synthesized and characterized. Structural characterization of the n = 2 complex shows marked bending of the two ligands cis (and perpendicular) to the plane of the NHC group in the direction of the carbene, suggestive of a pseudo-back-bonding interaction between adjacent ligands and the carbene p orbital, consistent with a bonding model recently proposed for d0 metal-NHC complexes. However, inspection of
Ti(L)(O i Pr)n(Br)3 - n(n = 1-3,L = t BuNHCH )形式的酰胺键合的N杂环卡宾(NHC)的一系列
钛(IV)加合物已经合成并表征了2 CH 2 [C N t Bu(CHCH)N}]。n = 2配合物的结构表征表明,两个
配体在卡宾方向上均与NHC基团平面成顺式(垂直)弯曲,这表明相邻
配体与卡宾p之间存在假反向键相互作用轨道,与最近针对d 0提出的键合模型一致
金属-NHC配合物。但是,对空间填充模型的检查和使用DFT方法计算键序的结果表明,弯曲是由于配合物中相邻的π供体
配体上的孤对之间的排斥所致,而不是NHC与顺式π之间的任何特定相互作用-供体
配体。