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  • 1
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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  • 2
    ISSN: 1434-6079
    Keywords: 74.30.Gn ; 74.70.Vy ; 76.60.Es
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract 13C and31P solid state NMR measurements on the organic ligands in ligated Au55, Ni8, Pt309, Cu36 and Cu70 clusters are reported. The ligands behave like diamagnetic organic molecules, giving rise to relatively narrow lines with excellent cross-polarization efficiency. The resonance lines of the nuclei directly bound to the metal core are systematically broadened in the conducting compounds. No pronounced Knight shifts or evidence of metallic-like relaxation were observed. These results support a model for the electrical conduction involving tunneling between metal cores with the ligands playing the role of a tunneling barrier.
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  • 3
    ISSN: 0044-2313
    Keywords: Synthesis of [iPr2P]2P—SiMe3 1 and [iPr2P]2PLi 2. Reactions of 1 with CBr4, of 2 with 1,2-dibromoethane, and MeCl, yielding iPr2P—P=P(Br)iPr2, [iPrP]2P—P[PiPr2]2, iPr2P—P=P(Me)iPr2, crystal structure of Tetrakis(di-isopropyl-phosphino)diphosphane ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: [iPr2P]2P—SiMe3 and [iPr2P]2PLi - Synthesis and Reactions Structure of [iPr2P]2P—P[PiPr2]2[iPr2P]2P—SiMe3 1 and [iPr2P]2PLi 2 were prepared to investigate the influence of the bulky alkyl groups on formation and properties of the ylides R2P—P=P(X)R2 (R = iPr, tBu; X = Br, Me) in reactions of 1 with CBr4 and of 2 with 1,2-dibromoethane or MeCl, resp. Compared to the iPr groups the tBu groups favour the formation of ylides. With CBr4 1 forms iPr2P—P=P(Br)iPr2 5 just as a minor product which decomposes already below -30°C. With 1,2-dibromoethane 2 yields only traces of 5 but [iPr2P]P—P[P(iPr)2]2 7 as main product. With MeCl 2 gives iPrP—P=P(Me)iPr2 9 and [iPr2P]2PMe 10 in a molar ratio of 1:1. 9 is considerably more stable than 5. 7 crystallizes triclinic in the space group P1 (No. 2) with a = 10.813 Å, b = 11.967 Å, c = 15.362 Å, α = 67.90°, β = 71.36°, γ = 64.11° and two formula units in the unit cell.
    Notes: [iPr2P]2P—SiMe3 1 und [iPr2P]2PLi 2 wurden synthetisiert. Die Umsetzungen von 1 mit CBr4 und von 2 mit 1,2-Dibromethan bzw. MeCl ermöglichen einen Vergleich des Einflusses der iPr- bzw. tBu-Gruppen auf Bildung und Eigenschaften der Ylide R2P—P=P(X)R2 (R = iPr, tBu; X = Br, Me) bei analogen Reaktionen.Die tBu-Gruppe begünstigt gegenüber der iPr-Gruppe die Ylidbildung. 1 bildet mit CBr4 das iPr2P—P=P(Br)iPr2 5 als Nebenprodukt, das sich schon unterhalb -30°C zersetzt. 2 bildet mit 1,2-Dibromethan das Ylid 5 nur in Spuren, aber [(iPr)2P]2P—P[P(iPr)2]2 7 als Hauptprodukt. 2 reagiert mit MeCl zum iPr2P—P=P(Me)iPr2 9 und [iPr2P]2PMe 10 im Molverhältnis 1:1. 9 ist erheblich beständiger als 5. 7 kristallisiert triklin in P1 (Nr. 2) mit a = 10,813 Å, b = 11,967 Å, c = 15,362 Å, α = 67,90°, β = 71,36°, γ = 64,11°. Die Elementarzelle enthält zwei Formeleinheiten.
