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  • 1980-1984  (3.838)
  • 1970-1974  (4.290)
  • 1850-1859
  • Inorganic Chemistry  (7.371)
  • Electron microscopy  (757)
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  • 1
    ISSN: 1432-2307
    Schlagwort(e): Calcifying epithelial odontogenic tumor ; Electron microscopy ; Histoenzymology ; Ameloblast ; Amyloid-like substance
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A calcifying epithelial odontogenic tumor, simultaneously located in the two jaws (maxilla and mandible) was examined by histochemical and electron microscopic methods. Squamous tumor cells without secretory polarity were different from those of common ameloblastoma. High activities of alkaline phosphatase and ATPases were demonstrated by light and electron microscopy on the cytoplasmic membrane, findings similar to those in the stratum intermedium cells of the normal dental germ from which these tumor cells seem to arise. The tumor cells, like preameloblasts of the dental germ, also produce a granulo-filamentous material in intracytoplasmic vesicles and discharge it into the stroma. This “pseudo-amyloid” substance represents an abnormal protein of the enamel matrix and calcification, mainly occurring in that substance, might be an attempt at mineralization.
    Materialart: Digitale Medien
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  • 2
    ISSN: 1432-2307
    Schlagwort(e): Gastric carcinoma ; Scirrhous carcinoma ; Collagen ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Collagen types I and III were examined immunohistochemically in 32 cases of gastric carcinoma classified as poorly differentiated adenocarcinoma with scirrhous stroma, well differentiated adenocarcinoma with intermediate stroma, or poorly differentiated adenocarcinoma with medullary stroma. In the stroma of scirrhous carcinoma, types I and III collagens were distributed abundantly in fibrillar or granular patterns with little difference in the intensity of staining. In well differentiated adenocarcinoma, type I collagen was diffusely distributed in the stroma with type III collagen distributed sparsely. In poorly differentiated adenocarcinoma with medullary stroma, the two types of collagen were only found around capillaries, constituting the tumor interstitium. Electron microscopic examination of scirrhous carcinoma showed tumor cells partially covered with fibroblasts, and discontinuous basal lamina, collagen fibers and microfibrils present between tumor cells and fibroblasts. In well differentiated carcinoma, tumor cells were surrounded by fibroblasts, and well developed basal lamina was observed beneath the tumor cells. In poorly differentiated carcinoma with medullary stroma, the stroma consisted of capillaries and very few fibroblasts with discontinuous basal lamina occasionally being present between tumor cells and fibroblasts.
    Materialart: Digitale Medien
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  • 3
    ISSN: 1432-2307
    Schlagwort(e): Alloxan ; Culture ; Electron microscopy ; 6-Hydroxydopamine ; Pancreaticβ-cells ; Stereology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Stereological techniques on electron microscopy micrographs were used to evaluate the morphological changes of cultured isletβ cells that had been exposed to alloxan or 6-hydroxydopamine. Trypan Blue exclusion by cells cultured for 3 days indicated that the cells were 100% viable. Electron microscopy revealed that nearly all of the surviving cultured cells wereβ cells. Exposure to 5 mmol/l alloxan or 1–5 mmol/l 6-hydroxydopamine for 10 or 30 min caused a general swelling of the cultured cells with a concomitant swelling of mitochondria and nuclei. The size of the secretory granules was not affected by the drugs. Only 3–10% of the cells excluded Trypan Blue after exposure to 5 mmol/l alloxan or 6-hydroxydopamine. The data conform with the hypothesis that a primary action of alloxan and 6-hydroxydopamine is at the plasma membrane level ofβ cells.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 404 (1984), S. 213-221 
    ISSN: 1432-2307
    Schlagwort(e): Oat cell carcinoma ; Male breast ; Immunocytochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A case of small cell neuroendocrine (oat cell) carcinoma of the breast in a 52-year old male is presented. Oat cell carcinomas have been reported in various extrapulmonary sites, but this is the second case of a primary oat cell carcinoma of the breast and the first one to have been documented in a male. The tumor was investigated histologically, immunocytochemically and ultrastructurally. The relationship to so-called “carcinoid” mammary tumors is discussed.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 404 (1984), S. 427-434 
    ISSN: 1432-2307
    Schlagwort(e): Elephantiasis neuromatosa ; Neurofibromatosis ; Electron microscopy ; Immunohistochemistry ; S-100 protein
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary An example of elephantiasis neuromatosa, an unusual variant of neurofibromatosis, coexistent with lipomatosis is presented. This dual cell population produced a diffuse swelling of the gluteal sulcus of a young female. The neurogenous origin of the spindle cell component was substantiated by immunoreactivity for S-100 protein as well as by the fine structural observation of a regular basement membrane coating and a profusion of Luse bodies. As far as can be ascertained, this is the first reported immunohistochemical and ultrastructural study of this particular variant of peripheral nerve sheath lesion.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 403 (1984), S. 27-40 
    ISSN: 1432-2307
    Schlagwort(e): Spleen ; Ellipsoids ; Morphometry ; Electron microscopy ; Lymphocyte traffic
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A study of ellipsoids (EL) in the human spleen was done on 25 surgically resected specimens in order to assess the number of EL, their structure, the nature of the cuff cells and the problem of lymphocyte traffic through their wall. The results show that an average spleen of 200 g contains 1.6 × 107 EL. They are localized in a constant segment of the vascular tree, just at the transition of the penicillary arterioles into capillaries and they consist of a capillary (not an arteriole) surrounded by a cuff of cells. These cells are neither endothelial nor smooth muscle cells, display lysosomal activity and are considered as fixed specialized pericapillary cells capable of cytoplasmic expansion. Since their number is inconstant in different individuals and in different species they are considered to be dynamic histological structures. Because of the constant presence of lymphocytes in their walls we consider the EL to be a transit system for lymphocytes and the splenic equivalent of the high endothelial venules in the lymph nodes.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 403 (1984), S. 391-400 
    ISSN: 1432-2307
    Schlagwort(e): Immunohistochemistry ; Electron microscopy ; Light microscopy ; Granular cell tumour ; Mammary gland neoplasm
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Primary granular cell tumours of the breast in 35 2and 55 year old women were studied by light microscopy, transmission electron microscopy and immunohistochemistry. Light and electron microscopy revealed a neural origin of the tumours and this was further substantiated by immunohistochemical studies, with positive S-100 protein reaction and negative reactions for surface heavy and light chains, CEA, alfa-1-antitrypsin, muramidase and GFA-protein. Granular cell tumour of the mammary gland is a very rare tumour. Clinically it sometimes simulates carcinoma because of its fibrous consistency, fixation to pectoral fascia and skin retraction. The diagnosis of granular cell tumour should be included in the differential diagnosis of carcinoma of the breast. The granular cell tumour is derived from neuro-ectodermal tissue. Whether it represents a neurogenic cell-confined metabolic disturbance with lysosomal activation, or a true neoplasm remains to be elucidated.
    Materialart: Digitale Medien
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  • 8
    ISSN: 1432-0568
    Schlagwort(e): Meconium corpuscles ; Apoptosis ; Foetal intestine ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary During the embryonic development of the intestine, programmed deletion of epithelial cells plays a vital role in the formation of secondary lumina and of villi. Electron microscopy shows that this deletion is effected by apoptosis, a distinctive mode of cellular death recently recognised as being implicated in normal tissue involution in the adult, as well as during intrauterine development. The process involves cellular condensation and budding to form membrane-bounded apoptotic bodies containing well-preserved organelles. These are then either engulfed by neighbouring principal cells or sloughed off into the intestinal lumen. Engulfed apoptotic bodies that show various degrees of lysosomal degradation have previously been reforred to as “meconium corpuscles”.
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 169 (1984), S. 9-20 
    ISSN: 1432-0568
    Schlagwort(e): Peroxisomes ; Marginal plates ; DAB-Cytochemistry ; Electron microscopy ; Freeze-etching
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In the canine circumanal gland, the morphological alterations of peroxisomes during differentiation and maturation of the glandular cells were studied by electron microscopy, cytochemistry and freeze-etch technique. Each of the following three cell types has its own characteristic peroxisomal population: 1) The basal cell contains only a few small peroxisomes, which appear as spherical and tubular profiles showing strong DAB reaction. In the differentiating basal cells, these are joined by a few dilated, hemispherical organelles with intensely stained small marginal plates. 2) In the intermediate cell, additional to spherical and tubular peroxisomes, numerous clongated organelles with distinct marginal plates are observed, displaying weak catalase activity. 3) In the mature cell, dumbbell-shaped peroxisomes with enlarged marginal plates predominate. Serial section analysis and freeze-etching studies reveal that these dilated particles are of erythrocyte-like shape. They exhibit very weak catalase activity or do not contain any visible DAB reaction product. In their flattened, thin central portions, the memoranes enclose the marginal plates and form straight cisternae, which are closely associated with adjacent fenestrated cisternae of ER on both sides, referred to as paramarginal cisternae. Dumbbell-shaped peroxisomes with their corresponding paramarginal cisternae form large peroxisome-ER-complexes. Furthermore, three to five dumbbell-shaped particles are often stacked in parallel. Only at their flat poles are the organelles in close contact with paramarginal cisternae. The observation of continuities, in particular between erythrocyte-like organelles and tubular peroxisomes in mature glandular cells, indicates the existence of a peroxisomal compartment composed of two segments in the mature stage. In freeze-etch replicas of mature glandular cells, only the dilated segments of the peroxisomal compartment can be easily recognized because of their unusual size and erythrocyte-like shape. Additionally, on the E-face of their central portion, a straight, square or rectangular area with a distinct crystalline pattern is seen, which corresponds to the marginal plate. These findings indicate that the circumanal gland of the dog offers unique possibility to analyze the biological properties of a well-defined peroxisomal compartment.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 169 (1984), S. 261-270 
    ISSN: 1432-0568
    Schlagwort(e): Peroxisomes ; DAB-cytochemistry ; Electron microscopy ; Three-dimensional reconstruction ; Preputial gland ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The ultrastructure of peroxisomes in partially differentiated cells of the mouse preputial gland was investigated using serial thin sections and three-dimensional reconstruction as well as the alkaline diaminobenzidine technique for visualization of the peroxidatic activity of catalase. An analysis of serial sections indicates that the different types of intensely stained peroxisomal profiles, classified according to their shape, represent random planes through highly complex peroxisomes. These organelles exceed 4 μm in length and exhibit a focal heterogeneity with respect to their size, shape and enzyme distribution. The graphical three-dimensional reconstruction demonstrates that the most intricate peroxisomes are characterized by tortuous, elongate, and branched tubular segments of varying diameter equipped with enlarged terminal hollow-spherical structures which engulf areas of cytoplasm. A close spatial relationship is established between adjacent peroxisomes and peroxisomes and mitochondria, the latter two of which synchronously develop into highly complex structures. A close association is also observed between peroxisomes and the endoplasmic reticulum, whereby membrane continuities between the two compartments cannot be demonstrated. These observations are inconsistent with traditional concepts concerning peroxisomal shape and size, the number per cell, as well as their biogenesis from the endoplasmic reticulum. The functional significance of individual highly complex peroxisomes and their assemblage forming an extensive netlike membraneous system throughout the cell is discussed with respect to intracellular energy transport and trans-membrane electron exchange.
    Materialart: Digitale Medien
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  • 11
    ISSN: 1432-0568
    Schlagwort(e): Implantation ; Blastocyst ; Zona pellucida ; Decidual reaction ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Ultrastructural studies were undertaken to investigate the temporal relationship between loss of the zona pellucida around the blastocyst and the appearance of decidual changes in the endometrial stroma during normal implantation in rats. Blastocyst-free and blastocyst-containing sites of pregnant uterine horns were studied and compared with control sites from contralateral salpingectomized horns and horns of pseudopregnant animals from 24.00 h on Day 4 and onwards. There were no membrane contacts between the blastocyst and the uterine epithelium at 10.00 h on Day 5 and earlier because of an intervening zona pellucida. From 14.00 h onwards, however, such contacts were present and at 18.00 h, the zona pellucida had disappeared and the blastocyst had attached onto the uterine epithelium. The stromal cells of pregnant and control horns were indistinguishable from each other at 24.00 h on Day 4, but from 06.00 h on Day 5 onwards specific changes were noted in the stromal cell nucleoli of the pregnant horns. The results therefore suggest that the first morphological sign of decidualization occurs about 12 h before the Pontamine Blue reaction and is initiated by the blastocyst early on Day 5 while it is still encased by the zona pellucida.
    Materialart: Digitale Medien
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  • 12
    ISSN: 1432-0533
    Schlagwort(e): Polyneuropathy ; Hereditary disease ; Chiloren ; Sural nerve biopsy ; Electron microscopy ; Morphometry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Ten autosomal recessive/sporadic cases of hereditary motor and sensory neuropathy type I (HMSN I), nine of which originated from the northern part of Sweden, were included in the study. Parents were free from neurologic symptoms. Motor and sensory conduction velocity was normal when recorded, i.e., in 19 and 17 parents, respectively. Sural nerve biopsies from the ten cases revealed a varying degree of onion bulb formation. In eight of the cases the onion bulbs consisted of abundant basement membranes, whereas the Schwann cells were few and sometimes lacking. There were in some cases considerable differences between separate fascicles as to the loss of myelinated nerve fibers. In the six biopsies in which teasing was performed signs of present and previous demyelination were noticed. Numerous internodal segments were abnormally thin with reference to their length. In many such segments there were marked local thickenings of the nerve fiber. In cross sections the probable counterparts to these thickenings were nerve fibers with unduly thick myelin sheaths and complex folding of the myelin. Ultrastructural axonal changes were seen in the majority of the cases. The pathogenetic and diagnostic implications of the present findings are discussed.
    Materialart: Digitale Medien
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  • 13
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 63 (1984), S. 255-263 
    ISSN: 1432-0533
    Schlagwort(e): Carbon disulphide ; Electron microscopy ; Giant axonopathy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Adult Wistar rats were exposed to carbon disulphide (CS2) vapour at a concentration of 2.4 mg/l of air for 5 days a week (6h a day), and the ultrastructure of peripheral nerves, neuromuscular junctions and muscles was investigated after 6 months of exposure to CS2. Numerous giant axons, i.e. paranodal or internodal swellings, were seen in the peripheral nerves. At the swollen paranodes, the myelin sheath was thinned, in other regions large intramyelinic vacuoles indicative of more dramatic demyelination were observed at axonal enlargements. Axonal enlargements consisted essentially of whorls of tightly packed neurofilaments. A number of nerve fibres underwent complete degeneration, but at the same time there was evidence of nerve regeneration. Nerve terminals were affected in a similar way following CS2 exposure. At neuromuscular junctions, filamentous swellings of nerve terminals preceded their degeneration and eventual denudation of synaptic gutters. As a rule, the postsynaptic part of neuromuscular junctions remained unimpaired by CS2 treatment. Muscles were affected by both atrophy and degeneration. Clusters of dense and lamellar bodies and numerous autophagosomes indicative of direct myotoxic effect of CS2 were frequently encountered in the investigated muscles. Some muscle fibres apparently underwent necrosis judging from the occurrence of myotubes characteristic of muscle degeneration and regeneration. The pathomorphology of CS2 neuropathy resembles that of other toxic neuropathies which presumably have a common origin in impaired energy metabolism.
    Materialart: Digitale Medien
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  • 14
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 64 (1984), S. 108-113 
    ISSN: 1432-0533
    Schlagwort(e): Image analysis ; Electron microscopy ; Muscle fibers
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Based on a fixed number of EM photomicrographs a semiautomatic image analysis is made of normal gastrocnemius muscle fibers to obtain reference values for comparison with pathologic data. Z disc, mitochondria, tubular system, and sarcoplasmic reticulum are measured. It is stated that no definite fiber type differentiation is possible based on these quantitative data. However, measurements of Z disc and mitochondria are suggestive of such a differentiation. On the other hand, all data reach a Gaussian distribution on a logarithmic scale after a 5% correction factor is introduced.
    Materialart: Digitale Medien
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  • 15
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 64 (1984), S. 122-128 
    ISSN: 1432-0533
    Schlagwort(e): Hydrocephalus ; Blood-brain barrier ; Tight junctions ; Paracellular pathway ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Considering the possibility of a paracellular route for edema resolution we studied the microvasculature of the subependymal and subcortical white matter in hydrocephalic rats. Normal adult rats were used as controls. After injection of kaolin suspension into the cisterna magna, the animals were killed at intervals of 1, 2, 4, and 8 weeks. In hydrocephalic rats at 1 week after kaolin injection, widening of the interendothelical cleft between the tight junction (dehiscence) was seen in 27 of 76 (35%) vessels. At 2 weeks after kaolin injection, the number of the dehiscences had increased (39/7:56%) and some were enlarged, forming interendothelial blisters. At 4 weeks in hydrocephalic rats, both dehiscences and blisters were still prominent (45/73∶63%) and at 8 weeks the dehiscences were still prominent, but the number of the blisters had decreased (25/81∶31%). The blisters and dehiscences were most pronounced in the corpus callosum and occipital regions. Following i.v. injection of horseradish peroxidase, the interendothelial dehiscences and blisters were completely devoid of the marker substance. These findings indicate that in obstructive hydrocephalus the tight junctions may constitute part of a paracellular pathway for the resorption of interstitial edema fluid.
