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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 623 (1997), S. 1855-1856 
    ISSN: 0044-2313
    Keywords: Zirconium compound ; phosphorane iminato complex ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: [Zr2Cl4(NPMe3)4(HNPMe3)] · CH3CN, a Phosphorane Iminato Complex with Zr=N Double BondsThe title compound has been prepared from a molten mixture of ZrCl4 with Me3SiNPMe3 in the presence of potassium fluoride and subsequent extraction with acetonitrile. According to the crystal structure determination the zirconium atoms are linked by three μ2-N atoms of two NPMe3- groups and by the HNPMe3 molecule. Two terminal bounded chlorine atoms and a terminally coordinated NPMe3- ligand complete the distorted octahedral surrounding of the zirconium atoms thus forming an edge sharing double octahedron. The ZrN bond lengths of the terminal NPMe3- groups of 194.6 pm correspond with double bonds.
    Additional Material: 1 Ill.
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  • 2
    ISSN: 0044-2313
    Keywords: Phosphoraneiminato Complexes ; Boron Compounds ; Crystal Structures ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Phosphoraneiminato Complexes of Boron. Syntheses and Crystal Structures of [BBr2(NPMe3)]2, [B2Br3(NPiPr3)2]Br, [B2(NPEt3)4]Br2, [B2Br2(NPPh3)3]BBr4 and [{B2(NMe2)2}2(NPEt3)2]ClThe bromoderivatives of the title compounds are prepared from the corresponding silylated phosphoraneimines Me3SiNPR3 and boron tribromide. The boron subcompound [{B2(NMe2)2}2(NPEt3)2]Cl2 derives from Me3SiNPEt3 and B2Cl2(NMe2)2. All complexes are characterized by NMR and IR spectroscopy as well as by crystal structure determinations.[BBr2(NPMe3)]2 (1): Space group P21/n, Z = 2, R = 0.031. Lattice dimensions at -50°C: a = 723.8, b = 894.2, c = 1305.4 pm, β = 92.35°. 1 forms centrosymmetric molecules in which the boron atoms are linked via μ2-N bridges of the NPMe3- groups of from B2N2 four-membered rings with B—N distances of 149.9 and 150.9 pm.B2Br3(NPiPr3)2]Br (2): Space group P21, Z = 2, R = 0.059. Lattice dimensions at -80°C: a = 817.6, b = 2198.7, c = 851.5 pm, β = 115.09°. In the cations of 2 the boron atoms are lined via the μ2-N atoms of the NPiPr3- groups to form planar, asymmetric B2N2 four-membered rings with B—N distances of 143 and 156 pm.[B2(NPEt3)4[Br2·4CH2Cl2 (3): Space group C2/c, Z = 4, R = 0.042. Lattice dimensions at -50°C: a = 1946.1, b = 1180.3, c = 2311.3 pm, β = 101.02°. The structure contains centrosymmetric dications in which both the boron atoms are lined by the N atoms of two of the NPEt3- groups to form a B2N2 four-membered ring with B—N distances of 149.6 pm. The remaining two NPEt3- groups are terminally bonded with very short B—N distances of 133.5 pm.B2Br2(NPPh3)3]BBr4 (4): Space group P1, Z = 2, R = 0.065. Lattice dimension at -50°C: a = 1025.7, b = 1496.1, c = 1807.0 pm, α = 85.09°, β = 82.90°, γ = 82.72°. In the cation the boron atoms are lined via the μ2-N atoms of two of the NPPh3- groups to form a nearly planer B2N2 four-membered ring with B—N distances of 149.3-153.1 pm. The third NPPh33 group is terminally connected with teh sp2 hybridized boron atom and with a B—N distance of 134.1 pm along with an almost linear BNP bond angle of 173.6°.[{B2(NMe2)2}2(NPEt2)2]Cl2 · 3CH2Cl2 (5): Space group C2/c, Z = 4, R = 0.098. Lattice dimensions at -70°C: a = 1557.9, b = 1294.7, c = 2122.9 pm, β = 96.08°. The structure of 4 contains centrosymmetric dications in which two by two B-B dumb-bells are linked via the μ2-N atoms of the two NEPt3- groups to form B4N2 six-membered rings with B—N distances of 150 and 156 pm and B-B distances of 173 pm. The B—N distances of the terminally bonded NMe2- groups correspond to 138 pm double bonds.