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  • 4
    ISSN: 0044-2313
    Keywords: Li(THF)2[η2-(tBu2P)2P] ; Li(TMEDA)[η2-(tBu2P)2P] ; Li(THF)2[η2-(iPr2P)2P] ; Li(THF)2[η2-(Et2N)2P—P—PtBu2] ; Li(THF)2[η2-(tBu2P—P—PiPr2)] ; (tBu2P)2P—SiMe3 ; crystal structures ; 1H, 31P, 7Li-NMR spectra ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Formation and Structure of Li(THF)2[η2-(tBu2P)2P], Li(TMEDA)[η2-(tBu2P)2P], Li(THF)2[η2-(iPr2P)2P], Li(THF)2[η2-(Et2N)2P—P—PtBu2], Li(THF)2[η2-(tBu2P—P—PiPr2] and (tBu2P)2P—SiMe3The formation and crystal structures of the compounds (tBu2P)2P—SiMe3 1, Li(THF)2[η2-(tBu2P)2P] 2, Li(TMEDA)[η2-(tBu2P)2P] 3, Li(THF)2[η2-(iPr2P)2P] 4, Li(THF)2[η2-(Et2N)2P—P—PtBu2] 5 and Li(THF)2[η2-(tBu2P—P—PiPr2)] 6 are reported. Compounds 3-6 are formed by reacting the corresponding silylated triphosphanes with nBuLi: 2 and 3 result from (tBu2P)2P—SiMe3 1, 4 from (iPrP)2P—SiMe3, 5 from (Et2N)2P—P(SiMe3)—PtBu2 and 6 from tBu2P—P(SiMe3)—PiPr2. 1 crystallizes in the orthorhombic space group P212121 (no. 19) with a = 910.87(7) pm, b = 1132.5(1) pm, c = 2373.5(2) pm (determined at 90 K). The structure determination of 2 was performed at 293 K and 200 K, respectively. 2 crystallizes in the monoclinic space group P21/n (no. 14) with a = 1069.7(3) pm, b = 1802.5(3) pm, c = 1604.0(7) pm, β = 98.11(2)° (200 K); 3 also in P21/n (no. 14) with a = 904.3(2) pm, b = 1936.4(5) pm, c = 1653.2(3) pm, β = 94.52(1)° (200 K). 4 crystallizes monoclinically in C2/c (no. 15) with a = 1650.0(5) pm, b = 945.6(3) pm, c = 1779.8(5) pm, β = 108.81(2)° (200 K); 5 in P21/n (no. 14) with a = 939.4(5) pm, b = 1736.8(6) pm, c = 1943.3(7) pm, β = 98.17(4)° (200 K). All compounds contain Z = 4 molecules in the unit cell.The 1H, 31P and 7Li NMR spectra of 2-6 are discussed.
    Notes: Es wird über die Verbindungen (tBu2P)2P—SiMe3 1, Li(THF)2[η2-(tBu2P)2P] 2, Li(TMEDA) · [η2-(tBu2P)2P] 3, Li(THF)2[η2-(iPr2P)2P] 4, Li(THF)2[η2-(Et2N)2P—P—PtBu2] 5 und Li(THF)2[η2-(tBu2P—P—PiPr2)] 6 berichtet. Letztere bilden sich durch Umsetzung der entsprechenden silylierten Triphosphane mit nBuLi: 2 und 3 aus (tBu2P)2P—SiMe3 1, 4 aus (iPr2P)2P—SiMe3, 5 aus (Et2N)2—P · (SiMe3)—PtBu2, 6 aus tBu2P—P(SiMe3)—PiPr2.1 kristallisiert orthorhombisch in P212121 (Nr. 19) mit a = 910,87(7) pm, b = 1132,5(1) pm, c = 2373,5(2) pm (bei 90 K bestimmt). Die Strukturbestimmung von 2 erfolgte bei 293 K und 200 K. 2 kristallisiert monoklin in P21/n (Nr. 14) mit a = 1069,7(3) pm, b = 1802,5(3) pm, c = 1604,0(7) pm, β = 98,11(2)° (200 K), 3 ebenfalls in P21/n (Nr. 14) mit a = 904,3(2) pm, b = 1936,4(5) pm, c = 1653,2(3) pm, β = 94,52(1)° (200 K). 4 kristallisiert monoklin in C2/c (Nr. 15) mit a = 1650,0(5) pm, b = 945,6(3) pm, c = 1779,8(5) pm, β = 108,81(2)° (200K), 5 in P21/n (Nr. 14) mit a = 939,4(5) pm, b = 1736,8(6) pm, c = 1943,3(7) pm, β = 98,17(4)° (200 K). Alle fünf Verbindungen enthalten jeweils vier Formeleinheiten in der Elementarzelle.Es wird über die Untersuchung der 1H-, 31P- und 7Li-NMR-Spektren der Verbindungen 2-6 berichtet.