    Materialart: Digitale Medien
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  • 16
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 276 (1984), S. 2-11 
    ISSN: 1432-069X
    Schlagwort(e): Photochemotherapy ; Freckles ; Electron microscopy ; Melanocytes ; Langerhans cells ; Retinoid therapy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Photochemotherapy (PUVA)-induced freckles were found in 25 patients (41%) who had received more than 1,000 J/cm2 of PUVA. The patients had been treated with PUVA for more than 2 years, with more than 150 exposures before PUVA lentigines appeared on the thighs, the upper arm, the mid-lower arm, the waist, and the buttocks. The histopathology of these freckles was analyzed by light and electron microscopy. Light microscopy showed an increased amount of pigment and melanophages and increased numbers and size of melanocytes. The keratinocytes often displayed atypical features such as enlarged nuclei, giant size, or fibrillar degeneration. Homogenization of the papillary dermis was observed in 11 patients. The activation of melanocytes was confirmed electron microscopically, and pathological features such as large amounts of lipid droplets and lysosome-melanosome complexes within the melanocytes were seen. The Langerhans cells were mostly normal, whereas the keratinocytes showed cytolytic changes, fibrillar degeneration, and vacuolization. A close follow-up of patients with prolonged PUVA treatment is recommended.
    Materialart: Digitale Medien
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  • 17
    Digitale Medien
    Digitale Medien
    Springer
    Archives of microbiology 138 (1984), S. 273-277 
    ISSN: 1432-072X
    Schlagwort(e): Cyanobacteria ; Secondary metabolite ; Allelopathy ; Photosynthesis ; Electron transport ; Thylakoids ; Herbicides ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Cyanobacterin is a secondary metabolite produced by the cyanobacterium, Scytonema hofmanni. Highly purified cyanobacterin was found to inhibit the growth of many cyanobacteria at a minimum effective dose of 2 μg/ml (4.6 μM). The antibiotic had no effect on eubacteria including the photosynthetic Rhodospirillum rubrum. The site of action of cyanobacterin was further investigated in the unicellular cyanobacterium, Synechococcus sp. Electron micrographs of antibiotic-treated Synechococcus cells indicated that cyanobacterin affects thylakoid membrane structure. The antibiotic also inhibited light-dependent oxygen evolution in Synechococcus cells and in spheroplasts. These data support our conclusion that cyanobacterin specifically inhibits photosynthetic electron transport. This activity is similar to herbicides such as 3-(3,4-dichlorophenyl)-1,1-dimethyl urea (DCMU). The anhydro analog of cyanobacterin had no biological activity.
    Materialart: Digitale Medien
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  • 18
    Digitale Medien
    Digitale Medien
    Springer
    Archives of microbiology 140 (1984), S. 265-270 
    ISSN: 1432-072X
    Schlagwort(e): EcoRI ; EcoRI-DNA complexes ; EcoRI* activity ; Recognition sites ; Frequency of binding ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Electron microscopy of negatively stained isolated restriction enzyme EcoRI revealed particle projections with triangular or square outlines, indicating that the enzyme, in its tetrameric state, is tetrahedron-like. The two dimers making up the tetramer appear to be arranged in two planes orthogonal to each other. Complexes formed by EcoRI with the plasmids pBR322 or pGW10 were investigated by electron microscopic spreading techniques. In the presence of Mg2+, EcoRI was bound to the DNA molecules to form pearl necklace-like aggregates. The number of bound EcoRI particles was much higher as the sum of EcoRI-and 5′..AATT..3′ sites (with exceptions, the 5′..AATT..3′ sites may function as one type of EcoRI* sites) along the DNAs, indicating unspecific binding. In the absence of Mg2+, EcoRI was bound to the DNA only at the recognition site for EcoRI and the sites where the tetranucleotide sequence 5′..AATT..3′ was present. A direct correlation of the local concentrations of the bases A and T within the flanking sequences of the binding sites with the frequency of EcoRI to the DNA was observed. Dimers and tetramers of the enzyme was found to bind to the DNA. Tetramers occasionally exhibited two binding sites for DNA as indicated by the observation of DNA loops originating at the sites of bound tetrameric EcoRI particles.
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  • 19
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 277 (1984), S. 44-54 
    ISSN: 1432-069X
    Schlagwort(e): Birbeck granule ; Birbeck granule-like structure ; Electron microscopy ; Langerhans cell ; Lymph node
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary To understand contact hypersensitivity, it is important to know the kinetics of Langerhans cells (LC) and related cells in the lymph node (LN), as well as in the skin. For this purpose, we tried experimentally to induce increased numbers of LCs, Birbeck granule-like structure (BgS)-containing cells, and interdigitating reticulum cells (IDC) in DNCB-sensitive mice and studied them by means of electron microscopy with the following results: (1) cytologically, LC, BgS-containing cells and IDC were closely related; (2) BgS seemed to arise from rough-surfaced endoplasmic reticulum (r-ER), and BgS-containing cells were midway in nature between LC and IDC from the morphological view point. From these findings, it appears that IDC, BgS-containing cells, and LCs were simultaneously involved in the contact hypersensitivity reactions of LNs.
    Materialart: Digitale Medien
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  • 20
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 65 (1984), S. 128-137 
    ISSN: 1432-0533
    Schlagwort(e): Quantitative ; Electron microscopy ; Microangiopathy ; Pi granules ; Schwann cells
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A significant reduction in the myelinated nerve fiber population was observed during quantitative electron-microscopic examination of peripheral nerves in chronic alloxan diabetic rats. Dystrophic axonal abnormalities and regenerating fibers were more numerous in diabetics than age-matched controls. Schwann cells showed reactive changes including prominent pi granules of Reich and intracytoplasmic filament accumulation. Enumeration of these alterations, however, revealed no singificant difference from controls. Endoneurial macrophages in diabetic rats were also filled with lamellar intracytoplasmic inclusions characteristic of a chronic neuropathy. Quantitation of pathologic lesions in teased nerve fibers confirmed the preponderance of axonal over demyelinative disease and showed demyelination to be segmental. Microangiopathy was noted throughout the vasa nervorum of diabetic rats, and quantitative electron microscopy showed endothelial proliferation with doubling of the number of endothelial cells and proportional capillary mural thickening. Swollen, reactive endothelial cells appeared to effece the vascular lumen and may impair capillary perfusion. These microcirculatory changes, in the presence of biochemical and rheologic disturbances may contribute to tissue hypoxia and underly the loss of axons in experimental diabetic neuropathy.
    Materialart: Digitale Medien
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  • 21
    Digitale Medien
    Digitale Medien
    Springer
    Journal of cancer research and clinical oncology 107 (1984), S. 242-244 
    ISSN: 1432-1335
    Schlagwort(e): Phospholipase ; Plasma membrane ; Cytochemistry ; Electron microscopy ; Human tumors
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Phospholipase activity was localized for the first time by cytochemical staining at the plasma membrane of malginant cells in gastric adenocarcinomas by electron microscopy. This activity was not found in benign cells of the same tumor, e.g., in components of the connective tissue underlying the glandular epithelium, or in cells beyond the margin of the same tumor. Neither benign nor maligant cells of colorectal tumors, nor those in malignant melanoma, had any phospholipase activity that could be demonstrated by the method.
    Materialart: Digitale Medien
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  • 22
    Digitale Medien
    Digitale Medien
    Springer
    Journal of cancer research and clinical oncology 107 (1984), S. 229-232 
    ISSN: 1432-1335
    Schlagwort(e): Prolymphocytic leukemia ; Cytoplasmic inclusions ; X-ray microanalysis ; Chronic lymphocytic leukemia ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A patient with prolymphocytic leukemia is described. The peripheral blood and bone-marrow cells contained nuclear pockets, bridges, and appendices, as well as cytoplasmic inclusions that were not membrane bound or connected with the endoplasmic reticulum. X-ray microanalysis of the cells showed them to contain large amounts of phosphorus, sulfur, chlorine, and calcium, as well as a smaller amount of sodium and magnesium in comparison with control lymphocytes. When compared with lymphocytes of a patient with chronic lymphocytic leukemia (CLL), the patient's cells showed higher amounts of magnesium, sulfur, and chlorine, while the sodium content was decreased. The usefulness of electron microscopy and X-ray microanalysis in the diagnosis of this type of leukemia is discussed.
    Materialart: Digitale Medien
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  • 23
    Digitale Medien
    Digitale Medien
    Springer
    European archives of oto-rhino-laryngology and head & neck 240 (1984), S. 55-61 
    ISSN: 1434-4726
    Schlagwort(e): Inner ear ; Adenylcyclase ; Ouabain-insensitive endothelial ATPase ; Cytochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The cytochemical localization of adenylcyclase in the lateral cochlear wall was studied using a modification of the Reik-Howell method. All the cell membranes of the stria vascularis and spiral prominence cells, except the vascular endothelium, showed a low enzyme activity. In the marginal cell and spiral prominence epithelium facing the endolymph, this activity was limited to the perilymphatic membrane sections. The results are discussed.
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  • 24
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 63 (1984), S. 96-107 
    ISSN: 1432-0533
    Schlagwort(e): Hereditary coproporphyria ; Hereditary hepatic porphyrias ; Sural nerve biopsy ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In spite of several cases reported in the literature, the exact pathogenetic mechanism of neuropathic changes in porphyric neuropathy remains uncertain. Various authors have ascribed the neuropathologic findings to either a dying-back axonal degeneration or segmental demyelination. In recent years, the hypothesis of an axonal and myelinic disorder has received support by the demonstration of a combined and simultaneous involvement of both these structures. Such different opinions are also a consequence of the reduced number of detailed bioptic observations in the different forms of acute porphyria not only during acute phases but also between attacks. In this paper we report the results of light- and electronmicroscopic examination of two sural nerve biopsies from subjects with hereditary coproporphyria. The first was performed 6 months after an acute attack, the second specimen was obtained from a patient without acute attacks, who had clinical and electrophysiologic signs of a chronic progressive neuropathy. In both cases a dying-back axonal degeneration is considered the primary change. The pathogenetic mechanism of peripheral nerve lesions in porphyric neuropathy will be discussed finally.
    Materialart: Digitale Medien
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  • 25
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 62 (1984), S. 225-229 
    ISSN: 1432-0533
    Schlagwort(e): Dandy-Walker syndrome ; Dandy-Walker cyst ; Ependymal cell ; Ultrastructure ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The ultrastructure of the wall of the Dandy-Walker cyst has been described rarely. A boy aged 2 years was confirmed clinically, neuroradiologically, and operatively as having a Dandy-Walker cyst in the posterior fossa. The cyst wall obtained during surgery consisted of an outer arachnoid cell layer, intermediate interwoven neuroglial strands, and an inner layer of cells which lacked the characteristic appearance of ependyma. An unusual finding was a small, buried island of ependymal cells in the intermediate layer of the neuroglial tissue. Ultrastructural study of the cyst wall provides a better understanding of the pathogenesis of the Dandy-Walker syndrome.
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  • 26
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 62 (1984), S. 324-331 
    ISSN: 1432-0533
    Schlagwort(e): Human skeletal muscle ; Hemiplegia ; Cerebral vascular disease ; Histopathology ; Electron microscopy ; Rehabilitation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Anterior tibial muscle biopsies of the hemiplegic side of 16 patients with a cerebrovascular accident in the middle cerebral artery region were analyzed qualitatively and quantitatively by enzyme histochemistry and electron microscopy. Patients grouped according to the time lapsed as from the occurrence of the accident (1–17 months) demonstrated a progressive decrease in the fiber diameter and changes in fiber type distribution with predominant type II atrophy and type I predominance. Nuclear internalization, myopathic alterations, and perifascicular fatty infiltrations were observed constantly. In the affected fibers the ultrastructural findings were myofibrillar alterations with the formation of rods and cytoplasmic bodies. There was accumulation of lipofuscin, glycogen, and lipid droplets. Microvascular changes were observed frequently. Biopsies from the asymptomatic legs were either normal or showed age-related muscle alterations. Correlation was noted between the clinical and functional status of the patients and the morphological aspects seen in muscle biopsies.
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  • 27
    Digitale Medien
    Digitale Medien
    Springer
    Plant and soil 76 (1984), S. 127-137 
    ISSN: 1573-5036
    Schlagwort(e): Adenylate pool ; Biomass volume ; CO2 evolution ; Chitin ; DNA ; Electron microscopy ; Enzymes ; Fluorescent antibody ; Fumigation-respiration ; Fungi Histochemistry ; Imunofluorecence ; Jones-Mollison technique ; Microcosms ; Monoclonal antibodies ; Nitrogen ; Nutrients ; Oxygen consumption ; Phosphorus ; Phytotoxins ; Plate counts ; Rhizobium ; Rhizosphere ; Sulphur ; Xenobiotics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary There is an immense literature on biological and biochemical analyses of soils. Such analyses have revealed the enormous richness of species in soil and their vast range of metabolic potentials and ecological diversity. Accordingly, the approaches used to investigate the soil biota and its biochemistry usually have to be modified or adapted depending upon the purpose of the investigation. Studies of micro-organisms in the soil environment, are complicated because microbial cells are commonly attached to surfaces where they live side-by-side with other populations in consortia usually containing different morphological and physiological types. Such assemblages of organisms cannot be described quantitatively using cultural techniques, such as plate counts, which underestimate both cell numbers and viable biomass. The development of more powerful observational and staining techniques has improved our knowledge of the diverse morphological and biochemical composition of soil micro-communities. Such findings have been amplified at a grosser level by laboratory studies with multi-component systems (microcosms) to mimic field situations and to assess the range of biochemical potentials of microbial consortia. But despite notable advances in analytical methods we are still, with a few exceptions, unable to detect or identify those microorganisms which carry out specific biochemical transformations or determine whether particular cells are alive, dormant or dead at the time of observation. Considerable work has been done to define some of the fundamental ecological attributes of microbial assemblages in soil. Productive work on the metabolic activities of the soil microbiota, specially geochemical transformations of C, N, S and P, has been under way for more than a century. But only in more recent years have more sensitive and reproducible analytical methods become available to measure viable biomass in soil. This will enable some insight to be gained into the role that microbial biomass plays as a labile source and sink for plant nutrients.
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  • 28
    Digitale Medien
    Digitale Medien
    Springer
    Plant and soil 76 (1984), S. 319-337 
    ISSN: 1573-5036
    Schlagwort(e): Aggregates ; Aluminium ; Bacterial mucilage ; Binding agents ; Calcium ; Cation bridges ; Complexing agents ; Dispersion ; Electron microscopy ; Electrophoretic mobility ; Fungal hyphae ; Glues Iron ; Management Periodate ; Polysaccharides ; Rhizosphere ; Roots ; Slaking
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The stability of pores and particles is essential for optimum growth of plants. Two categories of aggregates macro- (〉 250 μm) and micro- (〈250 μm) depend on organic matter for stability against disruptive forces caused by rapid wetting. Dispersion of clay particles from microaggregates is promoted by adsorption of complexing organic acids which increase the negative charge on clays. The acids are produced by plants, bacteria and fungi. However, the dispersibility of clay in microaggregates is offset by the binding action of polysaccharides, mainly mucilages produced by bacteria, but also by plant roots and fungal hyphae. The stability of microaggregates is also enhanced by multivalent cations which act as bridges between organic colloids and clays. Macroaggregates are enmeshed by plant roots, both living and decomposing, and are thus sensitive to management, and increase in number when grasses are grown and the soil is not disturbed. Lack of root growth,i.e. fallow, has the opposite effect. Various implications for management of soil structure are discussed.
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  • 29
    Digitale Medien
    Digitale Medien
    Springer
    Urological research 12 (1984), S. 17-22 
    ISSN: 1434-0879
    Schlagwort(e): Urinary calculi ; Electron microscopy ; X-ray microanalysis ; Artefacts
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Material in urinary calculi is prone to irradiation damage during electron microscopy and this suggests the need for care in the interpretation of data. It is shown, however, that minimum-dose transmission microscopy is feasible for single-crystal electron diffraction work, and that although internal damage in severe, morphological artefacts are unlikely in the SEM unless the incident electron flux is greater than 10-13 A nm-2. During EDX micro-analysis, the detection of light elements is impaired by irradiation effects unless a minimum-dose procedure is used. For the preparation of SEM samples, artefacts can be created by cleaving air-dried material-and it is therefore important to consider more lengthy preparation methods such as cryogenics.
    Materialart: Digitale Medien
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  • 30
    ISSN: 1434-0879
    Schlagwort(e): Concanavalin A ; Lectin receptors ; Bladder tumor ; Electron microscopy ; X-ray microanalysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We used concanavalin A (con A)-peroxidase-iron dextran-diaminobenzidine (DAB) technique for the electron microscopic detection of con A binding sites on cell membranes. Normal bladder mucosa showed a sparse distribution of con A binding sites with both transmission (TEM) and scanning (SEM) electron microscopy, but bladder tumors showed a higher concentration in the distribution of con A binding sites in proportion to the histopathological grade of transitional cell carcinoma. Quantitative estimation of the con A binding sites was attempted using scanning X-ray pulse analysis of iron elements contained in the reaction complexes. Con A binding sites were quantitatively the smallest in normal mucosa, increasing proportionate to the grade of the bladder tumor. Some specimens were compared by the ferritin-labelled method and the pattern of ferritin conjugates distribution was similar to that seen with the con A-peroxidase-iron dextran method.
