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  • 1
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The VIS-laser irradiation of enol lactones 1a, b and benzoquinone in an argon atmosphere led to the fenestrane-type oxetane 2a and the propellane-type oxetane 2b, with regioselective preference for the acetal structure. Under an oxygen atmosphere both regioisomeric fenestrane-type 1,2,4-trioxanes 4a and 5a were obtained from enol lactone 1a, while no oxygen trapping to the propellane-type trioxanes was observed with 1b. Significant quantities of photooxygenation products were obtained from both enol lactones 1a, b due to singlet oxygen derived from oxygen quenching of benzoquinone triplets. The present study demonstrates that Qinghaosu analoga are accessible via trapping of Paterno-Büchi triplet 1,4-diradicals by molecular oxygen.
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  • 2
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 3
  • 4
    ISSN: 0044-2313
    Keywords: K2Fe[P2S6] ; Hexathiodiphosphate(IV) ; Hexathiohypodiphosphate ; Crystal Structure ; Magnetism ; Vibrational Spectrum ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthese, Kristallstruktur, Magnetismus und Schwingungsspektrum von Dikaliumeisen(II)hexathiodiphosphat(IV), K2Fe[P2S6]K2Fe[P2S6] wurde aus den Elementen bei 1173 K in evakuierten, abgeschmolzenen Quarzampullen dargestellt. Die Verbindung bildet transparente, orangefarbene, luft- und feuchtigkeitsbeständige Kristalle. K2Fe[P2S6] kristallisiert monoklin, Raumgruppe P21/n (Nr. 14), mit den Gitterkonstanten (T = 298,5 K): a = 6,0622(4), b = 12,172(1) und c = 7,3787(8) Å, β = 101,113(7)°, Z = 2. Der neuartige Strukturtyp (mP22) wird durch Säulen von alternierend flächenverknüpften S6-Oktaedern und trigonalen Antiprismen (beide verzerrt) charakterisiert, die parallel zur a-Achse verlaufen und durch K+-Kationen (KZ 10; {2,6,2}-Polyeder; d(K—S) = 3,231 - 3,845 Å) miteinander verbunden sind. Die S6-Polyeder der Säulen werden alternierend durch Fe (d̄(Fe—S) = 2,577 Å) bzw. P2-Paare zentriert, die zur a-Achse um 73,4° geneigt sind. Die Bindungslängen in den Hexathiodiphosphat(IV)-Anionen [P2S6]4- mit angenäherter 32/m - D3d-Symmetrie betragen d(P—P) = 2,20 und d̄(P—S) = 2,02 Å. Die Titelverbindung ist oberhalb TN = 28 K paramagnetisch mit μ = 4,69 B.M. und ordnet unterhalb TN antiferromagnetisch. Die beobachteten inneren Moden der Raman- und Infrarotspektren von K2Fe[P2S6] stehen im Einklang mit der Faktorgruppenanalyse. Die Schwingungsbanden werden auf der Basis von [P2S6]4--Einheiten unter Berücksichtigung der Abweichungen von der D3d-Symmetrie zugeordnet.
    Notes: K2Fe[P2S6] was synthesized from the elements at 1173 K in sealed quartz tubes. The compound forms transparent orange crystals, stable against air and moisture. K2Fe[P2S6] crystallizes in the monoclinic system, space group P21/n (No. 14), with cell dimensions (T = 298.5 K) a = 6.0622(4), b = 12.172(1) and c = 7.3787(8) Å, β = 101.113(7)°, Z = 2. The novel structure type (mP22) is characterized by columns of alternating face-sharing S6 octahedra and trigonal antiprisms (both distorted) parallel to the a axis, which are interconnected by inserted K+ (CN 10; {2,6,2}-polyhedra; d(K—S) = 3.231 - 3.845 Å). The S6 polyhedra of the columns are centered alternately by Fe (d̄(Fe—S) = 2.577 Å) and P2 pairs which are inclined to the a axis by 73.4°. The bond lengths in the hexathiodiphosphate(IV) anions, [P2S6]4-, with approximate 3 2/m - D3d symmetry, are d̄(P—P) = 2.20 and d̄(P—S) = 2.02 Å. The compound is paramagnetic above TN = 28 K with μ = 4.69 B.M. and orders antiferromagnetically below TN. The internal modes of the observed Raman and FIR spectra of K2Fe[P2S6] are in accord with the factor group analysis, and the spectra are assigned on the basis of [P2S6]4- units, taking into account the deviation from D3d symmetry.
