测定了meso-和dl-2,3-二氰基-2,3-二(p-X苯基)丁二酸二乙酯(X=OCH_3,CH_3,H,Cl,NO_2)的~(13)C NMR谱。结果表明,中心碳—碳键两端相连基团的各碳原子的化学位移值相同,与dl-异构体相比,所有相应meso-异构体的乙氧羰基~(13)C NMR吸收峰均处于高场。苯环对位取代基的Hammett基团常数σ与氰基碳原子和乙氧羰基中的羰基碳及次甲基碳的化学位移间线性相关,而且meso-异构体比dl-异构体有更好的线性关系。 The determination of ~ (13) C in meso- and dl-2,3-dicyano-2,3-di (pX phenyl) succinate (X = OCH_3, CH_3, H, Cl, NO_2) NMR spectrum. The results showed that the chemical shifts of carbon atoms in the two adjacent carbon-carbon bond groups were the same. Compared with the dl-isomer, the ethoxycarbonyl- (13) C NMR absorption of all the corresponding meso-isomers Peaks are in high field. The Hammett group constant σ of the para-position substituent of the benzene ring is linearly related to the chemical shifts of the carbonyl carbon and the methine carbon in the cyano carbon atom and the ethoxycarbonyl group, and the meso-isomer has a linear correlation with the chemical shifts of the dl-isomer Better linear relationship.