    Materialart: Digitale Medien
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  • 31
    ISSN: 1434-0879
    Schlagwort(e): Urinary calculi ; Stone ultrastructure ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A study of urinary stones obtained from patients after surgery in the Medical College Hospital, Trivandrum, under the scanning electron microscope showed the presence of calcium oxalate and calcium biphosphate crystals as the main constituents. However, the pattern of the different phases of crystal growth was not uniform. Within the crystal lattice, fibrous structures, possibly of protein matrix, were invariably observed. Electron microscopy may be usefully adapted as a particularly suitable method for ultramicroscopic investigation of the fine structure of urinary stones including single crystal surface structure, section of urinary calculi and for possible presence of hitherto unknown components within the calculus.
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  • 32
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 402 (1984), S. 289-296 
    ISSN: 1432-2307
    Schlagwort(e): Epithelium ; Chorion laeve ; Diabetes mellitus ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The epithelium of human chorion laeve from pregnancies complicated by diabetes mellitus was examined under the light and electron microscopy. In comparison with normal chorion laeve, the epithelium of chorion laeve in diabetes mellitus shows the following morphological changes: 1. The trophoblast cells display more microvilli and cell processes on their surface. 2. Trophoblast cells with different cytoplasmic characteristics can be seen. Some display few organelles and large glycogen depositions; other are rich in organelles. Furthermore, some cells with electron dense filaments and few cell organelles can be found. 3. Necrotic cells are frequently present in the outer epithelial layers. 4. The intercellular spaces in the epithelial layers near the basement membrane are narrower. Since vasculopathy of the decidual arteries with disturbance of blood circulation is often found in pathological pregnancies, we assume that the morphological changes found are due to deficiency in nutrient and oxygen supply.
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  • 33
    ISSN: 1432-0878
    Schlagwort(e): Ovulation (rabbit) ; Graafian follicle ; Perfusion ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Isolated ovaries from untreated, sexually mature rabbits were introduced into an in vitro perfusion system and perfused with a chemically defined medium containing albumin. The ovaries were perfused for up to 15 h (mean 11.5 h) and then processed for morphological investigation. Both at the light- and electron-microscopical levels, most of the ovaries exhibited a normal structure comparable with ovaries in situ. In two cases, however, marked accumulations of bacteria were found, although not inside the follicles. Since ovulation in the rabbit normally occurs between 9.5–13 h after mating or human chorionic gonadotrophin treatment, this model seems adequate for studies of ovulation in vitro. It is, however, important to study the ovaries microscopically after the perfusion to detect artifacts, e.g., bacterial infection, that may have influence on the process of ovulation.
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  • 34
    ISSN: 1432-0878
    Schlagwort(e): Tannic acid ; Acetylcholine receptors ; Tissue culture ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Spinal cord neurons from 9-day chick embryos were maintained in culture for up to 35 days and then fixed in 4% cacodylate-buffered glutaraldehyde containing 2% tannic acid. After about 15 days in culture a small percentage of the synaptic specializations present were characterized by striking electron-dense striations averaging 15 nm in width, oriented perpendicular to the postsynaptic membrane. These structures increased in frequency with time in culture (to a maximum of about 10% of all synapses in the oldest cultures); they were asymmetrical, protruding approximately 8 nm into the synaptic cleft, and more deeply (approximately 15–18 nm), into the postsynaptic cytoplasm. On the basis of earlier work by Sealock (1980) they are interpreted as concentrations of acetylcholine receptors. Similar membrane differentiations were also seen associated with active-zone areas of a few presynaptic membranes, and the possibility that these represent presynaptic acetylcholine receptors is discussed. Additional observations reported are (1) the presence of striations resembling those seen at the postsynaptic membrane in the membranes of some postsynaptic vesicles, and (2) filamentous links between the striations and cytoskeletal elements of the postsynaptic cell.
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  • 35
    ISSN: 1432-0878
    Schlagwort(e): Ovulation ; Perfusion ; Graafian follicle (rabbit) ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Ovulation was induced in rabbits by intravenous administration of human chorionic gonadotrophin (HCG), and 4–5 h later the ovaries were isolated and introduced into an in-vitro perfusion system containing synthetic medium with albumin. Rupture of follicles occurred in vitro within the physiological time range (mean 11.3 h after injection of HCG), although with a reduced frequency. Preovulatory and ruptured follicles were studied in detail by light and electron microscopy. In the granulosa layer of ruptured or preovulatory follicles cytoplasmic blebbing activity, disappearance of CallExner bodies and differentiation toward luteinized cells were found. Perhaps the most important sign of normal preovulatory development in vitro was that the basement membrane surrounding the granulosa layer was penetrated by projections of granulosa cells. In the absence of this penetration phenomenon the granulosa layer prolapsed out of the follicle. Immediately before rupture, follicles showed marked degeneration, restricted to the outer layers of the apical wall, which is compatible with the hypothesis that degradative enzymes are released close to the surface of preovulatory follicles. Although the majority of follicles that ovulated under in-vitro conditions showed the same kind of morphological alterations as can be seen in vivo, occasional atypical ruptures occurred without any overt signs during perfusion. Also technical manipulations of the perfusion system, e.g., nonphysiological increase of perfusion pressure, could force follicles to rupture. This illustrates the importance of careful morphological study of all ovaries perfused in vitro before conclusions are drawn.
    Materialart: Digitale Medien
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  • 36
    Digitale Medien
    Digitale Medien
    Springer
    Protoplasma 119 (1984), S. 48-54 
    ISSN: 1615-6102
    Schlagwort(e): Electron microscopy ; Marine alga ; Membrane contrast ; Osmium-azole complexes ; X-ray microanalysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Addition of certain heterocyclic nitrogen-carbon compounds to standard osmium tetroxide solutions used as secondary fixative resulted in an enhanced general membrane contrast in cells of the marine algaEmiliania huxleyi (Lohmann) Kamptner. Ultrastructural cell morphology and the contrast distribution were compared between cells treated according to a standard secondary fixation procedure and cells post-fixed when above mentioned heterocyclic compounds were introduced; in both cases some of the ultrathin sections were post-stained. Different compounds were tested: 1,2,4-triazole (TRA), 3-amino-1,2,4-triazole (A-TRA), 5-amino-tetrazole (A-TEA) and 2,4,6-tri-amino-1,3,5-triazine (melamine). The results were interpreted to indicate the possible bonding types arising from interaction of the heterocyclic compounds with osmium tetroxide and with membrane constituents. Interpretations were partly inspired by considerations from coordination chemistry. All above tests which did not include post-staining of thin sections could be performed at alkaline pH, and consequently calcified structures were preserved. The enhanced osmium accumulation at membranes was verified with X-ray microanalysis, which also showed that in the cases where membranes were visibly contrasted, localization of probable sites of intracellular non-crystalline calcium was facilitated.
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  • 37
    ISSN: 1432-0878
    Schlagwort(e): Lactating cell ; Lipid droplets ; Secretory vesicles ; Mitochondria ; Intracellular associations ; Electron microscopy ; Milk secretion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The size, cellular location, and identity of surface-associated components were determined for lipid droplets in lactating cells. Transmission electron-microscopic measurements were made involving 3801 droplets in approximately 211 cells from three rats and 1197 droplets in 66 cells from a mouse. For the purposes of droplet evaluation, cells were divided into seven locations ranging from basal to secreting positions. Droplets were also categorized with respect to contact with other droplets, basolateral plasma membrane, mitochondria, Golgi apparatus, secretory vesicles, and endoplasmic reticulum-cytoplasm (ERC). Data on droplet size showed that droplet growth occurs mainly in the secretory position, confirming previously published findings. Lipid droplets from mouse tissue, although somewhat smaller in size showed similar growth trends to those of the rat. Data on numbers of droplet contacts and percentages of droplet circumferences involved in associations with other cell components showed that the dominant interaction of lipid droplets was with the ERC. However, intimate association of droplets with mitochondria was noted in all cellular locations. In addition, nursed animals exhibited a greater proportion of droplet surface association with secretory vesicles and less in contact with mitochondria in comparison to those not nursed. The significance of these relationships to milk synthesis and secretion is discussed.
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  • 38
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 235 (1984), S. 243-249 
    ISSN: 1432-0878
    Schlagwort(e): Gap junction ; Electron microscopy ; Freeze fracture ; Cell-to-cell communication
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Gap junctions exist in the septa between the segments of the lateral giant axons in the ventral nerve cord of the crayfish Procambarus. A large increase in the resistance (uncoupling) of these gap junctions was brought about by mechanical injury to the axonal segments. Both thin sections and freeze-fracture preparations were used to monitor the morphological changes which occurred up to 45 min after injury. There was no apparent change in the organization (a loose polygonal array) of the intramembrane particles which make up the junctional complex up to 45 min after injury. In some instances, however, the intramembrane particles appeared to have moved away from the junctional area. Other junctional regions were internalized and appeared similar to what have been called annular gap junctions. Also at this time (20–25 min after injury), a dense cytoplasmic plug formed in uninjured axon near the junctional region. It is concluded that the gap junctions that exhibit a loose polygonal organization of the intramembrane particles may be either in a state of low resistance (coupled) or a state of high resistance (uncoupled).
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  • 39
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 235 (1984), S. 479-484 
    ISSN: 1432-0878
    Schlagwort(e): Monoamine-containing cells ; Taste bud ; Paracrine cells ; Mechanoreceptors ; Electron microscopy ; Teleosts
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The taste buds on the barbels in three species of teleosts (Cyprinus carpio, Misgurnus anguillicaudatus, Parasilurus asotus) were studied by means of fluorescence and electron microscopy. Intensely yellow-fluorescent cells, which are disk-shaped and located exclusively in a basal position, are observed in the barbel-buds of all fishes examined. The basal cells contain a large number of small clear vesicles approximately 40–60 nm in diameter, which show a tendency to aggregate in the cytoplasm facing the junction of the nerve terminals; chemically transmitting synapses are seen in the latter region. It is suggested from the present observations that the basal cells in the barbel-bud may originate from Schwann cells and have a dual function both as mechanoreceptors and paracrine elements. Since the administration of 5,6-DHT results in an appearance of small dense vesicles among the small clear vesicles, the possibility exists that the basal cell may be capable of taking up monoamines and storing them in the small clear vesicles.
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  • 40
    ISSN: 1432-0878
    Schlagwort(e): Exocrine pancreas ; Calcium pool ; Calcium release ; Electron microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In an attempt to identify a cellular Ca2+-pool, from which calcium is released when secretagogues are applied, tissue fragments of the rat exocrine pancreas were incubated and fixed with glutaraldehyde in the presence of calcium. By means of this procedure electron-dense deposits were found on plasma membranes. X-ray microanalysis showed that these deposits contain calcium. Stimulation of tissue fragments with the use of the secretagogues carbachol or cholecystokinin reduced the number of deposits by about 80%. When the antagonist atropine was applied after carbachol stimulation, deposits reappeared on cell membranes, which then disappeared again after a second stimulation with cholecystokinin. In the presence of procaine, carbachol was inhibited and only slightly reduced the Ca2+-deposits on the plasma membranes. These results suggest that a calcium pool, from which calcium is released to induce enzyme secretion on stimulation, is located in the cell membrane
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  • 41
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 237 (1984), S. 149-154 
    ISSN: 1432-0878
    Schlagwort(e): Pituitary gland, pars distalis ; Innervation ; Synaptoid contacts ; Electron microscopy ; Rana temporaria L
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In the pars distalis of the hypophysis of adult Rana temporaria, three types of nerve-fiber profiles were found at two distinct sites, in both lateral parts of the bordering regions of the anterior lobe with the intermediate lobe of the hypophysis. The first type of nerve-fiber profile consists of bundles of very fine axonal elements (diameter: 〈0.7 μm). The second type is formed by larger nerve fibers (diameter up to 4 μm) containing a few neurosecretory granules of approximately 100 nm. The third type of nervefiber profile resembles the second type but these nerve fibers make synaptoid contacts on at least two different types of glandular cells. The possible functional significance of these nerve fibers in the pars distalis is discussed. No nerve fibers were found (1) in the central part of the bordering region of the pars distalis with the intermediate lobe, (2) at the bordering region with the median eminence and (3) with the neurohypophysial stalk, and (4) in all other parts of the pars distalis.
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  • 42
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 237 (1984), S. 219-226 
    ISSN: 1432-0878
    Schlagwort(e): Spermatogonia ; Spermatocytes ; Carbohydrates ; Guppy ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The structure of guppy (Poecilia reticulata) spermatogonia and spermatocytes has been studied using electron microscopy. The spermatogonia, situated at the apex of the seminiferous tubule, are almost all surrounded by a network of Sertoli cells; they have very diffuse chromatin and one or two large nucleoli. The cytoplasm contains relatively few organelles, although annulate lamellae are found. The mitochondria have few cristae and are concentrated at one pole of the cell; they are sometimes found with intermitochondrial cement. These spermatogonia are separated from each other, having no intercellular bridges or inclusion in Sertoli cells, and are relatively undifferentiated; they correspond to stem cells. The spermatogonia beneath the apex are organized into cysts. First-generation spermatogonia are more dense and heterogeneous, their nuclei becoming smaller and their chromatin becoming denser during successive generations. In spermatocytes, the synaptinemal complex exists as a modified form until metaphase. The concentration of organelles in the cytoplasm increases and the organelles become more diversified as spermatogenesis progresses. Many cytoplasmic bridges are observed (several per cell), indicating that the cells remain in contact after several divisions. These changes in germ cell structure have been related to some of the characteristic features of spermatogenesis in guppy, e.g. the large number of spermatogonial generations and the complexity of spermiogenesis.
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  • 43
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 238 (1984), S. 165-175 
    ISSN: 1432-0878
    Schlagwort(e): Mesonephros ; Pig embryo ; Glomerulus ; Microvasculature ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Vascularization of the pig mesonephros was investigated in embryos 5–8 cm in length. Vascular injections with microfil were cleared and dissected; corrosion casts were studied under the scanning electron microscope (SEM). Perfusion-fixed tissue was used for SEM and transmission electron microscope (TEM) studies, including freeze-fracture specimens. The branches of one mesonephric artery carry up to 15 glomeruli. Several glomeruli occupy the same arterial branch, with very short afferent arterioles proper. The efferent vessels, frequently 2–5, leave the extensive vascular pole opposite the entering arteriole and split into peritubular capillaries radiating towards the superficial veins. These capillaries form vascular regions in the shape of flattened pyramids. Along its course, one nephron is supplied by vessels derived from 4–7 glomeruli. The nephrons have less vascular contact than in the definitive kidney. The ultrastructure of the single mesonephric vessels matches the metanephric counterparts. Epithelioid cells with renin granules are common in afferent arterioles, larger arteries, and efferent vessels. The lobulated glomeruli are up to 750 μm long and flattened, showing the usual features of podocytes, mesangial cells, and an attenuated endothelium with fenestrations between 50 and 250 μm. It partially retains its own basement membrane. There is no proximal mesangium.
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  • 44
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 238 (1984), S. 413-416 
    ISSN: 1432-0878
    Schlagwort(e): Peroxisomes ; DAB-cytochemistry ; Electron microscopy ; Liver, amphibian ; Gymnophiona ; Ichthyophis glutinosus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructure of hepatic peroxisomes was investigated in Ichthyophis glutinosus (Amphibia: Gymnophiona), employing perfusion fixation and the diaminobenzidine (DAB) technique for the visualization of catalase. The majority of peroxisomes is circular or rod-shaped, although elongated particles occasionally occur. They contain a finely granular matrix, lightly stained after the DAB procedure. Their mean diameter is approximately 0.25 μm. Serial sections reveal that the circular and rod-shaped peroxisomal profiles are cross and oblique sections of highly tortuous, tubular organelles exceeding 2 μm in length. In addition to tubular profiles, elongated, rectangular particles, as well as straight dumbbell-shaped organelles with distinct marginal plates are observed. They range from 900 to 1650 nm in length (mean = 1200 nm). In the flattened, thin central portion of the dumbbell-shaped particle, the peroxisomal membranes form a cisterna enclosing one or two uniformly thick marginal plates, which display a definite substructure with a periodicity of 10 nm. These findings indicate that peroxisomes in the liver of Ichthyophis exhibit a complex organization. It is suggested that the organelles undergo a specific differentiation process, morphologically characterized by the formation of enlarged segments of unusual shape.
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  • 45
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 508 (1984), S. 187-190 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Komplexe von Halogeniden der IV. Gruppe mit einzähnigen Schiffschen BasenVerschiedene Komplexe, die bei der Reaktion von N-(phenyl)benzalaldimin und seinen Derivaten mit einer Methylgruppe in verschiedenen Positionen des Anilinringes mit Halogeniden der IV. Gruppe, MX4, (M = Si bzw. Sn und X = Cl bzw. Br) entstehen, wurden hergestellt und mittels UV-, IR- und Raman-Spektren charakterisiert.
    Notizen: Coordination compounds resulting from the interaction of N-(phenyl)benzalaldimine and its derivatives containing a methyl group in different positions of the aniline ring and group(IV) halides, MX4 (where M = Si or Sn and X = Cl or Br), have been prepared and characterized by elemental analyses and electronic, infrared and Raman spectra.
