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  • 1985-1989  (6)
  • Inorganic Chemistry  (5)
  • Cell & Developmental Biology
  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 525 (1985), S. 7-13 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: NMR Spectroscopic Studies of 15N Labelled N-Methyl-imidodiphosphoric Acid Derivatives15N labelled compounds (EtO)mCl2-m(O)P—NMe—P(O)(OEt)nCl2-n (m = 0-2, n = 0-2) were prepared as a mixture 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.
    Notes: 15N-markierte Verbindungen der Substitutionsreihe (EtO)mCl2-m(O)P—NMe—P(O)(OEt)nCl2-n (m = 0-2, n = 0-2) wurden im Reaktionsgemisch 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.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 523 (1985), S. 112-120 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: NMR Spectroscopic Studies on the Thiolysis Reaction of Decachlorocyclopentaphosphazenen, N5P5Cl10A series of different but exclusively geminally substituted products, N5P5Cl10-n(SR)n, is formed by reactions of decachlorocyclopentaphosphazene, N5P5Cl10, with sodium ethanethiolate, NaSEt, or benzenethiolate, NaSPh, in benzene or ether. The degree of substitution is low (mainly up to n = 4); intensified conditions do not result in further substitution but in decomposition. The compounds were separated by column chromatography and identified by 31P NMR spectroscopy. 31P chemical shifts and P - P coupling constants of the investigated compounds systematically change with the progressive substitution by SR groups. The chlorine-replacement pattern is discussed.
    Notes: Bei Umsetzungen von Decachlorocyclopentaphosphazen, N5P5Cl10, mit Natriumethanthiolat, NaSEt, order -benzenthiolat, NaSPh, in Benzen bzw. Ether entsteht eine Reihe unterschiedlicher, aber ausschließlich geminaler Substitutionsprodukte, N5P5Cl10-N(SR)n, niederen Substitutionsgrades (im wesentlichen bis zu n = 4); verschärfte Reaktionsbedingungen führen nicht zu weiterer Substitution, sondern zur Zersetzung. Die Verbindungen wurden säulenchromatographisch getrennt und mit Hilfe der 31P-NMR-Spektroskopie identifiziert. 31P-chemische Verschiebungen und P - P-Kopplungskonstanten der untersuchten Verbindungen ändern sich systematisch mit fortschreitender Substitution durch SR-Gruppen. Der Substitutionsverlauf wird diskutiert.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The sex differential in coronary heart disease is well documented but poorly understood. Previous studies have demonstrated receptors for dihydrotestosterone (DHT) in the myocardium and smooth muscle cells of arteries from a number of species. In this autoradiographic study, we further investigated and characterized the in vivo uptake and retention of the androgen binding in the male baboon. Adult castrated male baboons were injected with 1 μg/kg bw 3H-testosterone; 1 hr after the injection, the animals were rapidly exsanguinated while under anesthesia. The heart and arterial system were removed and processed for autoradiography. As a negative control, one animal received both 3H-testosterone and 100-fold unlabeled testosterone. For positive controls, the pituitary gland, prostate, seminal vesicles, and other tissues were also removed and processed for autoradiography. In contrast to our previous finding with 3H-DHT, no nuclear uptake and retention of 3H-steroid was found in any of the cells in either the heart or the arterial system. In the positive control tissues, pituitary gland, prostate, seminal vesicles, and others, a very distinct nuclear uptake and retention of 3H-steroid was observed, which was completely inhibited by the simultaneous injection of 100-fold unlabeled testosterone. In the binding study, Scatchard analysis of the cytosol prepared from a 17-year-old female baboon demonstrated levels of androgen receptor (as determined by the use of radiolabeled R1881) comparable to that found in young adults. The results of these studies suggest that, in contrast to the generally accepted hypotheses, (1) circulating DHT, not testosterone, is the androgenic hormone that interacts with the cardiovascular tissue of the baboon and (2) there are separate receptors for testosterone and DHT in different tissues rather than a single receptor capable of binding both steroids.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies on Systems of Salts and Mixed Solvents. XXXIV. 27Al and 1H N.M.R. Spectroscopic Investigations of AlCl3-Water-N,N-Dimethylformamide SolutionsAl3+ ions exist in aqueous solutions as well as in DMF solutions in a sixfold coordination; the coordination of DMF exclusively occurs via the oxygen atom. Because of the small shift difference between the pure aqueous and the pure DMF solution at the 27Al n.m.r. spectra no separated signals were found corresponding to the species with mixed coordination. From the changes of the Al chemical shifts and of the linewidths in dependence of the solvent composition a selective solvation process is suggested. At the 1H n.m.r. spectra for the formyl and methyl protons of DMF separated signals appear for the molecules of the first coordination sphere and of the bulk, respectively. From this the number of directly coordinated DMF molecules can be determined. Up to a DMF content of about x = 0.45 DMF is preferentially coordinated, after that a change of selectivity takes place and accordingly water is preferred at the first coordination sphere.
