Liu You-cheng, Yang Dilun, Yang Qingchuan
Oct 10, 1986
Citations
0
Influential Citations
0
Citations
Journal
Journal name not available for this finding
Abstract
Diethyl 2, 3-dicyano-2, 3-diphenylsuccinate was prepared through the oxidative coupling of ethyl α-cyanophenylacetate with Cu~(++)-TMEDA-O_2 system. The product gave, upon chromatography, two crystalline compounds 1 and 2. The single crystals of 1 and 2 were identified by X-ray crystallographic analysis to be meso-and racemie-diethyl 2,3-dicyano-2,3-diphenylsuccinate respectively. It is noteworthy that in the molecules of 1 and 2 there is a remarkable lengthening effect of the bond length for the central C—C bond, i. e. 1: 1.585; 2: 1.62. It is also observed that there is steric hindrance between the substituent groups attached to the two carbon atoms of the central C—C bond respectively. These data provide the structural basis for the facile dissociation into radicals and the action of polymerization initiator of the title compound. CNDO/2 calculation of charge density and Wiberg bond order for compound 1 yields the results, which are consistent with the crystallographic data.