Low-Symmetry Self-Assembled Coordination Complexes with Exclusive Diastereoselectivity: Experimental and Computational Studies
作者:Srabani S. Mishra、Srinath V. K. Kompella、Shobhana Krishnaswamy、Sundaram Balasubramanian、Dillip K. Chand
DOI:10.1021/acs.inorgchem.0c01964
日期:2020.9.8
prepared from a common ligand system. Two diastereomers (i.e., (2,0) and (1,1)-forms) are possible for Pd2L′2Lun2 type complex, whereas four diastereomers (i.e., (4,0), (3,1), trans(2,2), and cis(2,2)-forms) can be imagined for the Pd2Lun4 type complex. However, exclusive diastereoselectivity was observed, and the complexes formed belong to (1,1)-Pd2L′2Lun2 and cis(2,2)-Pd2Lun4 forms. The diastereomers
在这项工作中研究的吡啶/苯胺附加的不对称双齿配体N-(4-(4-氨基苄基)苯基)烟酰胺具有两个完全分开的配位点。配体与顺式保护的钯(II)(即PdL')和钯(II)在单独的反应中结合产生相应的Pd 2 L' 2 L un 2和极为罕见的Pd 2 L un 4型自组装双核配合物。值得注意的是,两种类型的复合物都是从共同的配体系统制备的。对于Pd 2 L' 2 L un 2,可能有两个非对映异构体(即(2,0)和(1,1)形式)Pd 2 L un 4型复合物可以想象有四个非对映异构体(即(4,0),(3,1),反式(2,2)和顺式(2,2)-形式)。然而,观察到非对映选择性独占,并且形成属于(1,1)-Pd络合物2 L' 2大号未2和顺式- (2,2)-Pd 2大号未4种形式。非对映异构体是通过NMR研究在气相和隐溶剂介质中进行溶液和DFT计算得出的;然而,两种配合物的单晶结构均提供了明确的支持。罕见的Pd