure Arrhenius parameters at 1100 K are given by the rate expressions log k2 (sec-1) = (16.2 ± 0.3) - (74.4 ± 1.5)/θ for M2P and log k3 (sec-1) = (16.4 ± 0.3) - (71.4 ± 1.5)/θ for DM2P where θ = 2.303RT kcal/mol. The A factors were assigned from the results of recent shock-tube studies of related alkynes. Inclusion of a decrease in gas-wall collision efficiency with temperature would lower both activation energies by ∼1 kcal/mol. The critical energies together with the assumption of zero activation energy for recombination of the product radicals at 0 K lead to DH0[CH3CCCH(CH3)—CH3] = 76.7 ± 1.5, ΔHf0[CH3CCCH(CH3)] = 65.2 ± 2.3, DH0[CH3CCCH(CH3)—H] = 87.3 ± 2.7, DH0[CH3CCC(CH3)2—CH3] = 72.5 ± 1.5, ΔHf0[CH3CCĊ(CH3)2] = 53.0 ± 2.3, and DH0[CH3CCC(CH3)2—H] = 82.3 ± 2.7, where all quantities are in kcal/mol at 300 K. The resonance stabilization energies of the 1,3-dimethylpropargyl and 1,1,3-trimethylpropargyl radicals are 7.7 ± 2.9 and 9.7 ± 2.9 kcal/mol at 300 K. Comparison with results obtained previously for other propargylic radicals indicates that methyl substituents on both the radical center and the terminal carbon atom have little effect on the propargyl resonance energy.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130305
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Temperature-dependent a factor in thermal unimolecular reactions II. Exponential dependence (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 283-293 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It is assumed that A∞ in the limiting high-pressure unimolecular rate constant expression k∞ = A∞ exp(-Ea∞/kT) is given by A∞ = A″∞eBkT. The test case is the decomposition butane → 2 ethyl, where a negative B reproduces the temperature dependence of A∞ about as well as the previously considered power law A∞ = A′∞(kT)n. It is shown that the term eBkT modifies significantly the high-temperature falloff of the general-pressure rate constant kuni and its various derivatives, and admits of a fairly simple interpretation in terms of Benson's restricted rotor theory. On physical grounds, the exponential law appears more reasonable than the power law.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130307
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Preliminary announcement (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 323-323 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130312
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    From energy profiles to structure-reactivity correlations (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 333-365 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Models for the energy profile along the reaction coordinate are utilized to determine the barrier's height and location as a function of ΔG. These form the basis for structure-reactivity correlations and afford a unified formulation for various postulates in the field of physical organic chemistry. Current experimental evidence is examined for the resulting correlations, and some of their applications as an aid to the chemical kineticist are presented.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130403
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    The hydrolysis of phosphoranes in aqueous dioxanePresented at the International Conference on Reactions in Solution, Canterbury, England, July 8-13, 1979 (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 411-416 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The entropy of activation for the hydrolysis of pentaphenoxyphosphorane in 25% aqueous dioxane is -188 J/mol deg. The enthalpy of activation is 22.5 kJ/mol, which is small for the relatively slow reaction. This suggests that the reaction is a multistep process having a preliminary equilibrium with a negative heat of reaction. This conclusion is supported by the results obtained for the hydrolysis of C6H5[OCH(CF3)2]2. A kinetic isotope effect kH2O/kD2O of 3.46 was found for the latter reaction. Orders in water were obtained, and a mechanism of hydrolysis is proposed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130407
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Persulfate and perphosphate oxidation of 2-propanol: A relative rate study (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 497-501 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A competitive reaction study for two isoelectronic peroxides (peroxodisulfate S2O82- and peroxodiphosphate P2O84-) interacting with the free radical ·Clpar;CH3)2OH is described. The radical formation is initiated by photolysis, the amounts of peroxide remaining analyzed volumetrically. It is found that persulfate reacts with the organic radical over 100 times more rapidly than does perphosphate. Mechanistic consequences in relation to previous work are briefly discussed.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130507
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    Rate constants for the reaction of tert-butyl radicals with chloroform in solution (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 527-541 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The decay of photochemically generated tert-butyl radicals in methylcyclopentane solutions containing chloroform is studied by time-resolved ESR spectroscopy. In the pure solvent it perfectly follows the second-order rate law for radical self-termination. Increasing chloroform concentrations cause increasing admixture of a pseudo-first-order decay from which the rate constant of the title reaction is obtained. For 273 K ≦ T ≦ 323 K, \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}\,{\rm k(}M^{{\rm - 1}}\sec ^{ - 1}) = (8.41 \pm 0.14) - \frac{{8.12 \pm 0.18}}{\theta } $$\end{document} where θ = 2.303RT kcal/mol. CIDNP studies of the reaction mechanism and NMR product yields show H and Cl abstractions to occur with the temperature-independent ratio kH/kCl = 1.4 ± 0.1. The results point to polar effects in the transfer reactions of tert-butyl. The potential of time-resolved ESR spectroscopy in studies of first- and pseudo-first-order reaction rates is discussed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130603
