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  • 1
    ISSN: 0009-2940
    Keywords: Silicenium ion ; Iminosilane ; Aluminate ; Silicon ; Aluminium ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Lithiated text-butylaminolfluorosilanes react with aluminum trichloride in ether, eliminating LiF to give AlCl3 adducts of iminosilanes  -  aminosiliceniotrichloroaluminates {R2Si-NCMe3·AlCl3}, which thermally form the dimethylazomethine- aluminium trichloride, Me2C=NH·AlCl3.
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  • 2
    ISSN: 0044-2313
    Keywords: 1,4,2λ5,5λ5-Dioxadiphosphorinane ; NMR-Spectra ; Structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: P,P′-(2,5-Dimethoxy-3,6-dimethyl-2,5-dioxo-2λ5,5λ5-[1,4,2,5]dioxadiphosphinane-2,5-diyl)-bis-phosphonic acid tetramethylesterThe title compound 1 is formed by reaction of the corresponding phosphonic acid 2 and orthoformicacidmethylester as a mixture of four stereoisomeres. The RRSS isomer was separated. It crystallizes in the triclinic space group P -1 with a = 649.2 pm, b = 976.1 pm, c = 1 571.7 pm, α = 80.9°, β = 88.1°, γ = 78.6° and Z = 2. The 31P and 13C NMR spectra (4 and 5 spin systems) are discussed.
    Notes: Die Titelverbindung 1 entsteht aus der zugrundeliegenden Phosphonsäure 2 und Orthoameisensäuremethylester als Gemisch aus vier Stereoisomeren, von denen das RRSS-Isomer präparativ abgetrennt werden konnte. Dieses kristallisiert triklin in der Raumgruppe P -1 mit a = 649,2 pm, b = 976,1 pm, c = 1 571,7 pm, α = 80,9°, β = 88,1°, γ = 78,6° und Z = 2. Die 4- und 5-Spinsysteme der 31P- und 13CNMR-Spektren werden analysiert.
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 622 (1996), S. 1038-1046 
    ISSN: 0044-2313
    Keywords: Binuclear antimony(V) complexes ; structure ; dynamics ; NMR spectra ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: d, h-μ-Benzylalkoxophosphonato-e-μ-alkoxo-f-μ-oxo-bis[trichloroantimony(V)] CompoundsThe binuclear antimony(V) complexes Cl3Sb(O)[R3(R1O)PO2](OR2)SbCl3 1 - 6 with R1 = R2 = CH3, C2H5 and R3 = C6H5CH2, (CH3)3C6H2CH2 in solution slowly exchanges the R2 groups between the oxygen atoms of the Sb2O2 ring. The SbOPOSb ringsystem makes rapid pseudorotation. The isomeres are detected by nmr spectroscopy. 1 (R1 = R2 = CH3) crystallizes in the orthorhombic space group Pnma with a = 1247.0, b = 1324.1, c = 1207.9 pm and Z = 4. 2 (R1 = CH3, R2 = C2H5) and 5 (R1 = R2 = CH3, R3 = (CH3)3 · C6H2CH2) crystallizes triclinic in the space group P-1 with a = 984.1, b = 1026.7, c = 1079.9 pm, α = 87.93, β = 75.70, γ = 87.62° and Z = 2 and a = 1164.6, b = 1296.9, c = 1712.9 pm, α = 109.9, β = 96.3, γ = 100.2° and Z = 4 resp., with two crystallographically independent molecules in the asymmetric unit.
    Notes: Die zweikernigen Antimon(V)-Komplexe Cl3Sb(O)[R3(R1O)PO2](OR2)SbCl3 1 bis 6 mit R1 = R2 = CH3, C2H5 und R3 = C6H5CH2, (CH3)3C6H2CH2 tauschen bei RT in Lösung langsam die R2-Gruppen aus. Daneben erfolgt rasches Umklappen des SbOPOSb-quasi-Fünfringes. Die Isomerenbildung wird NMR-spektroskopisch nachgewiesen. 1 (R1 = R2 = CH3) kristallisiert orthorhombisch in der Raumgruppe Pnma mit a = 1247,0, b = 1324,1, c = 1207,9 pm und Z = 4. 2 (R1 = CH3, R2 = C2H5) und 5 (R1 = R2 = CH3, R3 = (CH3)3C6H2CH2) kristallisieren triklin in der Raumgruppe P-1 mit a = 984,1, b = 1026,7, c = 1079,9 pm, α = 87,93, β = 75,70, γ = 87,62° und Z = 2 bzw. a = 1164,6, b = 1296,9, c = 1712,9 pm, α = 109,9, β = 96,3, γ = 100,2° und Z = 4 mit zwei kristallographisch unabhängigen Molekülen in der asymmetrischen Einheit.
