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  • 1985-1989  (724)
  • 1975-1979
  • 1870-1879
  • 1987  (724)
  • Inorganic Chemistry  (658)
  • Electron microscopy
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Years
  • 1985-1989  (724)
  • 1975-1979
  • 1870-1879
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 411 (1987), S. 311-314 
    ISSN: 1432-2307
    Keywords: Human pituitary adenomas ; Granules ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Light bodies are large cytoplasmic granules originally described in the gonadotrophic cells of the rat pituitary gland. In order to determine whether similar bodies occur in the human anterior pituitary gland, 89 pituitary adenomas and periadenomatous tissue from 20 cases were examined by transmission electron microscopy. Double membrane bound bodies with filamentous internal structure identical to rodent light bodies were identified in 10 hormone-producing adenomas: 5 PRL, 1 PRL-GH, 2 GH, and 2 ACTH-producing tumours. No light bodies were found in the remaining 79 tumours nor in the pituitary cells in periadenomatous tissue from 20 cases. These results show that some human pituitary adenomas may contain light bodies identical to those seen in gonadotrophs of rat pituitary.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 410 (1987), S. 83-92 
    ISSN: 1432-2307
    Keywords: Buschke-Loewenstein tumour ; Giant condyloma ; Anogenital region ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Results on the light- and electron microscopic studies of six cases of Buschke-Loewenstein tumour are presented. The role of chronic irritation is emphasized in the aetiology of the tumour. Fistulas and abscesses arising in the tumour are dangerous as they give rise to chronic sepsis. In two perianal tumours, in situ or invasive carcinoma developed. Electron microscopy revealed varying degrees of differentiation of keratinocytes. As a result of the defective desmosomes, the tumour cell underwent segregation, with widened intercellular spaces containing oedema, erythrocytes and leucocytes. This phenomenon is probably responsible for frequent bleeding and fistula formation. The investigations disclosed that the Buschke-Loewenstein tumour is a special form of squamous carcinoma and therefore, radical surgical excision must be attempted even in case of a benign histological picture.
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  • 3
    ISSN: 1432-2307
    Keywords: Thrombocytopenic purpura ; Idiopathic thrombocytopenic purpura ; Liver sinusoidal fibrosis ; Electron microscopy ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 10 patients with thrombocytopenic purpura (TP) underwent splenectomy. Eight of these patients had idiopathic TP (certain or probable). All had normal liver function tests. Liver histology of the surgical biopsy was normal with the exception of a non specific mild portal infiltration in 6 cases. On Sirius red staining the perisinusoidal network was normal in 3 cases, mildly or moderately increased in 5 cases and often associated with perivenular fibrosis. Collagen types I, III, IV, laminin and fibronectin were increased in the 8 biopsies tested. On semi-thin sections, numerous Kupffer cells were observed. Under the electron microscope, sinusoidal abnormalities were very similar in all 7 patients studied: numerous Kupffer cells containing abundant lysosomes, numerous collagen bundles in the Disse space, active endothelial cells, transformation of some perisinusoidal cells into cells with some of the characteristics of fibroblasts (increased RER) and myofibroblasts (peripheral condensations of the filamentous network), increased fragments of basement membrane-like material. In two cases there was an increase in the number of perisinusoidal cells loaded with lipids. The similarity of the lesions and the absence of other fibrogenic causes (except in 2 cases) suggest that TP may represent another group of diseases with perisinusoidal fibrosis. The aetiology of fibrosis remains unknown but platelet derived growth factor and activated macrophages may play a major role.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular evolution 26 (1987), S. 347-357 
    ISSN: 1432-1432
    Keywords: Ribosome structure ; Electron microscopy ; Image analysis ; Evolutionary lineages
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Multivariate statistical analysis and classification techniques are powerful tools in sorting noisy electron micrographs of single particles according to their principal features, enabling one to form average images with an enhanced signal-to-noise ratio and a better reproducible resolution. We apply this methodology here to determining the characteristic views of the large (50S) ribosomal subunits from the eubacteriumEscherichia coli and the archaebacteriaMethanococcus vannielii, Sulfolobus solfataricus, andHalobacterium marismortui. Average images were obtained of the subunit in the common crown and kidney projections, but views of the particle in orientations intermediate between these two extremes were also elucidated for all species. These averages show reproducible detail of up to 2.0 nm resolution, thus enabling the visualization and interspecies comparison of many structural features as a first step toward comparing the actual three-dimensional structures. Our results disprove evolutionary lineages recently postulated on the basis of electron microscopical images of ribosomal subunits.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 65 (1987), S. 144-146 
    ISSN: 1432-1440
    Keywords: Campylobacter pyloridis ; Duodenal ulcer ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of campylobacter-like organisms found within duodenal biopsy specimens from 7 of 24 patients (28%) with active duodenal ulcer is described. Their curved shape and variable size are similar to what has previously been reported in descriptions of light microscopies. The organisms were found at the edge of active duodenal ulcers exclusively near neutral-mucous producing antral cells, to which they can adhere. The presence of these bacteria within cells and in the intercellular fluid implies that they can penetrate through the cell membrane or through tight intercellular junctions. The occurrence of these bacteria as well as numerous polymorphonuclear leukocytes in the afflicted regions suggests that the bacteria originally described by Warren and Marshall are indeed pathogenic and that their influence on ulcer healing should be included in designing treatment protocols.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Archives of toxicology 59 (1987), S. 385-390 
    ISSN: 1432-0738
    Keywords: Lung ; Methyl isocyanate ; Gas poisoning ; Electron microscopy ; Rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The static exposure of rats to 0.25 mg/l methyl isocyanate for 1 h resulted in damage to the epithelium of the proximal bronchioles and upper airways. Bronchiolar cells exhibited both nuclear and cytoplasmic damage; many epithelial cells, particularly in the bronchi and trachea, were killed and/or dislodged from the basement membrane. A “raft” of cell debris and fibrin lined most of the airways during the 1st week after exposure but repair to the underlying epithelium was well advanced within 2–3 days. The majority of airways were lined by a normal epithelium within 3 weeks of exposure, but isolated foci of hyperplasia and occluded airways probably accounted for continued respiratory impairment.
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  • 7
    ISSN: 1432-0738
    Keywords: Isopropyl alcohol ; Tracheal mucosa ; Ciliary activity ; Recovery process ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The toxicity of isopropyl alcohol (IPA) on the tracheal mucosa was studied experimentally with special reference to the recovery process of the organ. The results showed that 400 ppm IPA has an acute effect on the mucociliary system in the tracheal mucosa, and that recovery from such degeneration can occur in 2 weeks. When functional and morphological damage was induced by a higher level (5500 ppm) of IPA, recovery did not occur in 2 weeks. The conclusion is that the present allowable level of IPA is reasonable from the viewpoint of the effects of short-term exposure to IPA on the tracheal mucosa. In addition, a higher level of IPA exposure has longer-term effects on the tracheal mucosa, and workers exposed to such a higher level of IPA vapor should be given careful otolaryngological follow-up observations.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 75 (1987), S. 116-122 
    ISSN: 1432-0533
    Keywords: Rat ; Lead ; Brain edema ; Electron microscopy ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Newborn rats were exposed to daily intraperitoneal injections of 10 mg lead nitrate per kg body weight for the first 15 postnatal days. The growth and mortality of the lead-exposed animals did not differ from their control litter-mates, injected with vehicle only. In our previous studies, focal hemorrhages and spongy areas as well as breakdown of blood-brain barrier to plasma proteins were shown by light microscopy in the cerebellar parenchyma of 15-day-old rats exposed to this dose. In spite of these signs of edema, measurements of brain tissue specific gravity did not show increased water content. In the present investigation we examined the ultrastructure of the brain lesions in these rats with low-dose lead encephalopathy, focusing on signs of edema, and evaluated astroglial reaction by immunocytochemical staining for glial fibrillary acidic protein (GFAP). The electron microscopic findings were compatible with extracellular edema in the cerebellum of 15-day-old lead exposed rats. The number of GFAP-positive cell bodies in the gray substance of the cerebellar cortex was increased in the 15-day-old lead-exposed rats as compared with the controls of the same age, a finding which is presumably related to the leakage of plasma proteins. Both these findings were lacking at 20 days of age, suggesting reversibility of the lead-induced changes.
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  • 9
    ISSN: 1432-0533
    Keywords: Pleomorphic xanthoastrocytoma ; Epithelial properties ; Circumscribed growth ; Electron microscopy ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Three cases of pleomorphic xanthoastrocytoma (PXA), one of which showed anaplastic evolution, are described. In all three the PXA tumors were well circumscribed and could be totally removed. Light-microscopically, pleomorphic tumor cells clustered gregariously and often formed alveolar structures. Electron microscopy revealed various epithelial properties, such as junctions and interdigitations between apposing tumor cells, and prominent basal laminae surrounding tumor nests. The circumscribed growth of PXA, as contrasted with an infiltrative growth of usual astrocytoma, can be attributed to the cellular cohesion based on the epithelial properties of the tumor cells. In the third patient, tumor recurred 6 months postoperatively. Although the recurrent tumor retained the alveolar structures, pleomorphism and various degenerative features of the tumor cells diminished with advance in the proliferative activities.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 176 (1987), S. 251-258 
    ISSN: 1432-0568
    Keywords: Decidua ; Involution ; Electron microscopy ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Involution of the antimesometrial decidua was analysed by electron microscopy on days 9, 10 and 11 of pregnancy in the mouse. During this period, the width of the antimesometrial decidua decreases considerably. Involution begins in the decidual cells situated closest to the embryo (internal decidua) and proceeds towards the myometrium. The cells of the internal decidua showed signs of deterioration characterized by accumulation of clumps of chromatin in the nuclei and dilation of the perinuclear cisterna and endoplasmic reticulum cisternae. Autophagosomes and heterophagosomes accumulated in the cytoplasm of these cells. Cells particularly strongly affected became spherical and were devoid of their plasma membrane. Some cells near the trophoblast as well as the mature decidual cells situated farther from the embryo showed a normal morphology. The trophoblastic cells established close contact with healthy decidual cells and engulfed fragments of disorganized decidual cells. It is suggested that the death of decidual cells is a type of programmed cell death and that it is not due to a direct lytic action by the trophoblast.
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 279 (1987), S. S30 
    ISSN: 1432-069X
    Keywords: Cicatricial pemphigoid ; Vegetating lesions ; Immunopathology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case with widespread vegetating-pustular skin lesions, oral erosions, ulcerations and scarring, and conjunctival synechiae is reported. Clinically, histopathologically, and by immunofluorescence and electron microscopy this patient combined the features of pemphigoid vegetans, as described by Winkelmann and Su, and the mucocutaneous type of cicatricial pemphigoid. This observation suggests that a third subset of cicatricial pemphigoid can now be added to the two existing ones, the mucocutaneous and Brunsting-Perry types, and the designation vegetating cicatricial pemphigoid is proposed for this heretofore undescribed condition.
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 73 (1987), S. 370-378 
    ISSN: 1432-0533
    Keywords: Electron microscopy ; Factor VIII ; Glial fibrillary acidic protein ; Hemangioblastoma ; Tissue culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The histogenesis of stromal cells in capillary hemangioblastoma has been the subject of debate. The light and electron microscopic studies of hemangioblastomas presented here showed pericytic and leiomyoblastic features in stromal cells. Cells cultured by the monolayer method showed similar features to those of the original tumors. Immunohistochemical studies for glial fibrillary acidic protein and factor VIII/von Willebrand factor indicated that stromal cells were antigenically distinct from astrocytes and endothelial cells. These findings suggest that stromal cells are closely related to pericytes and smooth muscle cells, and support Rhodin's speculation that pericytes serve as a precursor to smooth muscle cells.
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  • 13
    ISSN: 1432-0533
    Keywords: Hypoglycemia ; Rat striatum ; Glutamate ; Excitotoxic nerve cell injury ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In rat striatum severe hypoglycemia causes an irreversible nerve cell injury, which does not become manifest until during the post-insult recovery period. This injury can be ameliorated by lesions of the glutamatergic cortico-striatal pathway, which suggests that an “excitotoxic” effect mediated by the glutamatergic input is the likely cause of the posthypoglycemic nerve cell destruction. In this paper we further characterize the protective effect of abolishing the glutamatergic innervation to striatum at the ultrastructural level. Two weeks after a unilateral cortical ablation rats were subjected to 30 min of severe hypoglycemia with isoelectric EEG and killed either immediately after the insult or following 60 min of recovery induced by restoring the blood glucose levels. Immediately after the hypoglycemic insult the structure of striatum was similar on both sides (except for the changes attributable to the ablation); i.e., the neurons and their dendrites had pale cytoplasm with condensed mitochondria, sparse RER and pinpoint ribosomes. After 60 min restitution numerous striatal neurons on the non-protected, non-ablated side had turned variably dark and condensed, whereas under-neath the ablation they remained similar as immediately after hypoglycemia. This sequence indicates that the most likely cause of nerve cell destruction on the non-protected side is the “excitotoxic” effect mediated by the glutamatergic innervation, which is superimposed on the action of the hypoglycemic insultper se. Furthermore, the primary condensation of neurons and their dendrites indicate existence of another type of acute “excitotoxic” nerve cell injury which differs from the previously described injury characterized by neuronal swelling.
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 75 (1987), S. 131-139 
    ISSN: 1432-0533
    Keywords: Cerebral ischemia ; Hyperglycemia ; Substantia nigra ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Preischemic hyperglycemia induced by feeding or glucose infusion worsens the brain damage and the clinical outcome following ischemia of a given duration and density, and characteristically causes postischemic seizure activity. Light microscopy has previously showed that, in the rat, transient hyperglycemic ischemia induced by bilateral carotid occlusion in combination with arterial hypotension causes a uni- or bilateral lesion in the pars reticulata of the substantia nigra. Since this region has a central role in preventing seizure discharges the present study was carried out to determine the ultrastructural characteristics of this lesion. In rats with 10 min of transient hyperglycemic ischemia followed by recirculation for 1 to 18 h, the pars reticulata of the substantia nigra showed signs of status spongiosus, as well as extensive nerve cell alterations. These changes were observed after all recovery periods studied. The spongiotic appearance was mainly caused by swelling of dendrites and, to a lesser degree, by astrocytic swelling. The dendrites were expanded at all recovery times but the severity increased during the later periods of recirculation. These swollen dendrites contained severely expanded mitochondrias and endoplasmic reticulum. The cytoskeletal elements showed disordered lining of microtubules. Two major types of nerve cell alterations were present: a “pale” and a “dark” variety. The pale type was the most frequent cell alteration. It occurred in all experimental groups and at all time points. Redistribution of the nuclear chromatin and of cytoplasmic organelles as well as swelling of the same type as in the dendrites were the essential changes. The dark neurons were much fewer in number and occupied a peripheral position in the pars reticulata. Astrocytic foot processes appeared to be dilated around the dark neurons. Swelling of astrocyte processes was most pronounced in the 1 h recovery animals. Both types of neurons showed severe mitochondrial alterations of the type observed in dendrites. Occasionally, mitochondrial alterations were found in astrocytic processes as well. Blood vessel alterations were lacking. Previous studies have shown that in this model of ischemia the substantia nigra has a relatively well-preserved blood perfusion. In view of this the extensive histopathological lesions are surprising. We speculate that the lesions primarily involve excitotoxic damage to dendrites, with pronounced lactic acidosis playing a contributory role in causing axonal and glial pathology as well.
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 176 (1987), S. 525-530 
    ISSN: 1432-0568
    Keywords: Placenta ; Guinea pig ; Labyrinth ; Syncytiotrophoblast ; Tracers ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The permeability of the materno-fetal barrier in the chorioallantoic placenta was studied in guinea pigs with gestation at term applying a variety of electron-opaque tracers via maternal circulation. None of the tracers tested was seen permeating the syncytiotrophoblast in the materno-fetal direction up to a 20 min interval when the fine structure of the placenta was satisfactorily preserved. The lanthanum chloride, cationized ferritin and horseradish peroxidase bound to the trophoblast surface, apparently due to electrostatic forces more than to specific receptors, and no uptake of these probes was detected in the cytoplasm. Albumin-colloidal gold complex, also used as a tracer, yielded similar results. As reported in other species with more complex syncytiotrophoblastic organization, this layer investing maternal lacunae is a highly selective permability barrier.
