内消旋和外消旋2,3-二乙氧基-2,3-二苯基丁二腈的晶体和分子结构——受-授取代基效应对分子构象的影响

用X射线单晶衍射法测定了两个新的具有受-授取代基的乙烷衍生物--内消旋和外消旋2,3-二乙氧基-2,3-二苯基丁二腈1a(meso)和1a(dl)的晶体及分子结构。发现在两个分子中,中心碳-碳键及与其相连的化学键都有明显的键长伸长效应。通过构象分析说明了这种分子的变形是由于取代基的空间效应,电子效应及受-授取代基效应引起的。

Crystal and Molecular Structure of Meso and d l-2,3 -Diethoxy-2,3-Diphenylsuccinonitriles--The Influence of Capto-dative Effect upon the Conformation of the Molecules

The crystal and molecular structure of meso- and dl-2,3-diethoxy-2,3-diphe-nylsuccinonitriles, 1a(meso)and 1a(dl), which are substituted ethane derivatives with capto-dative substituents, have been determined by X-ray crystallography. It is found that the central carbon-carbon bonds and chemical bonds attached to them are all obviously stretched. The deformation of the molecules is explained by steric, electronic and capto-dative subtituent effects through conformational analysis.