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 623 (1997), S. 1633-1638 
    ISSN: 0044-2313
    Keywords: (CH3)2S derivatives ; Structure ; Spectra ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: (CH3)2SBr2 - Reactions and Structures(CH3)2SBr2 (1) is a donor acceptor complex (8-S-3 + 10-Br-2) which reacts with (CH3)2S(=O)NSi(CH3)3 to yield [(CH3)2S(O)=N—S(CH3)2]+Br- (2). With SbBr3 (CH3)2SBr+SbBr4- (3) can be isolated. 1 crystallizes monoclinic in the space group P21/c with a = 733.8, b = 734.2, c = 1132.7 pm, β = 92.8° and Z = 4. 2 crystallizes in the orthorhombic space group Pnma with a = 967.2, b = 793.3, c = 1168.3 pm and Z = 4. The SBr and BrBr force constants of 1 are compared with those of S2Br2, 3 and Br2 resp. The nmr and mass spectra of 1 and 2 are communicated.
    Notes: (CH3)2SBr2 (1) ist ein (8-S-3 + 10-Br-2) Donor-Akzeptor-Komplex(8-S-3 + 10-Br-2) bedeutet: acht Valenzelektronen am S-Atom, das von drei Bindungspartnern umgeben ist, und zehn Valenzelektronen am Br-Atom, das zwei Bindungspartner hat; s.: S. W. Perkins, J. C. Martin, A. J. Arduengeo III, W. Lau, A. Alegria, J. K. Kochi, J. Am. Chem. Soc. 1980, 102, 7753. und reagiert mit (CH3)2S(=O)NSi(CH3)3 zu [(CH3)2S(O)=N—S(CH3)2]+Br- (2), mit SbBr3 zu (CH3)2SBr+SbBr4- (3). 1 kristallisiert monoklin (P21/c) mit a = 733,8, b = 734,2, c = 1132,7 pm, β = 92,8° und Z = 4. 2 kristallisiert orthorhombisch in der Raumgruppe Pnma mit a = 967,2, b = 793,3, c = 1168,3 pm und Z = 4. Die SBr- und BrBr-Kraftkonstanten von 1 werden mit denen von S2Br2 und 3 bzw. Br2 verglichen. Die NMR- und Massenspektren von 1 und 2 werden kurz diskutiert.
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  • 5
    ISSN: 0044-2313
    Keywords: Chromium(II)-orthophosphate ; crystal growth ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Beiträge zum thermischen Verhalten und zur Kristallchemie von wasserfreien Phosphaten. XIX. Tri-chrom(II)-bis-phosphat Cr3(PO4)2 (≙ Cr6(PO4)4) - Ein Übergangsmetall(II)- Orthophosphat mit neuem StrukturtypIntensiv blau-violette Kristalle des bislang unbekannten Tri-chrom(II)-bis-phosphats, Cr3(PO4)2, entstehen bei der Reduktion von CrPO4 mit Chrom oberhalb von 1050°C (evakuierte Quarzglasampullen, wenige mg NH4I oder I2 als Mineralisator). Die Kristallstruktur von Cr3(PO4)2 enthält sechs kristallographisch unabhängige Cr2+ in der Elementarzelle (P212121, Z = 8, a = 8,4849(10) Å, b = 10,3317(10) Å, c = 14,206(3) Å). Davon sind fünf in der ersten Koordinationssphäre von vier Sauerstoffatomen leicht verzerrt quadratisch-planar umgeben (1,96 Å ≤ d(Cr—O) ≤ 2.15 Å). Deren Koordination wird vervollständigt durch zwei bzw. drei weiter entfernte Sauerstoffatome (2,32 Å ≤ d(Cr—O) ≤ 3,21 Å). Das sechste Cr2+-Ion ist stark verzerrt oktaedrisch koordiniert (d(Cr—O): 1,97, 2,04, 2,15, 2,28, 2,29, 2,53 Å).Die vier kristallographisch unterschiedlichen [PO4]-Gruppen zeigen nur geringe Abweichungen von der Geometric eines idealen Tetraeders (1,51 Å ≤ d(P—O) ≤ 1,57 Å; 104,3° ≤ ∠(O—P—O) ≤ 114,4°).Für die Cr2+ wurde mit μexp = 4,28(2) μB (θP = -54,8(5) K) ein ungewöhnlich niedriges mittleres magnetische Moment gefunden.
