Synthesis and structure elucidation of allyl Pd(II) complexes of NHC ligands derived from substituted imidazo[1,5-a]quinolin-1(2H)-ylidene
作者:Rumen Lyapchev、Petar Petrov、Miroslav Dangalov、Nikolay G. Vassilev
DOI:10.1016/j.jorganchem.2017.09.036
日期:2017.11
Nine Pd(II) complexes involving N-heterocyclic carbenes (NHCs) derived from 2-substituted and 2- and 7-substituted imidazo[1,5-a]quinolin-1(2H)-ylidene with auxiliary allylic ligands were synthesized and characterized. The structure and configuration of the complexes were elucidated on the basis of combination of dynamic NMR and DFT studies. Conformational studies in respect of hindered rotation around
合成并表征了9种Pd(II)配合物,它们涉及由2-取代的,2-和7-取代的咪唑并[1,5 - a ]喹啉-1(2H)-亚烷基与辅助烯丙基配体衍生的N-杂环卡宾(NHC)。。根据动态NMR和DFT研究的结合,阐明了配合物的结构和构型。在相对于旋转受阻的周围的Pd-C键和η的构象研究3 -η 1 -η 3进行伪烯丙基转动。从动态NMR和DFT研究的结果证实了选择性η的机构3 -η 1 -η 3异构化,其能垒受氮原子上取代基的空间位阻的影响。异构化的能垒(16.7-18.8 kcal / mol)受咪唑并[1,5 - a ]喹啉-1(2H)-亚烷基部分第七位取代基的电子性质的影响。DFT计算的结果与实验能垒高度吻合。