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 74 (1987), S. 169-178 
    ISSN: 1432-0533
    Keywords: Cerebral gangliocytoma ; Parieto-frontal lobe ; Intracytoplasmic inclusion bodies ; No synapse ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We report a case of cerebral gangliocytoma (GC) with a variety of unusual structures in the tumor cells. Light microscopically, the tumor consisted of typical ganglion cells, atypical cells which has argyrophilic granules in the cytoplasm, and a few astrocytes. Electron microscopically, the tumor cells showed typical gangliocytic features, which had abundant rough endoplasmic reticula, ribosomes and cored vesicles of 90–150 nm diameter, a few 50-nm-diametered non-cored vesicles, and other common organelles in their cytoplasm. Furthermore, neoplastic ganglion cells contained a variety of abnormal structures, including membranous cytoplasmic bodies (MCB), Zebra bodies (ZB), tubular structures, branched tubular structures (BTS), concentrical laminated bodies and curvilinear bodies (CB). The MCB, ZB and CB resembled those in GM2 gangliosidosis (GMG), and the BTS that in infantile neuroaxonal dystrophy (INAD). Although the significance of these inclusions is still unknown, it is considered that some common mechanism might play a role in the metabolism of both neoplastic neuronal cells and degenerating neurons (GMG and INAD). Synapses could not be observed anywhere despite complete neuronal differentiation of many tumor cells.
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 176 (1987), S. 145-154 
    ISSN: 1432-0568
    Keywords: Neurological mutant mice ; ‘Purkinje cell degeneration’ (pcd) ; Weaver ; Neural transplants ; Cerebellum ; Light microscopy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Embryonic cerebellar grafts from genetically normal donors were implanted into the cerebellomedullary cistern of adult ‘Purkinje cell degeneration’ (pcd) and weaver mutant mice, which are respectively characterized by the selective loss of Purkinje and granule cells. Grafts placed into both mutant recipients exhibited a layered cellular organization reminiscent of the normal cerebellar cortex. Molecular, Purkinje, and granule cell layers were identifiable. Grafted Purkinje cells displayed characteristic cytological features, such as hypolemmal cisterns in association with mitochondria in the perikaryon, and lamellar structures in their axons. The cytological features of granule cell somata in the grafts appeared similar to those of mature granule cells. Electron microscopic examination of the molecular layer of the grafts revealed the presence of parallel fibers, which were not oriented in a parallel fashion; axon terminals of such fibers were often presynaptic to dendritic spines. The number of parallel fibers was markedly reduced in grafts implanted into both mutants compared to the normal cerebellar cortex; however, this phenomenon is commonly seen in cerebellum in tissue culture and in cerebellar transplants into normal hosts. It is concluded, therefore, that the environment of the mutant hosts does not affect the survival of Purkinje or granule cells and that transplantation of solid cerebellar grafts in the neurological mutants studied does not seem to pose any apparent limitations beyond those inherent to the process of cerebellar growth and differentiation outside its normal environment.
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Acta neurochirurgica 88 (1987), S. 142-146 
    ISSN: 0942-0940
    Keywords: Electron microscopy ; immunohistochemistry ; pituitary ; rhabdomyosarcoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Intracranial extension of rhabdomyosarcoma from the face, nasopharynx or middle ear is rare. A 16-year-old boy presented with deterioration of vision and headache. CT scan revealed a soft tissue mass occupying the sphenoid and ethmoid sinuses, extending to the suprasellar fossa and impinging on the optic chiasm. The tumour, mimicking pituitary carcinoma, was removed by transsphenoidal craniotomy. Morphologic studies, including immunohistochemistry and electron microscopy, revealed that the tumour was a rhabdomyosarcoma. This case stresses the value of immunohistochemical and ultrastructural studies in the diagnosis of tumours occurring in the region of the sella turcica. The origin of this tumour was thought to be the sphenoid or ethmoid sinus. The pituitary gland appeared intact.
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  • 19
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    Springer
    Acta neurochirurgica 85 (1987), S. 56-62 
    ISSN: 0942-0940
    Keywords: Electron microscopy ; erythropoietin ; haemangioblastoma ; immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Immunohistochemical studies for erythropoietin were carried out in six capillary haemangioblastomas, three of which were also studied by electron microscopy. The immunohistochemical studies showed that positively stained cells were scattered in the vicinity of capillaries, and that neither endothelial cells nor stromal cells were stained. In their morphology and distribution, the positively stained cells were identical to mast cells as observed by electron microscopy. In one case, erythropoietin was demonstrated in the cyst fluid of the tumour. These findings suggest that mast cells with abundant secreting granules in haemangioblastomas are capable of producing erythropoietin.
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  • 20
    Electronic Resource
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    Springer
    Acta neuropathologica 72 (1987), S. 341-348 
    ISSN: 1432-0533
    Keywords: Carbon disulphide neuropathy ; Pacinian corpuscles ; Denervation and reinnervation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Adult Wistar rats were exposed to carbon disulphide vapours at a concentration of 2.4 mg/l of air for 5 days a week (6 h a day), and the ultrastructure of Pacinian corpuscles and their nerve supply was investigated after 6 months of exposure. Both degenerative and regenerative changes were observed in sensory axons and the corpuscles. In a sample of corpuscles examined, 30% were denervated and about 60% showed clear signs of reinnervation. Some of the reinnervated corpuscles were supplied by unmyelinated axons. In others, one to three myelinated axons were already found at the nerve entry. The axons branched and formed three to eight terminals in the inner core. Due to continuous intoxication, most regenerated terminals were again undergoing degeneration. In peripheral nerves, the evidence of axonal regeneration has been reported in various toxic distal axonopathies. However, the reinnervation of Pacinian corpuscles has not been described before. It can be expected that reinnervation of Pacinian corpuscles and other end-organs also occurs in other axonopathies, if not during continuous poisoning, then at least after its cessation.
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  • 21
    ISSN: 1432-0983
    Keywords: Electron microscopy ; Replicative intermediates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Some physicochemical properties of the mitochondrial DNAs (mtDNA) from plants of flax, broad bean and mung bean, and from tissue culture cells of jimson weed, soybean, petunia and tobacco were determined. Circular molecules were observed in electron microscope preparations of each mtDNA. In soybean, petunia, broad bean and mung bean mtDNAs, the circular molecules had a continuous distribution of lengths (ranges between 1 to 36 kb, and 1 to 126 kb), heavily skewed toward smaller molecules. Eighty-six percent of the flax circular molecules were from 27 to 54 kb in size, and 78% of the jimson weed circular molecules were from 4 to 15 kb. Replicative forms of 1.2–1.6 kb circular molecules were observed in electron microscope preparations of broad bean mtDNA.
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  • 22
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    Archives of dermatological research 279 (1987), S. 167-172 
    ISSN: 1432-069X
    Keywords: Morphometry ; Electron microscopy ; Cytological atypia ; Nevus cells ; Melanoma cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cytological atypia, revealed in the course of routine light microscopy, is considered a valuable indicator of malignancy in melanocytic lesions. A clear definition of the term cytological atypia, however, is lacking. Therefore, by morphometric analysis of ultrathin sections of 11 malignant melanomas (7 invasive, 3 in situ, and 1 lentigo maligna melanoma) and 10 compound nevi, we evaluated the discriminating power of the various facets of cytological atypia, i. e., nuclear area, area of the nucleolus, area of the total cell, and nuclear irregularity. In each case, at least 50 intraepidermal melanocytic cells were examined. The two-sided U-test showed significant differences between intraepidermal nevus and melanoma cells, with regard to the mean values (x) and standard deviations (s) of the nuclear area (x and s, p=0.00011), area of the nucleolus (x, p=0.00043; s, p=0.00011), and area of the total cell (x, p=0.00011; s, p=0.00093). However, only the mean values and standard deviations of the nuclear area allowed a clear distinction in each individual case. The area of the nucleus can be estimated in the course of routine histology. We therefore think that the size and variation of the nuclear area should be considered in the histological differential diagnosis between malignant melanomas and benign nevi.
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  • 23
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    Archives of dermatological research 279 (1987), S. 308-314 
    ISSN: 1432-069X
    Keywords: Congenital cutis laxa ; Collagen synthesis ; Electron microscopy ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of congenital cutis laxa (CCL) of unclear mode of inheritance associated with multiple pulmonary artery branch stenosis was extensively investigated to assess possible correlations between clinical, ultrastructural, and biochemical features. Light microscopy revealed that elastic fibers were absent in the papillary dermis, while hypoplastic elsewhere. Transmission electron microscopy showed a poor elastin matrix content in some elastic fibers, variable diameters of collagen fibrils, and abundant glycogen granules in most dermal cells. Measurement of collagen fibril diameters, using an image analyzer, was carried out in the patient and two age- and site-matched controls. A biomodal distribution was found in the upper reticular dermis of the patient. In vitro analysis of collagen in skin fibroblast cultures of the patient showed increased collagen synthesis with a balanced production of type I and type III procollagens. Our study confirms that CCL represents a disorder both of collagen and elastic connective tissue.
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  • 24
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    Experimental brain research 66 (1987), S. 175-184 
    ISSN: 1432-1106
    Keywords: Dorsal column nuclei ; Gracile nucleus ; Inferior olive ; Dorsal accessory olive ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This study examined the termination pattern within the dorsal accessory subdivision of the cat inferior olive of axons arising from the gracile nucleus. The gracile terminals were labeled by anterograde transport of wheat germ agglutinin complexed to horseradish peroxidase and visualized with tetramethyl benzidine. Gracile terminals were found to contain round synaptic vesicles and form asymmetric synaptic contacts. Of particular interest was the finding that gracile axons, like axons from the spinal cord, terminate primarily outside of synaptic glomeruli. Yet most of the gracile terminals did not synapse on isolated dendritic elements. Rather, the majority contacted distal dendrites which directly contacted other dendritic elements, forming simple complexes termed dendritic thickets. Typically the dendritic thickets were composed of two or three dendrites that received input from more than one round vesicle-containing synaptic terminal. Only one terminal per thicket was labeled by injections in the gracile nucleus. This clustering of pre-and postsynaptic elements within the thickets provides opportunities for many of the same interactions allowed by synaptic glomeruli, in particular divergence and convergence of information.
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  • 25
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    Experimental brain research 67 (1987), S. 380-390 
    ISSN: 1432-1106
    Keywords: Adrenal medulla ; Periaqueductal gray ; Neural implants ; Analgesia ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Recent findings in our laboratory indicate that adrenal medullary grafts produce significant alterations in pain sensitivity. Electron microscopic studies were undertaken to correlate these behavioral changes with the neural interactions of the host and graft tissue in the periaqueductal gray. A striking change found 8 weeks after transplantation is that pronounced myelination has taken place both in the graft and in the host tissue. The new myelin formation in the graft has the typical appearance of PNS myelination and, in the host the appearance of CNS myelination. The endothelial cells of the capillaries in the grafted tissue are attenuated and fenestrated in contrast to those of the surrounding parenchymal tissue of the host. By 8 weeks, the graft becomes heavily encapsulated with collagen, while the host CNS tissue develops layers of glial processes outlining the graft. However, collagen and glial layers apparently do not form an absolute barrier to either cellular or humoral interaction between the host and graft tissue. Chromaffin cells can be found protruding into the host CNS tissue and sometimes forming synapses with presumably the host neuronal processes. Grafted chromaffin cells may participate as both postsynaptic and, less often, as presynaptic components of synaptic junctions. The behavioral relevance of these synaptic contacts is unclear, since similar implants of adrenal medullary tissue into the dorsal spinal cord subarachnoid space, which also induce potent analgesia, do not contain synapses. Thus, it is more likely that behavioral changes are brought about by diffusion of neuroactive substances from grafted chromaffin cells to host receptors.
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  • 26
    ISSN: 1432-1106
    Keywords: Ventral mesencephalic grafts ; Electron microscopy ; Afferent synapses ; Tyrosine hydroxylase immunocytochemistry ; Dopaminergic neurons ; Dopaminergic boutons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In adult rats with a unilateral 6-hydroxydopamine-induced lesion of the nigrostriatal dopamine pathway, grafts of embryonic ventral mesencephalon can establish extensive efferent connections with the previously denervated host neostriatum and can compensate for motor and sensorimotor asymmetries induced by the lesion. The object of this study was to examine the afferent synaptic inputs to grafted dopaminergic neurons, implanted into a cortical cavity overlying the previously denervated caudate-putamen, using electron microscopic immunocytochemistry. The dopaminergic neurons of the grafts in the same animals had previously been shown to re-innervate the host neostriatum, to form synaptic connections therein and to attenuate the lesion-induced motor asymmetry that occured in response to amphetamine (Freund et al. 1985). In the light microscope, the grafts were found to contain numerous tyrosine hydroxylase-immunoreactive perikarya, dendrites, axons and axonal swellings which had distinct distributions. In addition axons and axonal swellings that were immunoreactive for either substance P or glutamate decarboxylase were present. Electron microscopic analysis of the boutons contacting tyrosine hydroxylase-immunoreactive neurons in the grafts revealed the presence of at least five distinct types of afferent synaptic boutons based on their immunochemistry, morphology, or types of membrane specialization. One type was itself immunoreactive for tyrosine hydroxylase; such synapses are extremely rare in the intact substantia nigra, none were found in the contralateral substantia nigrae or the substantia nigra of a control rat. Three of the remaining types had ultrastructural features that were similar to synaptic terminals that were immunoreactive for substance P or glutamate decarboxylase. These synapses were similar to the types of synapses found contacting dopaminergic neurons in the substantia nigra contralateral to the graft or the substantia nigra of a control rat. The results demonstrate that, in the absence of the normal extrinsic afferent inputs, the intracortical mesencephalic grafts have a well-developed local synaptic circuitry. It is suggested that local circuit regulation of dopaminergic neurons within the graft may, at least in part, be responsible for the maintenance of a normal or close to normal functional activity.
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  • 27
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    Archives of dermatological research 279 (1987), S. 270-272 
    ISSN: 1432-069X
    Keywords: Atopic eczema ; Hyperlinear palms ; Autosomal dominant ichthyosis vulgaris ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
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  • 28
    ISSN: 1432-2013
    Keywords: Sugar transport ; Electron microscopy ; Chicken cecum and jejunum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We have investigated the possible relation between the phloridzin-sensitive influx of α-methyl-D-glucoside (concentration 5 mmol/l) and the brush border surface area, in chicken isolated enterocytes. The intestinal regions studied were: jejunum and proximal cecum (both with high affinity sugar transport sites), medial cecum (with a low affinity transport system) and distal cecum (which lacks any transport ability). Cell apical surface measured by electron microscopy gave the following results; jejunal cells (0.41 μm2) 〉proximal cecal cells (0.23 μm2)〉medial cecal cells (0.15 μm2)=distal cecal cells (0.14 μm2). This parameter is mainly determined by the length of microvilli. Sugar influx studies showed that the concentration of the substrate in cell water (in mmol/l) was jejunum (7.1)〉proximal cecum (2.9) 〉medial cecum (1.7)〉distal cecum (not different from zero). The decline in influx rate from proximal to distal cecum may be explained both by changes in surface and by the different carriers involved (differentK m). Results of sugar concentration in the distal cecal cells do not correlate with the other segments studied since the substrate enters in these cells by a passive process. It is concluded that the degree of development of microvilli should be taken into account when estimating nutrient transport rates in different intestinal segments.