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 621 (1995), S. 557-561 
    ISSN: 0044-2313
    Keywords: TlEu[PS4] ; Tetrathiophosphate(V) ; Crystal Structure ; Vibrational Spectrum ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Kristallstruktur und Schwingungsspektrum von Thallium(I)-Europium(II)-tetrathiophosphat(V), TlEu[PS4]TlEu[PS4] wurde aus den Elementen bei 1 150 K in einer evakuierten Quarzampulle dargestellt. Die Verbindung bildet transparente, orangefarbene, luft- und feuchtigkeitsbeständige Nadeln, die orthorhombisch, Pnma (Nr. 62) mit a = 12,157(2), b = 6,581(1), c = 8,802(2) Å, Z = 4 kristallisieren. Charakteristisch sind diskrete [PS4]3--Anionen, die durch Tl+ und Eu2+ verbunden sind. Sie sind verzerrt tetraedrisch mit P—S-Abständen zwischen 2,028 und 2,043 Å und so angeordnet, daß Liganden benachbarter Gruppen trigonale S6-Prismen bilden, entlang [0 0 1] zu Säulen verknüpft, die parallel (1 0 0) über gemeinsame Kanten zu gewellten Schichten kondensiert sind. Dazwischen sind leere, verzerrte Halbwürfel und zur Hälfte mit P-Atomen besetzte Tetraederlücken Durch die alternierende Besetzung mit Tl+ und Eu2+ sind diese Prismen leicht verzerrt. Man kann daher diese Struktur als eine geordnete, teilweise aufgefüllte Überstruktur des InNi2-Typs auffassen (InInNi4□2tet ≙ TlEuS4P□1tet), aber auch als zentrosymmetrische Variante der TlSn[PS4]-Struktur (Raumgruppe Pna21). Das Schwingungsspektrum entspricht der Strukturbestimmung, die beobachteten Raman- und Infrarotbanden lassen sich zwanglos auf der Basis von [PS4]3- -Einheiten mit C2v-Symmetrie zuordnen.
    Notes: TlEu[PS4] was synthesized from the elements in a sealed quartz ampoule at 1 150 K. The compound forms transparent orange needles, stable in air and moisture. It crystallizes in the orthorhombic system, space group Pnma (No. 62), with cell dimensions a = 12.157(2), b = 6.581(1), c = 8.802(2) Å, Z = 4. The crystal structure consists of discrete [PS4]3- anions interconnected by Tl+ and Eu2+. The tetrahedral [PS4]3- groups are slightly distorted with P—S bond lengths in the range 2.028 to 2.043 Å. These tetrahedral anions are arranged in such a way that the sulfur atoms form columns of distorted trigonal S6 prisms along [0 0 1]. The columns are condensed via common edges to puckered layers parallel to (1 0 0). The interlayer region consists of empty distorted half-cubes and tetrahedral holes, half of them filled by P atoms. The trigonal prisms in the columns are centered alternately by Tl+ and Eu2+. In this way, the structure can be regarded as an ordered superstructure of the InNi2 type, where half of the tetrahedral holes are filled by phosphorus atoms: InInNi4□2tet ≙ TlEuS4P□1tet. TlEu[PS4] is a centrosymmetric variant of the TlSn[PS4] structure type (space group Pna21). The vibrational spectrum is in accordance with the X-ray crystal structure, the Raman and infrared vibrations are assigned on the basis of [PS4]3- units with C2v symmetry.
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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: Formation and Structure of tert-Butyl(tert-butylamino) [tris(tert-butyloxy)silylthio]-boraneThe smooth addition of the SH bond of (tBuO)3SiSH to the BN bond of tBuB≡NtBu gives the title compound, which crystallizes in the triclinic system, space group P1, with an unexpectedly short BN bond, d(BN) = 137 pm, in a Z configuration.
