The effect of dielectric constant upon the ¹J_CH spin coupling constants in organic compounds

Abstract

A theoretical study is presented of the effects of solvent molecules on directly-bonded ¹³C-H nuclear spin-spin coupling constants (¹ J _CH) of acrylonitrile, dichloromethane, chloroform, difluoromethane and trifluoromethane. The solvent-solute interaction is estimated using Klopman's solvaton theory. Calculations of ¹ J _CH's are performed by the finite perturbation theory in the INDO approximation for acrylonitrile, difluoromethane and trifluoromethane, and in the CNDO/2 approximation for dichloromethane and chloroform. Calculated results are compared with the observed solvent effects.