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  • 29
    ISSN: 1437-160X
    Keywords: Chondrocalcinosis ; Calcium pyrophosphate dihydrate crystals ; Polymorphonuclear leukocyte ; Articular cartilage ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron microscopy was used to investigate the characteristics of calcium pyrophosphate dihydrate (CPPD) crystals in chondrocalcinosis (pseudogout syndrome). Crystals in midzone cartilage were frequently seen adjacent to chondrocytes. Great variation in crystal size and shape was observed. Most of the pyrophosphate crystals that had been phagocytosed by polymorphonuclear leukocytes of synovial fluid from patients with acute pseudogout were small (≦1 μm), indicating that small crystals can cause intense inflammation. Large numbers of polymorphonuclear leukocytes became attached to the eroded articular surface and phagocytosed microcrystals. Interaction of polymorphonuclear leukocytes with CPPD crystals in the superficial region of articular cartilage may stimulate the release of inflammatory mediators.
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  • 30
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    Colloid & polymer science 265 (1987), S. 855-859 
    ISSN: 1435-1536
    Keywords: Electron microscopy ; polyethylenemelt ; fine structure ; artifact
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract There are still two opinions on the fine structure of polymer melts and glasses: (a) that the structure is similarly homogeneous to that in lower molecular weight materials and (b) that the structure shows larger short-range order regions (2–20 nm), which consist of bundeled segments of the chain molecules. Whereas opinion a relies more on indirect methods of investigation, opinion b is based mainly on fine granular structures which become visible in electron microscope investigations of surfaces of glassy solidified polymers. Such a fine structure can now be observed directly in a polyethylene melt. However, the structure is exposed as an artifact, so opinion a is supported.
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  • 31
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    Journal of cancer research and clinical oncology 113 (1987), S. 392-399 
    ISSN: 1432-1335
    Keywords: Paget's disease of bone ; Osteosarcoma ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The authors report 12 cases (8 men and 4 women) of sarcomatous degeneration in Paget's bone disease, with an average age of 72.3 years. Sarcomatous degeneration occurred often in polyostotic Paget's disease, and osteitis deformans was seen in 4 cases. Femur and pelvis were the most affected bones. Pain was a constant feature, whereas tumefaction and fracture were less common. Osteolytic lesions were more frequent than condensed or mixed lesions and radiological signs of malignancy were usually found. Seven cases were histologically clasiified as osteogenic sarcoma and 3 cases as fibrosarcoma. Electron microscopy was performed on 2 osteogenic sarcomas and in 1 case revealed microcylindrical inclusion in Pagetic osteoclasts and in multinucleated giant tumor cells, but none in mononucleated tumor cells. The average survival time for the patients in this study was only 4.5 months.
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  • 32
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    European archives of oto-rhino-laryngology and head & neck 243 (1987), S. 361-365 
    ISSN: 1434-4726
    Keywords: Human inner ear ; Congenital anomalies ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We performed light and electron microscopic studies on the temporal bones of a patient with genetic aplastic deafness, in which the right ear had a Mondini-type defect and the left ear a Michel-type anomaly. The round window of each ear was absent. The stapedial foot plate of the right ear was depressed at its central part and was covered by thin membrane. The course of the internal auditory meatus of the left ear was deviated ventrally. There was total aplasia of the cochlea in the left ear, while that of the right ear showed only three-quarters of a turn. In this ear, three sites of spherical bulging were found and were believed to represent outer hair cells. Other structures of the normal cochlear duct were not present. The modiolus of the left ear was round and dome-shaped, contained sparse nerve fibers and a primitive spiral ganglion. The saccule, utricle and semicircular canals of each ear were missing, so that a common cavity of the vestibular system was present. Several otoliths could be seen under the surface of the membrane covering the common cavity. No sensory cells or their related tissues could be found in either ear.
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  • 33
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    European archives of oto-rhino-laryngology and head & neck 243 (1987), S. 382-386 
    ISSN: 1434-4726
    Keywords: Experimental tympanosclerosis ; Calcium antagonists ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of calcium antagonists in experimental tympanosclerosis following infection with Streptococcus pyogenes and vitamin D3 intoxication has been analyzed in a rat animal model. Compared with untreated animals, calcium antagonists exert a positive effect on the degenerative process and on secondary calcification in the subepithelial layer. This effect could be substantiated planimetrically.
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  • 34
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    European archives of oto-rhino-laryngology and head & neck 244 (1987), S. 180-184 
    ISSN: 1434-4726
    Keywords: Localized laryngeal amyloidosis ; Light microscopy ; Electron microscopy ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We performed light and electron microscopic studies in a case of localized supraglottic laryngeal amyloidosis involving a 55-year-old woman. Tissue specimens were stained with hematoxylin and eosin, and alkaline Congo red with or without permanganate (KMnO4) treatment, and were also examined with peroxidase-antiperoxidase immunohistochemistry. Biopsy specimens from the epiglottis showed diffuse replacement of the subepithelial region by amyloid, which showed a typical green birefringence under polarized light. Tissue affinity for Congo red was persistent after the KMnO4 treatment. However, the tissue sections showed a positive reaction only to the anti-P component antibody. Electron microscopic studies revealed some disorders of the plasma cells, suggesting that these cells play an important role in focal production of amyloid fibrils.
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  • 35
    ISSN: 1432-0533
    Keywords: Herpes simplex virus type 2 ; Genital infection ; Avidin-Biotin Method ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Mice were infected by the vaginal route with the MS strain of herpes simplex virus type 2 (HSV-2). Serial vaginal cultures were used to confirm infection and to select mice for this study. Two mice were killed by perfusion on days 2–6 post infection (p.i.) and lumbar and sacral cord with cauda were fixed and embedded for electron microscopy. Semithin Epon-sections were stained for viral antigen using a rabbit anti-HSV-2 antiserum and the Avidin-Biotin (ABC) method. Thin sections from antigen-positive blocks were examined by electron microscopy, and the number and types of infected cells detected by these two methods were compared. A good correlation was found between detection of infected cells by these methods. Infected cells included neurons of dorsal root ganglia and spinal cord, satellite cells of dorsal root ganglia, non-myelinating Schwann cells, astrocytes, oligodendrocytes and arachnoidal cells. Infected cells were first detected in the cauda on day 3 p.i. and in the spinal cord on day 5 p.i. The temporal and spatial distribution of infected cells was consistent with neural spread to and within the CNS. The pathological lesions showed a good correlation with the distribution and number of infected cells and are probably due to a direct virus effect. The similar sensitivity of the Epon-ABC method to electron microscopy in detecting infected cells indicates that this method may have useful applications in both experimental and diagnostic work.
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  • 36
    ISSN: 1432-0533
    Keywords: Cerebral calcification ; Fahr's disease ; Electron microscopy ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of idiopathic nonarteriosclerotic cerebral calcification was studied post mortem by histochemical and scanning and transmission electron microscopic methods. Calcification was found bilaterally in the basal ganglia, cerebral cortex, granular layer and white matter of the cerebellum. Histochemical examination revealed that deposits were composed of a mixture of glycoproteins, mucopolysaccharides, calcium salts and iron. Transmission electron microscopy revealed minute deposits mainly in the cytoplasm of adventitial cells of blood vessels and sometimes in the cytoplasmic processes of glial cells. Scanning electron microscopy showed that some of the spherical and hemispherical bodies, which were formed in the adventitial cells of blood vessels, were connected with filamentous cytoplasmic processes of surrounding cells. Small uncalcified deposits occurring in the cytoplasm of the adventitial cells had subsequently had minerals deposited in them. Some kind of impairment of the pericytes may play an important role at the onset of this disease.
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  • 37
    ISSN: 1432-0878
    Keywords: Mammary gland ; Tissue culture ; Collagen gel ; Electron microscopy ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Fragments of human breast epithelium, devoid of all stromal and basal lamina components, which maintain their in vivo topological organisation can be cultured for up to 28 days within a reconstituted rat-tail-derived collagen matrix. These organoids initially undergo a loss of structural and 3-dimensional organisation, typified by loss of lumina formed by epithelial cells, and myosin from myoepithelial cells. Their subsequent reorganisation is dependent on the presence of serum, insulin, hydrocortisone, and cholera toxin in tissue culture medium. After this preliminary phase, a reduction in the concentration of serum, insulin, hydrocortisone, and cholera toxin is necessary to allow the structural differentiation of epithelial and myoepithelial cells. The myoepithelial cells also regain their ability to produce the basal lamina component laminin. The use of bovine-dermal collagen as the matrix, rather than rat-tail-derived collagen is shown to result in more stable organisation and differentiation of the organoids. The successful use of single-cell pellets (derived by trypsinisation of the organoids) in place of organoids in such cultures illustrates that there is no requirement for pre-existing cell/ cell contact or topological organisation of cells prior to embedding within the collagen matrix.
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  • 38
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    Cell & tissue research 247 (1987), S. 457-459 
    ISSN: 1432-0878
    Keywords: Vomeronasal glands ; Autonomic innervation ; Electron microscopy ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The morphological evidence for a direct autonomic innervation of the mouse vomeronasal glands is presented. Axonal varicosities containing a few densecore vesicles and numerous clear vesicles (36–60 nm in diameter) make synaptic contacts with the secretory cells at the base of the glandular acini. The axonal presynaptic membrane is associated with a distinct dense material and it is separated from the secretory cell by a synaptic cleft of about 12–14 nm. At the postsynaptical level, coated vesicles can be found. Additional postsynaptical specializations have not been observed.
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  • 39
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    Cell & tissue research 248 (1987), S. 393-398 
    ISSN: 1432-0878
    Keywords: Adrenaline ; Phenylethanolamine-N-methyl transferase ; Immunocytochemistry ; Electron microscopy ; Central nervous system ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of adrenergic axon terminals was examined in the paraventricular nucleus of the thalamus (PNT) and in the hypothalamic arcuate nucleus-median eminence (ARC-ME) complex by use of phenylethanolamine-N-methyl transferase (PNMT) immunocytochemistry. In the PNT, immunoreactive terminals formed a dense and well-circumscribed plexus. In the ARC, labeled varicosities were less numerous and more evenly distributed. In the ME, they were scarce and confined to the inner zone. In all these areas, the diameter of immunoreactive varicosities ranged between 0.2 and 1.3 μm; in the ME and in the transitional zone between the ARC and the ME, a population of larger boutons (〉2 μm) was also visible. All immunoreactive varicosities exhibited densely packed small, clear vesicles associated with a few large granular vesicles. In the PNT and the ARC, but not in the ME, they formed synaptic contacts with dendritic elements and were occasionally apposed to neuronal cell bodies. These axo-somatic appositions showed no junctional specializations. In the ME and transitional zone, immunoreactive terminals were frequently juxtaposed to, and occasionally established differentiated synaptic contacts with, tanycytes. These data support a transmitter role for adrenaline in the diencephalon and suggest that adrenaline plays a role in hypothalamo-hypophysiotropic regulation through interactions with neural and glial elements.
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  • 40
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    Cell & tissue research 248 (1987), S. 169-180 
    ISSN: 1432-0878
    Keywords: M-band structure ; Fibre type ; Skeletal muscle ; Cryo ultramicrotomy ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the M-band in soleus (SOL) and extensor digitorum longus (EDL) muscles in newborn and four-week-old rats was studied using electron-microscopic techniques. In newborn rats, all myotubes and fibres in both muscles had an identical myofibrillar appearance. A five-line M-band pattern was seen in longitudinal sections and distinct M-bridges in cross-sections. The Z-discs were of medium width. On the other hand, in four-week-old rats, different muscle fibre types were observed on the basis of their myofibrillar pattern. In SOL two fibre types were distinguished in longitudinal sections. One had a four-line M-band pattern and very broad Z-discs, whereas the other type had five lines in the M-band and broad Z-discs. In EDL, three different myofibrillar patterns were observed. The M-bands were composed of three, four or five lines. Fibres had either thin, broad or medium Z-disc widths, respectively. In cross-sections of the SOL muscle one group of fibres showed indistinct M-bridges, whereas distinct M-bridges were seen in the other fibres and in all observed EDL muscle fibres. We conclude that initially there seems to be a single intrinsic program for M-band genesis; this program becomes modified upon the induction of functionally differentiated fibres.
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  • 41
    ISSN: 1432-0878
    Keywords: Human growth hormone-releasing factor (hGRF) ; Paraventricular nucleus ; Immunocytochemistry ; Electron microscopy ; Synapses ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary By means of a preembedding immuno-electronmicroscopic technique, a large number of nerve endings containing a substance related to human growth hormonereleasing factor (hGRF) have been demonstrated in the paraventricular nucleus of the guinea pig. They made synaptic contacts primarily with dendritic shafts: 80% of these contacts were symmetrical. The immunoprecipitate was located mainly in large granules and around small clear vesicles. These findings suggest that a peptide related to hGRF may play a role in neural communication in the paraventricular nucleus.
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  • 42
    ISSN: 1615-6102
    Keywords: Cytoskeleton ; Contractile proteins ; Lowicryl ; LR White ; Polyvinylalcohol ; Immunogold staining ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Three embedding media have been compared with respect to post-embedding immunolabeling of contractile and cytoskeletal antigens in aldehyde-fixed smooth muscle tissue: the methacrylate derivates lowicryl K4M (cured at −35 or 60°C) and LR White (cured at 0 or 60°C) and the water soluble resin, polyvinylalcohol (dried at 60°C). Measurements of intensity of labeling of ultrathin sections in the fluorescence microscope showed that five antigens (actin, myosin light chain, tropomyosin, filamin and vinculin) reacted more or less equally with their respective antibodies in all the embedding media, including those cured at 60°C. One antibody (anti-light meromyosin) reacted well only with polyvinylalcohol-embedded tissue. In contrast to the relative invariance of antibody reactivity between media clear differences in the preservation of ultrastructural integrity were observed. Embedding in polyvinylalcohol (dried at 60°C) and in Lowicryl (cured at −35°C) resulted in superior preservation as compared to Lowicryl or LR White cured at 60°C. Examples of uitrastructural immunocytochemistry with the antibodies against filamin and myosin light chain, using the immunogold staining procedure are presented: the sites of localization by these antibodies were the same with all the media tried. The relative merits of the different methods are discussed.
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  • 43
    ISSN: 1615-6102
    Keywords: Cytopathology ; Rhabdovirus ; Development ; Electron microscopy ; Cuscuta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Electron microscopic examination ofCuscuta odorata, used for transmission trials, revealed mycoplasma-like organisms (MLO) as well as rhabdovirus-like particles, unknown toCuscuta. The virus infection is confined to certain phloem-parenchyma cells and a 1–2 cell thick layer of parenchyma cells with thickened walls surrounding the central cylinder. Virus particles, mostly bacilliform, could be detected mainly in the nucleus but also in the cytoplasm. They reach a length of 350–400 nm and a diameter of approximately 75 nm. Virus assembly takes place exclusively in the nucleus. Virus maturation occurs in membrane bound areas within the nucleus, which have no connection with the perinuclear space. Formation of nucleocapsids is always associated with a nuclear viroplasm. Envelopment of virus particles occurs in these membrane bound areas. Budding into the perinuclear space does not occur. Virus infection leads to degeneration and finally to death of the protoplast.
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  • 44
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    Protoplasma 140 (1987), S. 100-109 
    ISSN: 1615-6102
    Keywords: Actin ; Conifer ; Electron microscopy ; Picea glauca ; Somatic embryo ; Tissue culture ; Ultrastructure ; White spruce
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Somatic embryos in embryogenic callus cultures derived from Immature zygotic embryos ofPicea glauca (White spruce) were examined by light and electron microscopy. Somatic embryos consist of an embryonic region of small densely cytoplasmic cells subtended by a suspensor consisting of long highly vacuolated cells. Mitotic figures are frequent in the embryonic cells but are not observed in the suspensor. Cell divisions in the embryonic region apparently produce rows of cells which elongate to form the suspensor. The presence of abundant polysomes, coated membranes and dictyosomes in the cytoplasm of embryonic and upper suspensor cells suggests rapid growth of the embryo. In contrast the basipetal suspensor cells appear to be senescing. While only a few scattered microfilaments are present in the meristematic cells, the upper suspensor cells contain numerous bundles of longitudinally oriented microfilaments. These bundles correspond to actin cables observed in light microscope preparations stained with rhodamine labelled phalloidin and are oriented parallel to the direction of active streaming in these cells.
