meso- And dl-2, 3-Diisobutyryloxy-2, 3-diphenylsuccinonitriles (dl-I), which are ethane derivatives with capto-dative substituents, have been prepared and their crystal and mol. structures determine by X-ray crystallog. The chem. bonds attached to the central carbon atoms are all obviously stretched, especially that of the Ca-Ob bond in dl-I. The deformation of the mols. is explained by steric, electronic and capto-dative substituent effects through conformational anal.

Key words: CRYSTAL STRUCTURE DETERMINATION, MOLECULAR STRUCTURE, X-RAY DIFFRACTION ANALYSIS, COMPUTER APPLICATIONS, BENZENE P, STRUCTURE AND PROPERTY CORRELATION, SUBSTITUENT EFFECT, ELECTRON ACCEPTOR, ETHANE P, ACYLOXY