    Notes: Die SH-Bindung von (tBuO)3SiSH addiert sich glatt an die BN-Bindung von tBuB≡NtBu unter Bildung der Titelverbindung. Diese kristallisiert triklin, Raumgruppe P1, mit einer unerwartet kurzen, Z-konfigurierten BN-Bindung, d(BN) = 137 pm.
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 377-384 
    ISSN: 0044-2313
    Keywords: One-pot reactions of tri-t-butoxychlorosilane, K-t-butanolate and substituted anilines. Crystal structure analyses of N-(tri-t-butoxysilyl)-aniline, C18H33NO3Si ; N-(tri-t-butoxysilyl)-p-nitroaniline, C18H32N2O5Si ; N-Methyl-(N-tri-t-butoxysilyl)-p-nitroaniline C19H34N2O5Si ; N-(tri-t-butoxysilyl)-p-cyanoaniline, C19H32N2O3Si ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Formation and Structures of N-(tri-t-butoxysilyl)aniline CompoundsPara-substituted N-(tri-t-butoxysilyl)anilines (t-BuO)3SiNRC4H4X-p, R = H, CH3, with substituents of high electron affinity (X = CN, NO2) were prepared by a one-pot reaction of tri-t-butoxychlorsilane, potassium t-butanolate and substituted anilines. Corresponding compounds with substituents of low electron affinity (X = OMe, H) preferably were prepared by metalation of anilines with sodium amide. Four crystal structures were determined. N-(tri-t-butoxysilyl)-p-nitro-aniline, N-methyl-(N-tri-t-butoxysilyl)-p-nitroaniline and N-(tri-t-butoxysilyl)-p-cyanoaniline crystallize at 298 K monoclinically, N-(tri-t-butoxysilyl)aniline crystallizes orthorhombically.
    Notes: Derivate des para-substituierten N-(Tri-t-butoxysilyl)anilins (t-BuO)3SiNRC6H4X-p, R = H, CH3 mit Substituenten hoher Elektronenaffinität (X = CN, NO2) wurden nach einem neuen Eintopfverfahren aus Tri-t-butoxychlorsilan, Kalium-t-butanolat und dem entsprechend substituierten Anilin dargestellt. Für Substituenten niederer Elektronenaffinität (X = OMe, H) wird die Methode der Metallierung von Anilinen mit Natriumamid bevorzugt. Vier Kristallstrukturen wurden bestimmt. N-(Tri-t-butoxysilyl)-p-nitroanilin, N-Methyl-(N-tri-t-butoxysilyl)-p-nitroanilin und N-(Tri-t-butoxysilyl)-p-cyanoanilin kristallisieren bei 298 K monoklin, N-(Tri-t-butoxysilyl)anilin kristallisiert orthorhombisch.
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 608 (1992), S. 131-134 
    ISSN: 0044-2313
    Keywords: Tetrahetero-tetrahedrane anions ; G44-, Sn44; ; infrared, Raman spectra; ; internal vibrations ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Internal Vibration of the Tetrahetero-Tetrahedrane Anions Ge44-, Sn44-, and Pb44The Frequencies of the internal vibrations ν1 (A1), ν2(E), ν3(T2) of the tetrahetero-tetrahedrane an ions Ge44- and Sn44- are determined from the infrared and Raman spectra of K7LiGe8 and KSn, respectively. A comparison of the characteristic vibration of tetrahedrane anions X44- (X = Si, Ge, Sn)and the isoelectronic neutral tetrahedranes Y4 of the neighbouring elements (Y = P, As, Sb) shows a rather constant ratio of the corresponding frequencies k = v˜(X44-) = 0,77. This allows for an estimate of v˜(Pb44-) from the known Bi4data. In the inflated spectrum of KPb bands are observed in the predicted frequency range.