    Zusätzliches Material: 4 Tab.
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  • 46
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 508 (1984), S. 208-208 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
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  • 47
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 509 (1984), S. 38-52 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Contributions to the Chemistry of Phosphorus. 134. On the Triphosphanes H(t-BuP)3H' Li(t-BuP)3Li, and Me3Si(t-BuP)3SiMe3The reaction of 1,3-diiodo-1,2,3-tri-tert-butyltriphosphane, I(t-BuP)3I, with lithium aluminium hydride leads to 1,2,3-tri-tert-butyltriphosphane, H(t-BuP)3H (1). 1 reacts with n-butyllithium to 1,3-dilithium-1,2,3-tri-tert-butyltriphosphide, Li(t-BuP)3Li (2), which reacts further with trimethylchlorosilane yielding 1,3-bis(trimethylsilyl)-1,2,3-tri-tert-butyltriphosphane, Me3Si(t-BuP)3SiMe3 (3). The triphosphanes 1, 2 and 3 could be isolated in a pure state. In solution 1 forms the threo, threo and the threo,erythro configurated diastereomers 1a and 1b in a ratio of about 2:1. 3 predominantly exists in form of the threo,erythro configurated diastereomer 3b by steric reasons.
    Notizen: Die Umsetzung von 1,3-Diiod-1,2,3-tri-tert-butyltriphosphan, I(t-BuP)3I, mit Lithiumaluminiumhydrid führt zu 1,2,3-Tri-tert-butyltriphosphan, H(t-BuP)3H (1). 1 reagiert mit n-Butyllithium zu 1,3-Dilithium-1,2,3-tri-tert-butyltriphosphid, Li(t-BuP)3Li (2), das mit Trimethylchlorsilan weiter zu 1,3-Bis(trimethylsilyl)-1,2,3-tri-tert-butyltriphosphan, Me3Si(t-BuP)3SiMe3 (3), umgesetzt werden kann. Die Triphosphane 1, 2 und 3 konnten in reiner Form isoliert werden. In Lösung bildet 1 die threo, threo- und threo,erythro-konfigurierten Diastereomere 1 a und 1 b im Verhältnis von etwa 2:1. 3 liegt aus sterischen Gründen hauptsächlich in Form des threo, erythro-konfigurierten Diastereomers 3 b vor.
    Zusätzliches Material: 3 Ill.
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  • 48
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 509 (1984), S. 145-152 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Oxidation Products of Intermetallic Compounds. III. Low Temperature Forms of K2Sn2O3 and Rb2Sn2O3 and a Notice about K2Ge2O3By controlled oxidation of KSn (at 320°C) and RbSn (at 410°C) with O2 the hitherto unknown low temperature forms of K2Sn2O3 (a = 8.4100(8) Å) and Rb2Sn2O3 (a = 8.6368(8) Å) are obtained, which are isotopic with cubic K2Pb2O3. Oxidation at higher temperatures (at 510-5207°C) leads to the well-known HT-forms. The Madelung Part of Lattic Energie, MAPLE, is calculated for both compounds.K2Pb2O3, Rb2Pb2O3, Cs2Pb2O3, and Cs2Sn2O3 have been prepared too by oxidation of KPb, RbPb, CsPb, and CsSn.Oxidation of KGe (at 400°C) leads to the first oxogermanate(II), K2Ge2O3 (cubic a = 8.339(1) Å, isotypic with K2Pb2O3) together with K6Ge2O7.
    Notizen: Aus KSn bzw. RbSn entstehen durch direkte Oxydation K2Sn2O3 bzw. Rb2Sn2O3 bei 320°C bzw. 410°C die bislang unbekannten „Tieftemperaturformen“ (a = 8,4100(8)Å bzw. a = 8,6368(8)Å), isotyp mit kubischem K2Pb2O3. Bei höherer Temperatur (510 bzw. 520°C) entstehen die bekannten Hochtemperaturformen.Der Madelunganteil der Gitterenergie, MAPLE, wird berechnet und diskutiert.Ebenso erhält man durch direkte Oxydation von KPb, RbPb, CsPb und CsSn die Oxide K2Pb2O3, Rb2Pb2O3, Cs2Pb2O3 und Cs2Sn2O3. Durch Oxydation von KGe wurde bei 400°C erstmals K2Ge2O3 (kubisch a = 8,339(1) Å; isotyp mit K2Pb2O3) neben K6Ge2O7 erhalten.
    Zusätzliches Material: 1 Ill.
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  • 49
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 509 (1984), S. 174-182 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Die Reaktion des SnCl2 mit Br2 und I2 in schwachen Donor-LösungsmittelnEs wurden die Verbindungen SnCl2Br2(MeCN)2, “Sn3Cl8Br4(THF)6” und “Sn3Cl10Br2(OEt)6” durch Reaktion zwischen SnCl2 und Br2 in Acetonitril (MeCN), Tetrahydrofuran (THF) und Diethylether (OEt2) gewonnen. Die zwei letzten Verbindungen sind feste Lösungen von SnCl4L2 und SnCl2Br2L2 (L = THF, OEt2) jeweils im Verhältnis 1:2 und 2:1. Die Verbindungen wurden mit Hilfe von IR-, Raman- und Mößbauer-Spektroskopie charakterisiert. Es wurde C1-Symmetrie für SnCl2Br2(MeCN)2 und C2v mit den Liganden in trans-Position für SnCl2Br2L2 (L = THF, OEt2) gefunden. Das bisher nicht bekannte Mößbauer-Spektrum des SnBr4(THF)2 wurde gemessen und ebenfalls die Reaktion zwischen SnCl2 und I2 in denselben Lösungsmitteln studiert. Die Bildung des SnCl4L2 (L = MeCN, THF, OEt2) SnI4 und einer kleinen Menge des SnI3Cl wurde beobachtet und Raman-spektroskopisch identifiziert.
    Notizen: The compounds SnCl2Br2(MeCN)2, “Sn3Cl8Br4(THF)6”, and “Sn3Cl10Br2(OEt2)6” were obtained by reaction between SnCl2 and Br2 in acetonitrile (MeCN), tetrahydrofuran (THF) and diethyl ether (OEt2). The two last are solid solutions of SnCl4L2 and SnCl2Br2L2 (L = THF, OEt2) in the proportions 1:2 and 2:1, respectively. The compounds are characterized by IR, Raman, and Mössbauer spectroscopy, a C1 symmetry being found for SnCl2Br2 (MeCN)2 together with a C2v symmetry, with the ligands in trans positions, for SnCl2Br2L2 (L = THF, OEt2). The Mössbauer spectrum of SnBr4(THF)2 was also obtained, which has not previously been reported. The reaction between SnCl2 and I2 has also been studied in the same solvents, and the formation of SnCl4L2 (L = MeCN, THF, OEt2), SnI4, and a small amount of SnI3Cl was observed, which have been identified by Raman spectroscopy.
    Zusätzliches Material: 1 Ill.
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  • 50
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 509 (1984), S. 192-200 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Einige Cobalt(II)-Komplexe von 4,6-Dimethylpyrimidin-2(1H)-on (HL) wurden dargestellt und mittels IR- und Elektronenspektren magnetochemisch und konduktometrisch untersucht. Der Ligand wird über das nicht protonierte N-Ringatom angelagert und in einem Fall auch über das O-Atom der Carbonylgruppe. Die “blauen” Komplexe [CoX2 · 2HL] (X2 = Cl2, CBr, Br2, (NCS)2) und [CoX2 · 2HL] · 2HL (X = Cl, Br) haben eine verzerrte C2v-Anordnung [CoX2N2]; die Thiocyanate sind über die N-Atome an das Metall gebunden. Die „grünen“ Komplexe CoX2 · 2HL (X = Cl(4H2O), Br) besitzen eine quadratisch-pyramidale Anordnung [CoX2N2O]. Die „rosa“ Komplexe CoX2 · 4HL · nH2O (X = ClO4, n = 2, X = BF4, n = 8, CF3CO2, n = 4) und die „cremefarbigen“ CoX2 · 4HL · 6H2O (X = J, ClO4) zeigen oktaedrische Anordnung; nur CF3CO2- ist koordiniert. Die „veilchenfarbenen“ Komplexe CoAcL · 2HL · 2H2O und Co3Ac4L2 · 2HL · 2H2O haben eine mehrkernige Struktur; das Acetation betätigt sich als zweizähniger Ligand.
    Kurzfassung: CoII-Komplexe von 4,6-Dimethylpyrimidin-2(1H)-on
    Notizen: Some cobalt(II) complexes of 4,6-dimethylpyrimidine-2(1H)-one (HL) have been prepared and studied by infrared and electronic spectra and by magneto-chemical and conductometric measurements. The ligand is coordinated through the unprotonated ring-nitrogen atom and in one case also through the carbonylic oxygen atom. The “blue” complexes [CoX2 · 2HL] (X2 = Cl2, ClBr, Br2, (NCS)2) and [CoX2 · 2HL] · 2HL (X = Cl, Br) have a distorted C2v [CoX2N2] coordination; the thiocyanate ion is N-bonded to the metal. The “green” complexes CoX2 · 2HL (X = Cl(4H2O), Br) have a square-pyramidal [CoX2N2O] coordination. The “pink” CoX2 · 4HL · nH2O (X = ClO4, n = 2; X = BF4, n = 8; X = F3Ac, n = 4) and “cream” CoX2 · 4HL · 6 H2O (X = I, ClO4) complexes have an octahedral coordination; only the F3Ac- ion is coordinated. The “cyclamen” CoAcL · 2HL · 2 H2O and Co3Ac4L2 · 2HL · 2H2O complexes have a polynuclear constitution; the Ac- ion behaves as bidentate ligand.
    Zusätzliches Material: 1 Ill.
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  • 51
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 510 (1984), S. 31-36 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Raman Spectroscopic Investigations of Coordination Polymeric Metal TricyanmethanidesThe Raman spectra of 3d-metal tricyanmethanides M{C(CN)3}2 as well as of [Ni{C(CN)3}2py2] are investigated. The observed Raman lines are assigned, characteristic variations of position and intensity of these lines are discussed.
    Notizen: Es werden die Ramanspektren der koordinationspolymeren 3d-Metalltricyanmethanide M{C(CN)3}2 (M = Mn, Fe, Co, Ni, Zn) sowie von [Ni{C(CN)3}2py2] untersucht. Die beobachteten Ramanlinien werden zugeordnet, charakteristische Variationen der Lage und Intensität dieser Linien werden diskutiert.
    Zusätzliches Material: 1 Tab.
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  • 52
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 510 (1984), S. 51-60 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Chemistry and Structural Chemistry of Phosphides and Polyphosphides. 34. Vapor Pressure Measurements in the Europium-Phosphorus SystemThe vapor pressure of the europium phosphides EuP7, α-EuP3, ß-EuP3, EuP2 and Eu3P4 were measured using the Knudsen-Effusion technique. These compounds were vaporized incongruently according to the general reaction a EuPm, (s) = a EuPn, (s) + P4, (g) where a (m - n) = 4. The following enthalpies and entropies of reaction were calculated (δH)kJ · mol-1/δS (J · K-1 mol-1)/ T(K). [δH/δS/T]: EuP7 → ß-EuP3 [191/215/698]; α-EuP3 → EuP2 [212/162/847]; ß-EuP3 → EuP2 [261/212/847]; EuP2 → Eu3P4 [209/144/868]; Eu3P4 → EuP [240/131/1110]. The temperature and pressure ranges over which these phosphides exist were determined from the above values. Standard enthalpies of formation relative to EuP(s) were calculated by combining different reaction enthalpies. The results demonstrate the relatively high stability of ß-EuP3, EuP7 and the instability of EuP2.
    Notizen: Für die Europiumphosphide EuP7, α-EuP3, ß-EuP3, EuP2 und Eu3P4 wurden die Dampfdrucke der inkongruenten Verdampfungsreaktionen a EuPm, (f) = a EuPn, (f) + P4, (g) mit a(m - n) = 4 mit der Knudsen-Methode gemessen. Zur Abspaltung von einem Mol P4,(g) wurden bei den mittleren Temperaturen T(K) die folgenden Reaktionsenthalpien δH(kJ · mol-1) und Reaktionsentropien δS(J · K-1 · mol-1) erhalten: [δH/δS/T]: EuP7 β ß-EuP3 [191/215/698]; α-EuP3 → EuP2 [212/162/847]; ß-EuP3 → EuP2 [261/212/847]; EuP2 → Eu3P4 (209/144/868); Eu3P4 → EuP [240/131/1110]. Hierdurch wurden die Existenzfelder der verschiedenen Europiumphosphide in Abhängigkeit von Druck und Temperatur festgelegt. Durch Kombination der verschiedenen Reaktionsenthalpien werden die Standardbildungsenthalpien der Phosphide relativ zu EuP berechnet. Sie zeigen die hohe Stabilität von ß-EuP3 und EuP7 sowie die Instabilität von EuP2.
    Zusätzliches Material: 5 Ill.
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  • 53
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 508 (1984), S. 86-92 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Synthesis and Crystal Structure of (PPh4)2[Mo2Cl10]The title compound is obtained in the reaction of [MoCl4(Ph—C≡C—Ph)]2 with tetraphenylphosphonium chloride in dichloro methane, forming brown crystals. It is characterized by the i.r. spectrum and a crystal structure analysis by the aid of X-ray diffraction data. The complex crystallizes triclinic in the space group P1 with one formula unit per unit cell. The cell dimensions are a = 1122 pm, b = 1137 pm, c = 1283 pm; α = 63.4°, β = 69.1°, γ = 86.5°. The crystal structure determination (2959 observed, independent reflexions, R = 4.5%) shows the constants of the unit cell to consist of on centrosymmetric anion, two cations and one disordered molecule of dichloro methane. The distance Mo—Mo in the anion is 380 pm, which excludes direct magnetic interaction between the molybdenum atoms.
    Notizen: Die Titelverbindung entsteht in Form brauner Kristalle durch Umsetzung von [MoCl4(Ph—C≡C—Ph)]2 mit Tetraphenylphosphoniumchlorid in Dichlormethan; sie wird durch das IR-Spektrum und durch eine Kristallstrukturbestimmung charakterisiert. Der Komplex kristallisiert triklin in der Raumgruppe P1 mit einer Formeleinheit pro Elementarzelle. Die Zellparameter betragen a = 1122 pm, b = 1137 pm, c = 1283 pm, α = 63,4°, β = 69,1°, γ = 86,5°. Die röntgenographische Kristallstrukturbestimmung (2959 beobachtete, unabhängige Reflexe, R = 4,5%) zeigt, daß die Struktur aus zentrosymmetrischen, dimeren Anionen, isolierten Kationen, und einem fehlgeordneten Molekül Dichlormethan pro Elementarzelle besteht. Der Mo—Mo-Abstand im Anion beträgt 380 pm, was eine direkte magnetische Wechselwirkung zwischen den Mo-Atomen ausschließt.
    Zusätzliches Material: 1 Ill.
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  • 54
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Preparation and Crystal and Molecular Structure of Tris(diethyldithiocarbamato)dimethylphenylphosphinetechnetium (III)The title compound Tc(S2CNEt2)3(Me2PhP) I has been prepared by the reaction of TcCl3(Me2PhP)3 with NaS2CNEt2. The crystal structure of I has been determined by single-crystal X-ray diffraction methods at room temperature. Crystals are rhombic, space group P212121, with a = 8.708(1), b = 12.012(1), c = 29.626(3) Å and Z = 4. The compound consists of discrete I molecules. The technetium atom has a seven-coordinated environment which is best described as a distorted pentagonal bipyramid. The Tc - P distance (2.330(3) Å) is remarkably short compared with other technetium complexes with mono-dentate phosphine ligands.
    Notizen: Die Titelverbindung Tc(S2CNEt2)3(Me2PhP) I wurde durch Reaktion von TcCl3(Me2PhP)3 mit NaS2CNEt2 dargestellt und ihre Kristall- und Molekülstruktur durch Röntgenstrukturanalyse ermittelt. Die Kristalle sind rhombisch, Raumgruppe P212121, mit a = 8,708(1), b = 12,012(1), c = 29,626(3) Å und Z = 4. Die Verbindung besteht aus diskreten monomeren Molekülen. Das Technetiumatom hat siebenfache Koordination, die am besten als geringfügig verzerrte pentagonale Bipyramide beschrieben werden kann. Die Tc - P-Bindungslänge (2,330(3) Å) ist bemerkenswert kurz im Vergleich zu anderen Technetiumkomplexverbindungen mit einzähnigen Phosphanen.
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  • 55
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 510 (1984), S. 152-162 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Thermodynamics and Structure of Molten Mixtures Alkali Halide-Alkaline Earth HalideThermodynamic quantities ai, fi, GE, and SE were calculated on the basis of vapour pressures of molten mixtures of the type alkali halide-alkaline earth halide. Negative deviations from ideality were found in all systems. The influence of cations or anions on the properties of mixtures is discussed. There is a good correlation between GE and the change of polarization energy δEp. Strong ionic interactions were found in molten mixtures, especially in the system RbBr - CaBr2. The existence of stable complex ions in melts could not be shown by Raman spectroscopy.