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    Masthead (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981) 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130701
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    Infrared photochemistry of cyclobutyl chloride (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 615-625 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The decomposition of cyclobutyl chloride following multiple infraredphoton excitation has been investigated. The primary photolysis products are butadiene, from elimination of HCl, and ethylene and vinyl chloride, fromring scission. The vinyl chloride undergoes secondary decomposition to acetylene and HCl. In addition to these products, known from thermal VLPP experiments, we also find 1-butene, which may arise from a higher energy C—Cl homolysis channel. Collisions with either reactant molecules oradded buffer gas lead to cooling of the laser-produced vibrational energy distributions. The average amount of energy removed per collision is 15-20 kcal/mol for self-collisions and 2-4 kcal/mol with argon.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130703
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    The rate of reaction of methyl radicals with ozone (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 667-675 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The absolute rate constant for the reaction of methyl radicals with ozone has been measured as a function of temperature. Small concentrations of CH3 were generated by flash photolyzing CH3NO2 at 193 nm with an ArF laser. A photoionization mass spectrometer was used to follow the rate of decay of CH3 at various ozone concentrations. The resulting rate constants could be fit by the expressions \documentclass{article}\pagestyle{empty}\begin{document}$$ k_1 = (5.4 \pm 1.5) \times 10^{ - 12} \exp [(- 216 \pm 80)/T]{\rm cm}^3 /{\rm molec}\,{\rm s} $$\end{document} \documentclass{article}\pagestyle{empty}\begin{document}$$ k_1 = (2.6 \pm 0.7) \times 10^{ - 12} {\rm (T/300)}^{{\rm 0}{\rm .71} \pm {\rm 0}{\rm .34}} {\rm cm}^3 /{\rm molec}\,{\rm s} $$\end{document} over the temperature range of 243-384 K. These rate constants can be modeled by simple transition state theory using reasonable parameters for the activated complex. Use of this rate constant shows that less than 1% of the methyl radicals formed in the stratosphere react with ozone.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130707
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Erratum (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 693-693 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130709
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    The √t law in solid-phase reactions. Analysis of the hypothesis on rate constant distribution (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 707-728 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction C2H5 + O2 → C2H5O2 in glassy methanol-d4 and the H-atom abstraction by CH3, C2H5, and n-C4H9 radicals in C2H5OH + C2D5OH and CD3CH2OH + C2D5OH glassy mixtures have been studied by electron spin resonance. The analysis of the dependence of the reaction rates on the concentration of O2 (oxidation) and C2H5OH, CD3CH2OH (H-atom abstraction) has shown that the √t law is not conditioned by the existence of regions characterized by different rate constants.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130803
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Masthead (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981) 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130901
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Reaction of hydrogen atoms with diethyldisulfide and ethylmethyldisulfide (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 799-815 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: H atoms react with C2H5SSC2H5 to give C2H5SH as the sole retrievable product with φ = 2.32 at 25°C and 2.84 at 145°C. The primary reaction is postulated to be H + C2H5SSC2H5 ← C2H5SH + C2H5S with k1 = (4.73 ± 0.64) × 1013 exp [-(1710 ± 69)/RT] cm3/mol·s relative to the rate constant of the H + C2H4 ← C2H5 reaction. The high value of the entropy of activation suggests the presence of partial hydrogen bonding in diethyldisulfide which is broken in the transition state.Ethylmethyldisulfide reacts similarly: H + C2H5SSCH3 ← C2H5SH + CH3S or CH3SH + C2H5S. The thiyl radicals propagate a chain of radical exchange reactions forming the symmetrical disulfides with exposure-time-dependent quantum yields. The overall kinetics conform to a 16-step mechanism from which the rate constants of the elementary reactions could be established by computer modeling. Thiyl radicals react considerably more slowly with disulfides than H atoms.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130905
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Reactions of the fluorobromocarbene radical studied by laser-induced fluorescence (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 873-881 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: CFBr radicals produced by the reaction of atomic oxygen with F2CCFBr were monitored in a discharge flow system by fluorescence excited at 424 nm. The rate coefficients for reactions of the CFBr radicals were measured between 298 and 358 K, and the following values were obtained in units of cm3/molec·s: O2 〈 2 × 10-16 at 353 K; NO 〈 10-14 at 298 K; F2CCFBr 〈 10-15 at 298 K; Cl2 (1.9 ± 0.6) × 10-12 exp(-762 ± 92/T) Br2 (1.4 ± 0.3) × 10-12 exp(-533 ± 62/T).