    Notes: Aus den Infrarot-und Raman-Spektren von K7LiGe8 und KSn werden die Frequenzen der inneren Schwingungen ν1(A1), ν2(E) und ν3(T3) der Tetrahetero-Tetrahedran -Anionen Ge44- und Sn44- bestimmt. Der Vergleich der charakteristischen Schwingungen von Tetrahedran-Anionen X44-(X = Si, Ge, Sn) und isoelektronischen neutralen Tetrahedranen Y4 der Nachbarelemente (Y = P,As, Sb)ergibt ein nahezu konstantes Verhältnis für die einander entsprechenden Frequenzen k = v˜(X44-)/v˜(Y4) = 0,77. Damit werden aus den Frequenzen v˜(Bi4) Werte für v˜(Pb44-) abgeschätzt, welche mit Banden im Infrarot-Spektrum von KPb übereinstimmen.
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  • 9
    ISSN: 0044-2313
    Keywords: Gold ; thiolate complex ; synthesis ; structure ; X-ray ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Beiträge zur Chemie der Silicium-Schwefel-Verbindungen. 65. Darstellung, Kristall- und Molekülstruktur von cyclo-Tetrakis[tri-tert-butoxysilanthiolatogold(I)], [(t-C4H9O)3SiSAu]4, dem ersten Komplex mit einem Au4S4-Ring-SystemDie Darstellung des ersten Silanthiolato-Goldkomplexes - cyclo-Tetrakis[tri-tert-butoxysilanthiolatogold(I)] - ist beschrieben. Die Kristallstruktur wurde bei 200 K an einem farblosen, orthorhombischen Prisma bestimmt. Bei 187 K wurde eine reversible Phasenumwandlung beobachtet. Das Zentrum des Moleküls ist ein gefalteter Au4S4-Achtring mit alternierender Abfolge aus dreifach koordinierten Schwefel- und zweifach koordinierten Goldatomen. Charakteristische Abstände und Winkel: Au—S 228,4 und 229,6 pm, Si—S 216,9 pm, S—Au—S 178,8° und 178,3°, Au—S—Au 90,3°, Si—S—Au 103,7° und 101,9°. Der kürzeste Abstand zwischen zwei Goldatomen beträgt 324,8 pm.
    Notes: The preparation of the first silanethiolate complex of gold, cyclo-tetrakis[tri-tert-butoxysilanethiolatogold(I)] from tri-tert-butoxysilanethiol and tetrachloroauric acid is described. The compound forms colorless orthorhombic crystals, and the molecular structure was determined at 200 K by single crystal X-ray diffraction. At 187 K, a possible, reversible phase transition is observed. The center of the molecule is a distinctly folded eight-membered Au4S4 ring of alternating three-fold coordinated sulfur and two-fold coordinated gold atoms. The relevant bond lengths and angles are: Au—S 228.4 and 229.6 pm, Si—S 216.9 pm, S—Au—S 178.8° and 178.3°, Au—S—Au 90.3°, Si—S—Au 103.7° and 101.9°. The gold atoms are separated by 324.8 pm.