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  • 45
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    Child's nervous system 3 (1987), S. 74-80 
    ISSN: 1433-0350
    Keywords: Medulloblastoma ; GFAP-positivity ; Electron microscopy ; Postoperative follow-up
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Eighty-four cases of medulloblastoma were examined immunohistochemically and 12 by electron microscopy to assess differentiation in these tumors. Based upon the largest series of medulloblastoma studied to date, we demonstrated glial fibrillary acidic protein (GFAP) positivity, in 25% (21/84) of these tumors showing glial differentiation. GFAP-positive cells were seen more frequently in the desmoplastic variant of medulloblastoma (7/10). Under electron microscopy, the major part of the 12 tumors studied appeared primitive and undifferentiated. In 7 cases, groups of cells were found with primitive neuronal and/or glial features. GFAP positivity was confirmed at light microscopy level in all cases where cells showed glial differentiation in the form of glial-like filaments in cytoplasma. However, a follow-up questionnaire study of those patients who had received only surgical treatment revealed no difference in mean survival time between GFAP-positive and GFAP-negative medulloblastoma.
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  • 46
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    European archives of oto-rhino-laryngology and head & neck 244 (1987), S. 30-35 
    ISSN: 1434-4726
    Keywords: Central venous hemangioma ; Mandible ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To date, 96 cases of central hemangiomas of the jawbones have been described in the literature. Of these cases, the mandible has been more affected than the maxilla, while approximately 50% of all cases occur in the first and second decades of life. Histopathologically, cavernous and capillary types are often found, in contrast to the central venous type, which is rare. We have recently treated a 44-year-old man, who was found to have a central venous hemangioma in his mandible. Immunohistochemical studies were performed using factor-VIIIrelated antigen as well as various lectins as markers for tumor endothelial cells. Our results showed that four kinds of lectins (UEA-I, PNA, ConA, and DBA) were useful for the marker as factor-VIII-related antigen. Scanning electron microscopic findings of this tumor demonstrated that the lumina of the blood vessels were more rough, while the lining endothelial cells were more irregular when compared with those of the normal vascular system.
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  • 47
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    Cell & tissue research 247 (1987), S. 167-177 
    ISSN: 1432-0878
    Keywords: Arteriovenous anastomoses ; Autonomic innervation ; Synaptic vesicles ; Histochemistry ; Electron microscopy ; Tongue ; Dog
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The innervation of the arteriovenous anastomoses in the dog tongue has been investigated. At the lightmicroscopic level, the vessels were found to be densely supplied with adrenergic and AChE-positive nerve plexuses and less densely with the quinacrine-binding nerve plexus. At the electron-microscopic level, at least two apparently different types of axon profiles were identified: 1) Small vesicle-containing axons, characterized by many small granular vesicles, variable numbers of small clear vesicles and large granular vesicles. Storage of endogenous amines and uptake of exogenous amines into most small granular vesicles and many large granular vesicles was demonstrated. These axons stained only lightly with reaction products for AChE activity and thus seemed to be adrenergic in nature. Some axons contained numerous large granular vesicles, whose cores occasionally stained with uranyl ions; this suggests a co-localization of ATP or peptides as neurotransmitters. 2) Small granular vesicle-free axons, containing small clear vesicles and large granular vesicles in variable ratio. Most cores of these large granular vesicles were heavily stained with uranyl ions. No storage or uptake of amine into the synaptic vesicles was detected. Some axons appeared to be typically cholinergic, some, typically non-adrenergic, noncholinergic, and the rest, intermediate between the two. All axons stained heavily with reaction products for AChE activity, suggesting their cholinergic nature.
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  • 48
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    Cell & tissue research 247 (1987), S. 573-582 
    ISSN: 1432-0878
    Keywords: Seminal vesicle ; Histology ; Histochemistry ; Electron microscopy ; Physiology ; Clarias gariepinus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The seminal vesicle of the African catfish, Clarias gariepinus, consists of 36–44 fingerlike lobes built up of tubules in which a fluid is secreted containing acid polysaccharides, acid-, neutral- and basic proteins, and phospholipids. In this fluid sperm cells are stored. The seminal vesicle fluid immobilizes the sperm cells. After ejaculation, it prolongs the period of sperm activity. The seminal vesicle fluid is secreted by the epithelium lining the tubules. The tubules in the proximal part of the lobes are predominantly lined by a simple cylindrical and those of the distal part by a simple squamous epithelium. These epithelial cells contain enzymes involved in energy-liberating processes, the enzyme activites being proportional to the height of the cells. Interstitial cells between the tubules have enzyme-histochemical and ultrastructural features indicative of steroid biosynthesis. Similar characteristics are found in testicular interstitial cells. The most rostral seminal vesicle lobes and the most caudal testicular efferent tubules form a network of tubules that opens at the point where the paired parts of the sperm ducts fuse with each other. The tubules of most seminal vesicle lobes, however, form a complex system that fuses with the unpaired part of the sperm duct.
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  • 49
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    Electronic Resource
    Springer
    Cell & tissue research 248 (1987), S. 675-682 
    ISSN: 1432-0878
    Keywords: Molluscan muscles ; Innervation ; Chromatophores ; Cephalopods ; Electron microscopy ; Eledone cirrhosa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cephalopod chromatophores are made of a central pigment cell surrounded by 10 to 20 radially arranged muscle fibres under direct nervous control. Innervation of these muscle fibres was studied with anterograde cobalt fills of peripheral nerve bundles and light and electron microscopy. Individual axons branch repeatedly to innervate the muscles of chromatophores scattered over several millimeters. Axons contained in several dermal nerves converge to innervate the same chromatophores. Among the chromaophores, axons were found running either singly or in small bundles, often accompanied by sheath cells. Single chromatophore muscles were innervated by at least one axon running across or along its length. Since nerves terminating on chromatophore muscles are very rare, neuromuscular contact seems to be made “en passant”. Varicosities of the axons apposed to the muscles are thought to be presynaptic sites. However, morphological differentiations of the pre-or post-synaptic membranes were not visible. Two types of innervating processes were found containing either electron-clear or a mixture of electron-clear and dark-core synaptic vesicles.
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  • 50
    ISSN: 1432-0878
    Keywords: Microtubules ; Terminal web ; Small intestine ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The terminal web (TW) region of mature absorptive cells in the small intestine of the rat contains an elaborate cytoskeleton which supports the apical microvillus membrane. In studies regarding the structural organization of the cytoskeleton and associated proteins in the small intestine, microtubules have not been mentioned as components of the TW. By transmission electron microscopy of conventional resin-embedded sections of rat small intestine, we observe many microtubule profiles in the TW of mature absorptive cells. These microtubules are found in various orientations, although most course parallel to the long axis of the cell, and many microtubule profiles are seen in close association with smooth-surfaced vesicles.
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  • 51
    ISSN: 1432-0878
    Keywords: Alpha-bungarotoxin ; Autoradiography ; Cholinergic receptors ; Electron microscopy ; Suprachiasmatic nucleus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of (125I) alpha bungarotoxin (α-BTX) binding sites in the suprachiasmatic nucleus (SCN) of the adult female rat was examined by electron-microscopic autoradiography. The ultrastructural distribution of silver grains was analysed by line source, direct point count, and 50% probability circle methods. Real grain distribution was significantly different from that of randomly generated hypothetical grains. Line source analysis demonstrated two populations of sources: one associated with membranes, and one inside neuronal structures. Probability circle analysis of shared grains indicated that membrane-bound-radioactive sources were mainly asssociated with axo-dendritic appositions. Only a small proportion of labeled neuronal interfaces exhibited synaptic differentiations in the plane of section. However, the compartment containing synaptic terminals was the most enriched when comparing real to hypothetical grains. Probability circle analysis of exclusive grains demonstrated that sources that were not associated with neuronal plasma membranes were likely to be within nerve cell bodies and dendrites. It is concluded that the majority of specifically labeled α-BTX binding sites in the SCN is membrane bound, and may be associated with axodendritic synaptic transmission. The presence of a significant proportion of the label in the soma and dendrites of suprachiasmatic neurons 24 h after ventricular infusion suggests that some of the labeled binding sites (junctional or nonjunctional) may be internalized within these two compartments.
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  • 52
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    Cell & tissue research 248 (1987), S. 49-54 
    ISSN: 1432-0878
    Keywords: Enterochromaffin cells ; Serotonin ; Duodenum ; Immunocytochemistry ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Enterochromaffin cells of the rat duodenum have been studied immunocytochemically by use of a specific antiserum to serotonin. At the light-microscopic level serotonin immunoreactivity was observed in enterochromaffin cells located in the epithelium of the duodenal mucosa. Most of the serotonin-immunoreactive material was localized to the basal portion of the enterochromaffin cells, but small amounts of immunoreactive material were regularly observed in the apical portion. At the electron-microscopic level serotonin immunoreactivity in enterochromaffin cells was found to be concentrated over the dense cores of the cytoplasmic granules. The majority of these granules was located in the basal cytoplasm of the enterochromaffin cells, but serotonin-immunoreactive granules were also observed in the apical cytoplasm immediately beneath the microvilli. These observations indicate that duodenal enterochromaffin cells are bipolar and that they secrete serotonin both basally, to the circulation, and apically, to the gut lumen. Rat duodenal enterochromaffin cells thus appear to have an exocrine as well as an endocrine function.
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  • 53
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 544 (1987), S. 122-126 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Oxidefluorides of Niobium and TantalumThe reaction of NbF5 with SiO2 (silica glass ampules) at 310°C or with SiO2 (Aerosil) at 180°C always leads to NbO2F. To the contrary the reaction with laboratory glass (Jenaer Geräteglas) at 130°C leads to NbOF3.TaF5 reacts in silica glass ampules at 400°C by formation of TaO2F, however at 300°C or 260°C by formation of TaOF3.Silica glass did not react with NbF5 at 130°C, however Nb2O5 and NbF5 gave at 130°C in silica glass ampoules NbOF3. Similarly, TaF5 and Ta2O5 or TaO2F formed at 260°C in nickel ampoules TaOF3. The chemical and the thermochemical behaviour of oxidefluorides have been investigated.The compounds NbOF3 and TaOF3 are isomorphic. Lattice constants are mentioned.
    Notes: Die Reaktion von NbF5 mit SiO2 (Quarzglasampullen) bei 310°C oder mit SiO2 (Aerosil) bei 180°C führte stets zu NbO2F. Dagegen reagierte NbF5 mit Jenaer Geräteglasampullen bei 130°C zu NbOF3. TaF5 reagierte mit Quarzglasampullen bei 400°C unter Bildung von TaO2F, bei 300 oder 260°C jedoch unter Bildung von TaOF3.Quarzglas reagierte bei 130°C nicht mit NbF5, jedoch gaben Nb2O5 und NbF5 bei 130°C in Quarzglasampullen NbOF3. Analog bildeten TaF5 mit Ta2O5 oder TaO2F bei 260°C in Nickelampullen TaOF3.Das chemische und thermische Verhalten der Oxidfluoride wurde untersucht.Die Verbindungen NbOF3 und TaOF3 sind isomorph. Gitterkonstanten werden angegeben.
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  • 54
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    Zeitschrift für anorganische Chemie 544 (1987), S. 167-180 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ligand-Exchange Reactions on TcNX4- Complexes (X = Cl, Br)Ligand exchange reactions on the nitridotechnetium(VI) compounds (Bu4N)TcNCl4 and (Bu4N)TcNBr4 are reported. The use of various organic ligands having different donor atom sets produces TcV nitrido complexes. The reaction of (Bu4N)TcNCl4 with (Bu4N)TcNBr4 is characterized by the formation of TcVI complex species with mixed Cl/Br coordination spheres. EPR detection of the mixed-ligand complexes results in a well-defined dependence of the EPR parameters on the composition of the first coordination sphere of the complexes.
    Notes: Es wird über Ligandenaustauschreaktionen an den Nitridotechnetium(VI)-Komplexen (Bu4N)TcNCl4 und (Bu4N)TcNBr4 berichtet. Dabei entstehen bei Verwendung organischer Liganden mit unterschiedlichen Donoratomen Nitridokomplexe des Technetiums(V). Bei der Reaktion von (Bu4N)TcNCl4 mit (Bu4N)TcNBr4 in unterschiedlichen Mischungsverhältnissen entstehen Komplexspezies des TcVI mit gemischter Cl/Br-Koordinationssphäre. Bei Untersuchungen mittels EPR-Spektroskopie konnte für die gebildeten Gemischtligandkomplexe eine definierte Abhängigkeit der Spektrenparameter von der Zusammensetzung der ersten Koordinationssphäre nachgewiesen werden.
    Additional Material: 5 Ill.
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  • 55
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 544 (1987), S. 181-191 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Methoxostibanes. Structure and Vibrational SpectraThe crystal and molecular structure of Sb(OMe)3 (1) was determined by X-ray analysis. 1 forms layers in which the Sb atoms are coordinated by 6 O atoms. The halogenomethoxostibanes SbCl(OMe)2 (2), SbCl2(OMe) (3), SbBr(OMe)2 (4), SbBr2(OMe) (5), and SbI(OMe)2 (6), which were partially prepared for the first time, as well as 1 were examinated by vibrational spectroscopy. The spectra were discussed in view of the structure in the solid state. 2, 4, and 6 posses a structure similar to that of 1 with Sb2O2 and Sb2Cl2 ring systems. The coordination number of Sb is 6. In 3 and 5 there are also Sb2O2 and Sb2Hal2 rings, but the structures are probably different from those of 2 and 4.
    Notes: Die Kristall- und Molekülstruktur von Sb(OMe)3 (1) wurde mittels Röntgenstrukturanalyse bestimmt. 1 bildet ein Schichtengitter, bei dem die Sb-Atome durch O-Atome 6fach koordiniert sind. Die z. T. erstmals dargestellten Halogenomethoxostibane SbCl(OMe)2 (2), SbCl2(OMe) (3), SbBr(OMe)2 (4), SbBr2(OMe) (5) und SbI(OMe)2 (6) sowie 1 wurden schwingungsspektroskopisch untersucht. Die Spektren wurden im Hinblick auf die Struktur im festen Zustand diskutiert. Danach zeigen 2, 4 und 6 eine zu 1 vergleichbare Struktur mit Sb2O2- und Sb2Hal2-Vierringen und Sb der KZ 6. Auch in 3 und 5 liegen Sb2O2- und z. T. Sb2Hal2-Vierringe vor. Die Strukturen dürften sich allerdings von denen von 2 und 4 unterscheiden.
    Additional Material: 3 Ill.
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  • 56
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electrochemical Reduction of CSSe and CSe2 in Dimethylformamide: Heterocyclic 1,2-Dichalcogenolates and their Coordination ChemistryStarting from carbon diselenide or carbon selenidesulfide the electrochemical preparation (electrosynthesis) of heterocyclic dichalcogenolates C3X52- (X = Se: dsis; X = S/Se: C3SxSey2-) is outlined. The 1,2-dichalcogenolate compounds were isolated and characterized as dibenzoyl derivatives. Bis- or tris-chelates of general type Am[M(C3X5)n] (with A = Bu4N+, Ph4As+; M = ZnII, PtII, PdII, NiIII, CuIII, AuIII, InIII; X = Se, S/Se; m = 1, 2, 3; n = 2, 3, respectively) are available directly from methanolic solutions of the dibenzoylates after hydrolytic cleavage of the latter with sodium methanolate. In addition bis-chelates Bu4N[Ni(C3X5)2] (X = Se, S/Se) have been characterized by cyclovoltammetry and epr spectroscopy and compared with the corresponding all-sulfur ligand compound Bu4N[Ni(dmit)2] (X = S). Arguments are given for the fact that the allselenium ligand dsis (X = Se) yields the CuIII or NiIII chelate at once whereas with dmit using identical conditions the metal(II) compounds are formed.