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130911
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    On the frequency factor in electron transfer reactions and its role in the highly exothermic regime (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 865-872 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Consideration of current information on the dependence of the electron transfer rate on the radial separation distance and on the reactants′ radial distribution function suggests for adiabatic transfers a frequency factor closer to 1012M-1 s-1 than to 1011M-1 s-1. One effect is to raise the λ values estimated from self-exchange rate constants, and to extend thereby the range of ΔG°'s in which the “inverted region′” is masked by a diffusion-controlled reaction rate.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130910
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Masthead (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981) 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130201
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Effect of brownian diffusion on chemical kinetics (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 125-133 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new method of theoretical prediction of the kinetic rate constants of fast chemical reactions in solutions is presented. It takes into account the effect of finite diffusive displacements of the reacting molecules. The approach is based on the solution of the steady-state Fokker-Planck equation by the moments method of Grad developed in the theory of coagulation of aerosol particles. A comparison of the predicted rate constants with the experimental data provided by Schuh and Fischer for the self-reaction of tert-butyl radicals in n-alkanes shows a good correspondence.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130204
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    On the prediction of reaction rates by simple correlations (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 317-320 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130310
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    The rate constant for t-C4H9 → H + i-C4H8 and the thermodynamic parameters of t-C4H9 (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 303-316 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rate of the reverse reaction of the system has been measured in the range of 584-604 K from a study of the azomethane sensitized pyrolysis of isobutane. Assuming the published value for the rate constant of recombination of t-butyl we obtain \documentclass{article}\pagestyle{empty}\begin{document}$$ \log k_{{\rm - 1}} (\sec ^{- 1}) = 14.67 - 39.4\,{\rm kcal}/{\rm mol}/(2.3{\rm RT}) $$\end{document} Combination with our published data for k1 permits the evaluation \documentclass{article}\pagestyle{empty}\begin{document}$$ \log K_1 ({\rm atm}^{ - 1}) = 7.94\,\,{\rm at}\,\,600{\rm K} $$\end{document}We have modified a previously published structural model of t-butyl by the inclusion of a barrier to free rotation of the methyl groups in order to calculate values of the entropy and enthalpy of t-butyl as a function of temperature. Using standard data for H and for i-C4H8 we obtain \documentclass{article}\pagestyle{empty}\begin{document}$$ \Delta H_ f^\circ(t - {\rm butyl},\,300\,{\rm K})({\rm kcal}/{\rm mol}) = 10.6 \pm 0.5 $$\end{document}We have obtained other, independent values of this quantity by a reworking of published data using our new calculations of the entropy and enthalpy of t-butyl. There is substantial agreement between the different values with one exception, namely, that derived from published data on the equilibrium \documentclass{article}\pagestyle{empty}\begin{document}$$ i - {\rm C}_{\rm 4} {\rm H}_{{\rm 10}} + {\rm I}\rightleftharpoons t{-} {\rm C}_4 {\rm H}_9 + {\rm HI} $$\end{document} which is significantly lower than the other values.We conclude that the value \documentclass{article}\pagestyle{empty}\begin{document}$$ \Delta H_ f^\circ(t - {\rm butyl},\,300\,{\rm K})({\rm kcal}/{\rm mol}) = 10.5 \pm 1.0 $$\end{document}obtained from the present work and a reworking of published data which involves the use of experimental data on t-butyl recombination is incompatible with the result based on iodination data.
    Additional Material: 9 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130309
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    The pyrolysis kinetics of 4-chloro-2-butanone in the gas phase (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 403-410 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rates of pyrolysis of 4-chloro-2-butanone in the gas phase have been determined in a static system seasoned with the products of decomposition of allyl bromide. The reaction is catalyzed by hydrogen chloride. Under maximum catalysis of HCl, the kinetics were found to be of order 1.5 in the substrate suggesting that a complex elimination is involved. The reaction, when maximally inhibited with propene, appears to undergo a unimolecular elimination and follows a first-order law kinetics. The products are methylvinyl ketone and hydrogen chloride. The kinetics have been measured over the temperature range of 402.0-424.4°C.The rate coefficients are given by the Arrhenius equation \documentclass{article}\pagestyle{empty}\begin{document}$ \log k_1 (\sec ^{ - 1}) = (13.67 \pm 0.69) - (225.2 \pm 8.6)\,{\rm kj}/{\rm mol}/2.303RT\angle $\end{document}. Thepyrolysis of 4-chloro-2-butanone is 31 times greater in rate than that of ethyl chloride at 440°C. This large difference in rate may be attributed to the -M effect of the acetyl substituent in the pyrolysis of the former halo compound.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130406
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    Gas-phase pyrolysis of neopentyl bromide (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 7-21 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The pyrolysis of gaseous neopentyl bromide to 2-methyl-2-butene, 2-methyl-1-butene, and hydrogen bromide was studied under conditions of maximal inhibition by cyclohexene over the temperature range of 389-444°C. This reaction was shown to beconsistent with a first-order homogeneous molecular process, with Arrhenius parameters of E = 247 ± 5 kJ/mol and log A (sec-1) = 14.2 ± 0.3. Examination of the uninhibited reaction showed it to be a radical process, simpler than that with neopentyl chloride, there being only one propagation step, thedissociation of the γ-radical to 1,1-dimethylcyclopropane and a bromine atom.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130103
