A Study of the Dipole Moments and Theoretical Vibrational Frequencies of Dihydroxy Benzenes

Dihydroxy benzenes are of considerable interest because the stabilities of the molecular H-bond as well as the interaction between the pi charges of the benzene ring and the OH group[1]. The three isomers of di-hydroxy benzene namely, catechol, resorcinol, hydroquinol are taken into consideration here. Gaussian software[2] was used to carry out the studies. The dipole moments and the theoretical vibrational frequencies are analyzed. Only hydroquinol being a symmetrical molecule has a zero dipole moment. Substitution also has a marked effect on the dipole moment. The dipole moment is extremely high for tetra substitution. The vibrational frequencies reflect the steric hindrance caused by the position of the two hydroxyl groups and confirm the earlier findings of CC bond elongation or contraction and ∠CCO bending.