    Notes: Ausgehend von Selenkohlenstoff und Selenschwefelkohlenstoff wird die elektrochemische Darstellung heterocyclischer Dichalkogenolate C3X52- (X = Se: dsis; X = S/Se: C3SxSey2-), die als Dibenzoylverbindungen isoliert und charakterisiert werden, beschrieben. Aus den mit Alkalimethanolat erhaltenen Verseifungslösungen dieser Dibenzoylverbindungen sind Metall-bis- und -tris-Chelate der heterocyclischen 1, 2-Dichalkogenolate vom Typ Am[M(C3X5)n] (A = Bu4N+, Ph4As+; M = ZnII, PtII, PdII, NiIII, CuIII, AuIII, InIII; X = Se, S/Se; m = 1, 2, 3; n = 2, 3) unmittelbar zugänglich. Cyclovoltammetrisch und mittels EPR werden die Nickel(III)-Verbindungen Bu4N[Ni(C3X5)2] (X = Se, S/Se) charakterisiert und der analogen Schwefelverbindung Bu4N[Ni(dmit)2] (X = S) gegenübergestellt. Für die bei der Chelatisierung mit dsis (X = Se) beobachtete Metall(II)-Metall(III)-Oxydation bei Kupfer und Nickel werden Argumente erörtert.
    Additional Material: 4 Ill.
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  • 57
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    Zeitschrift für anorganische Chemie 544 (1987), S. 232-240 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: About the pH-Dependence of 31P and 13C NMR Spectra of Cyclohexane-, Cyclohexene-, and Benzenephosphonic Acids31P and 13C chemical shifts as well as P—C coupling constants of phosphonic acids are affected by the pH of the investigated solutions. This dependence was measured for aqueous solutions of cyclohexane-, cyclohex-1-ene-, cyclohex-2-ene-, cyclohex-3-ene-, and benzenephosphonic acid. It is shown that the 31P chemical shift and various 13C chemical shifts are well suited for the determination of pKa values.
    Notes: 31P- und 13C-chemische Verschiebungen wie auch P—C-Kopplungskonstanten von Phosphonsäuren werden entscheidend vom pH-Wert der untersuchten Lösungen beeinflußt. Für Cyclohexan-, Cyclohex-1-en-, Cyclohex-2-en-, Cyclohex-3-en- und Benzenphosphonsäure wurde die pH-Abhängigkeit von δP, δC und JPC ermittelt. An Hand von Beispielen wird gezeigt, daß sich die 31P-chemische Verschiebung und ausgewählte 13C-chemische Verschiebungen gut zur Bestimmung von pKS-Werten eignen.
    Additional Material: 2 Ill.
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  • 58
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    Zeitschrift für anorganische Chemie 545 (1987), S. 47-55 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Acetylene Bis(Phosphonous Diamides), Bis(Phosphonous Fluoride Amides), and Bis-(Phosphonous Difluoride)Synthesis and properties of the acetylene bis(phosphonous diamides) 2-5, the acetylene bis(phosphonous fluoride amides) 6 and 7 and of acetylene bis(phosphonous difluoride), 8, are described. The result of the X-ray structural analysis of 2 is reported.
    Notes: Synthese und Eigenschaften der Acetylenbis(phosphonigsäurediamide) 2-5, der Acetylenbis(phosphonigsäurefluoridamide) 6 und 7 sowie von Acetylenbis(phosphonigsäuredifluorid) 8 werden beschrieben. Von 2 wird das Ergebnis der Röntgenstrukturanalyse mitgeteilt.
    Additional Material: 2 Ill.
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  • 59
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    Zeitschrift für anorganische Chemie 545 (1987), S. 75-82 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition Metal Complexes [Et2P(S)NR]M/n, Chelates containing 4-membered Rings and Phosphinothioic-organylamidato LigandsPhosphinothioic-organylamidato complexes [Et2P(S)NR]M/n (R = Me, Et, tBu, cHex, Ph; M = TiIII, VIII, CrIII, CoII, ZnII) are obtained by reaction of metal halides with [Et2P(S)NR]Li or from ZnEt2 and Et2P(S)NHR. In contrast to the analogous phosphinothioic complexes [R′2P(S)X]M/n (X = O, S, Se) they are extremely hydrolyzable. The ligand field parameters Δ and β of Et2P(S)NR- are found to be similar to those of R′2P(S)S- indicating a low ligand field strength and a strong nephelauxetic effect. In contrast to [R′2P(S)O]2M (M = Co, Zn), which are highly polymerised, there is only a weak tendency of the corresponding tetrahedral phosphinothioicorganylamidato complexes to form ligand bridges.
    Notes: Thiophosphinsäure-organylamidato-Komplexe [Et2P(S)NR]M/n (R = Me, Et, tBu, cHex, Ph; M = TiIII, VIII, CrIII, CoII, ZnII) erhält man durch Umsetzung von [Et2P(S)NR]Li mit Metallhalogeniden oder aus ZnEt2 und Et2P(S)NHR.Im Gegensatz zu den analogen Thiophosphinaten [R′2P(S)X]M/n (X = O, S, Se) sind sie äußerst hydrolyseempfindlich. Die Ligandenfeldparameter Δ und β von Et2P(S)NR- sind denen von R′2P(S)S- ähnlich und lassen eine nur geringe Ligandenfeldstärke und einen starken nephelauxetischen Effekt erkennen. Im Gegensatz zu den Komplexen [R′2P(S)O]2M (M = Co, Zn), die hochpolymer sind, zeigen die entsprechenden tetraedrischen Komplexe mit Thiophosphinsäureorganylamidato-Liganden nur eine geringe Tendenz zur Bildung von Ligandenbrücken.
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  • 60
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    Zeitschrift für anorganische Chemie 545 (1987), S. 109-117 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ein thermodynamisches Modell des Hg0,8Cd0,2Te-Iod Transportsystems. II. Ausgangsmaterial innerhalb des HomogenitätsbereichesDas Näherungsmodell zur Berechnung von Diffusions-Transportraten des Hg0,8Cd0,2Te-Iod-Systems [1] wurde für Zusammensetzungen des Ausgangsmaterials innerhalb des Homogenitätsbereiches erweitert. Dazu wurde die Hg-Leerstellenbildung berücksichtigt und experimentell ein Überschuß an elementarem Hg in System benutzt. Die gute Übereinstimmung von berechneten und beobachteten Transportraten (senkrechte Ampullenstellung, höhere Temperatur oben) bestärkt die Richtigkeit dieses Modells.
    Notes: The first order approximation model for the computation of diffusion limited mass transport rates for the Hg0.8Cd0.2Te-iodine system, based on Te-saturated source materials [1], was extended to include source compositions within the homogeneity range. This required the consideration of Hg vacancy formation, and the experimental employment of excess elemental mercury in the system. The close agreement between computed and observed (vertical, stabilizing conditions) mass transport rates supports the validity of this model.
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  • 61
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    Zeitschrift für anorganische Chemie 545 (1987), S. 143-147 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Tetrafluoro-1, 2-ethanedisulfenyldichloride with Ketones and OlefinesThe reaction of ClSCF2CF2SCl 1 with (CH3)3C—C(O)CH3, hexene, diacetyl, cyclobutanone, and H2C=CHC(O)CH3 leads to the cyclic and acyclic products 2-6. They are destillable liquids, which have been characterized on the basis of elemental analysis, mass spectra, 19F-, 13C-, and 1H-n.m.r. spectra. The reaction mechanism will be discussed.
    Notes: Die Reaktion von ClSCF2CF2SCl 1 mit (CH3)3C—C(O)CH3, Hexen, Diacetyl, Cyclobutanon und H2C=CHC(O)CH3 führt zu den cyclischen und acyclischen Substitutionsprodukten 2-6. Es sind destillierbare Flüssigkeiten, die anhand von Elementaranalysen, Massenspektren, 19F-, 13C- und 1H-NMR-Spektren charakterisiert wurden. Der Reaktionsmechanismus wird diskutiert.
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  • 62
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    Zeitschrift für anorganische Chemie 545 (1987), S. 134-142 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Magnetic Properties of Ti3-xMxO5 Phases (M = V3+, Cr3+, Nb4+)The magnetic properties of Ti3-xVxO5, Ti3-xCrxO5, and Ti3-xNbxO5 phases are reported. In the case of V3+ and Cr3+ the magnetic leaping-temperature decreases, however Nb4+ shift the phase-transition towards higher temperatures. All samples show a “memory-effect” in magnetic properties, i. e. the results of heating- and cooling-cycles are higher susceptibilities of the α-phase of Ti3O5. Endowed Ti3O5 phases show for the α- and β-Ti3-xMxO5 til the leap Curie-Weiss characteristic in 1/X vs. temperature measurements. Exception is β-Ti3-xNbxO5, its susceptibility is independend of the temperature up to x ≤ 0.3.
    Notes: Es wird über die magnetischen Eigenschaften von Ti3-xVxO5, Ti3-xCrxO5 und Ti3-xNbxO5 berichtet. Für V3+ und Cr3+ verschiebt sich die magnetische Sprungtemperatur zu kleineren Werten, Nb4+ dagegen verlagert den Phasenübergang in Richtung höherer Temperaturen. Alle Präparate zeigen einen “Gedächtniseffekt” im magnetischen Verhalten, d.h. Aufheiz- und Abkühlzyklen führen zu höheren Suszeptibilitätswerten der α-Form von Ti3O5. Dotiertes Ti3O5 zeigt für α- und β-Ti3-xMxO5 bis zum Sprung in den 1/X über T-Kurven Curie-Weiss-Verhalten. Ausnahme ist β-Ti3-xNbxO5, dessen Molsuszeptibilität bis x ≤ 0,3 temperaturunabhängig ist.
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  • 63
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    Zeitschrift für anorganische Chemie 545 (1987), S. 184-190 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dimethylaminophosphonium SaltsThe amides and chlorides of phosphoric acid 1 and 2 react with N-chlor-dimethylamine or chlorine, respectively, to dimethylaminophosphonium salts 3 and 4. Phosphor trichloride and N-chlor-dimethylamine as well as dimethylamino-dichloro-phosphine and chlorine react to bis(dimethylamino)-dichloro-phosphonium hexachlorophosphate 7.
    Notes: Aus Phosphorigsäureamiden und -chloriden wurden durch Reaktion mit N-Chlordimethylamin bzw. Chlor die Dimethylaminophosphoniumsalze 3 und 4 dargestellt. Die Reaktion von Phosphortrichlorid mit N-Chlordimethylamin bzw. von Dimethylamino-dichlorphosphin mit Chlor führte zum Bis(dimethylamino)dichlorphosphonium-hexachlorophosphat 7.
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  • 64
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    Zeitschrift für anorganische Chemie 545 (1987), S. 191-196 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Calcium-diazido-di-dimethylformamide, Ca(N3)2[OCHN(CH3)2]2, Preparation and Crystal StructureThe title compound was prepared by the reaction of Ca(N3)2 with OCHN(CH3)2 in aqueous solution. The crystals are orthorhombic, a = 968.5(3), b = 1 479.6(15), c = 1 945.3(17) pm, space group Cmca, Z = 8. The crystal structure was determined by single crystal X-ray diffraction techniques and refined to R = 0.061. Calcium atoms are surrounded by four terminal nitrogen atoms of azide groups and by two oxygen atoms of dimethylformamide (DMF). The polyhedra around Ca are octahedra which are linked via four azide groups to form Ca(N3)2 layers. The DMF molecules are located between these layers, and they are highly disordered.
    Notes: Die im Titel angegebene Verbindung wurde durch Reaktion von Ca(N3) mit Dimethylformamid in wäßriger Lösung hergestellt. Die Kristalle sind rhombisch, a = 968, 5(3), b = 1 479, 6(15), c = 1 945, 3(17) pm, Raumgruppe Cmca, N = 8. Die Kristallstruktur wurde mittels Röntgen-Einkristallmethoden bestimmt und zu R = 0, 061 verfeinert. Die Calciumatome werden oktaedrisch von vier Endstickstoffatomen der Azidgruppen und von zwei Sauerstoffatomen des Dimethylformamids (DMF) umgeben. Die Oktaeder sind über vier Azidgruppen zu Ca(N3)2-Schichten verknüpft. Die DMF-Moleküle befinden sich zwischen den Schichten und sind stark fehlgeordnet.
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  • 65
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 544 (1987) 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 66
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 545 (1987), S. 197-201 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Das System Ga2S3—Pr2O3Das Zustandsdiagramm des Ga2S3—Pr2O3-Systems wird mittels DTA, HT-DTA, Röntgenphasen-, Mikrostruktur- und thermodynamischer Analysen sowie durch Bestimmung der Mikrohärte untersucht. Das System ist eutektisch, die Löslichkeit auf der Seite des Ga2S3 beträgt 8 Mol.-% bei 295 K. Im System wird die Existenz einer inkongruent schmelzenden Verbindung von Ga2S3 · 2 Pr2O3 gefunden.
    Notes: The diagram of state of Ga2S3—Pr2O3 has been investigated by the methods of differential thermal, high-temperature differential thermal, X-ray diffraction, microstructural and thermodynamic analyses and by measurement of microhardness of the samples. It has been found that the system is eutectic, the solubility on the part of Ga2S3 at 295 K reaches 8 mol.%. In the system the existence of one incongruently-melting compound of Ga2S3 · 2 Pr2O3 was found.
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  • 67
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    Zeitschrift für anorganische Chemie 545 (1987), S. 219-223 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Preparation of Alkylammoniumfluoroferrates(III) in Anhydrous MethanolPure Alkylammoniumfluoroferrates(III) can be obtained in good yield by reaction of the corresponding alkylammoniumfluorides with FeBr3 in methanolic solution. Excess of fluoride in the molar ratio F/Fe ≥ 12 yields hexafluoroferrates(III), which rearrange after addition of methanolic FeBr3 solution stepwise to pentafluoroferrates(III) and last not least to tetrafluoroferrates(III). Usually alkylammoniumfluoroferrates(III) are extremely hygroscopic. Above 340 K they decompose forming FeF3, alkylamines, and HF as main products besides small amounts of fluorinated alkylamines.
    Notes: Alkylammoniumfluoroferrate(III) können formelrein und in guter Ausbeute durch Reaktion der entsprechenden Alkylammoniumfluoride mit FeBr3 in methanolischer Lösung dargestellt werden. Bei einem Überschuß an Fluorid (Mol-Verh. F/Fe ≥ 12) werden Hexafluoroferrate(III) gebildet, die bei weiterer Zugabe von FeBr3-Methanollösung über Pentafluoroferrate(III) zu Tetrafluoroferraten (III) abgebaut werden. Die Alkylammoniumfluoroferrate(III) sind in der Regel stark hydrolyseempfindlich; beim Erhitzen zersetzen sie sich ab etwa 340 K unter Bildung von FeF3, Alkylaminen und HF als Hauptprodukten, neben geringen Mengen fluorierter Alkylamine.
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  • 68
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    Zeitschrift für anorganische Chemie 545 (1987), S. 235-240 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thermogravimetric Investigations of Vanadium ComplexesExtensive studies on oxovanadium(IV) and (V) complexes with bidentate chelating ligands include thermogravimetric investigations. TG, DTG, and DTA data provide additional facts to redox behaviour and stability of the complexes. These data also allow a critical appreciation of the given melting temperatures.
    Notes: Im Rahmen grundlegender Untersuchungen zu Oxovanadium(IV)- bzw. (V)-Komplexen mit zweizähnigen Chelatbildnern werden aus den TG-, DTG- und DTA-Kurven ausgewählter Chelate zusätzliche Daten zum Redoxverhalten und zur Stabilität der Komplexe gewonnen. Die Thermogramme gestatten eine kritische Wertung gemessener Schmelzpunkte.