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    The reaction of atomic oxygen O(3P) with propane (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 69-84 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of O(3P) atoms with propanehas been studied at temperatures near 300 K by using a discharge flow system. Oxygen atoms were generated in the absence of molecular oxygen by the reaction N + NO → N2 + O, nitrogen atoms having been generated in a microwave discharge. Rate constants for the reaction were measured in two ways, either by measurement of O-atom decay in the presence of excess propane or by measuring the change in propane concentration after an appropriate time in the presence of an excess of oxygen atoms. The two methods were in good agreement, and the mean rate constant at 306 K is given by \documentclass{article}\pagestyle{empty}\begin{document}$$ k_1 = (4.7 \pm 0.8) \times 10^6 {\rm dm}^3 /{\rm mol}\;\sec $$\end{document} A study of the products of the reaction under conditions corresponding to complete removal of oxygen atoms has shown that an important product of the reaction in the early stages is propene. This is difficult to explain interms of a mechanism involving alkoxy radicals similar to that which has been proposed for some other O(3P)-hydrocarbon reactions. An alternative mechanism is proposed in terms of successive hydrogen abstraction reactions.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130107
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Reactivity of amines toward tert-butoxy radicals: Effect of solvent and amine structure (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 119-123 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reactivity of amines towards tert-butoxy radicals depends upon the amine ionization potential and the solvent, indicating that polar structures contribute to the reactivity of these compounds. Nevertheless, the dependence with the amine potential is smaller than the one obtained for the quenching of carbonyl excited states by amines and other factors as the strength of the broken hydrogen bond and steric hindrance are also significant in determining the rate of the process.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Thermal reactions of ethane-d6-acetylene and D2-acetylene mixtures behind shock waves (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 741-753 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A study of the thermal decomposition of an acetylene-ethane-d6 mixture indicates that the rate constant for hydrogen abstraction from acetylene by methyl is more than 20 times less than for abstraction from ethane. Isotopic exchange is initiated by a rapid reaction between product D atoms and C2H2. A series of experiments involving the reactions of a D2-acetylene mixture indicated that a molecular exchange process was also occurring, and it was shown that d[C2HD]/dt = k[D2]0.7[C2H2]0.3, effective activation energy = 15.8 kcal/mol. This mechanism made an insignificant contribution to isotope exchange in C2H2-C2D6 mixtures.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130806
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Nonisothermal decomposition of methyl nitrate: Anomalous reaction order and activation energies and their correction (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 817-831 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Methyl nitrate decomposition is accompanied by self-heating. Using very fine thermocouples, direct measurements of excess temperatures have been made to establish the intensity and extent of self-heating in nonisothermal reaction. The measurements are displayed as contourlines of equal degrees of temperature excess on the pressure-temperature ignition diagram.A twofold kinetic investigation has been made of the overall reaction. One part concentrates on achieving isothermal conditions and full characterization of intermediate products. It uses mass-spectrometric analyses both to establish stoichiometry throughout decomposition and to validate velocity constant measurements derived from continuous pressure-time records. The best value for E = 151 ± 3 kJ/mol is about 10 kJ/mol less than previously.The other part deliberately invades the nonisothermal region to test the qualitative and quantitative predictions of theory (1) that uncorrected reaction orders and activation energies will exceed their isothermal values, (2) that their relative excess (δn/n, δE/E) will be about the same, and (3) that they will be dependent in a simple and predictable way on the reduced excess central temperature.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130906
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Editor's note (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 785-786 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130902
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Professor Keith J. Laidler (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 787-788 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130903
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Arrhenius parameters for the alkoxy radical decomposition reactions (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 833-844 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Arrhenius parameters for the decomposition reactions of various alkoxy radicals are evaluated. The recommended values for tert-butoxy radical decomposition reaction are log A (s-1) = 14.1, Ea = 15.3 kcal/mol. The parameters give reasonably self-consistent results with related rate constants, product distributions of hydrocarbon oxidation reactions, and the values reported in different laboratories in different environments.A reworking of data by Batt et al. on RO + NO and RO + NO2 leads to a lowering of his A factors for these reactions by a factor of 5. It also leads to a similar lowering of the A factors for RO decompositions. The intrinsic activation energies E for the addition of alkyl radicals R to the carbonyl group are not only found to be a function of the exothermicity of reaction, but they are also dependent on the nucleophilicity of the alkyl radicals. For each radical R (Me, Et, i-Pr) the data can be fit to an Evans-Polanyi plot E = a + b (δH), where a uniform slope b = 0.58 can be found for all R. The intercepts a are then found to decrease nearly linearly with the decreasing ionization potential of R, namely, a = 2.1 [IP] - 6.2 (kcal/mol), with the ionization potential given in electron volts.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130907