    Notes: Deep blue-violet single crystals of hitherto unknown chromous orthophosphate have been obtained reducing CrPO4 by elemental Cr at temperatures above 1050°C in evacuated silica ampoules (NH4I or I2 as mineraliser). The complex structure of Cr3(PO4)2 (P212121, Z = 8, a = 8.4849(10) Å, b = 10.3317(10) Å, c = 14.206(2) Å) contains six crystallographically independent Cr2+ per unit cell. Five of them are coordinated by four oxygen atoms which form a distorted (roof shaped) square plane as first coordination sphere at interatomic distances 1.96 Å ≤ d(Cr—O) ≤ 2.15 Å. Their coordination is completed by additional oxygen atoms (2 or 3) at distances 2.32 Å ≤ d(Cr—O) ≤ 3.21 Å. The sixth Cr2+ shows six-fold octahedral coordination with strong radial distortion (d(Cr—O): 1.97, 2.04, 2.15, 2.28, 2.29, 2.53 Å).The four different [PO4] groups exhibit only minor deviations from ideal tetrahedral geometry (1.51 Å ≤ d(P—O) ≤ 1.57 Å, 104.3° ≤ ∠(O—P—O) ≤ 114.4°).An unusually low magnetic moment μexp = 4.28(2) μB (θP = -54.8(5) K) has been observed for Cr2+.
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  • 6
    ISSN: 0044-2313
    Keywords: Ag1 complexes ; N-acyl thiourea complexes ; potentiometry ; stability constants ; X-ray structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Coordination of Silver(I) by N,N-Diethyl-N′-benzoyl Thiourea in Solution and in the Solid StateSilver(I) reacts in dioxane/water solution with N,N-diethyl-N′-benzoyl thiourea HL to give cationic, neutral, and anionic complexes depending on the pH value, the molar ratio of the reactants and their concentrations. The ligand in these complexes coordinates in various ways. Complex stability constants have been determined by pAg and pH potentiometry. Representative complexes have been isolated in the solid state. One of them is a cyclic tetramer [AgL]4 the structure of which has been determined by X-ray diffraction.
    Notes: Silber(I) bildet mit N,N-Diethyl-N′-benzoyl-thioharnstoff HL in Dioxan/Wasser-Mischung, abhängig vom pH-Wert, dem molaren Verhältnis der Reaktanden und ihren Konzentrationen, kationische, neutrale und anionische Komplexe, in denen der Ligand in unterschiedlicher Weise koordiniert. Für diese Komplexe wurden pAg- und pH-potentiometrisch Stabilitätskonstanten bestimmt. Repräsentative Komplexe konnten in festem Zustand isoliert werden, darunter ein cyclischer Komplex [AgL]4, dessen Struktur durch Röntgenbeugung bestimmt wurde.
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 623 (1997), S. 174-178 
    ISSN: 0044-2313
    Keywords: Bismuth tellurites ; phase diagram ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations to the Ternary System Bi/Te/O. I. The Phase Diagram of the Pseudobinary System Bi2O3/TeO2For the pseudobinary system Bi2O3/TeO2 have been studied the compounds by x-ray and thermal analysis and concluded the phase diagram. Besides the known phases Bi10Te2O19, Bi16Te5O34, Bi2TeO5-Bi2Te2O7, Bi2Te4O11 and two Bi2O3-rich mixedcrystals Bi2(1-x)TexO(3+x) we found the following new ternary phases in the described system: 6 Bi2O3 · TeO2 = Bi12TeO20 and β-Bi16Te5O34.