    Notizen: Aus den Dampfdrücken der geschmolzenen Mischungen vom Typ Alkalimetallhalogenid-Erdalkalimetallhalogenid wurden die thermodynamischen Daten ai, fi, GE sowie Orientierungswerte für SE berechnet. In allen Systemen treten z. T. beträchtliche negative Abweichungen von der Idealität auf. An ausgewählten Beispielen wird der Einfluß der Kationen bzw. Anionen auf die Mischungseigenschaften diskutiert. Für die GE-Werte ergibt sich eine gute Korrelation mit der Änderung der Polarisationsenergie δEp. Ramanspektroskopische Untersuchungen konnten die Existenz stabiler komplexer Ionen nicht belegen, weisen aber besonders bei den Mischungen RbBr - CaBr2 auf starke interionische Wechselwirkungen hin.
    Zusätzliches Material: 7 Ill.
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  • 56
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 510 (1984), S. 189-193 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Die binären und ternären Gleichgewichte im System MoO3 - TeO2 - Al2O3 wurden rötgenographisch untersucht. Bei 750°C in Luft wurden in diesem System die im Abstract angegebenen koexistierenden Bereiche gefunden. Eine Bildung ternärer Verbindungen konnten im untersuchten Temperaturbereich (450 - 750°C) nicht beobachtet werden.
    Notizen: The binary and ternary equilibrium reactions of Al2O3 with TeO2 and MoO3 were studied by X-ray diffraction methods and the following compatibility ranges were determined in the TeO2 - MoO3 - Al2O3 system at 750°C in air: TeO2, Te2MoO7, Al2TeO6; Te2MoO7, MoO3, Al2TeO6; MoO3, Al2(MoO4)3, Al2TeO6; Al2(MoO4)3, Al2O3, Al2TeO6. Ternary compound formation was not observed in the temperature range investigated (450 - 750°C).Phasengleichgewichte im System MoO3 - TeO2 - Al2O3.
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  • 57
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: N.M.R. Spectroscopic Studies of 15N Labelled N-Phosphorylphosphazenes and Imidodiphosphoric Acid Derivatives15N labelled compounds were prepared and investigated by means of 31P- and 15N-NMR spectroscopy. The chemical shift values δP and δN, and the coupling constants 1JPN and 2JPP are discussed and interpreted qualitatively by semiempirical quantumchemical calculations (CNDO/2) using POPLE'S ΔE-model.
    Notizen: 15N-markierte Verbindungen der Substitutionsreihen wurden synthetisiert und mit Hilfe der 31P- und 15N-NMR-Spektroskopie untersucht. Die chemischen Verschiebungen δP und δN sowie die Kopplungskonstanten 1JPN und 2JPP werden diskutiert und qualitativ mit Hilfe halbempirischer quantenchemischer Rechnungen (CNDO/2) im Rahmen des POPLE-schen ΔE-Modells interpretiert.
    Zusätzliches Material: 5 Ill.
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  • 58
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Reaction of the Two-component System Triethylphosphite/Carbon Tetrachloride with Nucleophiles Containing Hydrogen. 1. Reaction with Acyl AmidesAcyl amides react with the two-component system triethylphosphite/carbon tetrachloride yielding N-acyl phosphazenes, (EtO)3P=N—Ac. In this way (EtO)3P=N—P(O)(OEt)2, (EtO)3P=N—CN, (EtO)3P=N—C(O)Ph, and (EtO)3P=N—SO2Ph were prepared. Ethyl esters of phosphoric acid and trichloromethane phosphonic acid were obtained as by-products.
    Notizen: Säureamide reagieren mit dem Zweikomponentensystem Triethylphosphat/Tetrachlorkohlenstoff zu N-Acylphosphazenen, (EtO)3P=N—Ac. Auf diese Weise wurden aus entsprechenden Amiden (EtO)3P=N—P(O)(OEt)2, (EtO)3P=N—CN, (EtO)3P=N—C(O)Ph und (EtO)3P=N—SO2Ph dargestellt. Als Nebenprodukte werden Phosphorsäureethylester und Trichlormethanphosphonsäureester erhalten.
    Zusätzliches Material: 2 Tab.
    Materialart: Digitale Medien
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  • 59
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Discrete Polynuclear Metal Complexes from Polysulfide Solutions: [Cu6S17]2-, a Novel Binary Polynuclear CuI Complex with Several Remarkable Structural FeaturesThe complex [Cu6S17]2-, obtained from Cu(acac)2 and an ethanolic polysulfide solution, contains an unusual arrangement of the metal atoms and novel types of ligand coordination, particularly of polysulfido (S42- and S52-) ions. The relevance of the synthesis with respect to the “dilemma of transporting metals together with sulfur” for the process of metal sulfide rock formation is evidenced. (PPh4)2[Cu6S17] crystallizes in the space group C2/c with Z = 4 (for further details see Inhaltsübersicht).
    Notizen: Der Komplex [Cu6S17]2-, der als Tetraphenylphosphonium-Salz (1) aus Cu(acac)2 und einer ethanolischen Polysulfidlösung erhalten wurde, zeigt eine ungewöhnliche Anordnung der Metall-Atome und eine neuartige Koordination von Polysulfidoliganden (S42- und S52-). Auf die Relevanz der Synthese bezüglich der Problematik der Entstehung von Metall-Sulfid-Mineralien wird hingewiesen. 1 kristallisiert monoklin in der Raumgruppe C2/c mit Z = 4 (Gitterdimensionen a = 20,270(7), b = 11,605(5), c = 26,331(9) Å, β = 109,68(4)°).
    Zusätzliches Material: 1 Ill.
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  • 60
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 511 (1984), S. 108-131 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Formation of Organosilicon Compounds. 97. About the Influence of the Si-Substituents (Me, Cl) upon the Formation and the Reactions of Ylides1,3-disilapropanes with different grade of chlorination or methylation at the silicon atoms and containing a CCl2 group cleave the Si—P bond of Me3SiPMe2. By subsequent rearrangement ylides with = PMe2Cl group are formed. The reactivity of the CCl2 group depends on the grade of Si-chlorination resp. Si-methylation. Si-methylation decreases the reactivity of the CCl2 group. The reaction of 1,3-disilapropanes and Me3SiPMe2 (molar ratio 1:1) runs in a sequence shown in “Inhaltsübersicht”. Ylid C is able either to react with the initial compound A forming B, or in competition decomposes forming D. Reacting Si-perchlorinated carbosilanes, the decomposition forming D is not to be observed. In Si-methylated ylides like (Me3Si)2C=PMe2—PMe2 and (Me3Si)2C=PMe2—P(Me)SiMe3 the ylid carbon atom is able to abstract a proton of the P—CH3 group resp. P—H groups of the trivalent phosphorus forming (Me3Si)2C(H)PMe2. The rearrangement is proved by deuterated derivatives. The different behaviour is due to the increased basicity of the ylid-C atom in Si-methylated phosphorus ylides. Quite the same behaviour show the phosphorus ylides of 1,3,5-trisilacyclohexane.
    Notizen: Die am Si-Atom unterschiedlich chlorierten und methylierten 1,3-Disilapropane mit der CCl2-Gruppe ermöglichen die Spaltung von Me3Si—PMe2 unter Bildung der P-halogenierten Phosphorylide, wobei mit steigendem Methylierungsgrad die Reaktivität abnimmt. Die Umsetzungen verlaufen in folgender Reaktionsfolge: Das Ylid C kann mit der nicht umgesetzten Ausgangsverbindung A zu B zurückreagieren oder es zersetzt sich in einer Konkurrenzreaktion zu D. Bei Si-chlorierten Yliden wird die Bildung von D nicht beobachtet. In Si-methylierten Yliden wie (Me3Si)2C=PMe2—PMe2 und (Me3Si)2C=PMe2—P(Me)SiMe3 vermag das Ylid-C-Atom ein H-Atom aus der P—CH3-Gruppe oder der PH-Gruppe des dreibindigen Phosphors zu abstrahieren unter Bildung von (Me3Si)2C(H)PMe2. Die Umlagerung wird anhand deuterierter Derivate belegt. Das unterschiedliche Verhalten wird auf die erhöhte Basizität des Ylid-C-Atoms in den Si-methylierten Phosphoryliden zurückgeführt. Ganz entsprechend verhalten sich die Phosphorylide 1,3,5-Trisilacyclohexans.
    Zusätzliches Material: 2 Tab.
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  • 61
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 511 (1984), S. 176-184 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Polymorphism of SrTa2O6Orthorhombic SrTa2O6 is a new low temperature modification related to orthorhombic CaTa2O6. SrTa2O6(orh.) was obtained when the wellknown modification SrTa2O6(TTB) which is related to the tetragonal tungsten bronzes was heated in the presence of a transporting agent (chlorine) or a mineralizer (melt of B2O3) at temperatures below 1150°C. It could be prepared by the reaction of a 1:1 mixture of Sr(NO3)2 or SrCO3 with Ta2O5 in a sealed quartz glass tube as well. SrTa2O6(orh.) also occurred as an intermediate phase of the reaction of the corresponding 1:2 mixture at temperatures below 900°C (e. g. 840°C). Indexing of Guinier powder patterns led to the following unit cell: a = 11.006 Å, b = 7.638 Å, c = 5.622 Å. At temperatures above 1220°C SrTa2O6(orh.) changes (in air) to SrTa2O6(TTB). A reversal of this transition could not be achieved without the presence of a mineralizer or a transporting agent. CaxSr1-xTa2O6 solid solutions of the low temperature form could not definitely be established. However, at 1300°C solid TTB solutions of CaxSr1-xTa2O6 were formed. For x 〉 0.05 the TTB unit cells are orthorhombically distorted. For x ≥ 0.85 the x-ray powder patterns of the solid solutions looked like the one of CaTa2O6(orh.) and no TTB-structure was observed at 1300°C.
    Notizen: Von SrTa2O6 wurde eine neue, mit orthorhombischem CaTa2O6 strukturverwandte Tieftemperatur-Modifikation erhalten. SrTa2O6(orh.) ließ sich bei Temperaturen unter 1150°C sowohl aus der bisher bekannten, den tetragonalen Wolframbronzen verwandten Modifikation SrTa2O6(TWB) in Gegenwart eines Transportmittels (Chlor) bzw. eines Mineralisators (B2O3-Schmelze), wie auch durch Umsetzen von Gemengen (1:1) aus SrCO3 oder Sr(NO3)2 und Ta2O5 in geschlossenen Quarzglasampullen erhalten. Auch als Zwischenprodukt der Umsetzung entsprechender 1:2-Gemenge bei Temperaturen unter 900°C (z. B. 840°C) tritt diese Modifikation auf. Die Gitterkonstanten von SrTa2O6(orh.) sind aufgrund von Pulverdaten: a = 11,006 Å, b = 7,638 Å, c = 5,622 Å. Beim Erhitzen auf etwa 1 220°C (an der Luft) wandelt sich SrTa2O6(orh.) in SrTa2O6(TWB) um. Eine Rückumwandlung von SrTa2O6(TWB) in SrTa2O6(orh.) ohne Mineralisator- oder Transportmittelzusatz war nicht zu erreichen. Mischkristalle CaxSr1-xTa2O6 der Tieftemperaturform ließen sich nicht sicher nachweisen. Die bei Mischkristallen mit 0,05 〈 x ≤ 0,20 (1300°C) vorliegende TWB-Struktur ist orthorhombisch verzerrt. CaTa2O6(orh.) zeigte dagegen ab x ≥ 0,85 (1300°C) keine Entmischung.
    Zusätzliches Material: 1 Ill.
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  • 62
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 509 (1984), S. 167-173 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Preparation, Isolation, and Characterization of Mixed Thiocyanato(1.3-diaminopropane) -chromium(III) ComplexesThe complexes [Cr(NCS)4dap]- and trans-[Cr(NCS)2(dap)2]+ (dap = 1.3-diaminopropane) are prepared for the first time, isolated as salts and characterized by CHN analysis, chromium contents, the electrophoretic behaviour in dimethylformamide, and by UV, VIS, and IR spectra.
    Notizen: Die Komplexe [Cr(NCS)4dap]- und trans-[Cr(NCS)2(dap)2]+ (dap = 1,3-Diaminopropan) werden erstmals dargestellt, als Salze isoliert und durch CHN-Analyse, Chrombestimmung, elektrophoretisches Verhalten in Dimethylformamid sowie Spektren im UV, VIS und IR charakterisiert.
    Zusätzliches Material: 5 Ill.
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  • 63
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 509 (1984), S. 201-208 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Schwefel-Stickstoff-Chelatbildner. IV. Einige Kupfer(II)-Komplexe von Thioaminopyridinen. IR- und ReflexionsspektroskopieEine Reihe von CuII-Komplexen sind dargestellt und charakterisiert worden. Die angenommenen Strukturen beruhen auf ihren IR -und VIS-Spektren. Die Thioaminopyridine können in verschiedener Weise koordiniert sein. Im Gegensatz zu unseren Befunden an aliphatischen Thioaminen ergab sich kein Zusammenhang zwischen der Struktur der CuLX2-Verbindungen und der Art des X--Anions. Ein Hinweis auf die Struktur der CuL2+-Komplexe in wäßriger Lösung kann aus festem CuLX2 nicht erhalten werden.
    Notizen: A series of solid state CuII complexes with thia-aminopyridines . S(CH2)mNH2 have been prepared and characterized. The postulated structures of these CuLX2 (X = OAc-, NO3-, ClO4- or Cl-) compounds were based on their I.R. and electronic spectra. It was found that the thiaaminopyridines may coordinate in quite different ways. In contrast with what was found for the aliphatic thiadiamines, no relation was stated between the structure of the CuLX2 compounds and the nature of the X- anion.Moreover the solid state compounds do not give a clear indication for the structure of the CuL2+ species in aqueous solution.
    Zusätzliches Material: 1 Ill.
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  • 64
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 510 (1984), S. 199-207 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Thermochemische Eigenschaften und Aufwachsen von Hg1-xCdxTe auf CdTeNach thermodynamischen Rechnungen enthält die Gasphase des epitaktischen Hg1-xCdxTe - HgI2 - CdTe Systems vorwiegend Hg(g) und HgI2(g) durch die andere Moleküle vom Ausgangsstoff zum CdTe Substrat wandern. Transportversuche im Temperaturgradienten 590° → 535°C zeigten, daß man dünne Schichten von Hg1-xCdxTe auf CdTe von einem ternären Ausgangsmaterial in Gegenwart von HgI2 erhält.
    Notizen: Based on a thermodynamic analysis, the vapor phase of the Hg1-xCdxTe - HgI2 - CdTe epitaxy system consists predominantly of Hg(g) and HgI2(g) through which nutrient species migrate from the source to the CdTe substrate. Growth experiments in the 590° → 535°C temperature gradient showed that Hg1-xCdxTe layers can be grown on CdTe substrates using a preannealed, ternary source material in the presence of HgI2.
    Zusätzliches Material: 3 Ill.
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  • 65
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Chemical Transport Reactions of Ni-Sulfides and Some Relationships in C.T.R. of Complex Solids in the Case of Sulfides of Fe, Co, NiCrystals of α-Ni3S2, NiS, and NiS2 as well as solid solutions Fe1-yNiySx were grown by C.T.R. The coexistence equilibrium pressure of the solution equilibrium pressure p(S2), the activity of the metal component, the stability of gaseous metal halides concerning decomposition as well as their stability related on the transport agent have to be taken into account to choose a suitable transport agent, which have a sometimes opposite influence on the transport behaviour. Halogenes, hydrogen halides, and GeI2 were used as transport medium.
    Notizen: Durch chemische Transportreaktionen wurden Kristalle der Phasen α-Ni3S2, NiS und NiS2 sowie Mischkristalle Fe1-yNiySx erhalten. Bei der Auswahl des Transportmittels sind der Koexistenzzersetzungsdruck bzw. Löslichkeitsdruck p(S2) und die Metallaktivität im Bodenkörper, die Stabilität der gasförmigen Metallhalogenide bezüglich Zerfall und ihre Stabilität relativ zum Transportmittel zu beachten, die z. T. gegenläufigen Einfluß haben. Geeignete Transportmittel sind Halogene, Halogenwasserstoffe und GeI2.
    Zusätzliches Material: 7 Ill.
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  • 66
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 511 (1984), S. 57-71 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Chemical Transport of Zinc Oxide and the Estimation of its Phase WidthThe chemical transport behaviour of zinc oxide using different transport agents and the influence of the transport conditions (T, ΔT, p) on transport rate and deposition form was studied. The range of homogeneity of ZnO is very narrow. The best agents for deposition of ZnO with the upper phase boundary are Cl2 and Br2, for the deposition of the lower phase boundary HBr and NH4Br are more suitable. The deviation from stoichiometry depends on the deposition temperature and amounts to 10 till 250 ppm in the range of 1073 up to 1373 K.
    Notizen: Das chemische Transportverhalten von Zinkoxid mit Cl2, Br2, HCl, HBr, NH4Cl und NH4Br und der Einfluß der Transportbedingungen (T, ΔT, p) auf die Abscheidungsgeschwindigkeit und Abscheidungsform wurde studiert. ZnO weist ein sehr schmales Homogenitätsgebiet auf. Zur Abscheidung von ZnO der oberen Phasengrenzzusammensetzung sind Cl2 und Br2 am besten geeignet. Für die Abscheidung von ZnO der unteren Phasengrenzzusammensetzung sind am besten HBr und NH4Br geeignet. Die Abweichung von der Stöchiometrie hängt von der Präparationstemperatur der Kristalle ab und liegt zwischen 10 und 250 ppm im Temperaturbereich 1073 bis 1373 K.
