ISSN:
0044-2313
Keywords:
Phosphido-bridged dinuclear complexes
;
crystal structure
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
Phosphido- and Arsenido-bridged Dinuclear Complexes. Synthesis and Molecular Structure of (η5-C5H4R)2Zr{μ-P(SiMe3)2}2M(CO)4 (R = Me, M = Cr; R = H, M = Mo) and Synthesis of (η5-C5H5)2Zr{μ-As(SiMe3)2}2Cr(CO)4The reaction of (η5-C5H4R)2Zr{E(SiMe3)2}2 with M(CO)4(NBD) (NBD = norbornadiene) yields the dinuclear phosphido- or arsenido-bridged complexes (η5-C5H4R)2Zr{μ-E(SiMe3)2}2M(CO)4 (R = Me, E = P, M = Cr (1); R = H, E = P, M = Mo (2); R = H, E = As, M = Cr (3)). No formation of dinuclear complexes was observed in the reaction of (η5-C5H4Me)2Zr{P(SiMe3)2}2 with Ni(PEt3)4, Ni(CO)2(PPh3)2 or with NiCl2(PPh3)2 in the presence of Mg. Complexes 1-3 were characterised spectroscopically (i. r., n. m. r., m. s.), and X-ray structure investigations were carried out on 1 and 2. The central four-membered ZrP2M ring is slightly puckered (dihedral angle between planes ZrP2/CrP2 14.7°, ZrP2/MoP2 14.2°). The Zr—P bond lengths are equivalent (1: Zr—P1 2.654(4), Zr—P2 2.657(4) Å; 2: Zr—P1 2.6711(9), Zr—P2 2.6585(7) Å), as are the M—P bond lengths (M = Cr (1): Cr—P1 2.513(4), Cr—P2 2.502(4) Å; M = Mo (2): Mo—P1 2.6263(7), Mo—P2 2.6311(10) Å). The long Zr ··· M distances of 3.414 Å (M = Cr (1)) and 3.461 Å (M = Mo (2)) indicate the absence of a metal-metal bond.
Notes:
Die Reaktion von (η5-C5H4R)2Zr{E(SiMe3)2}2 mit M(CO)4(NBD) (NBD = Norbornadien) liefert die phosphido- oder arsenido-verbrückten Zweikernkomplexe (η5-C5H4R)2Zr{μ-E(SiMe3)2}2M(CO)4 (R = Me, E = P, M = Cr (1); R = H, E = P, M = Mo (2); R = H, E = As, M = Cr (3)). Hingegen führen die Umsetzungen von (η5-C5H4Me)2Zr{P-(SiMe3)2}2 mit Ni(PEt3)4, Ni(CO)2(PPh3)2 oder mit NiCl2(PPh3)2 in Gegenwart von Mg nicht zu entsprechenden Zweikernkomplexen. Die Verbindungen 1-3 wurden spektroskopisch charakterisiert (IR, NMR, MS), 1 und 2 zusätzlich durch eine Röntgenstrukturanalyse. Der zentrale Vierring ZrP2M ist leicht gewellt (Diederwinkel zwischen den Ebenen ZrP2/CrP2 14,7°, ZrP2/MoP2 14,2°). Die Zr—P- oder M—P-Bindungslängen sind nahezu gleich (1: Zr—P1 2,654(4), Zr—P2 2,657(4) Å, Cr—P1 2,513(4), Cr—P2 2,502(4) Å; 2: Zr—P1 2,6711(9), Zr—P2 2,6585(7) Å; Mo—P1 2,6263(7), Mo—P2 2,6311(10) Å). Der lange Zr ··· M-Abstand von 3,414 Å (M = Cr (1)) und 3,461 Å (M = Mo (2)) weist auf das Fehlen einer Metall-Metall-Bindung hin.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/zaac.19956210514
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