Isomerization of 1,2-dichloroethane in polar and non-polar solvents

We study the solvent effects on the isomerization of 1,2-dichloroethane in acetonitrile, chloromethane and carbon tetrachloride by molecular dynamics simulation. The stabilization of the gauche conformer in polar solvents is found to be accompanied by a decrease in the (transition state) isomerization rate. To analyze frictional effects, the transmission coefficient is plotted against the vibrational relaxation time of the torsion. While non-polar solvent points lie in the low friction region, polar solvent data are located near the maximum of a master curve connecting the ‘energy controlled’ domain to the ‘diffusion controlled’ region.