    Notes: Auf dem quasibinären Schnitt Bi2O3/TeO2 wurde durch Temperversuche und chemischen Transport der Phasenbestand untersucht und mittels thermischer Analysenmethoden ein Zustandsdiagramm erstellt. Neben den bereits bekannten Verbindungen Bi10Te2O19, Bi16Te5O34, Bi2TeO5-Bi2Te2O7, Bi2Te4O11 sowie zwei Bi2O3-reichen Mischkristallen Bi2(1-x)TexO(3+x) bei hohen Temperaturen wurden eine neue ternäre Phase mit der Zusammensetzung 6 Bi2O3 · TeO2 = Bi12TeO20 und ein β-Bi16Te5O34 identifiziert.
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 953-956 
    ISSN: 0009-2940
    Keywords: Molybdenum oxadiene complex ; Cycloaddition ; Catalysis ; Stereoselectivity ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The pentacyclic unsaturated ketone 3 is obtained as the sole product by the reaction of pinocarvone (1) with cycloocta-triene in the presence of catalytic amounts of dicarbonyl-bis(η4-pinocarvone)molybdenum (2). Compound 3 formally resulting from a [4 + 2] cycloaddition reaction of bicy-clo[4.2.0]octa-2,4-diene with the alkene fragment of pinocarvone was characterised by means of spectroscopy (1H, 13CNMR, IR, MS) as well as by X-ray crystal structure analysis. A mechanism is proposed involving rigid molybdenum complexes as intermediates in order to explain the stereospecificity of the reaction.
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  • 9
    ISSN: 0009-2940
    Keywords: Magnesium tetrahydridoaluminate ; Magnesium halide tetrahydridoaluminate ; (Organyloxo)magnesium tetrahydridoaluminates ; X-ray structures ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The molecular structures of XMg(A1H4) · 4 THF (1a, 2, 3a) (X = A1H4, Cl, Br) have been determined by X-ray structural analysis. Each compound possesses a hexacoordinated Mg center and AlH4- groups bound to this center via a single hydride bridge bond. Attempts to prepare ROMg(AlH4) compounds were successful only for sterically demanding groups R (R = CMe3, CPh3, naph, mes, smes). The 2-naphthoxy derivative 7, a compound with the composition (naphO)Mg-(AlH4) · 2.5 THF, is a dimer with a central Mg2O2 ring. One of its two AlH4- groups is terminally bound to one Mg atom, the other bridges the two Mg centers. This structure indicates how AlH4- transfer may occur from ROMg(AlH4) compounds to form Mg(OR)2 and Mg(AlH4)2.
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 453-462 
    ISSN: 0009-2940
    Keywords: Cycloadditions ; Catalysis ; 1-Oxa-1,3-dienes ; Molybdenum ; stereoselectivity ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Molybdenum-mediated [6 + 2]-cycloaddition reactions of unsaturated ketones to cyclotri- or -tetraenes, e.g. cyclohepta-1,3,5-triene or cyclooctatetraene, proceed under very mild conditions, in high yields and with excellent stereoselectivity starting from the appropriate dicarbonylbis[π4-(1-oxa-1,3-diene)]molybdenum complexes. The stereochemistry of the product arising from the reaction of dicarbonylbis[π4-(5-methylhex-3-en-2-one)]molybdenum with cyclohepta-1,3,5-triene allows one to deduce a stepwise mechanism for this addition. The reactants are fused, as would be expected from an exo-type approach, thus indicating an intermolecular attack of the cycloheptatriene. Tungsten oxadiene complexes are effective in analogous reactions at somewhat reduced reaction rates. Catalytic cycloadditions are observed in several cases when 1-5 mol% of the highly reactive dicarbonylbis[π4-(R-(+)-pinocarvone)]molybdenum is employed as the catalyst. Cycloadducts are formed diastereospecifically in most cases. When cyclooctatrienes are employed as reactants, a sequence of electrocyclization of the triene and subsequent [4 + 2]-cycloadditon occurs with high selectivity and efficiency, leading to a pentacyclic ketone. The product structure reveals an endo-type approach of the polyene in this case.
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