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  • 69
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    Zeitschrift für anorganische Chemie 546 (1987), S. 42-47 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Rubidium Hexaamidolanthanate and -neodymate, Rb3[La(NH2)6] and Rb3[Nd(NH2)6]; Compounds. Structurally Related to K3[Cr(OH)6] and K4CdCl6Colourless Rb3[La(NH2)6] (a = 12.298(4) Å, c = 13.759(2) Å, N = 6, R3c) and pale blue Rb3[Nd(NH2)6] (a = 12.199(6) Å, c = 13.626(4) Å, N = 6, R32) have been prepared by the reaction of the corresponding metals (Rb: La resp. Nd = 3:1) with NH3(P(NH3) = 4-4.5 kbar) at 300°C. Single crystal x-ray methods gave their structures. It is shown by space group relations that these compounds are structurally related to one another and to further ternary amides as well as to K3[Cr(OH)6] and K4CdCl6.
    Notes: Farbloses Rb3[La(NH2)6] (a = 12,298(4) Å, c = 13,759(2) Å, Z = 6, R3c) und hellblaues Rb3[Nd(NH2)6] (a = 12,199(6) Å, c = 13,626(4) Å, Z = 6, R32) wurden durch Umsetzung der entsprechenden Metalle (Rb: La bzw. Nd = 3:1) mit NH3 (P(NH3) = 4-4,5 kbar) bei 300°C dargestellt. Die Atomanordnung der Verbindungen wurde röntgenographisch an Einkristallen bestimmt. Über Raumgruppenbeziehungen wird die Strukturverwandtschaft zu weiteren ternären Amiden sowie zu K3[Cr(OH)6] und K4CdCl6 erläutert.
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  • 70
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    Zeitschrift für anorganische Chemie 546 (1987), S. 48-54 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Twisted Tetrahedra Chains ∞1[Li(NH2)4/2-] in the Structure of the Hexagonal Modification of Cesium Lithium Amide, CsLi(NH2)2The ternary amides, CsLi(NH2)2 (dimorphous) and CsLi2(NH2)3, were prepared by reaction of the metals with ammonia in high pressure autoclaves. The structure of the hexagonal modification of CsLi(NH2)2 was established inclusive the hydrogen atom positions from single crystal x-ray data. The compound crystallizes in the space group P6222 with N = 3. The lattice parameters are a = 6.331(1) Å and c = 8.410(1) Å.Lithium ions occupy distorted nitrogen tetrahedra. These tetrahedra are connected by translocated edges along [001]. The cesium ions combine the equally oriented chains ∞1[Li(NH2)4/2-]. The amide ions are twisted out of the hexagonal aa-plane. If we assume sp3-hybridized valence electrons of the nitrogen atoms the bonding interaction between free electron pairs and lithium ions are thereby strenghtened.
    Notes: Ternäre Amide im System CsNH2/LiNH2—CsLi(NH2)2 (dimorph) und CsLi2(NH2)3 - wurden durch Umsetzung der Metalle mit NH3 in Hochdruckautoklaven dargestellt.Die Struktur der hexagonalen Form von CsLi(NH2)2 wurde aus Röntgenbeugungsintensitäten eines Einkristalls einschließlich der H-Atom-Lagen bestimmt. Die Verbindung kristallisiert in der Raumgruppe P6222 mit Z = 3 und den Gitterkonstanten a = 6,331(1) Å und c = 8,410(1) Å.Die Lithiumionen befinden sich in verzerrten Stickstofftetraedern. Diese bilden über transständige Kanten längs [001] Ketten. Die Caesiumionen verknüpfen die gleichsinnig orientierten Ketten ∞1[Li(NH2)4/2-]. Die Amidionen sind aus der hexagonalen aa-Ebene gedreht. Bei einer sp3-Hybridisierung der Valenzelektronen der Stickstoffatome wird dadurch die Wechselwirkung zwischen freien Elektronenpaaren und den Lithiumionen begünstigt.
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  • 71
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    Zeitschrift für anorganische Chemie 546 (1987), S. 79-98 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition Metal Phosphido Complexes. XII. Diphosphene Complexes (DRPE)Ni[η2-(PR′)2] and the Structure of (DCPE) NiP (SiMe3)2LiP(SiMe3)2 reacts with the complexes (DRPE)NiCl2 1 (DRPE = R2PCH2CH2PR2; R = Et: DEPE a; R = Cy: DCPE b; R = Ph: DPPE c) to form the diphosphene complexes (DRPE)Ni[η2-(PSiMe3)2] 5a-c. Using low temperature nmr measurements the monosubstitution products (DRPE)Ni[P(SiMe3)2]Cl 2a-c and the disubstitution products (DRPE)Ni[P(SiMe3)2]2 3a, 3c can be detected as intermediates. From the reaction of 1b the paramagnetic nickel(I) complex (DCPE)NiP(SiMe3)2 4b can be isolated. Reacting 1a, 1b with LiP(SiMe3)CMe3 the complexes (DRPE)Ni[P(SiMe3)CMe3]Cl 8a, 8b, which are analogous to 2, and the nickel(0) diphosphine complex (DEPE)Ni[η1-P(SiMe3)CMe3P(SiMe3)CMe3] 9a can be detected n.m.r. spectroscopically, but no diphosphene complexes can finally be isolated. The diphosphene complexes (DRPE)Ni[η2(PPh)2] 10a-c are available from reactions of PhP(SiMe3)2with l a - c. MeP(SiMe,), reacts only with 1b to give a diphosphene complex (DCPE)Ni[η2(PMe)2] 11 b. Reacting [P(SiMe3)CMe3]2 with 1a-c the diphosphene complexes (DRPE)Ni[η2(PCMe3)2] 12a-c can be obtained. 4b crystallizes monoclinic in the space group P2Jc with a = 1228.6 pm, b = 2387.1 pm, c = 2621.8 pm, β = 92.16°, and Z = 8 formula units. The nickel atom is nearly planar coordinated by three phosphorus- atoms, the phosphorus atom of the terminal P(SiMe3)2 group is pyramidally coordinated. The Ni—P bond distances of the two four-coordinated phosphorus atoms are with 219.2 pm and 220.2 pm only slightly shorter than the corresponding distance of the P-atom of the P(SiMe3)2 group with 223.5 pm. N.m.r. and mass spectral data are reported.
    Notes: LiP(SiMe3)2 reagiert mit den Komplexen (DRPE)NiCl2 1 (DRPE = R2PCH2CH2PR2; R = Et: DEPE a; R = Cy: DCPE b; R = Ph: DPPE c) unter Bildung der Diphosphenkomplexe (DRPE)Ni[η2-(PSiMe3)2] 5a-c. Als Zwischenstufen können durch Tieftemperatur-NMR-Messung die Monosubstitutionsprodukte (DRPE)Ni[P(SiMe3)2]Cl 2a-c und die Disubstitutionsprodukte (DRPE)Ni[P(SiMe3)2]2 3a, 3c nachgewiesen werden. Bei der Umsetzung von 1b lässt sich der paramagnetische Nickel(I)-Komplex (DCPE)NiP(SiMe3)2 4b isolieren. Bei den Reaktionen von 1a, 1b mit LiP(SiMe3)CMe3 lassen sich NMR-spektroskopisch die zu 2 analogen Komplexe (DRPE)Ni[P(SiMe3)CMe3]Cl 8a, 8b und der Nickel(0)-Diphosphankomplex (DEPE)Ni[η1-P(SiMe3)CMe3P(SiMe3)CMe3] 9a nachweisen, aber keine Diphosphenkomplexe als Folgeprodukte isolieren. Die Diphosphenkomplexe (DRPE)Ni[η2-(PPh)2] 10a-c sind durch Reaktionen von PhP(SiMe3)2 mit 1a-c erhältlich. MeP(SiMe3)2 reagiert nur mit 1b zu einem Diphosphenkomplex (DCPE)Ni[η2-(PMe)2] 11b. Durch Umsetzungen von [P(SiMe3)CMe3]2 mit 1a-c sind die Diphosphenkomplexe (DRPE)Ni[η2-(PCMe3)2] 12a-c zugänglich. 4b kristallisiert monoklin in der Raumgruppe P21/c mit a = 1228,6 pm, b = 2387,1 pm, c = 2 621,8 pm, β = 92,16° und Z = 8 Formeleinheiten. Das Nickel wird von drei Phosphoratomen nahezu planar koordiniert. Der Phosphor der terminalen P(SiMe3)2-Gruppe ist pyramidal koordiniert. Die Ni—P-Abstände der beiden vierfach koordinierten Phosphoratome sind mit 219,2 pm und 220,2 pm nur wenig kürzer als der Abstand zum P-Atom der P(SiMe3)2-Gruppe mit 222,5 pm. NMR-spektroskopische und massenspektrometrische Daten werden mitgeteilt.
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    Zeitschrift für anorganische Chemie 546 (1987), S. 142-146 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Reactivity of Sodium DialkylphosphonoformatesThe reaction of sodium dialkylphosphonates with CO2 forming sodium dialkylphosphonoformates, (RO)2P(O)C(O)ONa, I, as well as the further reaction of I are described, 14C-isotope exchange and the n.m.r. spectra are discussed.
    Notes: Die Reaktion von Natrium-dialkylphosphiten mit CO2 zu Natrium-dialkylphosphonoformiaten, (RO)2P(O)C(O)ONa, I, und deren Folgereaktionen werden beschrieben. 14C-Isotopenaustausch und NMR-Spektren werden diskutiert.
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  • 73
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    Zeitschrift für anorganische Chemie 546 (1987), S. 152-160 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Complexes with Substituted 2,5-Dihydroxy-p-benzochinones: EAC6(C6H5)2O4 · 4 H2O (EA = Sr2+, Ba2+)Single crystals of the isotypic compounds EAC6(C6H5)2O4 · 4 H2O were grown in aqueous silicagel. EA2+ has CN 8. It is surrounded by four water molecules and four oxygen atoms of the bis-chelating polyporate dianions. Thereby folded chains are formed which are interlinked by hydrogen bonds. Thus building up corrugated layers with the phenyl substituents almost perpendicular to the layer plane. The layer stacking provides that they can engage into another.
    Notes: Einkristalle der isotypen Verbindungen EAC6(C6H5)2O4 · 4 H2O wurden in wässerigem Kieselgel gezüchtet. EA2+ besitzt KZ 8. Es ist von 4 Wassermolekülen und 4 Sauerstoffatomen der als Bis-chelatliganden agierenden Polyporatdianionen umgeben. Dadurch bilden sich gefaltete Ketten, die miteinander durch Wasserstoffbrückenbindungen verbunden sind. Die Phenylsubstituenten stehen annähernd senkrecht auf den hierdurch entstandenen gewellten Schichten. Die Schichtabfolge ermöglicht ein platzsparendes Verzahnen der Schichten.
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  • 74
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    Zeitschrift für anorganische Chemie 546 (1987), S. 177-182 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: [ReCl3(NSCl)2(CH3CN)]. Synthesis, I. R. Spectrum, and Crystal StructureBlack, moisture sensitive crystals of the title compound are obtained from [ReCl3(NSCl)2]2 and acetonitrile in dichloromethane. The complex is characterized by its i.r. spectrum and an X-ray crystal structure determination (2483 observed independent reflexions, R = 0.035). Crystal data: triclinic, space group P1, Z = 2, a = 681.8, b = 899.9, c = 1104.0 pm, α = 110.50, β = 97.90 and γ = 101.34°. In the monomeric [ReCl3(NSCl)2(CH3CN)] molecule the Re atom has a distorted octahedral coordination with meridional arrangement of the Cl atoms. The chlorothionitrene ligands have nearly linear ReNS groups with bond lengths that correspond to double bonds (ReN 178 and 179 pm); this agrees with the NReN bond angle of 100°.
    Notes: Die Titelverbindung entsteht in Form schwarzer, feuchtigkeitsempfindlicher Kristalle aus [ReCl3(NSCl)2]2 und Acetonitril in Dichlormethan. Der Komplex wird durch das IR-Spektrum und durch eine röntgenographische Strukturbestimmung charakterisiert. [ReCl3(NSCl)2(CH3CN)] kristallisiert triklin in der Raumgruppe P1 mit Z = 2 und den Gitterkonstanten a = 681,8; b = 899,9; c = 1104,0 pm; α = 110,50°; β = 97,90°; γ = 101,34° (2483 unabhängige beobachtete Reflexe, R = 3,5%). In dem monomeren Molekülkomplex ist das Rheniumatom verzerrt oktaedrisch von drei meridional angeordneten Chloratomen, von dem N-Atom des Acetonitrilliganden und von den N-Atomen der beiden cis-ständigen Chlorthionitrengruppen umgeben. Die ReN-Abstände der ReNSCl-Gruppen entsprechen Doppelbindungen (178 bzw. 179 pm); im Einklang hiermit beträgt der NReN-Bindungswinkel 100°.
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  • 75
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    Zeitschrift für anorganische Chemie 546 (1987), S. 217-228 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Separation on a Preparative Scale and Quantitative Aanalysis of Oligophosphates by Means of Liquid ChromatographyNew methods for the chromatographic analysis and isolation of oligophosphates have been developed. The qualitative separation has been optimized for thin layer chromatography. Quantitative analysis and isolation of the various oligophosphate species has been achieved using liquid chromatography. For ion exchange and molecular sieve-gel columns packing material, column parameters, and eluent were optimized. The on line detection system included a differential refractometer coupled to a strip chart recorder.The applicability of the technique was demonstrated by the quantitative analysis of oligophosphate mixtures. Good reproducibility and accuracy was found. It has been ascertained that the stability of polyphosphates is sufficient to allow efficient separations.
    Notes: Es wurden neue Verfahren für die chromatographische Bestimmung und Isolierung von Oligophosphaten entwickelt. Qualitative Trennungen wurden an Ionenaustauscherfolien und Cellulose-Dünnschichtfolien optimiert. Mit Flüssigkeits-Säulenchromatographie wurden erstmals quantitative Bestimmungen und Trennungen von Oligophosphaten im präparativen Maßstab realisiert. Für die selbstgepackten Ionenaustauscher- und Molekularsieb-Gelsäulen (Niederdruckbereich) wurden Packungsmaterialien, Säulenparameter und Elutionsmittelgemische optimiert. Die Detektion erfolgte „on line“ mit einem Differential-Refraktometer.Die Anwendbarkeit der entwickelten Verfahren wurde durch quantitative Bestimmungen von Oligophosphatgemischen belegt. Die Wiederfindungsraten weisen eine gute Reproduzierbarkeit der Verfahren aus. Es wird gezeigt, daß die Hydrolysebeständigkeit der Phosphate unter den gewählten Trennbedingungen hinreichend groß ist, um eine einwandfreie Isolierung einzelner Spezies zu gewährleisten.
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  • 76
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Salts of Halogenophosphoric Acids. XV. Sulfane-α,ω-diyl-bis(fluorodithiophosphates). Products of the Fluoride Degradation of Sulfur-rich Phosphorus SulfidesBy the reaction of sulfur-rich phosphorus sulfides „P4S10+m“ (m = 0,5 to 6) with fluorides MF (M = Na, K, NH4) in acetonitrile or 1,2-dimethoxy-ethane mixtures of sulfane-α,ω-diyl-bis(fluorodithiophosphates) [(PFS2)2Sn]2- (n = 1 to 8) are formed. The average chain length n of the sulfane derivatives depends on the S:P ratio of the starting phosphorus sulfides. The compounds are identified by 19F and 31P n.m.r. spectroscopy.
    Notes: Sulfan-α,ω-diyl-bis(fluorodithiophosphate) [(PFS2)2Sn]2-, n = 1 bis 8, entstehen als Gemische bei der Reaktion schwefelreicher Phosphorsulfide „P4S10+m“, m = 0,5 bis 6, mit Fluoriden MF (M = Na, K, NH4) in Acetonitril bzw. 1,2-Dimethoxy-ethan. Die Verteilung der Komponenten dieser homologen Reihe, die 19F- und 31P-NMR-spektroskopisch charakterisiert wurden, hängt vom S:P-Verhältnis des eingesetzten Phosphorsulfids ab.