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Anchimeric assistance in the gas phase dehydrohalogenation of 5-chloro-2-methylpent-2-ene (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 1-6 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 5-Chloro-2-methylpent-2-ene decomposes at temperatures of 370-420°C with initial pressures from 61to 158 torr to yield hydrogen chloride and a mixture of methylpentadiene isomers. In a static system, with seasoned vessel and propene inhibitor, the reaction is homogeneous, unimolecular, and of the first order. The rate coefficient is expressed by the following Arrhenius equation: log k (sec-1) = (13.43 ± 0.30) - (215.0 ± 3.7) kJ/mol/2.303RT. The result ofthe present work additionally supports the participation of the neighboringaliphatic olefinic double bond in the rate of HCl elimination of alkenyl chlorides in the gas phase. Moreover, it also confirms the three-membered conformation as the most favored structure for anchimeric assistance.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130102
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    The kinetics of the reactions of C2F5 radicals with Br2 and HBr (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 59-67 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A mixture of Br2 + HBr + C2F5I was photolyzed in the vapor phase. The reaction \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm Br + C}_{\rm 2} {\rm F}_{\rm 5} {\rm I} \to {\rm IBr + C}_{\rm 2} {\rm F}_{\rm 5} $$\end{document} forms C2F5 radicals which are removed by Competitive studies over the range of 74-146°C gave ratios of k10/k9, and these were combined with values obtained previously by different methods at higher temperatures upto 515°C to give \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log(}k_{10} /k_9) = (- 0.47 \pm 0.03) - (12,500 \pm 300)/\theta $$\end{document} where θ = 2.303RT J/mol. A value is assigned to the activation energy E10, and this, with other data, leads to \documentclass{article}\pagestyle{empty}\begin{document}$$ D{\rm (C}_{\rm 2} {\rm F}_{\rm 5} - {\rm H}) = 429.8 \pm 2.1{\rm KJ}/{\rm mol} $$\end{document} at 25°C. This result is in excellent agreement with two previous independent determinations.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130106
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    Coupling rates and kinetics of arenediazonium cations with couplers utilized in the diazo reprographic process (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 97-107 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Stoichiometric and, in most cases, absolute rates of coupling of a series of m- and p-substituted benzenediazonium ions with 2,3-dihydroxynaphthalene-6-sulfonate ion (1) have been determined (i) at pH 5.6 (when one OH group is partly monoionized) and (ii) at pH 9.9 (when one OH group is completely ionized and the second slightly so). The rates at both pH values correlate with the σ+ parameter (except for the most reactive ArN2+ at pH 9.9) and the contributions of the two reactive forms of the coupler evaluated. Detailed pH dependences of the coupling rate of the p-chlorobenzenediazonium ion with (1) reveal a strong interaction between (1) and the borate ion, which strongly influences the coupling rate. Coupling rates have also been measured for both diazonium ions and couplers of importance in the diazo reprographic process.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130109
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Kinetic studies of free radical reactions by mass spectrometry. II. The reactions of SO + ClO, SO + OClO and SO + BrO (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 187-197 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rates of several novel elementary reactions involving ClO, BrO and SO free radicals in their ground states were studied in a discharge-flow system at 295 K, using mass spectrometry. The rate constant k2 was determined from the decay of SO radicals in the presence of excess ClO radicals: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm SO} + {\rm ClO} \to {\rm SO}_{\rm 2} + {\rm Cl;}} & {k_{\rm 2} = (2.3{\rm } \pm {\rm 0}{\rm .6}) \times 10^{ - 11} {\rm cm}^3 \sec ^{ - 1} } \\ \end{array}$$ \end{document}The SO + OClO overall reaction has a complex mechanism, with the primary step having a rate constant k5 equal to (1.9 ± 0.7) × 10-12 cm3 sec-1: \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm SO} + {\rm OClO } \to {\rm SO}_{\rm 2} + {\rm ClO} $$\end{document}A lower limit for the rate constant of the rapid reaction of SO radicals with BrO radicals was determined: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm SO} + {\rm BrO} \to {\rm SO}_{\rm 2} + {\rm Br;}} & {k_{17} } \\ \end{array} \ge 4 \times 10^{ - 11} {\rm cm}^3 \sec ^{ - 1} $$\end{document}
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130208
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Effect of cyano group substitution on metathetical reactions. IV. Substituent effects on the rates of cyanomethyl radical reaction with haloalkanesReference [5] of this article is part III of this series (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 219-230 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Gamma radiation-induced free radical chain reactions in liquid mixtures of BrCH2CN, eyelohexane (RH), and haloalkanes (XCCl3) were studied. The kinetics of hydrogen and chlorine atom abstraction from CHCl3, CH3CCl3, CH2ClCCl3, CHCl2CCl3, CF3CCl3, C2Cl6, CCl3CN, and CCl4 by CH2CN radicals were investigated by a competitive method. The reactions investigated were Rate constant ratios k3/k2, k5/k6, k7/k2, and k3/k7 were determined at 180°C. In the CCl4—RH—BrCH2CN system k3/k2 was determined in the temperature range of 100-180°C, yielding log k2 k3 = -0.11 ± 0.2 -(3.34 ± 0.39/θ): where θ = 2.3RT in kcal/mol. The value E2—E3 was combined with existing data on E3 to yield E2(CCl4) = 17.57 kcal/mol. The reactivity trend of CH2CN is compared with that of R radicals. It is shown that in spite of a difference of about four orders of magnitude in kCl values, the reactive cyclohexyl radical is somewhat more selective than CH2CN. It is proposed that the relative reactivities log[k2(XCCl3)/k2(CH3CCl3)] can be correlated in terms of a dual-parameter Taft equation which takes into account both resonance and inductive substituent effects.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130302