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  • 10
    ISSN: 0044-2313
    Keywords: Carbosilanes ; Cu-catalyzed reactions of silicon with C-chlorinated 1,1,3,3,5,5-hexachloro-1,3,5-trisilacyclohexanes ; crystal structures of hexadecachloro-1,3,5,7,9,11,13,14-octasiladispiro[5.1.5.1]tetradecane ; decachloro-1,3,5,7,9,11-hexasilatricyclo[6.4.0.02,7]dodecane and decachloro-2-trichlorosilyl-1,3,5,7,9,11-hexasilatricyclo[6.4.0.02,7]dodecane ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Formation of Organosilicon Compounds 113. Reactions of C-chlorinated 1,1,3,3,5,5-Hexachloro-1,3,5-trisilacyclohexanes with Si(Cu cat.). Structures of Hexadecachloro-1,3,5,7,9,11,13,14-octasiladispiro[5.1.5.1]tetradecane 12, Decachloro-1,3,5,7,9,11-hexasilatricyclo[6.4.0.02,7]dodecane 13 and Decachloro-2-trichlorosilyl-1,3,5,7,9,11-hexasilatricyclo[6.4.0.02,7]dodecane 14Elemental Si(Cu cat.) was treated with 1,1,2,2,3,3,5,5-octachloro-1,3,5-trisilacyclohexane 3, 1,1,2,2,3,3,4,4,5,5-decachloro-1,3,5-trisilacyclohexane 4 and with (Cl2Si—CCl2)3 5, resp., in a stirred bed reactor at 330°C. The products can be understood as to be formed by silylation, hydrogenation, degradation, rearrangement and condensation reactions all of them starting from the CCl2 groups of the trisilacyclohexanes. Especially remarkable is Si8C6H8Cl16 12 with a C-spiro linked framework formed by a trisilacyclohexane, a disilacyclobutane and another trisilacyclohexane building block. In two further tricyclic carbosilanes Si6C6H10Cl10 13 and Si7C6H9Cl13 14, two trisilacyclohexane rings each share an opposite Si—C bond with a disilacyclobutane. Another group of compounds includes compounds consisting of two 1,3,5-trisilacyclohexane rings linked by either a C=C or a C=C=C unit. Moreover some derivatives of 1,3-disilacyclopentenes are formed obviously by a contraction of the C-chlorinated 1,3,5-trisilacyclohexane rings. Compound 12 crystallizes in the monoclinic space group P21/n (no. 14) with a = 1 307.8, b = 1 184.2, c = 984.4 pm, β = 93.58° and Z = 2 molecules per unit cell. 13 crystallizes in the triclinic space group P1 (no. 2) with a = 885.7, b = 911.6, c = 868.3 pm, α = 113.15°, β = 75.36° γ = 119.22° and Z = 1. 14 crystallizes in the monoclinic space group P21/c (no. 14) with a = 1853.2, b = 912.9, c = 1725.3 pm, β = 112.69° and Z = 4.
    Notes: 1,1,2,2,3,3,5,5,-Octachlor-1,3,5-trisilacyclohexan 3, 1,1,2,2,3,3,4,4,5,5-Decachlor-1,3,5-trisilacyclohexan 4 und (Cl2Si—CCl2)3 5 wurden mit Si(Cu) bzw. Cu im Rührbett bei 330°C umgesetzt. Die Reaktionen gehen von den CCl2-Gruppen der Trisilacyclohexane aus, und die verschiedenen Reaktionsprodukte sind durch Silylierung, Hydrierung, Kondensation und Umlagerung zu erklären. Besonders bemerkenswert ist das Si8C6H8Cl16 12, in dessen Grundgerüst zwei 1,3,5-Trisilacyclohexane über einen Disilacyclobutanring C-spiroverbrückt sind. In zwei tricyclischen Carbosilanen, Si6C6H10Cl10 13 und Si7C6H9Cl13 14, sind zwei Trisilacyclohexane über einen Disilacyclobutanring verbunden, der unter Ausbildung von zwei Si—C-Bindungen zwischen gegenüberliegenden SiCl- und CCl-Gruppen aufgebaut ist. Eine weitere Gruppe enthält Verbindungen, in denen zwei 1,3,5-Trisilacyclohexanringe entweder über eine C=C- oder C=C=C-Gruppe verbunden sind. Es entstehen auch 1,3-Disilacyclopentenderivate, deren Bildung auf eine Ringverengung der C-chlorierten 1,3,5-Trisilacyclohexane zurückgeführt wird. Verbindung 12 kristallisiert monoklin in der Raumgruppe P21/n (Nr. 14) mit a = 1 307,8, b = 1 184,2, c = 984,4 pm, β = 93,58° und Z = 2 Molekülen pro Elementarzelle; 13: triklin in der Raumgruppe P1 (Nr. 2) mit a = 885,7, b = 911,6, c = 868,3 pm, α = 113,15°, β = 75,36°, γ = 119.22° und Z = 1; 14: monoklin in der Raumgruppe P21/c (Nr. 14) mit a = 1 853,2, b = 912,9, c = 1 725,3 pm, β = 112.69° und Z = 4.
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