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  • 77
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Influence of Seed Crystals on the Formation of Calcium Silicates with the Composition 3 CaO · 2 SiO2The formation of the calcium silicates kilchoanite and rankinite of the composition 3 CaO · 2 SiO2 is facilitated and enabled, respectively, in the presence of appropriate seed crystals. Kilchoanite (Ca6[(SiO4)(Si3O10)]) is formed from mixtures of CaO and SiO2 in the autoclave at 200°C and from C—S—H (di, poly) under normal atmosphere at 700°C by seeding for example with kilchoanite, aluminium compounds, γ-Ca2SiO4. Rankinite (Ca3Si2O7) can be synthesized under the same conditions, when rankinite itself is applied as seed crystal.
    Notes: Es wird gezeigt, daß die Bildung der Calciumsilicate Kilchoanit und Rankinit der Zusammensetzung 3 CaO · 2 SiO2 in Gegenwart entsprechender Impfkristalle erleichtert bzw. erst ermöglicht wird. Kilchoanit (Ca6[(SiO4)(Si3O10)]) bildet sich z. B. durch Animpfen mit Calciumaluminaten, γ-Ca2SiO4 und Kilchoanit aus CaO und SiO2 im Autoklaven bei 200°C und aus C—S—H(Di, Poly) unter Normaldruck oberhalb 700°C. Rankinit (Ca3Si2O7) entsteht unter den gleichen Bedingungen, wenn als Impfkristall Rankinit selbst eingesetzt wird.
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  • 78
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Salts and Esters of 1,2-Hydrazin-bis(thiocarboxylic)acid. Crystal Structures of K2[OSC—N2H2—CSO] · 2 H2O, CH3S—CO—N2H2—CO—SCH3, and CH3O—CS—N2H2—CS—OCH3 at 140 KThe anion [OSC—N2H2—CSO]2- and the molecules CH3S—CO—N2H2—CO—SCH3 and CH3O—CS—N2H2—CS—OCH3 exhibit nonplanar structures in the solid state. The dihedral angles beetween either of the two strictly planar R—CX—NH groups of each molecule are 78.8°, 77.5°, and 104.5°, respectively. The N—N bond lengths are 138.5 pm in all three compounds. The N—H groups participate in hydrogen bonds.
    Notes: Das Anion von K2[OSC—N2H2—CSO] · 2 H2O, sowie die Moleküle CH3S—CO—N2H2—CO—SCH3 und CH3O—CS—N2H2—CS—OCH3 besitzen im festen Zustand nichtplanare Konformationen. Die Diederwinkel zwischen den beiden jeweils planaren Molekülhälften betragen 78,8°, 77,5° bzw. 104,5°. Die N—N-Bindungslänge beträgt übereinstimmend in den drei Verbindungen etwa 138,5 pm. Die N—H-Gruppen sind an Wasserstoffbrückenbindungen beteiligt.
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  • 79
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 550 (1987), S. 133-139 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dimethyl-N-Fluoroamine, Dimethyl-N-Fluoroamine Boron Trihalide Adducts, and Dimethyl-N-Fluoroammonium SaltsThe vibrational assignment of (CH3)2 NF I is given and compared with the vibrational frequencies of the salts (CH3)2NHF+Cl- II and (CH3)2NHF+CF3SO3- III as well as the adducts (CH3)2NF · BHal3 (Hal = F IV, Cl, V, Br VI). In addition the results of a low temperature crystal structure analysis of V are reported.
    Notes: Es werden die Schwingungsfrequenzen von (CH3)2NF I zugeordent und vergleichend mit den Salzen (CH3)2NHF+Cl- II und (CH3)2NHF+CF3SO3- III und den Addukten (CH3)2NF · BHal3 (Hal = F IV, Cl, V, Br, VI) betrachtet. Ergänzend werden die Ergebnisse einer Kristallstrukturanalyse von V bei 140 K mitgeteilt.
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  • 80
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 550 (1987), S. 162-168 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Perfluoroorgano Tellurium Compounds: New Investigations on the Preparation of Te(Rf)2 and CH3TeRf (Rf = C2F5, C3F7, C6F5)Methyl(perfluoroorgano) tellurium and bis(perfluoroorgano) tellurium compounds are synthesized in high yields from the photochemical or the thermal reactions of (CH3)2 Te with perfluoroorgano iodides in the presence of (C2H5)3N. They are isolated in pure states. Another general method for the preparation of bis(perfluoroorgano) tellurium is the thermal reaction of TeCl4 with bis(perfluoroorgano) mercury. The preparations and properties of the partially new compounds are described.
    Notes: Methyl(perfluororgano)tellur-und Bis(perfluororgano) tellur-Verbindungen werden durch photochemische bzw. thermische Umsetzungen von Dimethyltellur mit Perfluoriodorganica in Gegenwart von (C2H5)3N in hohen Ausbeuten synthetisiert und in reiner Form isoliert. Ein weiteres allgemeines Darstellungsverfahren für Bis(perfluororgano) tellur ist die thermische Reaktion von TeCl4 mit Bis(perfluororgano) quecksilber. Die Darstellungsbedingungen und Eigenschaften der z. T. neuen Verbindungen werden beschrieben.
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  • 81
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 550 (1987), S. R1 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 82
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 550 (1987), S. R2 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 83
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 551 (1987), S. 21-32 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Identifizierung der wesentlichen Schwefel-Stickstoffverbindungen in Schwefel-AmmoniaklösungenDurch Vergleich der UV/VIS-Absorptionsspektren der Lösungen von Schwefel sowie von synthetisierten Schwefel-Stickstoffverbindungen in flüssigem Ammoniak und durch Vergleich der Ånderungen der Spektren bei Lichteinwirkung folgern wir, daß S7NH, S4NH und S3NH neben Polysulfiden als Hauptbestandteile in Schwefel-Ammoniaklösungen vorliegen. Die Gleichgewichte zwischen den Verbindungen werden durch photochemische Reaktionen reversibel, durch Ag2S-Ausfällung irreversibel verschoben. Als Endprodukt bei der Ag2S-Ausfällung verbleibt S3N3H in der Lösung, das durch Oxydation in S4N4 übergeht.
    Notes: By comparison of the UV-VIS absorption spectra of solutions of sulfur and of synthesized sulfur nitrogen compounds in ammonia and by comparison of their light induced changes we conclude that S7NH, S4NH and S3NH are besides polysulfides H2Sx the Main compounds in sulfur ammonia solutions. The equilibria between the species are shifted reversibly by photoinduced reactions and permanently by Ag2S precipitation (with AgNO3). As the only and final product on Ag2S precipitation S3N3H is identified which by oxidation forms S4N4.
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  • 84
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 548 (1987), S. 89-96 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Isomerisation of the Cyclotrisilazane System  -  Lithium Salts and Contraction Products2,2,4,4,6,6-Hexamethyl- and 2,2,4,4,6,6-hexamethyl-1-trimethylsilyl-cyclotrisilazane (1, 2) react with n-C4H9Li to give the lithium salts 3 and 4. At 30°C 4 isomerizes in solution to the cyclodisilazane 5 within 15 h. 4 reacts with Me2SiF2 to the substituted compound 6, whose Li salt contracts yielding the coupled product 7. 1,3-Bis(fluorodimethylsilyl)-2,2,4,4,6,6-hexamethylcyclotrisilazane isomerizes to the Li salt of the corresponding cyclodisilazane, which reacts with the half-molar quantity of SiF4 to the Si—N—Si—N—Si bridged cyclodisilazane dimer 8. The tendency of contraction of 4 is discussed on the basis of its crystal structure.
    Notes: 2,2,4,4,6,6-Hexamethyl- und 2,2,4,4,6,6-Hexamethyl-1-trimethylsilylcyclotrisilazan (1, 2) reagieren mit n-C4H9Li zu den Lithiumsalzen 3 und 4. 4 isomerisiert in Lösung bei 30°C innerhalb von 15 h zum Cyclodisilazan 5. Mit Me2SiF2 reagiert 4 unter Substitution zu 6, dessen Li-Salz kontrahiert und das Kopplungsprodukt 7 bildet. 1,3-Bis(fluordimethylsilyl)-2,2,4,4,6,6-hexamethyl-cyclotrisilazan isomerisiert zum Li-Salz des entsprechenden Cyclodisilazans, das mit der halbmolaren Menge SiF4 zum Si—N—Si—N—Si-verbrückten Cyclodisilazandimer 8 reagiert. Die Kontraktionstendenz von 4 wird anhand der Kristallstruktur diskutiert.
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  • 85
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 548 (1987), S. 97-102 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Sulfur Halides. 16. Dimethyliodosulfonium(IV) SaltsSome preparative methods of iodosulfonium(IV) salts, (CH3)2SI+AsF6- and (CH3)2SI+SbCl6-, are reported. These salts are stable up to -20°C and they are characterized by Raman and n.m.r. spectroscopy.
    Notes: Es werden mehrere Synthesewege für die Darstellung der Iodsulfonium(IV)-Salze, (CH3)2SI+AsF6- und (CH3)2SI+SbCl6-, angegeben. Diese Salze sind bis -20°C stabil, und sie werden Raman- und NMR-spektroskopisch charakterisiert.
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  • 86
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    Zeitschrift für anorganische Chemie 548 (1987), S. 117-124 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: PPh3Me[MoBr5(CH3CN)]. I.R. Spectrum, Magnetic Behaviour, and Crystal StructureMolybdenum tetrabromide and acetonitrile form MoBr4(CH3CN)2, from which PPh3Me[MoBr5(CH3CN)] is obtained by reaction with PPh3MeBr in dibromo methane. Both compounds are characterized by their IR spectra. By evaluation of the magnetic susceptibility of PPh3Me[MoBr5(CH3CN)] in the temperature range of 4.2 to 290 K the Curie-Weiss parameters μcw = 2.65 B.M. and Θ = -44 K were obtained. The crystal structure of PPh3Me[MoBr5(CH3CN)] was determined by X-ray diffraction (2426 observed reflexions, R = 0.082). Crystal data: a = 1064.9, b = 2172.1, c = 1330.4 pm, β = 119.92º, space group P21/c, Z = 4. In the crystal, PPh3Me+ and [MoBr5(CH3CN)]- ions are packed in alternate cation and anion layers perpendicular to a. In the anion the Mo atom has a distorted octahedral coordination. The bond length of the bromine atom in trans position to the N atom is considerably shorter than the other MoBr distances.
    Notes: Das aus Molybdäntetrabromid und Acetonitril gebildete MoBr4(CH3CN)2 reagiert mit Triphenylmethylphosphoniumbromid in Dibrommethan zu PPh3Me[MoBr5(CH3CN)]. Beide Addukte werden durch ihre IR-Spektren charakterisiert. Die Auswertung der Messung der magnetischen Suszeptibilität von PPh3Me[MoBr5(CH3CN)] im Temperaturbereich von 4,2 bis 290 K ergibt die Curie-Weiss-Parameter μcw = 2,65 B.M. und Θ = -44 K. Die Kristallstruktur von PPh3Me[MoBr5(CH3CN)] wurde mittels Röntgenbeugung bestimmt (2426 beobachtete Reflexe, R = 8,2%). Kristalldaten: a = 1064,9, b = 2172,1, c = 1330,4 pm; β = 119,92º, Raumgruppe P21/c, Z = 4. Im Kristall sind PPh3Me+- und [MoBr5(CH3CN)]--Ionen abwechselnd zu Schichten senkrecht zu a gepackt. Im Anion ist das Mo-Atom verzerrt oktaedrisch koordiniert. Der Bindungsabstand des Br-Atoms in trans-Stellung zum N-Atom ist deutlich kürzer als die übrigen Mo—Br-Abstände.
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  • 87
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: High-Temperature Hydrolysis of PCl3 and PBr3. I.R. Spectroscopic Identification of the Matrix Isolated Molecules OPCl and OPBrAt temperatures of about 700 K PCl3 und PBr3 can be partially hydrolysed in the vapor phase. In the equilibrium gas mixture, cocondensed with an excess of Ar, the molecules OPCl and OPBr are detected by their i.r. spectrum. This observation may be important for reactions of phosphorus trihalides in which traces of water are present.
    Notes: PCl3 und PBr3 können in der Gasphase bei etwa 700 K partiell hydrolisiert werden. Im Hochtemperaturgasgleichgewicht entstehen dabei die Moleküle OPCl und OPBr. Sie werden nach ihrer Kokondensation mit einem Überschuß Argon durch ihr IR-Spektrum nachgewiesen. Diese Beobachtung dürfte für etliche Reaktionen der Phosphortrihalogenide von Bedeutung sein, bei denen Spuren an Feuchtigkeit zugegen sind.
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  • 88
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    Zeitschrift für anorganische Chemie 548 (1987), S. 175-179 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Transition Metal Alkyl Compounds. 50. A non-common Organolanthanum CompoundLanthanum reacts with dibenzyl mercury in tetrahydrofuran as a solvent with splitting of solvent molecules and with formation of ethylene and a benzyl hydrido vinyloxide lanthanum complex of the composition C6H5CH2La(H)OCH=CH2 · 2 THF. This complex, primary well soluble in tetrahydrofuran, is extremely sensitive against air and moisture and undergoes a fast coordination polymerisation with a strong decrease of the solubility.The compound was characterized by elementary analysis, the hydrolysis and deuterolysis reaction, and by the i.r. spectra.
    Notes: Lanthan reagiert mit Dibenzylquecksilber in Tetrahydrofuran als Reaktionsmedium unter Spaltung von Lösungsmittelmolekülen zu Ethylen und einem Benzylhydridovinyloxid-lanthan-Komplex der Zusammensetzung C6H5CH2La(H)OCH=CH2 · 2 THF. Dieser anfangs in Tetrahydrofuran gut lösliche Komplex ist extrem luft- und feuchtigkeitsempfindlich und unterliegt rasch einer Koordinationspolymerisation unter starker Abnahme der Löslichkeit.Die Charakterisierung erfolgte durch Elementaranalyse, Verfolgung der Hydrolyse und Deuterolyse sowie Auswertung des IR-Spektrums.
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  • 89
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 548 (1987), S. 193-203 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclic Silicic Acid DerivativesBy reaction of SiCl4 with oxygen at elevated temperatures a number of chlorsiloxanes consisting of more or less fused rings can be prepared of which those components of low molecular weight can be separated by combining distillation and crystallization. Methyl and ethyl esters of silicic acids are obtained by reaction with methyl or ethyl nitrite, resp. The compounds are characterized by silicon n.m.r. and mass spectroscopy.
    Notes: Bei der Reaktion von SiCl4 mit Sauerstoff bei erhöhter Temperatur entstehen eine große Anzahl von Chlorsiloxanen, die aus mehr oder weniger kondensierten Ringen bestehen. Aus dem niedermolekularen Anteil können eine Reihe von Spezies durch die Kombination von Destillation und Kristallisation isoliert werden. Durch Umsetzung mit Methyl- bzw. Ethylnitrit lassen sich daraus die entsprechenden Ester der Kieselsäuren darstellen. Die Verbindungen werden durch 29Si-Kernresonanz und in gewissem Grade durch die Massenspektrometrie charakterisiert.