    Zusätzliches Material: 14 Ill.
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  • 67
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 511 (1984), S. 89-94 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Contributions to the Chemistry of Transition Metal Alkyl Compounds. XXXVIII. Reactions of Dibenzyl Manganese with Oxygene(C6H5CH2)2Mn · C4H8O2 reacts with oxygen forming an unstable deep violet compound which changes in a stable unsoluble yellow peroxide of the formula C6H5CH2MnO—OMnCH2C6 H5. With excess oxygen a polynuclear complex of 3 valent manganese is formed with the composition Mn4O4(OH)4(OCHC6H5)2.The compounds isolated were characterized by the products of hydrolyses and thermolyses, anaerobic reaction with iodine, magnetic moments, i.r. and e.s.r. spectra.
    Notizen: Dibenzylmangan-1,4-dioxan reagiert mit Sauerstoff zu einer tiefvioletten instabilen Substanz. Diese wandelt sich in ein stabiles gelbes, schwerlösliches Peroxid der Formel C6H5CH2MnO—OMnCH2C6H5 um. Mit überschüssigem Sauerstoff entsteht daraus ein Mehrkernkomplex des 3wertigen Mangans der Zusammensetzung Mn4O4(OH)4(OCHC6H5)2.Die isolierten Verbindungen wurden durch ihre Hydrolyse- und Thermolyseprodukte, anaerobe Iodierung, magnetischen Momente sowie IR- und ESR-Spektren näher charakterisiert.
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  • 68
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 508 (1984) 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 69
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 508 (1984), S. 19-25 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Preparation and Structure of Antimony (III) Tris (thiophosphinates)The title compounds are formed by the reaction of Sb(CH3COO)3 with thiophosphinic acids R2P(=S)OH (R = CH3 cyclo-C6H11, C6H5). The crystal and molecular structures of Sb((cyclo-C6H11)2POS)3 and Sb((C6H5)2POS)3 have been determined by single crystal X-ray methods. SbIII is pyramidally coordinated to the oxygen atoms of the R2POS ligands through short (primary) bonds with a mean length of 203 pm. The Sb—S distances of the mainly chelating ligands vary between 300 and 320 pm (secondary bonds). The lone electron pair is stereochemically active.
    Notizen: Die Umsetzung von Sb(CH3COO)3 mit Thiophosphinsäuren R2P(=S)OH (R = CH3, cyclo-C6H11, C6H5) führt zu Verbindungen der Formel Sb(R2POS)3. Die Strukturen der Verbindungen mit R = cyclo-C6H11 und C6H5 wurden an Einkristallen röntgenographisch bestimmt. SbIII ist über kurze (primäre) Bindungen mit der mittleren Länge von 203 pm pyramidal an die Sauerstoffatome der R2POS-Liganden gebunden. Die Sb—S-Abstände (sekundäre Bindungen) sind ungefähr 320 pm lang. Das freie Elektronenpaar ist stereochemisch aktiv.
    Zusätzliches Material: 2 Ill.
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  • 70
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 508 (1984), S. 43-49 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: I.R. and Mass Spectroscopic Investigations on α,ω-Dihydrochloro Silanes H(SiCl2)nH with n = 3-7Mass spectra of α,ω-dihydrochlorosilanes H(SiCl2)nH were analyzed respecting to their fragmentation. This shows, that the cleavage starts with the break of SiSi bonds, by preference in the middle of the chain. This is in accordance to the results of IR spectra which show very similar frequencies like perchlorooligo silanes. Thus, the lowest force constants of SiSi bondings in α,ω-dihydrochloro silanes, can be also expected in the middle of the chain.
    Notizen: Die Massenspektren der α,ω-Dihydrochlorsilane H(SiCl2)nH mit n = 3-7 werden bezüglich ihrer Fragmentierung analysiert. Es zeigt sich, daß die Spaltung mit einem Zerbrechen der SiSi-Bindung, vorzugsweise in der Mitte der Kette beginnt. Dies steht im Einklang mit den Ergebnissen der IR-Spektren, die sehr ähnliche Frequenzen zeigen, wie bei den Perchlorsilanen gefunden. Daraus kann geschlossen werden, daß auch bei den α,ω-Dihydrochlorsilanen die mittleren SiSi-Bindungen die kleinsten Kraftkonstanten zeigen.
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  • 71
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Phase Determinations by X-rays on the Thermal Dissociation and the Hydrolysis of Alkali Hexafluorogermanates at Higher TemperaturesFor a better understanding of the thermal dissociation of alcaline hexafluorosilicates investigations have been done on hexafluorogermanates. In these systems the formation of new phases has been studied by x-rays in dependence of temperature. Thermal behaviour of the substances strongly depends on the starting structure. Phase transformations taking place at lower temperatures are strongly determine the reaction at higher temperature. Therefore, we found differences to the analogous thermal reactions of hexafluorosilicates.There is a high sensitivity to hydrolysis of hexafluorogermanates above 600°C. We discuss the difference in reaction of thin powder layers and of powder samples in the volume.
    Notizen: Zum besseren Verständnis des thermischen Verhaltens von Alkalihexafluorosilicaten wurden Vergleiche mit analogen Germanium-Verbindungen angestellt. Die Phasenneubildung wurde als Funktion der Temperatur röntgenographisch untersucht. Es ergab sich eine starke Abhängigkeit des thermischen Verhaltens von der Ausgangsstruktur. Phasentransformationen, die bei niederen Temperaturen ablaufen, beeinflussen bei höherer Temperatur das Reaktionsgeschehen (thermische Vorgeschichte der Substanz). Deshalb resultieren gegenüber den Hexafluorosilicaten differierende Reaktionsabläufe. Durch Heizguinieraufnahmen unter getrocknetem, strömendem Inertgas wurde die enorme Hydrolysenempfindlichkeit der Hexafluorogermanate oberhalb 600°C bewiesen.Das unterschiedliche Verhalten von dünnen Pulverschichten und kompakten Pulverproben wird diskutiert.
    Zusätzliches Material: 1 Ill.
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  • 72
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Formation of Organosilicon Compounds. 99. Separation of Carbosilane and Silylphosphane Mixtures by Means of HPLCTest mixtures of Si-methylated carbosilanes were separated by means of reversedphase HPLC (nucleosil 5-C18; CH3OH:hexane = 90:10). The corresponding SiCl-containing mixtures were successfully separated only after reductin of the SiCl groups by means of LiAlH4 (CH3OH: C6H6 + H2O = 92.5:7.5 + 4 - 8%). A model separation of the silylphosphanes Me3SiPH2, (Me3Si)2PH and (Me3Si)3P using the same material but acetonitrile: toluene = 85:15 is also reported.
    Notizen: Testgemische Si-methylierter Carbosilane werden mit reversed-phase HPLC getrennt (Nucleosil 5-C18; CH3OH:Hexan = 90:10). Die Auftrennung entsprechender SiCl-haltiger Verbindungen gelingt nach Reduktion der SiCl-Gruppen mit LiAlH4 (CH3OH: C6H6 + H2O = 92,5: 7,5 + 4 - 8%). Über die Modelltrennung der Silylphosphane Me3SiPH2, ((Me3Si)2)2PH und (Me3Si)3P unter Verwendung des gleichen Säulenmaterials, jedoch mit dem Eluens Acetonitril: Toluol = 85:15, wird ebenfalls berichtet.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
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  • 73
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 512 (1984), S. 177-180 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Reactivity of Intramolecular Basestabilized Tin(II) Compounds with Halogens, Tin Tetrachloride, and TrichloromethaneIntramolecular basestabilized tin(II) compounds of the type RN(CH2CH2Y)2Sn (Y = O, S and R = Me, t-Bu) react with halogens, tin tetrachloride, and trichloromethan at room temperature by oxydative addition reaction to tin(IV) derivatives. These compounds are characterized by n.m.r. investigations and by Mössbauer studies.
    Notizen: Intramolekular basenstabilisierte Zinn(II)-Verbindungen des Typs RN(CH2CH2Y)2Sn (Y = O, S und R = Me, t-Bu) reagieren bei Raumtemperatur mit Halogenen, Zinntetrachlorid und Chloroform im Sinne von oxydativen Additionsreaktionen zu Zinn(IV)-Derivaten. Diese Derivate werden durch NMR-Untersuchungen und durch Mößbauerstudien charakterisiert.
    Zusätzliches Material: 3 Tab.
    Materialart: Digitale Medien
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  • 74
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 512 (1984), S. 231-239 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: On Chalcogenolates. 137. Alkyl Esters of Isothiocyanoformic, Isothiocyanomonothioformic and Isothiocyanodithioformic AcidsThe esters RO—CO—NCS, where R = CH3, C2H5, as well as RS—CO—NCS and RS—CS—NCS with R = C2H5, nC3H7 have been prepared by three different methods. The reaction between the corresponding chloro compound and KSCN in the presence of the phase transfer catalyst 18-crown-6 gives the highest yields.The electron absorption, infrared, nuclear magnetic resonance, and mass spectra of these compounds are reported.
    Notizen: Die Ester RO—CO—NCS mit R = CH3, C2H5 sowie RS—CO—NCS und RS—CS—NCS mit R = C2H5, nC3H7 wurden nach drei verschiedenen Verfahren hergestellt, wobei die Umsetzung der entsprechenden Chloroverbindung mit KSCN in Gegenwart des Phasentransferkatalysators 18-Krone-6 die besten Ausbeuten erbringt.Die Elektronenabsorptions-, Infrarot-, kernmagnetische Resonanz- und Massenspektren der Verbindungen werden mitgeteilt.
    Zusätzliches Material: 8 Tab.
    Materialart: Digitale Medien
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  • 75
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 508 (1984), S. 191-196 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Coordination and Extraction of Molybdenum(VI) with Bidentate LigandsA series of bidentate ligands as well as their thio derivatives from the groups of 8-quinolinols, β-diketones, acylpyrazolones, and N-acyl-phenylhydroxylamines was studied for the ability to extract molybdenum(VI) from heptamolybdate. The extraction principally runs only in acidic medium, sulfur-containing extractants having no advantage. The composition of the complexes was determined by the isolation of compounds in the solid state and also by the interpretation of distribution data.
    Notizen: Eine Reihe zweizähniger Liganden sowie entsprechende Thioderivate aus den Gruppen der 8-Hydroxychinoline, β-Diketone, Acylpyrazolone und N-Acyl-phenylhydroxylamine wurde auf ihr Extraktionsvermögen für Molybdän aus Heptamolybdat geprüft. Die Extraktion ist grundsätzlich nur im sauren Bereich möglich, schwefelhaltige Extraktionsmittel bringen keine Vorteile. Die Komplexzusammensetzung wurde durch Isolierung von Komplexen in Substanz und durch Auswertung der Verteilungsdaten ermittelt.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
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  • 76
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 508 (1984), S. 201-207 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Contributions to the Chemistry of Silicon-Sulphur Compounds. XXIX. 29Si-N.M.R. InvestigationsThree series of silicon-sulphur compounds (RO)3SiSR′ (I), (i-PrO)4-nSi(SEt)n (II) and cyclic Si—S compounds (III) were prepared, some of them at the first time and their 29Si-N.M.R. spectra were measured. In the series of trialkoxysilylthio derivatives (I) were the steric and inductive effects of the RO and R'S groups evaluated. In the series II were the 29Si-N.M.R. chemical shifts related to the relative paramagnetic screening constants σ* and netto charge at the silicon atom q(Si) using the EN-quantum-chemical model discussed. In the series III were the shift contribution of the (SiS)2 and 1-sila-2,5-dithiacyclopentan rings determined.
    Notizen: Drei Reihen von Silicium-Schwefel-Verbindungen: (RO)3SiSR'(I), (i-PrO)4-nSi(SEt)n (II) und cyclische Si—S-Verbindungen (III) wurden dargestellt, davon einige erstmalig, und ihre 29Si-NMR-Spektren vermessen. In der Reihe der Trialkoxysilylthio-Derivate (I) wurden die sterischen und induktiven Wirkungen der RO- und R'S-Gruppen abgeschätzt. In der Reihe II wurden die 29Si-NMR-chemischen Verschiebungen in Abhängigkeit von den relativen paramagnetischen Abschirmungskonstanten σ* und der Nettoladung am Silicium q(Si) im Rahmen des EN-quantenchemischen Modells diskutiert. In der Reihe III wurden die Beiträge des (SiS)2-und 1-sila-2,5-dithia-cyclopentan-Rings zur chemischen Verschiebung ermittelt.
    Zusätzliches Material: 3 Ill.
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  • 77
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 509 (1984), S. 61-66 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: On Chalcogenolates. 134. Studies on Esters of Haloformic Acids 2. Synthesis and Properties of Se-Alkyl Esters of Chloromonothiomonoselenoformic AcidThe hitherto unknown esters RSe—CS—Cl with R = C2H5 and nC3H7 have been prepared by reaction of thiophosgene with the corresponding alkane selenol. The compounds have been characterized with electron absorption, nuclear magnetic resonance (1H, 13C, and 77Se), infrared, and mass spectra.
    Notizen: Die bisher nicht bekannten Ester RSe—CS—Cl mit R = C2H5 und nC3H7 wurden durch Umsetzung von Thiophosgen mit dem entsprechenden Alkanselenol hergestellt. Die Verbindungen wurden mit Elektronenabsorptions-, 1H-, 13C- und 77Se-NMR-, Infrarot- und Massenspektren charakterisiert.
    Zusätzliches Material: 5 Tab.
    Materialart: Digitale Medien
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  • 78
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 509 (1984), S. 95-100 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Contributions to the Chemistry of Silicon and Germanium. XXXIV. A Further Contribution to the Preparation of Potassium SilylThe reaction time for the preparation of potassium silyl from monosilane in glyme is abridged considerably by the use of dispersed Na/K alloy. The preparation is simplyfied by the use of pure dispersed potassium instead of the dispersed alloy. In this case a further abridgement of the reaction time is observed and the filtration of the residue after the end of the reaction is easier because there is no sodium in the residue. Crystalline potassium silyl, free of potassium hydride and glyme, is obtained by recrystallisation followed by slow crystallisation from a glyme/benzene mixture. During a storage of 30 month the crystals turned out to be stable.
    Notizen: Die Reaktionszeit für die Darstellung von Kaliumsilyl aus Monosilan in Monoglyme verkürzt sich bei Verwendung von dispergierter Na/K-Legierung erheblich. Die Darstellung vereinfacht sich, wenn statt der dispergierten Na/K-Legierung reines dispergiertes Kalium eingesetzt wird. Hierbei wird eine weitere Verkürzung der Reaktionszeit festgestellt, und die Filtration des Rückstandes nach Ende der Reaktion ist durch das Fehlen des Natriums einfacher. Kaliumsilylkristalle, in denen weder Kaliumhydrid noch Monoglyme nachweisbar sind, werden durch Umkristallisieren und nachfolgende langsame Kristallisation aus einem Monoglyme/Benzol-Gemisch erhalten. Die Kristalle erwiesen sich bei einer 30monatigen Lagerung als stabil.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
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  • 79
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 509 (1984), S. 127-137 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: On Oxothorates of the Alkaline Metals: K3NaTh2O6For a first time single crystals of a (in addition: new) oxothorate were prepared starting with the binary oxides [1 200°C, 4d, then 1 300°C, 5d, Ni-bomb; powder: 650°C, 10d, Ag-bomb]. The colourless, transparent single crystals are monoclinic, C2/c, a = 629.64 pm, b = 1 089.93 pm, c = 1 259.75 pm, β = 99.66°, z = 4, Dx = 5.458 g cm-3 and Dpyc = 5.456 gcm-3. It is an ordered variant of the NaCl-type; MoKα, fourcircle diffractometer data (PW 1100), R = 7.67 and Rw = 7.35% for 1 083 of 1 236 I0 (hkl). The Madelung Part of Lattice Energy, MAPLE, is calculated and discussed.
    Notizen: Erstmals wurden Einkristalle eines zudem neuen Oxothorates, K3NaTh2O6, aus den binären Komponenten dargestellt [1 200°C, 4d, dann 1 300°C, 5d, Ni-Bömbchen; Pulver analog: 650°C, 10d, Ag-Bömbchen]. Die farblosen, durchsichtigen Einkristalle kristallisieren monoklin, C2/c, a = 629,64 pm, b = 1 089,93 pm, c = 1 259,75 pm, β = 99,66°, Z = 4, drö = 5,458 g cm-3 und dpyk = 5,456 g cm-3. Es liegt eine geordnete NaCl-Variante vor; MoKα, Vierkreisdiffraktometerdaten (PW 1100), R = 7,67 und Rw = 7,35% für 1 083 von 1 236 I0(hkl). Der Madelunganteil der Gitterenergie, MAPLE, wird berechnet und diskutiert.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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  • 80
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 509 (1984), S. 153-160 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Nitrate-, Thiosulphate-, Sulphate-, and Sulphide Cancrinite1For the synthesis of the compounds to a solution of sodium aluminate there is added in excess sodium nitrate, or sodium thiosulphate, or sodium sulphite, or sodium sulphide. After heating a solution of sodium silicate is added, and the suspension is hold at 110°C for a long time, the precipatite is filtered, washed, and dried.2The white compounds are characterized in composition and crystal structure by chemical and X-ray analysis and densities.3The unimolecular hexagonal cell of the compounds has the cancrinite structure (lattice constants and densities see „Inhaltsübersicht“).4By heating of thiosulphate cancrinite at 1 000°C in air there is produced a nice deep blue coloured pigment.
