Department of Chemistry, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan.
Dalton Trans. 2011 Jul 7;40(25):6778-84. doi: 10.1039/c0dt01833c. Epub 2011 May 24.
Nickel complexes having acetylated glucopyranosyl group incorporated N-heterocyclic carbene (NHC) ligands with methyl or benzyl groups as an N-substituent exhibit two kinds of dynamic behaviours in solution (1)H NMR spectroscopy. One of the dynamic behaviours is attributed to the anti- and syn-rotamers, which occur by the rotation of the unsymmetrical NHC ligands around the axes of the Ni-C bonds. The other is attributed to the diastereomers of the syn-rotamers, which occur by opposite rotation of the imidazolylidene rings and the chiral carbohydrate group incorporated into the NHC ligands. Crystallographic analysis of the nickel complex having the NHC ligand with acetylated glucopyranosyl and benzyl groups as N-substituents showed CH-π interaction between the glucopyranosyl unit of each NHC ligand and the phenyl ring of the other NHC ligand in the complex in the solid state.
含乙酰化吡喃葡萄糖基的镍配合物，其 N-杂环卡宾（NHC）配体具有甲基或苄基作为 N-取代基，在溶液中（1）H NMR 光谱中表现出两种动态行为。一种动态行为归因于反式和顺式旋转异构体，这是由不对称 NHC 配体围绕 Ni-C 键轴的旋转引起的。另一种归因于顺式旋转异构体的非对映异构体，这是由咪唑啉环和与 NHC 配体结合的手性碳水化合物基团的反向旋转引起的。对具有乙酰化吡喃葡萄糖基和苄基作为 N-取代基的 NHC 配体的镍配合物的晶体学分析表明，在固态中，每个 NHC 配体的吡喃葡萄糖单元与配合物中另一个 NHC 配体的苯基环之间存在 CH-π 相互作用。