    Notes: Die Bromoderivate der Titelverbindungen werden aus den entsprechenden silylierten Phosphaniminen Me3SiNPR3 und Bortribromid hergestellt. Die Borsubverbindung [{B2(NMe2)2}2(NPEt3)2]Cl2 entsteht aus Me3SiNPEt3 und B2Cl2(NMe2)2. Alle Komplexe werden durch NMR- und IR-Spektren sowie durch Kristallstrukturanalysen charakterisiert.[BBr2(NPMe3)]2 (1): Raumgruppe P21/n, Z = 2, R = 0,031. Gitterkonstanten bei -50°C: a = 723,8; b = 894,2; c = 1305,4 pm; β = 92,35°. 1 bildet zentrosymmetrische Moleküle, in denen die Boratome über μ2-N-Brücken der NPMe3--Gruppen zu B2N2-Vierringen mit B—N-Abständen von 149,9 und 150,9 pm verknüpft sind.[B2Br3(NPiPr3)2]Br (2): Raumgruppe P21, Z = 2, R = 0,059. Gitterkonstanten bei -80°C: a = 817,6; b = 2198,7; c = 851,5 pm; β = 115,09°. In den Kationen von 2 sind die Boratome über die μ2-N-Atome der NPiPr3--Gruppen zu planaren, asymmetrischen B2N2-Vierringen mit B—N-Abständen von 143 und 156 pm verknüpft.[B2(NPEt3)4]Br2 · 4 CH2Cl2 (3): Raumgruppe C2/c, Z = 4, R = 0,042. Gitterkonstanten bei -50°C: a = 1946,1; b = 1180,3; c = 2311,3 pm; β = 101,02°. Die Struktur enthält zentrosymmetrische Dikationen, in denen die N-Atome zweier NPEt3--Gruppen die beiden Boratome zu einem B2N2-Vierring mit B—N-Abständen von 149,6 pm verknüpfen. Die beiden übrigen NPEt3--Gruppen sind terminal gebunden mit sehr kurzen B—N-Abständen von 133,5 pm.[B2Br2(NPPh3)3]BBr4 (4): Raumgruppe P1, Z = 2, R = 0,065. Gitterkonstanten bei -50°C: a = 1025,7; b = 1496,1; c = 1807,0 pm; α = 85,09°; β = 82,90°; γ = 82,72°. In dem Kation sind die Boratome über die μ2-N-Atome zweier NPPh3--Gruppen zu einem nahezu planaren B2N2-Vierring mit B—N-Abständen von 149,3-153,1 pm verknüpft. Die dritte NPPh3--Gruppe ist mit dem sp2-hybridisierten Boratom terminal mit einem B—N-Abständ von 134,1 pm verbunden bei einem fast linearen BNP-Bindungswinkel von 173,6°.[{B2(NMe2)2}2(NPEt3)2]Cl2 · 3 CH2Cl2 (5): Raumgruppe C2/c, Z = 4, R = 0,098. Gitterkonstanten bei -70°C: a = 1557,9; b = 1294,7; c = 2122,9 pm; β = 96,08°. Die Struktur von 4 enthält zentrosymmetrische Dikationen, in denen je zwei B—B-Hanteln über die μ2-N-Atome der beiden NPEt3--Gruppen zu B4N2-Sechsringen mit B—N-Abständen von 150 und 156 pm sowie B—B-Abständen von 173 pm verknüpft sind. Die B—N-Abstände der terminal gebundenen NMe2--Gruppen entsprechen mit 138 pm Doppelbindungen.
    Additional Material: 5 Ill.
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  • 3
    ISSN: 0044-2313
    Keywords: Rare-Earth Complexes ; Syntheses ; Crystal Structures ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses and Crystal Structures of the Rare-Earth Complexes [LaI2(THF)5]+I3-, [SmCl3(THF)4], [ErCl2(THF)5]+ [ErCl4(THF)2]-, [ErCl3(DME)2], and [Na(18-Crown-6)(THF)2]+[YbBr4(THF)2]-[LaI2(THF)5]+I3- (1) is obtained as red crystals from lanthanum powder and 1,2-diiodoethane in THF on exposure to light. Space group Pbcn, Z = 4, lattice dimensions at -83°C: a = 1264.9, b = 2218.9, c = 1199.1 pm, R = 0.031. The lanthanum atom of the cation of 1 is coordinated with iodine atoms in the axial positions in a pentagonal-bipyramidal way.[SmCl3(THF)4] (2) originates as colourless crystals on heating SmCl3 with excess THF in the presence of Me3SiNPEt3. Space group P21/c, Z = 8, lattice dimensions at -50°C: a = 3092.7, b = 826.2, c = 1758.3 pm, β = 93.85°, R = 0.054. Just like the known sample that crystallizes within the space group F2dd, 2 forms monomeric molecules in which the samarium atom is coordinated with two chlorine atoms in the axial positions in a distorted pentagonal-bipyramidal way.[ErCl2(THF)5]+[ErCl4(THF)2]- (3). Pale pink single crystals of 3 were prepared according to the described method by reaction of erbium powder with trimethylchlorosilane and methanol in THF. Space group C2/c, Z = 4, lattice dimensions at -50°C: a = 1246.3, b = 1145.7, c = 2726.0 pm, β = 91.293°, R = 0.036. The erbium atom of the cation of 3 has a pentagonal-bipyramidal coordination with the chlorine atoms in the axial positions. Within the anion the THF molecules are in trans-arrangement of the octahedrally coordinated erbium atom.[ErC13(DME)2] (4) originates as pink single crystals from 3 with excess boiling 1,2-dimethoxyethane. Space group P21/c, Z = 4, lattice dimensions at -50°C: a = 1137.2, b = 886.5, c = 1561.1 pm, β = 104.746°, R = 0.032. 4 forms monomeric molecules in which the erbium atom has a pentagonal-bipyramidal surrounding with two chlorine atoms in the axial positions.[Na(18-Krone-6)(THF)2]+ [YbBr4(THF)2]- (5) is formed as by-product by the reaction of YbBr3 with NaN(SiMe3)2 in THF in the presence-of 18-crown-6 forming colourless crystals. Space group P1, Z = 1, lattice dimensions at -70°C: a = 934.6, b = 988.9, c = 1208.0 pm, α = 73.82°, β = 72.98°, γ = 76.89°, R = 0.029. 5 contains isolated [YbBr4(THF)2]-ions, in which the THF molecules are arranged in trans-position.