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  • 90
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 549 (1987), S. 15-25 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Oxidation of Intermetallic Phases: Na5InO4 from NaIn and Na2O2By oxidation of NaIn with Na2O2 [sealed Ag-cylinder 430°C, 1 d] Na5InO4 is formed as light yellow, coarse single crystals. The lattice constants of the orthorhombic cell are: \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm a = 1071,7}\left({\rm 3} \right)\quad{\rm b = 1055,0}\left({\rm 3} \right)\quad{\rm c = 1080,9}\left({\rm 3} \right){\rm pm, Z = 8} $$\end{document} According single crystal data [Pbca; four-circle diffractometer PW 1100, 1 748 out of 1 769 I0(hkl); R = 6.3% and Rw = 4.5%] Na5InO4 is isotypic with α-Li5GaO4. The Madelung Part of Lattice Energie, MAPLE, the Mean Fictiv Ionic Radii, MEFIR, and the Effectiv Coordination Numbers, ECoN, are calculated.
    Notes: Durch Oxydation von NaIn mit Na2O2 [geschlossener Ag-Zylinder, 430°C, 1 Tag] entsteht Na5InO4 in schwach hellgelben, derben Einkristallen. Die Gitterkonstanten der orthorhombischen Zelle sind: \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm a = 1071,7}\left({\rm 3} \right)\quad{\rm b = 1055,0}\left({\rm 3} \right)\quad{\rm c = 1080,9}\left({\rm 3} \right){\rm pm, Z = 8} $$\end{document} Nach Strukturaufklärung [Pbca; Vierkreisdiffrakrometer PW 1100, 1 748 von 1 769 I0(hkl), R = 6,3% und Rw = 4,5%] liegt Isotypie mit α-Li5GaO4 vor. Der Madelunganteil der Gitterenergie, MAPLE, die Mittleren Fiktiven Ionenradien, MEFIR, und die Effektiven Koordinationszahlen, ECoN, werden berechnet.
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  • 91
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    Zeitschrift für anorganische Chemie 549 (1987), S. 67-72 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Kristallstruktur von CH2[N(SO2F)2]2, N,N′,N,N′-Tetrakis (fluorosulfuryl)methylendiaminCH2[N(SO2F)2]2 ist monoklin, Raumgruppe P21/c, mit Z = 8. Die Struktur, die durch direkte Methoden gelöst und bis zu einem R-Wert von 0,082 für 2647 Diffraktometerdaten verfeinert wurde, besteht aus diskreten Molekülen.
    Notes: CH2[N(SO2F)2]2 is monoclinic, space group P21/c, with 8 molecules in the unit cell. The structure, which was solved by direct methods in a straightforward manner and refined to R = 0.082 for 2647 diffractometer intensities, consists of discrete molecules.
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  • 92
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 549 (1987), S. 87-102 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Constitution of ‘KPbO2’Transparent, orangered single crystals of K2Pb2O4 have been obtained by heating mixtures of K2O2 and PbO (K:Pb = 1:1) [Ag-cylinders, 560°C, 40 d, after cooling (15°C/h)]. The space group is P1, a = 1295.94(9), b = 753.35(7), c = 697.12(8) pm, α = 118.00(1)°, β = 106.15(1)°, γ = 93.44(1)°, Z = 4, dx = 6.573 und dpyk = 6.54 g · cm3. The structure is characterized by rutilanalogous chains of edge-connected [PbO6] octahedra along [001] according to [PbO4/2O2/1] = PbO4. On both sides of such a chain there are respectively three O2-, which belong to two octahedra, alternating capped with Pb2+ or not capped, corresponding to [PbO4]Pb2[PbO4]□2… = Pb2O4. Those capped chains are held together by K(1)…K(4), each of them with C.N. 6. The order of the chains corresponds to the motive of a closest packing.The Madelung Part of Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated and discussed.
    Notes: Transparente, orangerot aussehende, Einkristalle von K2Pb2O4 wurden aus Gemengen von K2O2 und PbO (K:Pb = 1:1) durch Tempern [Ag-Bömbchen, 560°C, 40 d, nach Abkühlen (15°C/h)] erhalten. Sie sind triklin, P1, a = 1295,94(9), b = 753,35(7), c = 697,12(8) pm, α = 118,00(1)°, β = 106,15(1)°, γ = 93,44(1)°, Z = 4, drö = 6,573 und dpyk = 6,54 g · cm3. Strukturcharakteristisch sind Rutil-analoge Stränge kantenverknüpfter [PbO6]-Oktaeder längs [001] gemäß [PbO4/2O2/1] = PbO4. Jeweils beidseitig eines solchen Stranges sind je drei O2-, die zwei Oktaedern zugehören, alternierend mit Pb2+ bekappt oder unbekappt, entsprechend [PbO4]Pb2[PbO4]□2… = Pb2O4. Derartige bekappte Stränge werden durch K(1)…K(4), jeweils C.N. 6 zusammengehalten. Die Anordnung der Stränge entspricht dem Motiv einer dichtesten Packung.Der Madelunganteil der Gitterenergie, MAPLE, Effektive Koordinationszahlen, ECoN, diese über Mittlere Fiktive Ionenradien, MEFIR, werden berechnet und diskutiert.
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  • 93
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    Zeitschrift für anorganische Chemie 549 (1987), S. 129-138 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Novel Periodate: On the Structure of K9Li3I2O13 = K9Li3O[IO6]2New obtained are weakly dichroitic (pale yellow/bluish) single crystals of K9Li3I2O13 by reaction of KIO4, K2O, and Li2O (KIO4:K2O:Li2O = 1:1:1.5; 800°C, 42 d). Space group P62c, Z = 2, a = 954.9 pm, c = 1172.2 pm, R = 6.2%, Rw = 5.6%, 957 symmetry independend I0(hkl), MoKα. Characteristic for this structure are „isolated“ O2- and octahedral groups [IO6]. The crystal structure has been determind. The Madelung Part of Lattice Energy, MAPLE, is calculated and discussed.
    Notes: Neu dargestellt wurde aus KIO4, K2O und Li2O in Form schwach dichroitischer (gelblich/bläulich) Einkristalle K9Li3I2O13 (KIO4:K2O:Li2O = 1:1:1,5; 800°C, 42 d) Raumgruppe P62c, Z = 2, a = 954,9 pm, c = 1172,2 pm, R = 6,2%, Rw = 5,6% für 957 symmetrieunabhängige Reflexe, MoKα. Charakteristisch für die Struktur sind neben „isolierten“ O2- oktaedrische Gruppen [IO6]. Die Struktur wird beschrieben und der Madelunganteil der Gitterenergie, MAPLE, berechnet und diskutiert.
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  • 94
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cobalt Chelates as Hydrogenation Catalysts. III. Hydride Formation of the [Co(dpnH)]+ Catalyst in the Presence of Pyridine as Axial BaseThe rate of the hydrogen uptake for [Co(dpnH)]+ is 2nd order with respect to the complex concentration and depends on the amount of added pyridine, in accord with the assumption of a more active mono- and an inactive bis-pyridine adduct. The rate law, formulated on this basis agrees very well with the measured data. The ΔH≠ - and ΔRH°-values, calculated from the temperature dependence of the rate constants and equilibrium constants are in agreement with the suggested model, whereas the ΔS≠ and ΔRS° values do not correspond completely with these expectations.
    Notes: Die Geschwindigkeit der Wasserstoffaufnahme des [Co(dpnH)]+-Komplexes ist 2. Ordnung bezüglich der Komplexkonzentration und abhängig von der Menge an zugesetztem Pyridin, in Übereinstimmung mit der Annahme eines aktiveren Mono- und eines inaktiven Bis-Pyridinaddukts. Das auf dieser Basis formulierte Geschwindigkeitsgesetz steht in sehr guter Übereinstimmung mit den Meßwerten. Die aus der Temperaturabhängigkeit der Geschwindigkeits- bzw. Gleichgewichtskonstanten berechneten ΔH≠- und ΔRH°-Werte stimmen mit dem angenommenen kinetischen Modell überein, während die ΔS≠- und ΔRS°-Werte diesen Erwartungen nicht ganz entsprechen.
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  • 95
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 554 (1987), S. 92-100 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Crystal Structure of (PPh4)2[Mo2NCl9]2, a μ-Nitrido Complex with Molybdenum (V) and (VI)The title compound is formed as a by-product in the partial oxidation of Mo2NCl7 with chlorine in POCl3 solution, when the reaction mixture is treated with PPh4Cl. The crystals, which are sensitive to moisture, are black in reflectance and red in transmittance. A more effective synthesis is the direct reaction of PPh4[MoNCl4] with MoCl5 in dichloro methane. (PPh4)2[Mo2NCl9]2 was characterized by the i.r. spectrum and by a structural analysis with X-ray data. The compound crystallizes triclinic in the space group P1 with two formula units per unit cell (9225 independent observed reflexions, R = 0.058). The cell parameters are (20°C): a = 1144 pm, b = 1517 pm, c = 2000 pm, α = 79.8°, β = 80.1°, γ = 72.1°. (PPh4)2[Mo2NCl9]2 consists of PPh4⊕ cations and the anions [Mo2NCl9]222⊖, which dimerize via chloro bridges with Mo—Cl bons lengths of 243 pm and 287 pm. In the [Mo2NCl9]22- units the molybdenum atoms are linked by MoVI≡N—MoV bridges (bond angles 179° and 174°, resp.) with Mo—N bond lengths of 167 pm and 212 pm.
    Notes: Die Titelverbindung entsteht als Nebenprodukt bei der partiellen Oxidation von Mo2NCl7 in POC3-Lösng mit Chlor und anschließender Umsetzung mit PPh4Cl in Form schwarzer, in der Durchsicht roter, feuchtigkeitsempfindlicher Kristalle. Zur Synthese besser geignet ist die direkte Umsetzung von PPh4[MoNCl4] mit MoCl5 in Dichlormethan-Lösng. (PPh4)2[Mo2NCl9]2 wurde durch das IR-Spektrum und durch eine röntgenographische Strukturanalyse charakterisiert. Die Verbindung kristallisiert triklin in der Raumgruppe P1 mit zwei Formeleinheiten pro Elementarzelle (9225 unabhängige, beobachtbare Reflexe, R = 5,8%). Die Gitterkonstanten sind bei 20°C: a = 1144, b = 1517, c = 2000 pm, α = 79,8°; β = 80,1°; γ = 72,1°. (PPh4)2[Mo2NCl9]2 besteht aus PPh4⊕-Kationen und Anionen Mo2NCl9⊖, die über zwei Chlorobrücken mit Mo—Cl-Abständen von 243 und 287 pm dimerisieren. In den Mo2NCl9⊖-Einheiten sind die Molybdänatome über gestreckte MoVI≡N—MoV -Brücken (Bindungswinkel 179° bzw. 174°) mit MoN-Abständen von 167 bzw. 212 pm verknüpft.
    Additional Material: 1 Ill.
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  • 96
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 550 (1987), S. 123-132 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Chemical Transport of MnCl2 with MeCl3 (Me = Al, Ga, In)The transport behaviour of MnCl2 with MeCl3 (Me = Al, Ga, In) has been calculated by the aid of the solubilities in the gas phase taking into account the gaseous chlorid complexes MnMeCl5, MnMe2Cl8, and MnMe3Cl11 and compared with the experimental results. The transport take place only from hot to cold with InCl3, where as a maximum of the solubility of the gas phase exists using AlCl3 and GaCl3. There is a good agreement between the calculated and the experimental results.
    Notes: Das Transportverhalten von MnCl2 mit MeCl3 (Me = Al, Ga, In) wird unter Berücksichtigung der gasförmigen Chloridkomplexe MnMeCl5, MnMe2Cl8 und MnMe3Cl11 über die Gasphasenlöslichkeiten berechnet und mit den experimentellen Ergebnissen verglichen. Während bei Verwendung von AlCl3 und GaCl3 ein Maximum der Gasphasenlöslichkeit auftritt, werden mit InCl3 als Transportmittel nur heiß-kalt-Transporte festgestellt. Die berechneten und experimentellen Ergebnisse zeigen eine gute Übereinstimmung.
    Additional Material: 7 Ill.
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  • 97
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 550 (1987), S. 177-185 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies on Nickel Oxide Mixed Catalysts. XVI. Reduction Behaviour of Amorphous NiO—Al2O3/SiO2 CatalystsThe reduction behaviour of NiO—Al2O3/SiO2 catalysts prepared by precipitationdeposition is influenced by the phase composition (amorphous nickel layersilicates and nickel alumino layersilicates, nickel spinels, nickel oxide) and the differences of the composition between surface and bulk. TPR measurements, determinations of the reduction degree, and the nickel particle sizes by static magnetic measurements showed that the reducibility of the NiO—Al2O3/SiO2 catalysts is enhanced and the nickel dispersity is decreased at low Al2O3 contents. The decrease of the reducibility at Al2O3 contents 〉5 mole% is caused by the formation of nickel spinels and the decrease of the NiII ion surface concentration.
    Notes: Das Reduktionsverhalten durch Auffällen hergestellter NiO—Al2O3/SiO2-Katalysatoren wird durch die Phasenzusammensetzung (amorphe Nickelschicht-und alumoschichtsilicate, Nickelspinelle, Nickeloxid) und durch die Unterschiede in der Zusammensetzung zwischen Volumen und Oberfläche bestimmt. TPR-Messungen, Bestimmungen des Reduktionsgrades und der Nickelpartikelgrößen durch statische magnetische Messungen zeigten, daß bei geringen Al2O3-Gehalten die Reduzierbarkeit der NiO—Al2O3/SiO2-Katalysatoren erhöht und die Nickeldispersität vermindert wird. Die Abnahme der Reduzierbarkeit bei Al2O3-Gehalten 〉5 Mol-% wird durch die Bildung von Nickelspinellen und durch die Abnahme der NiII-Ionenoberflächenkonzentration verursacht.
    Additional Material: 4 Ill.
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  • 98
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 550 (1987), S. 186-194 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Condensation Behaviour of Silanols. IV. Acid Catalyzed Condensation of Organodimethylsilanols in Dioxane/WaterThe condensation has been followed by GLC for silanols of the type XMe2SiOH in aqueous dioxane with HCl as catalyst. The obtained kinetic data and equilibrium constants are discussed with respect to the substituent dependence and the reaction mechanism.
    Notes: Für Silianole des Typs XMe2SiOH (X = Alkyl, Aryl, Halogenalkyl, Benzyl, Silyl) wurde gaschromatographisch die Kondensation in wäßrigem Dioxan mit HCl als Katalysator verfolgt. Die erhaltenen kinetischen Daten und Gleichgewichtskonstanten werden bezüglich ihrer Substituentenabhängigkeit sowie mechanistischer Aussagen diskutiert.
    Additional Material: 1 Ill.
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  • 99
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 554 (1987), S. 137-145 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Concerning Polymetaarsenites. Preparation and Crystal Structure of BaAs2O4. H2OBaAs2O4·H2O was prepared by hydrothermal reaction of BaO with As2O3 at a temperatur of 200°C. An X-ray structural analysis demonstrated that the phase contains polymetaarsenite anions [As4O84-]n, which adopt vierer single chains in the lattice. The relationship between the conformation of metaarsenite chains and cation size is discussed.
    Notes: BaAs2O4·H2O wurde durch hydrothermale Reaktion von BaO mit As2O3 bei einer Temperatur von 200°C dargestellt. Eine Röntgenstruktranalyse ergab, daß die Phase Polymetaarsenitanionen [As4O84-]n beinhaltet, die im Kristallgitter als Vierer-Einfachketten vorliegen. Die Beziehung zwischen Konformation von Polymetaarsenitketten und Kationgröße wird erlätert.
    Additional Material: 3 Ill.
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  • 100
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 554 (1987), S. 166-171 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations for Determination of Phase-Extension of Transported MnO-CrystalsWe determined the O/Mn relation of transported MnO crystals with the method of solid electrolyte coulometry. It follows the phase-extension of MnO in function of temperature from 0.0025 at 1091 K to 0.0128 at 1292 K.
    Notes: Das O/Mn-Verhältnis transportierter MnO-Kristalle wurde mit dem Verfahren der Festelektrolytcoulometrie bestimmt. Für MnO ergibt sich eine temperaturabhängige Phasenbreite, die sich von 0,0025 bei 1091 K bis zu 0,0128 bei 1292 K erstreckt.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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