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  • 5
    ISSN: 0044-2313
    Keywords: [η2-{tBu2P—P=PtBu2} PtBr(PPh3)] ; crystal structure ; 1H-, 13C-, 31P-NMR spectra ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Coordination Chemistry of P-rich Phosphanes and Silylphosphanes. XIII [1]. [η2-{tBu2P—P=PtBu2} PtBr(PPh3)][η2-{tBu2P—P=PtBu2} PtBr(PPh3)] 1 is the first transition metal complex compound resulting from a phosphino-phosphinidene-phosphorane. The yellow crystals of 1 (fp. 201-203°C, decomp.) were obtained by reacting tBu2P—P=P(Br)tBu2 with either (Ph3P)2Pt · C2H4, or with Pt(PPh3)4, resp. Compound 1 crystallizes triclinic in the space group P1 (no. 2) with a = 1076.80(8) pm, b = 1344.61(8) pm, c = 1381.16(9) pm, α = 81.773(6)°, β; = 85,110(8), γ = 88,776(7).
    Notes: [η2-{tBu2P—P=PtBu2} PtBr(PPh3)] 1 ist die erste Komplexverbindung aus einem Phosphino-phosphiniden-phosphoran. Die gelben Kristalle von 1, Smp. 201-203°C (unter Zersetzung) bilden sich bei der Umsetzung von tBu2P—P=P(Br)tBu2 mit (Ph3P)2Pt · C2H4 oder Pt(PPh3)4. 1 kristallisiert triklin in P1 (Nr. 2) mit a = 1076,80(8) pm, b = 1344,61(8) pm, c = 1381,16(9) pm, α = 81,773(6)°, β; = 85,110(8)°, γ = 88,776(7).
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  • 6
    ISSN: 0044-2313
    Keywords: Platinum complexes, tBu2P—P ; [η2-{tBu2P—P}Pt(PPh3)2] ; [η2-{tBu2P—P}Pt(PEtPh2)2] ; 1H-13C-, 31P-NMR Spectra ; Crystal Structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Coordination Chemistry of P-rich Phosphanes and Silylphasphanes. XIV. The Phosphinophosphinidene tBu2P—P as a Ligand in the Pt Complexes [η2-{tBu2P—P}Pt(PPh3)2] and [η2-{tBu2P—P}Pt(PEtPh2)2][η2-{tBu2P—P}Pt(PPh3)2 1 and [η2-{tBu2P—P}Pt(PEtPh2)2] 2 are the first complex compounds of tBu2P—P 5. They are formed in the reaction of tBu2P—P = P(Me)tBu2 3 with [η2-{H2C = CH2}Pt(PPh3)2] 6 or [η2-{H2C = CH2}Pt(PEtPh2)2] 7, respectively. Compound 1 is less stable than 2 and reacts on to [η2-{tBu2P—P} Pt(PPh3)(PtBu2Me)] 10 with the coincidently formed tBu2PMe. The molecular structures of 1 and 2 were derived from their 1H and 31P-NMR spectra, 2 was additionally characterized by a X ray structure determination. 2 crystallizes in the monoclinic space group P21/n with a = 1222.36(7) pm, b = 1770.7(1) pm, c = 1729.7(1) pm, β = 108.653(6)°.
