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  • 1
    Electronic Resource
    Electronic Resource
    Self-consistent truncation of the BBGKY hierarchy on the two-body level (1992)
    Springer
    The European physical journal 342 (1992), S. 161-167 
    Details
    ISSN: 1434-601X
    Keywords: 24.10.Cn ; 25.70.−z
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We present a coupled set of equations for the one-body density matrix and the two-body correlation function consistent with trace relations and conservation laws which provide an extension of correlation dynamics on the two-body level. The additional interaction terms are discussed in the context of time-dependent G-matrix theory and NQCD and studied numerically by one-dimensional calculations for colliding finite fermion systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01288464
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  • 2
    Electronic Resource
    Electronic Resource
    Correlation dynamics of finite fermion systems (1990)
    Springer
    The European physical journal 337 (1990), S. 175-183 
    Details
    ISSN: 1434-601X
    Keywords: 24.10.Cn ; 25.70.−z
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The dynamical description of strongly interacting finite Fermi systems is based on coupled equations of motion for the one-body density matrixρ(11′) and the two-body correlation functionc 2(12, 1′2′) as obtained from the density-matrix hierarchy. The truncation schemes considered exceed the conventional Brueckner-Hartree-Fock scheme and also apply for nonstationary problems. In the limit of slow processes in time the equation of motion for the two-body correlation functionc 2 can be integrated in time and closed expressions can be given for the dynamical evolution ofρ(11′). When performing a Wigner transformation and adopting semiclassical limits this gives a transport equation of the Uehling-Uhlenbeck type for the one-body phase-space distributionf(x,p;t). Furthermore, in the small amplitude limit, we obtain a set of coupled equations for particle-hole (p-h),2p-2p, 2h-2h, 2p-2h, 1p-3h, 1h-3p amplitudes beyond the level of second RPA which provide a genuine basis for the description of giant resonances and their damping width.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01294289
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  • 3
    Electronic Resource
    Electronic Resource
    Synthese und Strukturbestimmung von (i-Pr)2NB(t-BuP)3 und (i-Pr)2NB(t-BuP)4Professor Ernst-Otto Fischer zum 75. Geburtstage gewidmet (1994)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 8-15 
    Details
    ISSN: 0044-2313
    Keywords: P3B and P4B ring systems ; NMR data ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Structure Analysis of (i-Pr)2NB(t-BuP)3 and (i-Pr)2NB(t-BuP)4The diphosphide K(t-Bu)P-(t-BuP)2-P(t-Bu)K obtained by the cleavage reaction of the 3-membered ring system (i-Pr)2BN(t-BuP)2 with potassium reacts with t-BuPCl2 at -78°C under ring expansion to form the P3B ring system (i-Pr)2NB(t-BuP)3 - 1,2,3-tri-t-butyl-tri-phospha-4-diisopropyl-aminoboretane (1). - The 5-membered P4B ring system (i-Pr)2NB(t-BuP)4 - 1,2,3,4-tetra-t-butyl-tetraphospha-5-diisopropylaminoborolidine, (2) - is formed from K(t-Bu)P—(t-BuP)2—P(t-Bu)K and (i-Pr)2NBCl2 analogous to the above reaction. 1 and 2 could be obtained in a pure form and characterized NMR spectroscopically and by X-ray structure analysis. 1 shows at 200 K two conformation isomers; for 2 31P-10,11B-isotopic shifts could be identified.