    Notes: Al3+-Ionen werden sowohl in wäßrigen als auch in DMF-Lösungen sechsfach koordiniert, die Koordination des DMF erfolgt über Sauerstoff. Wegen der geringen Verschiebungsdifferenz zwischen der reinen wäßrigen und der reinen DMF-Lösung treten in den 27Al-NMR-Spektren mit gemischtem Lösungsmittel keine getrennten Signale für gemischt-koordinierte Spezies auf. Aus den Änderungen der Al-chemischen Verschiebung und der Halbwertsbreite der Signale in Abhängigkeit von der Lösungsmittelzusammensetzung werden Hinweise auf eine selektive Solvatation erhalten. In den 1H-NMR-Spektren erscheinen für die Formyl- und Methylprotonen des DMF getrennte Signale für die Moleküle in der ersten Koordinationssphäre und die des restlichen Lösungsmittels. Daraus läßt sich die Anzahl der direkt koordinierten DMF-Moleküle ermitteln. Bis zu einem DMF-Gehalt von x s≈ 0,45 wird bevorzugt DMF koordiniert, danach tritt ein Selektivitätswechsel auf, so daß bevorzugt Wasser koordiniert wird.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 544 (1987), S. 225-231 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: N.M.R. Investigations of Fluorodiazadiphosphetidines and Fluoro-λ5-monophosphazenesThe 19F and 31P n.m.r. data of 37 fluorodiazadiphosphetidines [RR′PF—NC6H4X]2, and 62 fluoro-λ5-monophosphazenes, RR′PF=NC6H4X, are submitted. In the case of tetrafluorodiazadiphosphetidines, [RPF2—NC6H4X]2, an intramolecular exchange of the fluorine atoms at phosphorus has to be concluded from the n.m.r. data. The influence of the substituents R and X on the n.m.r. parameters is discussed using simple models of molecular structure.
    Notes: Es werden die 19F- und 31P-NMR-Daten von 37 Fluorodiazadiphosphetidinen, [RR′PF—NC6H4X]2, und 62 Fluoro-λ5-monophosphazenen, RR′PF=NC6H4X, mitgeteilt. Aus ihnen muß für die Tetrafluorodiazadiphosphetidine, [RPF2—NC6H4X]2, auf einen intramolekularen Positionswechsel der Fluoratome am Phosphor geschlossen werden. Der Einfluß der Substituenten R und X auf die NMR-Parameter wird anhand einfacher Modelle der Molekülstruktur diskutiert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies on Systems of Salts and Mixed Solvents. XXXVI. 1H and 27Al N.M.R. Spectroscopic Investigations of the Solvation Behaviour in Concentrated AlCl3-Water-Alcohol Solutions1H. n.m.r. spectroscopic investigations in dependence on the solvent composition and the salt concentration are useful for the characterization of solvation processes in concentrated solutions of AlCl3-water-methanol, -ethanol, -ethylene glycol, and -diethylene glycol. In these systems water is preferentially coordinated at the first coordination sphere of the Al3+ ion within the whole region of the solvent composition.The nature of the solvation species has been investigated using 27Al n.m.r. spectroscopy. In order to reduce the „solid-type“ interactions in the concentrated solutions the Magic Angle Spinning method (MAS) was used. Particularly water-poor and water-free solutions produce structured 27Al-Mas-signals. For the system AlCl3-water-ethanol an identification of solvation species is given.
    Notes: Durch 1H-NMR-Untersuchungen in Abhängigkeit von der Lösungsmittel-zusammensetzung und der Salzkonzentration werden Solvatationsprozesse in konzentrierten Lösungen von AlCl3-Wasser-Methanol, -Ethanol, -Ethylenglycol und -Diethylenglycol näher charakterisiert. Es wird jeweils eine bevorzugte Solvatation des Al3+-Ions durch Wasser über den gesamten Zusammensetzungsbereich der Lösungsmittel festgestellt.27Al-NMR-Untersuchungen dienen zur Identifizierung von Solvatationsspezies. Zur Reduzierung der festkörperähnlichen Wechselwirkungen in den konzentrierten Elektrolytlösungen wurde die Methode der schnellen Probenrotation um den „magischen“ Winkel (MAS) eingesetzt. Insbesondere wasserarme und wasserfreie Lösungen der Systeme zeigen strukturierte 27Al-MAS-Signale. Im System AlCl3-Wasser-Ethanol wird eine Identifizierung von Solvatationsspezies vorgenommen.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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