    Notes: [η2-{tBu2P—P}Pt(PPh3)2] 1 und [η2-{t Bu2P—P}Pt(PEtPh2)2] 2 sind die ersten Komplexverbindungen des tBu2P—P 5. Sie entstehen bei der Umsetzung von tBu2P—P = P(Me)tBu2 3 mit [η2-{H2C=CH2}Pt(PPh3)2] 6 bzw. [η2-{H2C = CH2}Pt(PEtPh2)2] 7 unter Abspaltung von tBu2PMe. Verbindung 2 ist beständiger als 1. Mit tBu2PMe bildet 1 das [η2-{tBu2P—P} Pt(PPh3)(PtBu2Mc)] 10. Bei der Umsetzung von 6 mit 3 entsteht ebenfalls 10, weil das bei der Bildung von 1 freiwerdende tBu2PMe mit 1 weiterreagiert. Die Strukturen von 1 und 2 sind über ihre 1H- und 31P-NMR-Spektren, die von 2 zusätzlich durch eine Röntgenstrukturanalyse gesichert. 2 kristallisiert monoklin in P21/n mit a = 1222,36(7) pm, b = 1770,1(1) pm, c = 1729,7(1) pm, β = 108,653(6)°.
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  • 7
    ISSN: 0044-2313
    Keywords: [Li(DME)3]2{(SiMe3)[Cr(CO)5] 2 P—P = P—P[Cr(CO)5]2[(SiMe3)]} ; Bis[tris(1, 2-dimethoxyethan)lithium(1 +)]-1, 4-bis(trimethylsilyl)-1,1,4,4-tetrakis (pentacarbonylchrom(0))-tetraphos-2-phenat(2-) ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition Metal Complexes of P-rich Phosphanes and Silylphosphanes. VII. Formation and Structure of [Li(DME)3]2{(SiMe3)[Cr(CO)5]2 P-P = P-P[Cr(CO)5]2(SiMe3)}Deep red crystals of the title compound 1 are produced in the reaction of LiP(Me3Si)2[Cr(CO)5] with 1, 2-dibromoethane in DME. The structure of 1 was derived from the investigation of the 31P-NMR spectra and confirmed by a single crystal structure determination. 1 crystallizes in the space group P1 (no. 2); a = 1307.8(5)pm, b = 1373.1(5)pm, c = 1236.1(4)pm, α = 106.22(4)°, β = 88.00(3)°, γ = 115.52(4)° and Z = 1. 1 forms a salt composed of a dianion R2R4′P42- (R = SiMe3, R′ = Cr(CO)5) and solvated Li+ cations. The zigzag shaped dianion possesses the symmetry 1-Ci. The distances d(P—P) = 202.5(1)pm and d(P—P) = 221.9(1)pm correspond to a double bond and single bonds, respectively. The distances d(Cr—P) = 251.1(1) pm and 255.3(1) pm are larger than those observed so far which might be caused by the charge distribution in the dianion.
    Notes: Bei der Umsetzung von LiP(SiMe3)2[Cr(CO)5] mit 1, 2-Dibromethan in DME entstehen die rubinroten Kristalle der Titelverbindung 1. Die Struktur von 1 folgt aus der Untersuchung der 31P-NMR-Spektren und der Einkristallstrukturbestimmung. 1 kristallisiert in der Raumgruppe P1 (Nr. 2); a = 1 307,8(5) pm. b = 1373,1(5) pm, c = 1236, 1(4) pm, α = 106,22(4)°, β = 88,00(3)°, γ = 115,52(4)° mit Z = 1. 1 bildet ein Salz aus einem Dianion R2R4′P42 (R = SiMe3, R′ = Cr(CO)5) und solvatisierten Li+-Kationen. Das gewinkelte Dianion hat die Symmetrie 1-C1. Die Abstände d(P—P) = 202,5(1) pm und (d)P—P = 221,9(1) pm entsprechen einer Doppelbindung bzw. Einfachbindungen. Die Abstände d (Cr—P) = 251,1(1) pm bzw. 255,3(1) pm sind größer als bisher beobachtete, was auf die Ladungsverteilung im Anion zurückgeführt wird.
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