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    The rate constant for H + i-C4H8 → t-C4H9 in the range of 298-563 K (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 295-301 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The overall rate constant for hydrogen-atom addition to isobutene has been measured in the temperature range of 298-563 K in a flow discharge system coupled to a quadrupole mass spectrometer. Previously published results allow the determination of \documentclass{article}\pagestyle{empty}\begin{document}$$ \log {\rm }k_1 ({\rm cm}^3 /{\rm mol\,\, sec}) = 13.59 \pm 0.11 - 1.79 \pm 0.19\,\,{\rm kcal/mol/(2}{\rm .3}RT{\rm)} $$\end{document} where the error limits are 95% confidence limits.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130308
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Kinetics of acid catalyzed and Ag(I) catalyzed decomposition of peroxodisulfate in aqueous medium (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 555-564 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The mechanism of acid catalyzed decomposition of peroxodisulfate, (S2O82-) in aqueous perchlorate medium involves the hydrolysis of the species H2S2O8 and HS2O8- and the homolysis of the species H2S2O8, HS2O8- and S2O82- at the O—O bond. The overall rate law when 1.4M 〉 [HClO4] 〉 0.1M is \documentclass{article}\pagestyle{empty}\begin{document}$$ \frac{{ - d[{\rm S}_{\rm 2}{\rm O}_8^{2 - }]}}{{dt}}\, = \,k_0 [{\rm S}_{\rm 2}{\rm O}_8^{2 - }]\, + \,k' [{\rm S}_{\rm 2}{\rm O}_8^{2 - }][{\rm H}+]\, + \,k{''}[{\rm S}_{\rm 2}{\rm O}_8^{2 - }][{\rm H}+]^2 $$\end{document}The constants k′ and k″ contain the hydrolysis and homolysis rate constants of HS2O8- and H2S2O8, respectively. With added Ag(I), the acid catalyzed and Ag(I) catalyzed reactions take place independently. Ag(I) catalyzed decomposition appears to involve the species AgS2O8- (aq).
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130605
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Photolysis of ethyl-iodide in lithium chloride glassy aqueous solutions with light, λ = 254 nm at 77 K (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 543-554 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The photolysis of C2H5I in a glassy salt matrix (5M, 7.5M, 10M) of aqueous LiCl at 77 K with light of λ = 254 nm has been conducted, product analysis being by ESR and UV spectroscopy. The electrolytic medium causes the ionization of product HI, and I- concentrations can be continuously determined. During photolysis [I-] is less than the amount of C2H5I decomposed. But after photolysis thaw-freeze cycling is accompanied by progressive growth in [I-] until the yield matches the C2H5I loss, the quantum yields being 0.26, 0.20, and 0.17 for the three LiCl solutions, respectively. The quantum yield of unionized HI is unchanged, however, at around 0.36, the overall change being due to a fall in the extent to which the HI is ionized in the direct photolysis (ø = 0.22, 0.16, and 0.11). It is proposed that this is a consequence of the density increase of matrix packing as the LiCl concentration is increased so that fewer HI are in contact with the aqueous medium and cage recombination is favored.The results establish that the primary reaction is essentially exclusive: and that substantial aggregates of C2H5I exist within which HI are caged and cannot be ionized. The direct reaction \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm C}_{\rm 2}{\rm H}_{\rm 5}{\rm I}+ h\nu \to {\rm C}_{\rm 2}{\rm H}_5^. + {\rm I}^. $$\end{document} occurs only to a trivial extent, ø; = 10-4, C2H5 arising virtually totally via \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm C}_{\rm 2}{\rm H}_{\rm 4}+ {\rm H}^. \to {\rm C}_{\rm 2}{\rm H}_5^. $$\end{document}
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130604
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Steric factors in the kinetically controlled direction of elimination of secondary and tertiary esters in the gas phase. The pyrolysis of 4,4-dimethylpent-2-yl acetate (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 577-589 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The pyrolysis kinetics of 4,4-dimethylpent-2-yl acetate, in a static system and in a vessel seasoned with allyl bromide, have been studied in the temperature range of 300-350°C and the pressure range of 48-211 torr. The olefin products were 4,4-dimethylpent-1-ene, cis-4,4-dimethylpent-2-ene, and trans-4,4-dimethylpent-2-ene. The rate coefficient for the homogeneous unimolecular elimination of this ester is given by the following Arrhenius equation: log k(sec-1) = (12.87 ± 0.31) - (181.2 ± 3.4)kJ/mol/2.303RT. The direction of elimination of this acetate has been found to proceed to the formation of the corresponding olefin by kinetic control. The present data, together with other pyrolysis work subject to kinetic control, imply that the direction of elimination of bulky alkyl esters is determined by steric hindrance in the eclipsed cis conformation. However, further analyses reveal that if a series of esters are compared, in the case of a gradual increase of alkyl branching when adjacent to a hydrogen atom (alkyl-H interactions), the rate was determined by steric acceleration, owing to the crowding effect at the highly substituted carbon atom. Otherwise if this gradual alkyl increase in size happened to be adjacent to another alkyl substituent (alkyl-alkyl interactions), the rate was affected by steric hindrance of the eclipsed cis conformation.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130607
