Synthesis and Bonding in Carbene Complexes of an Unsymmetrical Dilithio Methandiide: A Combined Experimental and Theoretical Study
作者:Viktoria H. Gessner、Florian Meier、Diana Uhrich、Martin Kaupp
DOI:10.1002/chem.201303115
日期:2013.12.2
bis(thiophosphinoyl)‐substituted dilithio methandiide and its application for the synthesis of zirconium‐ and palladium‐carbene complexes. These complexes were found to exhibit remarkably shielded 13C NMR shifts, which are much more highfield‐shifted than those of “normal” carbene complexes. DFT calculations were performed to determine the origin of these observations and to distinguish the electronic structure of
本文中,我们报道了一种新的不对称双(硫代膦酰基)取代的二硫代巯基乙二胺的制备及其在合成锆和钯碳烯络合物中的应用。发现这些配合物表现出明显的屏蔽性13C NMR位移,比“常规”卡宾配合物的高场位移。进行了DFT计算以确定这些观测值的起源,并与经典的Fischer和Schrock型络合物相比,区分了这些和相关的卡宾络合物的电子结构。各种方法表明,这些系统最能描述为高度极化的Schrock型配合物,其中金属-碳键比原型Schrock系统具有更多的静电作用,或者甚至被称为“掩蔽”的二甲亚胺。这样,偕二价阴离子代表了一种“极端”施罗克基型配体有利于离子共振结构M的+ CR 2 - 通常在教科书中用来解释Schrock配合物的亲核性质。