    Notes: Das bei der Spaltung des Dreiringes (i-Pr)2BN(t-BuP)2 mit Kalium gebildete Diphosphid K(t-Bu)P—BN(i-Pr)2—P(t-Bu)K reagiert bei -78°C mit t-BuPCl2 unter Ringerweiterung zu (i-Pr)2NB(t-BuP)3-1,2,3-Tri-t-butyl-triphospha-diisopropyl-aminoboretan, (1) - mit einem P3B-Ringgerüst. In analoger Weise entsteht bei der Reaktion zwischen K(t-Bu)P—(t-BuP) - (t-BuP)2—P(t-Bu)K und (i-Pr)2NBCl2 das P4B-Ringsystem (i-Pr)2NB(t-BuP)4 - 1,2,3,4-Tetra-t-butyl-tetraphospha-5-diiso-propylaminoborolidin, (2) -, 1 und 2 konnten in reiner Form isoliert, NMR-spektroskopisch und durch Röntgenstrukturanalysen charakterisiert werden. 1 zeigt bei 200 K zwei Konformationsisomere; bei 2 konnten 31P-10,11B-Isotopieverschiebungen nachgewiesen werden.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19946200104
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  • 4
    Electronic Resource
    Electronic Resource
    CuSeTeCl, CuSeTeBr und CuSeTeI: Verbindungen mit geordneten ∞1[SeTe]-Schrauben (1995)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 621 (1995), S. 969-974 
    Details
    ISSN: 0044-2313
    Keywords: Copper(I) selenium tellurium halides ; chalcogen ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: CuSeTeCl, CuSeTeBr, and CuSeTeI: Compounds with ordered ∞1[SeTe] ScrewsThe hitherto unknown copper(I) chalcogen halides CuSeTeCl, CuSeTeBr and CuSeTeI have been prepared and their crystal structures were determined. The compounds of general composition CuSeTeX crystallize in the monoclinic system, space group P21/n (No. 14), Z = 4, a = 7.9796(9), b = 4.7645(8), c = 10.843(3) Å, β = 104.12(1)°, V = 399.8(1) Å3 (X = Cl), a = 8.155(3), b = 4.765(2), c = 11.286(4) Å, β = 104.21(3)°, V = 425.1(3) Å3 (X = Br) and a = 8.4370(9) b = 4.7652(5), c = 11.996(2) Å, β = 103.178(9)°, V = 469.6(1) Å3 (X = I). The crystal structures show infinite onedimensional screws YY′ of chalcogen atoms, with Y = Se and Y′ = Te alternately. The coordinations of Se and Te in these compounds are quite different.
    Notes: Die bisher unbekannten Kupfer(I)-chalkogenhalogenide CuSeTeCl, CuSeTeBr und CuSeTeI wurden erstmals erhalten und ihre Kristallstrukturen bestimmt. Sie kristallisieren monoklin, RG P21/n (Nr. 14), Z = 4, mit a = 7,9796(9), b = 4,7645(8) und c = 10,843(3) Å, β = 104,12(1)°, V = 399,8(1) Å3 (X = Cl), a = 8,155(3), b = 4,765(2) und c = 11,286(4) Å, β = 104,21(3)°, V = 425,1(3) Å3 (X = Br) sowie a = 8,4370(9), b = 4,7652(5) und c = 11,996(2) Å, β = 103,178(9)°, V = 469,6(1) Å3 (X = I). In den Kristallstrukturen liegen eindimensional unendliche Schrauben YY′ vor, mit alternierend Y = Se und Y′ = Te. Die Umgebungen von Se und Te sind deutlich verschieden.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19956210612
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  • 5
    Electronic Resource
    Electronic Resource
    CuClS0.94Te1.06 und CuBrS0.92Te1.08, zwei neue Kupfer(I)-chalkogenhalogenide mit neutralen ∞1[STe]-Schrauben (1996)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 622 (1996), S. 853-857 
    Details
    ISSN: 0044-2313
    Keywords: Copper(I) sulfur tellurium halides ; chalcogen ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: CuClS0.94Te1.06 and CuBrS0.92Te1.08, Two New Copper(I) Chalcogen Halides Containing Neutral ∞1[STe] ScrewsCuClS0.94Te1.06 and CuBrS0.92Te1.08 are two new, isotypic compounds of general composition CuXYY′ (X = halide, Y, Y′ = chalcogen) with a mixed chalcogen substructure. They crystallize in the monoclinic system, space group P21/n (No. 14), a = 7.878(2), b = 4.727(1), c = 10.759(2) Å, β = 103.97(2)°, V = 388.8(2) Å3 (CuClS0.94Te1.06) and a = 8.043(3), b = 4.746(2), c = 11.240(4) Å, β = 103.46(3)°, V = 417.3(3) Å3 (CuBrS0.92Te1.08), both with Z = 4. The crystal structures are dominated by ordered ∞1[STe±0]-screws. From a crystal chemical point of view the sulfur and tellurium atoms are significantly different. The melting points are 341 °C (CuClS0.94Te1.06) and 336 °C (CuBrS0.92Te1.08). The compounds CuXYY′ (X = Cl, Br, I; Y, Y′ = S, Se, Te) are compared and discussed.
