The solvent effect on the dimerization constant and electric dipole moment of ϵ-caprolactam

Abstract

Abstract The dimerization constant, and electric dipole moments of both monomeric and dimeric species, have been deduced for ϵ-caprolactam from dielectric polarization studies on dilute solutions in cyclohexane, carbon tetrachloride, benzene and dioxan. Results in carbon tetrachloride are consistent with a stereospecific interaction between the solute (as monomeric) and solvent, possibly leading to a charge-transfer complex. Part of monomeric ϵ-caprolactam interacts with n -basic dioxan, and at a lesser extent with π-basic benzene, giving a hydrogen-bonded complex, whose dipole moment contains a large term due to increase in the (NHCO) mesomeric moment. Incidentally, the dipole moments of 1-tetralone and NN -dimethylformamide have been measured and interpreted.