    Notizen: 1Zur Darstellung der Verbindungen wird zu einer Natriumaluminatlösung Natriumnitrat oder Natriumthiosulfat oder Natriumsulfat oder Natriumsulfid bei Zimmer-temperatur im Überschuß gegeben. Nach Aufheizen wird eine Wasserglaslösung zugetropft, die Suspension längere Zeit bei 110°C gehalten, der Niederschlag abfiltriert, gewaschen und getrocknet.2Die weißen Verbindungen werden in Zusammensetzung und Kristallstruktur durch chemische und röntgenographische Analyse sowie Dichten charakterisiert.3Mit 1 Molekel/Zelle kristallisieren die Verbindungen im hexagonalen Cancrinitgitter mit den Konstanten und Dichten: TextVerbindungGitterkonstanten in ÅDichten in g/ml a0c0RöntgenPyknometerNa8[Al6Si6O24](NO3)2 · 4 H0O12,68 ± 0,025,18 ± 0,012,522,30Na8[Al6Si6O24](S2O3) · 3 H2O12,73 ± 0,025,02 ± 0,032,512,28Na8[Al6Si6O24](SO4) · 3 H2O12,674 ± 0,0045,173 ± 0,0032,422,37Na8[Al6Si6O24](S) · 4 H2O12,669 ± 0,0075,187 ± 0,0032,312,244Durch Glühen des Thiosulfat-Cancrinits bei 1 000°C an Luft erhält man ein schönes tiefblaues Pigment.
    Zusätzliches Material: 2 Ill.
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  • 81
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 510 (1984) 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
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  • 82
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 510 (1984), S. 11-15 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Benzyl Nickel(II) Complexes and their ReactionsBy the oxydative addition of p-substituted benzyl chlorides to (Ph3P)2Ni(C2H4) at -20°C the violet nickel(II) complexes (Ph3P)2Ni(p-CH2C6H4R)Cl (R = CN, COOH, CH3, Cl) are, formed. In water containing solutions the carbonic acid (Ph3P)2Ni(p-CH2C6H4COOH)Cl is rearranged to the corresponding p-methylbenzoate.With carbon dioxide the complexes (Ph3P)2Ni(p—CH2C6H4R)Cl react like Grignard compounds. Diphenyl ethine and butadien-1,3 are inserted in the Ni - C bond at room temperature. Substituted nickel-σ-vinyl or π-allyl complexes are obtained. The reactivity of the nickel-σ-benzyl compounds is compared with that of other nickel(II)-alkyl compounds.
    Notizen: Die oxydative Addition von p-substituierten Benzylchloriden an (Ph3P)2—Ni(C2H4) bei -20°C ergibt die violetten Nickel(II)-Komplexe (Ph3P)2Ni(p—CH2C6H4R)Cl (R = CN, COOH, CH3, Cl). Die Carbonsäure (Ph3P)2Ni(p—CH2C6H4COOH)Cl lagert sich in Gegenwart von Wasser in das entsprechende p-Methylbenzoat ein.Die Verbindungen des Typs (Ph3P)2Ni(p—CH2C6H4R)Cl reagieren mit Kohlendioxid grignardanalog. Diphenylethin und Butadien-1,3 werden bei normaler Temperatur in die Ni - C-Bindung eingeschoben. Dabei entstehen substituierte Nickel-σ-vinyl- bzw. π-allyl-Komplexe. Das Reaktionsverhalten der Nickel-σ-benzylverbindungen wird mit dem anderer Nickel(II)-alkylverbindungen verglichen.
    Materialart: Digitale Medien
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  • 83
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 510 (1984), S. 46-50 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Darstellung und Kristallstrukturbestimmung von La3ReO8La3ReO8 wurde bei 1425°C dargestellt, die Strukturbestimmung ergab abweichende Resultate von einer Darstellung, die bei 900°C erfolgte (BAUD u. Mitarb. 1979). Die Hochtemperaturmodifikation kristallisiert in der monoklinen Raumgruppe P21/m mit a = 7,757(1), b = 7,777(1), c = 5,928(1) Å, γ = 111,1°, Z = 2. Die Struktur wurde durch Patterson und Fouriersynthesen gelöst und bis R(F) = 0,073 verfeinert. Die Struktur besteht aus isolierten, verzerrten ReO6-Oktaedern und Doppelketten von kantenverknüpften La4O-Tetraedern.
    Notizen: The crystal structure of La3ReO8, prepared at 1425°C, is reported to be different from a previous result on a preparation at 900°C (BAUD et al., 1979). The high temperature modification crystallizes in the monoclinic space group P21/m with a = 7.757(1), b = 7.777(1), c = 5.928(1) Å, γ = 111.1°, Z = 2. The structure was solved by Patterson and Fourier methods from single crystal diffractometer data and refined to final R(F) = 0,073. The structure consists of isolated, distorted ReO6 octahedra and double chains of edge-shared La4O tetrahedra.
    Zusätzliches Material: 1 Ill.
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  • 84
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 510 (1984), S. 72-78 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Resonance Raman Spectrum and Structure of Matrixisolated Te3By condensing a mixture of 76% Te atoms and 24% Te2 molecules in a nitrogen matrix at 15 K followed by annealing to nearly 25 K we obtained Te3 molecules by a matrix reaction. The resonance Raman spectrum of Te3 contains 8 overtones of the symmetric stretching vibration. The following values for ω1 and x11 have been calculated for the isotopically pure species 126Te3: ω1 = 206.33 ± 0.15 cm-1; x11 = 0.24 ± 0.03 cm-1 and 130Te3: ω1 = 203.1 ± 0.2 cm-1; x11 = 0.22 ± 0.05 cm-1. Using a 1:1 ratio of 126Te and 130Te in the synthesis of Te3 the band shape of the envelopes of the superimposed spectra of all possible Te3 species could only be explained assuming a bent structure (120° ± 10°). The value of the force constant fr + frr of 210 ± 10 Nm-1 reflects multiple bonding in this molecule. The proposed structure also agrees with thermodynamical considerations.
    Notizen: Wird eine Gasmischung aus 76% Te-Atomen und 24% Te2-Molekeln mit einem Überschuß Stickstoff bei 15 K abgeschreckt und anschließend kurz auf 25 K erwärmt, so entstehen durch eine Matrixreaktion Te3-Molekeln. Im Resonanzramanspektrum dieser Spezies werden 8 Obertöne der symmetrischen Streckschwingung beobachtet. Für zwei verschiedene Te-Isotope erhält man folgende Werte für ω1 und x11: 126Te3: 206,33 ± 0,15 cm-1, 0,24 ± 0,03 cm-1; 130Te3: 203,1 ± 0,20 cm-1, 0,22 ± 0,05 cm-1. Die Verwendung von Proben, die je 50% der beiden Isotopen enthalten führt zu einem Bandenmuster, bei dem die Intensität der einzelnen Banden und ihre Frequenzverschiebung für eine gewinkeltes Te3-Molekel sprechen (120° ± 10°). Der Wert der Kraftkonstante fr + frr von 210 ± 10 Nm-1 zeigt Mehrfachbindungsanteile an. Eine thermodynamische Betrachtung liefert zusätzliche Anhaltspunkte für eine offene (nicht ringförmige) Struktur vom Te3.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
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  • 85
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 510 (1984), S. 104-108 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Trialkylbismutines as Ligands in Carbonyl Complexes of Iron and Group VIa ElementsThe complexes (CO)4FeBiR3 (R = Et, Pr, Bu) are synthesized by reaction of Fe2(CO)9 and the corresponding bismutines. Complexes of the type Bu3BiM(CO)5 (M = Cr, Mo, W) are formed by irradiation of the hexacarbonyls of group VIa elements in tetrahydrofuran and subsequent addition of Bu3Bi. The novel compounds are obtained in 40 - 90% yield. They are stable in an inert atmosphere above 25°C. Their 1H-n. m. r., i. r., and m. s. data are discussed.
    Notizen: Die Komplexe (CO)4FeBiR3 (R = Et, Pr, Bu) werden durch Umsetzung von Fe2(CO)9 mit den entsprechenden Bismutinen synthetisiert. Komplexe des Typs Bu3BiM(CO)5 (M = Cr, Mo, W) entstehen durch Bestrahlung der Hexacarbonyle der VIa-Elemente in Tetrahydrofuran und nachfolgende Umsetzung mit Bu3Bi. Die neuen Verbindungen werden in 40 - 90% Ausbeute erhalten. Sie sind bei Luftausschluß auch oberhalb von 25°C stabil. Ihre 1H-NMR-, IR- und EI-MS-Daten werden diskutiert.
    Zusätzliches Material: 2 Tab.
    Materialart: Digitale Medien
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  • 86
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 510 (1984), S. 143-151 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Crystal Structure of Ag2Ge2O5: A New Ge2O52- Network StructureAg2Ge2O5 was prepared from the binary oxides at high O2 pressures. Single crystal X-ray diffraction work indicated monoclinic symmetry (P21/c; a = 1101.3(2); b = 1006.3(1); c = 1221.9(3) pm; ß = 94.6(1)°). The structure was determined by direct methods (3372 independent structure factors) and refined to a conventional R value of 0.084. A new Ge2O52- network structure was found with germanium coordinated octahedrally (­d(Ge - O) = 188,7 pm) and tetrahedrally (­d(Ge - O) = 175,9 pm), in equal proportions, by oxygen. The polyhedra share vertices and edges, thus forming a three dimensional channel system, which is occupied by Ag+ ions. The shortest Ag - Ag distance of 284 pm, like the pale yellow colour of the compound, indicates Ag+ - Ag+ interaction.
    Notizen: Durch Sauerstoffhochdrucksynthese wurde Ag2Ge2O5 aus den binären Komponenten dargestellt. Nach Einkristalluntersuchungen liegt monokline Symmetrie vor (P21/c; a = 1101,3(2); b = 1006,3(1); c = 1221,9(3) pm; ß = 94,6°(1); Z = 12). Die Struktur wurde mittels direkter Methoden (Ag-Positionen) und Fourier-Synthesen gelöst (3372 unabhängige Strukturfaktoren); der R-Wert konvergierte bei 8,4%. Das Anion Ge2O52- bildet eine neuartige Raumnetzstruktur, wobei die Germaniumatome jeweils zur Hälfte oktaedrisch [­d(Ge - O) = 188,7 pm] und tetraedrisch [­d(Ge - O) = 175,9 pm] von Sauerstoff koordiniert sind. Die Polyeder sind in der Weise über gemeinsame Ecken und Kanten verknüpft, daß dreidimensional vernetzte, kanalartige Hohlräume entstehen, die von den Gegenkationen (Ag+) ausgefüllt werden. Der kürzeste Ag - Ag-Abstand beträgt 284 pm und gibt, wie die blaßgelbe Eigenfarbe der Substanz, einen Hinweis auf bindende Ag+ - Ag+-Wechselwirkungen.
    Zusätzliches Material: 1 Ill.
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  • 87
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 510 (1984), S. 175-179 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Synthesis of Bis- and Tris(trimethylsilyl)-methyl-aminofluorosilanesLithium-tris(trimethylsilyl)methane reacts with fluoro-silanes to give (Me3Si)3C - SiF2R (1 - 3, R = F, C6H5, CMe3). 1 and 2 react with lithiated amines to aminofluorosilanes 4 a, 5 a, 6 a, and with a 1, 3-migration of a silyl group to the structure isomeric trimethylsilylaminofluorsilanes 4 b, 5 b, 6 b, 7, 8. The disubstituted NH-compound 9 is obtained in the reaction of 1 with LiNH2.
    Notizen: Lithium-tris(trimethylsilyl)-methan reagiert mit Fluorsilanen unter Substitution zu (Me3Si)3CSiF2R (1 - 3, R = F, C6H5, CMe3). Mit lithiierten Aminen reagieren 1 und 2 zu den Aminofluorsilanen 4a, 5a, 6a, und unter 1, 3-Silylgruppenwanderung zu den strukturisomeren Trimethylsilylaminofluorsilanen 4 b, 5 b, 6 b, 7, 8. In der Reaktion von 1 mit LiNH2 wird die disubstituierte NH-Verbindung 9 erhalten.
    Materialart: Digitale Medien
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  • 88
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 514 (1984), S. 69-71 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Tris-trimethylsilyl-tert.butyl-cyclotetraphosphaneP4(SiMe3)3CMe3 1, which was previously unknown in the series of the cyclotetraphosphanes P4(SiMe3)nCMe34-n, n = 0-4, could be obtained by the reaction of P3(SiMe3)5 with Me3CPCl2. 1 froms intensely coloured yellow crystals, melting point 143 ± 2°C. The 31P- and 1H-NMR data of 1 are given.
    Notizen: Das in der Reihe der Cyclotetraphosphane P4(SiMe3)n(CMe3)4-n, n = 0-4, bisher noch unbekannte P4(SiMe3)CMe3 1 konnte durch Umsetzung von P3(SiMe3)5 mit Me3CPCl2 dargestellt werden. 1 bildet intensiv gelbe Kristalle, Schmp. 143 ± 2°C. Die 31P- und 1H-NMR-Daten von 1 werden angegeben.
    Zusätzliches Material: 1 Tab.
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  • 89
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 514 (1984), S. 72-78 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: [PPh3Cl]⊕[ReCl4(N2S2)]⊖; Synthese, IR-Spektrum und Kristall StruktureThe title compound is prepared by the reaction of [ReCl3(NSCl)2(POCl3)] with triphenylphosphane; it formes black crystals. The crystal structure determination was solved with X-ray methods (2861 observed independent reflexions, R = 0.038). The compound crystallizes monoclinic in the space group P21/n with four formula units per unit cell. The structure consists of [PPh3Cl]⊕ cations and [ReCl4(N2S2)]⊖ anions, in which the rhenium atom is surrounded octahedrally by four chlorine ligands and the N atoms of a ReN2S2-five-membered ring in cis-position (symmetry C2v). The Re—N bond lengths (181 pm) and the NS bond lengths (152 pm) are in the range of double bonds; the S—S distance is very long (253 pm). The i.r. spectrum is reported.
    Notizen: Die Titelverbindung entsteht in Form schwarzer Kristalle bei der Reaktion von [ReCl3(NSCl)2(POCl3)] mit Triphenylphosphan. Die Kristallstruktur wurde mit Hilfe von Röntgenbeugungsdaten ermittelt ermittelt (2861 beobachtete unabhängige Reflexe, R = 0,038). Die Verbindung kristallisiert monoklin in der Raumgruppe P21/n mit vier Formeleinheiten pro Elementarzelle. Die Struktur besteht aus [PPh3Cl]⊕-Kationen und Anionen [ReCl4(N2S2)]⊖, in denen das Rhenium oktaedrisch von vier Chlorliganden und den beiden cis-ständigen Stickstoffatomen eines ReN2S2-Fünfringes umgeben ist (Symmetrie C2v). Die ReN-Abstände (181 pm) und die NS-Abstände (152 pm) entsprechen etwa Doppelbindungen; die S—S-Bindungslänge ist mit 253 pm sehr lang. Das IR-Spektrum wird mitgeteilt.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
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  • 90
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 514 (1984), S. 92-98 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: On Fluorides of Divalent Lanthanoids. II. Synthesis of MLnF3 from MLnF4CsEuF3, CsYbF3, and RbYbF3, which had already been prepared via reduction of the corresponding trifluorides with alkali metal, were also obtained by reducing MLnF4 with M (M = Cs, Rb, K; Ln = Eu, Yb). No additional alkali fluoroperovskites of lanthanoids were detected either by reduction of LnF3 or MLnF4 with metallic Cs, Rb, or K or by other reactions, e.g. 3CsF + 2SmF3 + Sm. It was shown that the reaction of CsF with EuF2 (350-850°C) produced only very little CsEuF3.
    Notizen: CsEuF3, CsYbF3 und RbYbF3, zuvor nur durch Reduktion von EuF3 bzw. YbF3 mit met. Cs bzw. Rb erhalten, entstehen auch bei der Reduktion von MLnF4 mit M (M = Cs, Rb, K; Ln = Eu, Yb). Weitere unbekannte Perowskite wie CsSmF3 erhält man auf diesem Wege nicht. Tempern von innigen Gemengen der binären Fluoride (z.B. CsF + EuF2) führt nur zu sehr unvollständiger Umsetzung. Auch Synthesen durch Komproportionierung (z. B. 3CsF + 2SmF3 + Sm) sind ohne Erfolg. Durchgeführt wurden alle Reduktionen von LnF3 (Ln = Sm, Eu, Tm, Yb) mit M (M = Cs, Rb, K).
    Zusätzliches Material: 5 Tab.