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    The correlation of rate coefficients for H-atom abstraction by HO radicals with C—H bond dissociation enthalpies (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 651-665 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: For H-atom abstraction reactions by HO radicals it has been shown that If Di is taken as the C—H bond dissociation enthalpy at 298 K, then a = 0.323 and D0is obtained from the empirical formula \documentclass{article}\pagestyle{empty}\begin{document}$$ D_0 ^{ - 1} = 1.062 \times 10^{ - 2} + 3.52 \times 10^{ - 6} T $$\end{document} where D0 is in kcal/mol and T is in K. Thisrelationship is valid for T between 200 and 400 K. Finally empiricalrelationships are given to help estimate Di.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130706
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    The temperature coefficient of the rates in the system Cl + CH4 ⇆ CH3 + HCl, thermochemistry of the methyl radical (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 677-691 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The bimolecular rate constant for the title reaction has been measured by very-low-pressure reactor techniques at 233 〈 T K 〈 338. The equilibrium constant has also been measured between 253 and 338 K. Our rate constants are in excellent agreement with recent measurements using very different techniques and reaction conditions, and the general agreement probably makes this one of the most accurately measured rateconstants. Transition state models of the reaction rule out a bent TS in favor of a TS with colinear Cl···H···C bonds. The curvature at higher temperatures (〉350 K) is quantitatively accounted for by transition state theory analysis. Tunneling is shown not to play a role. The measured values of K1 allow an experimental value of S° (CH3) to be fixed to only ±2.4 e.u. However, using known values of S° for all species gives ΔH°f298(CH3.) = 35.1 plusmn; 0.1 kcal/mol in excellent agreement with other measured values.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130708
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    Evidence for chamber-dependent radical sources: Impact on kinetic computer models for air pollution (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 735-740 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of NOx-air irradiations, with trace amounts of propane and propene present to monitor OH radical concentrations, have been carried out in a 5800-L evacuable environmental chamber to investigate radical levels and sources during such irradiations. The data obtained show conclusively that unknown radical sources are present, and that photolysis of initial nitrous acid can be, at best, only a minor source of radicals after ∼30-60 min of irradiation.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130805
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Kinetics and mechanism of the thermal decomposition of cyclopentyl cyanide (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 755-770 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The thermal decomposition of cyclopentyl cyanide has been investigated in the temperature range of 905-1143 K using both conventional stirred-flow reactor and very low-pressure pyrolysis (VLPP) techniques. The results from both techniques are consistent. The main primary processes are HCN elimination to form cyclopentene: and ring fragmentation to form vinyl cyanide plus propylene and ethylene plus cyanopropenes: Under the experimental conditions cyclopentene undergoes further decomposition to cyclopentadiene plus hydrogen. There is evidence for conversion of some of the reactant to a solid residue, presumably polymer. From the stirred-flow reactor results the following Arrhenius expressions were obtained: log k1(s-1) = (12.8 ± 0.3) - (65.6 ± 1.3)/θ and log k2(s-1) = (16.0 ± 0.3) - (80.0 ± 1.1)/θ, where θ = 2.303RT kcal/mol. Application of RRKM theory shows that the VLPP experimental rate constants are consistent with high-pressure Arrhenius parameters given by log k1(s-1) = (12.8 ± 0.3) - (67.8 ± 2.5)/θ for HCN elimination, and log k4(s-1) = (16.3 ± 0.3) - (80.1 ± 2.0)/θ for the sum of the ring fragmentation pathways. The rate parameters for HCN elimination are in good agreement with previous VLPP studies of alkyl cyanides and with theoretical predictions. The difference in activation energies for the ring opening of cyclopentane and cyclopentyl cyanide is reasonably close to the established value for the cyano stabilization energy. This supports the assumption of a biradical mechanism.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130807
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Masthead (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981) 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130101
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Free-radical chain dechlorination of chloroethanes in liquid triethylsilane (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 23-38 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics and mechanism of the free-radical chain dechlorination of C2Cl6, C2Cl5H, and sym-C2Cl4H2 in Et3SiH wereinvestigated over a wide temperature range. The propagation step of the dechlorination of chloroethanes (C2Clx H6-x) proceeds by the following reactions: Analysis of the temperature dependence of product formation gave the Arrhenius expressions for k4/k3 which in turn were utilized for the estimation of the absolute Arrhenius parameters for hydrogen abstraction from Et3SiH. Our results show that the values of Eabs are lower in Et3SiH than in c-C6H12 by about 2-3 kcal/mol, while the A factors are almost equal. In competitive studies k2 was determined versus Br abstraction from n-C5H11Br. The relative Arrhenius parameters determined by this method show that variations in both A factors and activationenergies are responsible for the reactivity trends observed in the Cl transfer reactions of Et3Si radicals.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130104
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    On the Michaelis-Menten behavior of pyridinium chloro chromate oxidations: Oxidation of dimethyl, dipropyl, and diphenyl sulfide in chlorobenzene-nitrobenzene mixtures (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 85-96 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of oxidation of dimethyl, dipropyl, and diphenyl sulfides by pyridinium chloro chromate in chlorobenzene-nitrobenzene mixtures are reported. The rate data show Michaelis-Menten behavior. The oxidation process is catalyzed by the organic acids like dichloro and trichloro acetic acids. The rate-determining step appears to be a unimolecular decomposition of a complex of the reactants.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130108
