Group 5 Imido Complexes Supported by Diamido-pyridine Ligands: Aryloxide, Amide, Benzamidinate, Alkyl, and Cyclopentadienyl Derivatives
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- 作者：Stephen M. Pugh ; Dominique J. M. Trö ; sch ; Michael E. G. Skinner ; Lutz H. Gade ; and Philip Mountford
- 刊名：Organometallics
- 出版年：2001
- 出版时间：August 6, 2001
- 年：2001
- 卷：20
- 期：16
- 页码：3531 - 3542
- 全文大小：182K
- 年卷期：v.20,no.16(August 6, 2001)
- ISSN：1520-6041
文摘
A family of new organometallic and coordination group 5 compounds supported by animido-diamido-pyridine ligand set are reported. Reaction of [M(NR)Cl(
3-N2Npy)(py)](M = Nb, R = tBu 1; M = Ta, R = tBu 2 or Ar 3, where N2Npy = MeC(2-C5H4N)(CH2NSiMe3)2and Ar = 2,6-C6H3iPr2) with LiOAr or LiPhC(NSiMe3)2 afforded the five-coordinate aryloxideand benzamidinate complexes [M(NR)(OAr)(3-N2Npy)] (R = tBu, M = Nb 4 or Ta 5; R = Ar,M = Ta 6) and [Nb(NtBu){PhC(NSiMe3)2}(3-N2Npy)] (7), respectively. Reaction of 1 or 2with LiN(SiMe3)2 or LiCH(SiMe3)2 gave the four-coordinate compounds [M(NtBu)(X)(2-N2Npy)] (M = Nb, X = N(SiMe3)2 8 or CH(SiMe3)2 9; M = Ta, X = CH(SiMe3)2 10). Reactionof 1 or 2 with the less sterically demanding alkyl reagent LiCH2SiMe3 gave, in the case ofniobium, only the four-coordinate [M(NtBu)(CH2SiMe3)(2-N2Npy)] (11), but for tantalum anequilibrium mixture of four- (2-) and five- (3-) coordinate isomers was identified by NMRspectroscopy. Reaction of 1 with PhCH2MgCl or LiC5H4Me gave the corresponding 
1- or5-hydrocarbyl complexes [Nb(NtBu)(CH2Ph)(3-N2Npy)(py)] (13) and [Nb(NtBu)(5-C5H4Me)(2-N2Npy)] (14). The X-ray crystal structures of the compounds 4, 6, and 9 are reported.
3-N2Npy)(py)](M = Nb, R = tBu 1; M = Ta, R = tBu 2 or Ar 3, where N2Npy = MeC(2-C5H4N)(CH2NSiMe3)2and Ar = 2,6-C6H3iPr2) with LiOAr or LiPhC(NSiMe3)2 afforded the five-coordinate aryloxideand benzamidinate complexes [M(NR)(OAr)(3-N2Npy)] (R = tBu, M = Nb 4 or Ta 5; R = Ar,M = Ta 6) and [Nb(NtBu){PhC(NSiMe3)2}(3-N2Npy)] (7), respectively. Reaction of 1 or 2with LiN(SiMe3)2 or LiCH(SiMe3)2 gave the four-coordinate compounds [M(NtBu)(X)(2-N2Npy)] (M = Nb, X = N(SiMe3)2 8 or CH(SiMe3)2 9; M = Ta, X = CH(SiMe3)2 10). Reactionof 1 or 2 with the less sterically demanding alkyl reagent LiCH2SiMe3 gave, in the case ofniobium, only the four-coordinate [M(NtBu)(CH2SiMe3)(2-N2Npy)] (11), but for tantalum anequilibrium mixture of four- (2-) and five- (3-) coordinate isomers was identified by NMRspectroscopy. Reaction of 1 with PhCH2MgCl or LiC5H4Me gave the corresponding 1- or5-hydrocarbyl complexes [Nb(NtBu)(CH2Ph)(3-N2Npy)(py)] (13) and [Nb(NtBu)(5-C5H4Me)(2-N2Npy)] (14). The X-ray crystal structures of the compounds 4, 6, and 9 are reported.