    Materialart: Digitale Medien
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  • 91
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 514 (1984), S. 120-128 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: On Chalcogenolates. 139. Studies on Dialkyl Esters of Chalcogenocarbonic Acids. 2. O,Se- and S, Se-Dialkyl MonothiomonoselenocarbonatesThe hitherto unknown esters RSe—CS—OR′, where R = C2H5, nC3H7 and R′ = C2H5, nC3H7, are formed by reaction of NaSeR with Cl—CS—OR′ and of RSe—CS—Cl with HOR′. At the first time, the esters RSe—CO—SR′ with R = R′ = C2H5, nC3H7 have been prepared by reaction between NaSeR and Cl—CO—SR′. The compounds have been characterized by means of diverse spectroscopic methods.
    Notizen: Die bisher nicht bekannten Ester RSe—CS—OR′ mit R = C2H5, nC3H7 und R′ = C2H5, nC3H7 entstehen bei der Reaktion von NaSeR mit Cl—CS—OR′ und bei der von RSe—CS—Cl mit HOR′. Erstmals wurden die Ester RSe—CO—SR′ mit R = R′ = C2H5, nC3H7 durch Umsetzung von NaSeR mit Cl—CO—SR′ hergestellt. Die genannten Verbindungen wurden mit Hilfe verschiedener spektroskopischer Methoden charakterisiert.
    Zusätzliches Material: 8 Tab.
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  • 92
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 514 (1984), S. 107-114 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Metal Sulfur Nitrogen Compounds. 16. Products of the Reaction of Lead- and Tin Salts with S4N4. Structures of PbN2S2 · NH3, PbN2S2, and SnCl4 · 2S4N4PbN2S2 · NH3 is monoclinic, P21/a, a = 5.671, b = 16.123, c = 6.102 Å, β = 95.12°, Z = 4, PbN2S2, however, orthorhombic, P212121, a = 4.375, b = 7.654, c = 12.274 Å, Z = 4. The planar five-membered PbN2S2 rings in both compounds show no remarkable differences. In PbN2S2 · NH3, the NH3 molecule is bound to Pb perpendicularly to the plane of the ring.The structure of the long known addition compound SnCl4 · 2S4N4 was determined. It is orthorhombic, Pc21b, a = 11.467, b = 11.995, c = 12.374 Å, Z = 4. Sn shows sixfold coordination, the two S4N4 rings are attached to Sn trans to each other via a N atom.
    Notizen: PbN2S2 · NH3 kristallisiert monoklin, Raumgruppe P21/a mit a = 5,671 Å, b = 16,123 Å; c = 6,102 Å, β = 95,12°, Z = 4, PbN2S2 dagegen orthorhombisch, Raumgruppe P212121 mit a = 4,375 Å, b = 7,654 Å, c = 12,274 Å, Z = 4. Die ebenen fünfgliedrigen PbN2S2-Ringe beider Verbindungen unterscheiden sich nur unwesentlich. Bei PbN2S2 · NH3 ist an Pb zusätzlich noch ein NH3-Molekül senkrecht zur Ringebene gebunden.Von der schon lange bekannten Additionsverbindung SnCl4 · 2S4N4 konnte ebenfalls die Struktur bestimmt werden: orthorhombisch, Raumgruppe Pc21b mit a = 11,467 Å, b = 11,995 Å, c = 12,374 Å, Z = 4. Sn ist 6fach koordiniert, die beiden S4N4-Ringe sind über je ein N-Atom in Transstellung an Sn gebunden.
    Zusätzliches Material: 4 Ill.
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  • 93
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 514 (1984), S. 149-163 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: On the Structure of Ill-crystallized Calcium Hydrogen Silicates. VI. Chemical, ESR, and Mössbauer-Spectroscopic Investigations on the Incorporation of Fe3+ into C—S—H(Di, Poly)C—S—H(Di, Poly), prepared by precipitation reactions from sodium silicate solutions in presence of Fe3+ ions, incorporates at least up to 0.09 Fe2O3/SiO2. Thereby the anion composition of the C—S—H(Di, Poly) ist not affected.The results of ESR and Mössbauer spectroscopic measurements show, that Fe is incorporated as Fe3+ at octahedral sites. Only less than 1% of the total amount of Fe3+ is situated at tetrahedral sites. In good accordance with that is the change of thermal stability of the silicate anions concerning condensation and degradation reactions.
    Notizen: In C—S—H(Di, Poly), das bei 80°C (353 K) über Fällungsreaktionen aus Natriumsilicatlösungen in Gegenwart von Fe3+-Ionen synthetisiert wurde, lassen sich bis mindestens 0,09 Fe2O3/SiO2 einbauen. Der Anionenaufbau des C—S—H(Di, Poly) wird dadurch nicht verändert. Aus ESR- bzw. Mößbauer-spektroskopischen Befunden geht hervor, daß das Eisen als Fe3+ hauptsächlich auf Oktaederplätzen vorliegt, während Tetraederplätze nur von weniger als 1% der Gesamteisenmenge besetzt werden. Die Änderung der thermischen Stabilität der Silicatanionen gegenüber Kondensations- und Abbaureaktionen steht mit dem Einbau von Fe3+ auf Oktaederplätzen in guter Übereinstimmung.
    Zusätzliches Material: 6 Ill.
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  • 94
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Lower Chalcogen Fluorides. IX. Preparation and Characterization of SF3SSFDuring cocondensation of SF2 and SSF2 the new compound 1,3-Difluorotrisulphane-1,1-difluoride is formed in low yield and can be isolated by means of low temperature fractionation. The compound was unequivocally characterized by 19F-n.m.r,i.r.,Raman, and mass spectra. The unstable compound ist a colourless, viscous liquid with an extrapolated boiling point of 94°C and a melting point of -62°C. It decomposes to SF4 and SSF2 in the gas phase.
    Notizen: Bei der Cokondensation von SF2 und SSF2 entsteht in geringen Ausbeuten die neue Verbindung 1,3-Difluor-trisulfan-1,1-difluorid, SF3SSF, die mittels Tieftemperaturfraktionierung isoliert werden konnte. Durch 19F-NMR-, IR-, Raman- und Massenspektren wurde die Verbindung eindeutig charakterisiert. Das sehr zersetzliche SF3SSF ist eine farblose, viskose Flüssigkeit mit einem extrapolierten Siedepunkt von 94°C und einem Schmelzpunkt von -62°C. Es zerfällt in der Gasphase in SF4 und SSF2.
    Zusätzliches Material: 3 Ill.
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  • 95
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 514 (1984), S. 205-212 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Bildung und Zersetzung von LanthanoxidcarbonatAmorphes Lanthancarbonat wird durch Hydrolyse von Lanthanisopropoxid mit wäßriger Ammoniaklösung an Luft dargestellt. Lanthanoxidcarbonat, La2O(CO3)2 · H2O, kristallisiert, wenn die amorphe Substanz mit heißem Wasser gewaschen wird. Die Kristallisation und das thermische Verhalten des kristallinen Materials werden röntgenographisch, thermoanalytisch und IR-spektroskopisch untersucht. Die Zersetzung des La2O(CO3)2 · H2O in das IA-(LaO)2CO3 wird bei 440 bis 540°C beobachtet. Die Zersetzungsisothermen können durch eine gebrochene rationale Funktion beschrieben werden; die Aktivierungsenergie beträgt 42,6 kcal · mol-1. IA-(LaO)2CO3 zersetzt sich dann zum A-La2O3 bei 750 bis 870°C. Die Kinetik wird ebenfalls durch eine gebrochene rationale Funktion interpretiert; die Aktivierungsenergie beträgt 58,3 kcal · mol-1.
    Notizen: Amorphous lanthanum carbonate was prepared by hydrolysis of lanthanum isopropoxide using ammonia water in the atmosphere. Lanthanum monoxocarbonate, La2O(CO3)2 · H2O, crystallizes when this amorphous material was washed with hot water. The crystallization and thermal behavior of the crystalline material are studied by X-ray diffraction, thermal analysis, and infrared spectroscopy. The decomposition of La2O(CO3)2 · H2O into type-IA (LaO)2CO3 is observed at 440 to 540°C. Decomposition isotherms are described by the contracting cube equation, the activation energy being 42.6 kcal mol-1. Type-IA (LaO)2CO3 subsequently decomposes to A-type La2O3 at 750 to 870°C. The kinetics is also interpreted in terms of the contracting cube equation, the activation energy being 58.3 kcal mol-1.
    Zusätzliches Material: 5 Ill.
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  • 96
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 514 (1984), S. 240-240 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
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  • 97
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Structural Chemistry of Phosphorus Containing Chains and Rings. 11. Crystal and Molecular Structures of the Two Stereoisomers of Tetraphospha-silaspiro[2.2]pentane (PBut)2Si(PBut)2The spirocyclic compound 1,2,4,5-tetra-tert-butyl-1,2,4,5-tetraphospha-3-silaspiro[2.2]pentane exists in tow diastereomers of point symmetry 4 and 2. The isomer with symmetry 4 even in the solid crystallizes tetragonally in I41/a with a = 1247.0, c = 1505.5 pm and Z = 4. The isomer of fairly exact symmetry 2 crystallizes triclinically in P1 with a = 612.8, b = 996.3, c = 1017.2 pm, α = 75.63, β = 72.38, γ = 88.71° and Z = 1. In this disordered structure the surroundings of Si is slightly distorted due to the influence of the substituents. The (average) bond lengths are (4, 2): d(Si—P) = 220.09(9), 221.5(5); d(P—P) = 225.5(2), 224.2(5); d(P—C) = 189.4(3), 190(2); d(C—C) = 151.4(4), 152(3) pm. The geometry of the substituents in both isomers is quite normal.
    Notizen: Die Spiroverbindung 1,2,4,5-Tetra-tert-butyl-1,2,4,5-tetraphospha-3-silaspiro[2.2]pentan liegt in zwei Diastereomeren der Punktsymmetrie 4 und 2 vor. Das Isomer der auch im Festkörper exakten Symmetrie 4 kristallisiert tetragonal in der Raumgruppe I41/a mit a = 1247,0, c = 1505,5 pm und Z = 4. Das sterisch weniger günstige Isomer der im Festkörper nicht streng erfüllten Symmetrie 2 kristallisiert triklin in der Raumgruppe P1 mit a = 612,8, b = 996,3, c = 1017,2 pm, α = 75.63, β = 72,38, γ = 88,71° und Z = 1. In dieser nur fehlgeordnet beschreibbaren Struktur wird die Umgebung des Si durch Substituenteneinflüsse etwas verzerrt. Die (mittleren) Bindungslängen betragen (4, 2): d(Si—P) = 220,09(9), 221,5(5); d(P—P) = 225,5(2), 224,2(5); d(P—C) = 189,4(3), 190(2); d(C—C) = 151,4(4), 152(3) pm. Die Geometrie der Substituenten ist in beiden Isomeren normal.
    Zusätzliches Material: 3 Ill.
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  • 98
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 515 (1984), S. 51-60 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Syntheses of the Anion S3N3O2-, a Stable Six-membered Sulfur-Nitrogen Ring with an 8π-Electron SkeletonThe dark blue-violet cyclotrithiazene-dioxide anion S3N3O2-has been synthesized on different pathways: 1. reaction of S4N4O2 with alkali azides, 2. metathesis of (CH3)3ES3N3O2 (E = Si, Sn) with CsF, 3. addition of S4N4O2 and alkali bis(trimethylsilyl)-amides followed by cation exchange with tetraphenylarsonium chloride, and 4. reaction of S4N4O2 with trimethylsilyliminotriphenylphosphorane in a molar ratio of 1:1. Excess iminophosphorane leads to the formation of a covalent 1.5-disubstituted S4N4 derivative. Reaction mechanisms will be discussed and structures of trithiatriazine-anions will be compared.
    Notizen: Das dunkelblauviolette Cyclotrithiatriazendioxid-Anion S3N3O2- konnte auf verschiedenen Wegen dargestellt werden: 1. Umsetzung von S4N4O2 mit Alkaliaziden, 2. Reaktion von (CH3)3ES3N3O2 (E = Si, Sn) mit CsF, 3. Addition von S4N4O2 und Alkali-bis(trimethylsilyl)-amiden mit anschließendem Kationenaustausch mit Tetraphenylarsoniumchlorid und 4. Umsetzung von S4N4O2 mit Trimethylsilyliminotriphenylphosphoran im Molverhältnis von 1:1. Ein überschuß des Iminophosphorans führt zur Bildung eines kovalenten 1,5-disubstituierten S4N4-Derivats. Reaktionsmechanismen werden diskutiert und Strukturvergleiche an Trithiatriazinanionen durchgeführt.
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  • 99
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 515 (1984), S. 69-80 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Reactions of Iron Trichloride with Trithyazyl Chloride. Crystal Structure of [S4N4Cl]+[FeCl4]-Iron trichloride reacts with (NSCl)3 yielding S4N4[FeCl4]2, S3N3Cl2[FeCl4] or S4N4Cl[FeCl4], depending on the reaction conditions. The i.r. spectra prove the presence of [FeCl4]⊖ ions for all three compounds. The 57Fe-Mössbauer spectra show a slight quadrupole splitting at 80 K for S3N3Cl2[FeCl4] (ΔEQ = 0.42 mm · s-1) and S4N4Cl[FeCl4] (ΔEQ = 0.23 mm · s-1), which indicates a slight deformation of the FeCl4⊖ tetrahedra. The crystal structure of S4N4Cl[FeCl4] was determined and refined with X-ray diffraction data (2549 independent reflexions, R = 0.026). S4N4Cl[FeCl4] crystallizes in the triclinic space group P1 with two formula units per unit cell. The lattice constants are a = 712, b = 911, c = 1006 pm, α = 76.5°, β = 83.8° and γ = 80.5°. The structure consists of the so far unknown [S4N4Cl]⊕ cations and slightly deformed FeCl4⊖ ions. The [S4N4Cl]⊕ ion consists of a S4N4 ring built up of two nearly planar S3N2 fragments having a dihedral angle of 136°. The average SN bond length is 157 pm, the SCI bond length 214 pm.
    Notizen: Eisen(III)-chlorid reagiert mit (NSCl)3 je nach den angewandten Versuchsbedingungen unter Bildung von S4N4[FeCl4]2, S3N3Cl2[FeCl4] oder S4N4Cl[FeCl4]. Nach den IR-Spektren enthalten alle Verbindungen das FeCl4⊖-Anion. Die 57Fe-Mößbauer-Spektren lassen anhand der endlichen Beträge der Quadrupolaufspaltung bei 80 K für S3N3Cl2[FeCl4] (ΔEQ = 0,42 mm · s-1) und für S4N4Cl[FeCl4] (ΔEQ = 0,23 mm · s-1) leicht verzerrte FeCl4⊖-Tetraeder erkennen. Die Kristallstruktur von S4N4Cl[FeCl4] wurde mit Hilfe von Röntgenbeugungsdaten ermittelt und verfeinert (2549 unabhängige, beobachtete Reflexe, R = 2,6%). S4N4Cl[FeCl4] kristallisiert in der triklinen Raumgruppe P1 mit zwei Formeleinheiten pro Elementarzelle. Die Gitterkonstanten sind a = 712, b = 911, c = 1006 pm; α = 76,5°, β = 83,8°, γ = 80,5°. Die Struktur besteht aus dem bisher unbekannten [S4N4Cl]⊕-Kation und leicht verzerrten FeCl4⊖-Anionen. Das [S4N4Cl]⊕-Ion bildet einen S4N4-Achtring, der aus zwei zueinander gefalteten, nahezu ebenen Ringfragmenten S3N2 besteht mit einem Faltungswinkel von 136°. Der mittlere SN-Bindungsabstand beträgt 157 pm, die S—Cl-Bindungslänge 214 pm.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 100
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 515 (1984), S. 95-100 
    ISSN: 0044-2313
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: On Li2[CuO2]At the first time single crystals of Li2[CuO2] are prepared by exchange reaction. The crystal structure (I mmm) with a = 365.4(0), b = 285.9(0), c = 937.4(0) pm, Z = 2, dx = 3.73 g/cm3, dpyk = 3.67 g/cm3 was refined (four-circle-diffractometer data PW 1100, 343 Io(hkl), MoKα, R = 0.046, Rw = 0.041). The characteristic structure element is the planar chain \documentclass{article}\pagestyle{empty}\begin{document}$ {}_\infty ^1 \left[{{\rm CuO}_{4/2}} \right]^{2 -} $\end{document}. The Madelung Part of Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated.
    Notizen: Einkristalle von Li2[CuO2] wurden erstmals durch „Austauschreaktion“ dargestellt und die Kristallstruktur (I mmm) mit a = 365,4(0), b = 285,9(0), c = 937,4(0) pm, Z = 2, drö = 3,73 g/cm3, dpyk = 3,67 g/cm3 aufgeklärt (Vierkreisdiffraktometerdaten, PW 1100, 343 Io(hkl), MoKα, R = 0,046, Rw = 0,041). Das charakteristische Strukturelement ist die planare Ketve \documentclass{article}\pagestyle{empty}\begin{document}$ {}_\infty ^1 \left[{{\rm CuO}_{4/2}} \right]^{2 -} $\end{document}. Der Madelunganteil der Gitterenergie, MAPLE, Effektive Koordinationszahlen, ECoN, diese über Mittlere Fiktive Ionenradien, MEFIR, werden berechnet.
    Zusätzliches Material: 5 Tab.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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