    Notes: [LaI2(THF)5]+I3- (1) wird aus Lanthanpulver und 1,2-Diiodethan in THF unter Lichteinwirkung als rote Kristalle erhalten. Raumgruppe Pbcn, Z = 4, Gitterkonstanten bei -83°C: a = 1264,9; b = 2218,9; c = 1199,1 pm; R = 0,031. Das Lanthanatom des Kations von 1 ist pentagonal-bipyramidal koordiniert mit den Iodatomen in den Axialpositionen.[SmCl3(THF)4] (2) entsteht beim Erhitzen von SmCl3 mit überschüssigem THF in Gegenwart von Me3SiNPEt3 als farblose Einkristalle. Raumgruppe P21/c, Z = 8, Gitterkonstanten bei -50°C: a = 3092,7; b = 826,2; c = 1758,3 pm; β = 93,85°; R = 0,054. 2 bildet wie das bereits bekannte, in der Raumgruppe F2dd kristallisierende Präparat, monomere Moleküle, in denen das Samariumatom verzerrt pentagonal-bipyramidal koordiniert ist mit zwei Chloratomen in den Axialpositionen.[ErCl2(THF)5]+ [ErCl4(THF)2]- (3). Blaßrosa Einkristalle von 3 erhielten wir nach der literaturbekannten Methode durch Reaktion von Erbiumpulver mit Trimethylchlorsilan und Methanol in THF. Raumgruppe C2/c, Z = 4, Gitterkonstanten bei -50°C: a = 1246,3; b = 1145,7; c = 2726,0 pm; β = 91,293°; R = 0,036. Das Erbiumatom des Kations von 3 hat pentagonal-bipyramidale Koordination mit den Chloratomen in den Axialpositionen, im Anion befinden sich die THF-Moleküle in der trans-Anordnung des oktaedrisch koordinierten Erbiumatoms.[ErCl3(DME)2] (4) entsteht als rosa Einkristalle aus 3 mit überschüssigem, siedendem 1,2-Dimethoxyethan. Raumgruppe P21/c, Z = 4, Gitterkonstanten bei -50°C: a = 1137,2; b = 886,5; c = 1561,1 pm; β = 104,746°; R = 0,032. 4 bildet monomere Moleküle, in denen das Erbiumatom verzerrt pentagonal-bipyramidale Umgebung hat mit zwei Chloratomen in den Axialpositionen.[Na(18-Krone-6)(THF)2]+ [YbBr4(THF)2]- (5) entsteht als Begleitprodukt bei der Umsetzung von YbBr3 mit NaN(SiMe3)2 in THF in Gegenwart von 18-Krone-6 als farblose Kristalle. Raumgruppe P1, Z = 1, Gitterkonstanten bei -70°C: a = 934,6; b = 988,9; c = 1208,0 pm; α = 73,82°; β = 72,98°; γ = 76,89°; R = 0,029. 5 enthält isolierte [YbBr4(THF)2]--Ionen, in denen die THF-Moleküle in trans-Stellung angeordnet sind.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Acta Polymerica 48 (1997), S. 432-437 
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Oxidative addition to a metal in a low valent state produces catalysts that allow reporter or functional groups to be introduced to a polymer chain end. Substituted allyltrifluoroacetates were added to Ni(0)(COD)2. The resulting π-allyl-Ni trifluoroacetates are dimeric in the solid state as well as in solution. The crystal structure of bis[(η3-2-phenylallyl)(trifluoroacetato)-nickel(II)], bis[(η3-2-trimethylsilylallyl)(trifluoroacetato)nickel(II)], are given and correlated with the reactivity as polymerization catalysts. Butadiene, styrene, and norbornene are used as monomers. The substituent of the allyl group is found quantitatively to be the end group of each macromolecule. Thus it is demonstrated that no chain transfer occurs.
    Additional Material: 8 Ill.
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