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Peroxy radical reactivities in the cooxidation of ethylbenzene and substituted 3-phenylindans (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 111-118 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rate constants of peroxy radical recombination in the oxidation of 1-methyl-3-phenylindan, 1,3-dimethyl-3-phenylindan, and 1,1-dimethyl-3-phenylindan were measured using the nonstationary-state technique. A cooxidation method was applied to obtain the reactivities of these compounds with respect to α-phenylethyl peroxy radicals.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130202
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Use of two-parameter correlations for studying the radical reactivity of aromatic compounds (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 173-186 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two-parameter equation correlations are reported for radical reactions of aromatic compounds. In these correlations polar and resonance substituent constants identical with the substituent constants of aliphatic compounds were used. The equations correlate the rate constants for H abstraction reactions and for the addition of a variety of free radicals to the ortho-, meta-, and para-substituted aromatic compounds. Besides, they correlate parameters of the spectra for substituted aromatic radicals. The correlations show that the effects of para substituents on the reactions studied are nearly entirely resonance effects, whereas for the meta- and ortho-substituted compounds polar (inductive) effects become essential. Application of the two-parameter correlations permits also to determine the structure of transition states (σ or π-complex) in free-radical reactions.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130207
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Mechanism of the azide-bromine reaction in aqueous medium (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 199-207 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Results on the oxidation of N3- by Br2 in neutral and acid media are presented. The rate of the reaction is found to be proportional to [N3-] and [Br2]. The gaseous product of oxidation is found to be pure nitrogen. The stoichiometry of the reaction is \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm Br}_2 + 2{\rm N}_{\rm 3}^ - \to 2{\rm Br}^ - + 3{\rm N}_{\rm 2} {\rm ([N}_{\rm 3}^ -]) 〉 [{\rm Br}_2] $$\end{document} The reaction shows a positive salt effect. It is found that the addition of Br- stabilizes the complex BrN3, which decomposes into Br- and N2: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm Br}_2 + {\rm N}_{\rm 3}^ - \rightleftharpoons {\rm BrN}_{\rm 3} + {\rm Br}^ - } \\ {{\rm BrN}_3 + {\rm N}_{\rm 3}^ - \to {\rm Br}^ - + 3{\rm N}_{\rm 2} } \\ \end{array} $$\end{document} The spectroscopic measurements also support the kinetic observation. The equilibrium constant K, the rate constants and the thermodynamic parameters were calculated. It is observed that H+ ion inhibits the reaction. The mechanism is discussed in terms of the kinetic results.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130209
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Very low-pressure pyrolysis (VLPP) of pentynes. I. Kinetics of the retro-ene decomposition of pent-1-yne (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 245-254 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The thermal unimolecular decomposition of pent-1-yne has been investigated over the temperature range of 923-1154 K using the technique of very low-pressure pyrolysis (VLPP). Under the experimental conditions the reaction proceeds predominantly via a molecular retro-ene pathway to yield allene and ethylene. There was some evidence for the occurrence of the higher energy C3—C4 bond fission pathway at the high end of the temperature range. Interpretation of the data with the aid of RRKM theory and taking into account a decrease in gas-wall collision efficiency with temperature yields the following high-pressure rate constant expression for the retro-ene pathway: \documentclass{article}\pagestyle{empty}\begin{document}$$ \log k(\sec ^{ - 1}) = (12.8 \pm 0.4) - (57.0 \pm 2.0)/\theta $$\end{document} at 1100 K where θ = 2.303 RT kcal/mol and the A factor was assigned from the results of shock-tube studies of similar molecules. These rate parameters are independent of the inclusion of the bond fission pathway in the RRKM calculations. The results are compared with previous data on the retro-ene decomposition of alkynes.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130304
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    Kinetics of competitive pathways in the thermal unimolecular decomposition of hex-1-yne (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 273-282 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The thermal unimolecular decomposition of hex-1-yne has been investigated over the temperature range of 903-1153 K using the technique of very low-pressure pyrolysis (VLPP). The reaction proceeds via the competitive pathways of C3—C4 fission and molecular retro-ene decomposition, with the latter being the major pathway under the experimental conditions. RRKM calculations, generalized to take into account two competing pathways, show that the experimental unimolecular rate constants are consistent with the high-pressure Arrhenius parameters at 1100 K given by \documentclass{article}\pagestyle{empty}\begin{document}$$ \log k(\sec ^{ - 1}) = (12.7 \pm 0.4) - (56.4 \pm 1.0)/\theta \;\;\;\hbox{for retro-ene} $$\end{document} and \documentclass{article}\pagestyle{empty}\begin{document}$$ \log k(\sec ^{ - 1}) = (15.9 \pm 0.3) - (70.7 \pm 2.0)/\theta \;\;{\rm for}\;{\rm C} {-} {\rm C}\,{\rm fission} $$\end{document} where θ = 2.303 RT kcal/mol and the A factors were assigned from the results of recent shock-tube studies of hex-1-yne and related alkynes. The results for C—C fission are consistent with previous VLPP and shock-tube determinations of the propargyl resonance energy, and the parameters for the molecular pathway are consistent with systematic trends for the retro-ene decomposition of unsaturated hydrocarbons.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550130306
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...