N.M.R. of substituted benzenes in the nematic phase Geometric distorition in benzonitrile,p-nitrobenzonitrile andp-dinitrobenzene

Abstract
A high-resolution N.M.R. study of benzonitrile, p-nitrobenzonitrile and p-dinitrobenzene in different liquid crystals is reported. Geometrical changes occurring in the benzene ring of these molecules are discussed and compared. A qualitative interpretation of geometric data with a semiempirical iterative extended Hückel (IEH) calculation is presented.