    Notes: Mit CuClS0.94Te1.06 und CuBrS0.92Te1.08 wurden zwei neue, isotype Verbindungen der Zusammensetzung CuXYY′ (X = Halogenid, Y, Y′ = Chalkogen) mit gemischtem Chalkogenteilgitter erhalten. Sie kristallisieren monoklin, RG P21/n (Nr. 14) mit a = 7,878(2), b = 4,727(1) und c = 10,759(2) Å, β = 103,97(2)°, V = 388,8(2) Å3 (CuClS0.94Te1.06) bzw. a = 8,043(3), b = 4,746(2) und c = 11,240(4) Å, β = 103,46(3)°, V = 417,3(3) Å3 (CuBrS0.92Te1.08), jeweils mit Z = 4. Strukturbestimmendes Merkmal sind die geordneten ∞1[STe±0]-Schrauben. Kristallchemisch sind die Schwefel- und Telluratome deutlich unterschiedlich. Die Schmelzpunkte liegen bei 341 °C (CuClS0.94Te1.06) bzw. 336 °C (CuBrS0.92Te1.08). Die Strukturen von CuXYY′ (X = Cl, Br, I; Y, Y′ = S, Se, Te) werden verglichen und diskutiert.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19966220517
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  • 6
    Electronic Resource
    Electronic Resource
    Thia- und Selena-arachno-undecaboran 6,7-μ-(CH3E)B10H13 Kristallstruktur von arachno-6,7-μ-(CH3Se)B10H13 Theoretische Untersuchungen der Molekülstrukturen und 11B-NMR-Verschiebungen von arachno-6,7-μ-(CH3E)B10H13 (1997)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 623 (1997), S. 1157-1162 
    Details
    ISSN: 0044-2313
    Keywords: Thia- and selena-arachno-undecaborane ; preparation ; spectroscopy ; ab initio/IGLO ; GIAO/NMR method ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thia- and Selena-arachno-undecaborane 6,7-μ-(CH3E)B10H13. Crystal Structure of arachno-6,7-μ-(CH3Se)B10H13. Theoretical Investigations of the Molecular Structures and 11B NMR Shifts of arachno-6,7-μ-(CH3E)B10H13The reaction of B10H14 with (CH3)2S yields with loss of H2 the base adduct 6,9-[(CH3)2S]2B10H12. Although an analogous reaction between B10H14 with disulfanes or diselenanes was expected to produce 6,9 bridged dichalcogen derivatives, (CH3)2S2 failed to react even under reflux conditions. Trisulfane (CH3)2S3 does react, but the pathway is different and leads to (CH3S)B10H13 2 without loss of H2. Unlike of (CH3)2S2, (CH3)2Se2 yields (CH3Se)B10H13, 3. Both 2 and 3 are formed by substitution of a bridging hydrogen and could be obtained in pure form and characterized 11B NMR spectroscopically. A single crystal X-ray structure analysis also was performed on 3 (space group P21/c). The molecular structures of 2 and 3 were optimized at the MP2 level and 11B NMR shifts were computed at the IGLO-SCF, GIAO-SCF and GIAO-B3LYP levels of theory.
    Notes: Bei der Reaktion zwischen B10H14 und (CH3)2S erfolgt unter H2-Abspaltung eine zweifache Adduktbildung, die zu 6,9-[(CH3)2S]2B10H12 führt. Die analoge Umsetzung zwischen B10H14 mit Disulfanen bzw. Diselenanen führte jedoch nicht zu den 6,9-Dichalkogen-verbrückten Derivaten. Bei der Umsetzung mit (CH3)2S2 findet selbst unter Refluxbedingungen keine Reaktion statt, wohl aber mit dem Trisulfan (CH3)2S3. Die Reaktion verläuft aber nicht unter H2-Abspaltung. Vielmehr wird dabei ein Brücken-H-Atom durch eine CH3S-Gruppe substituiert unter Bildung von (CH3S)B10H13 2. Im Gegensatz zu (CH3)2S2 findet aber mit (CH3)2Se2 ebenfalls eine Brücken-H-Substitution statt, wobei (CH3Se)B10H13 3 gebildet wird. 2 und 3 konnten in reiner Form isoliert und 11B-NMR-spektroskopisch charakterisiert werden. Von 3 wurde eine Röntgenstrukturanalyse durchgeführt (Raumgruppe P21/c) und von 2 und 3 die Molekülstrukturen auf MP2-Niveau optimiert sowie 11B-NMR- Verschiebungen mit IGLO-SCF, GIAO-SCF und GIAO-B3LYP berechnet.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19976230725
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