Ground-state geometry preferences in (tris(pyrazolyl)borato)- and cyclopentadienylniobium alkyne complexes

被引：23

作者：

Etienne, M ^{[1
]}

Donnadieu, B ^{[1
]}

Mathieu, R ^{[1
]}

Baeza, JF ^{[1
]}

Jalon, F ^{[1
]}

Otero, A ^{[1
]}

RodrigoBlanco, ME ^{[1
]}

机构：

[1] UNIV CASTILLA LA MANCHA,FAC CIENCIAS QUIM,DEPT QUIM INORGAN ORGAN & BIOQUIM,CIUDAD REAL 13071,SPAIN

来源：

ORGANOMETALLICS | 1996年 / 15卷 / 21期

关键词：

D O I：

10.1021/om960404t

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

Reaction of NbCl3(DME)(RC=CR') with KTp (DME = 1,2-dimethoxyethane, Tp = hydrotris(pyrazolyl)borate) yields TpNbCl(2)(RC=CR') (R = Ph, R' = Me (2a); R = R' = Me (2b), Et (2c), SiMe(3) (2d), Ph (2e)), which has the alkyne in the molecular mirror plane in the solid state (X-ray crystal structure for 2a) and in solution. The barriers to alkyne rotation are low, the highest being measured for complex 2d (52 kJ mol(-1) at 273 K), which contains the bulky SiMe(3) group on the alkyne. In TpCpNb(Cl)(PhC=CMe) (3a), formed by reaction of 2a with NaCp . DME, the alkyne is parallel to the Cp plane, as observed in solution and in the crystal structure. Extended Huckel molecular orbital calculations indicate that in complexes 2 the geometry is mainly governed by steric interactions, whereas in the case of 3a orbital interactions dictate the observed geometry.

引用

页码：4597 / 4603

页数：7

共 34 条

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