Cyclic Voltammetric Study of 2-hydroxybenzophenone (HBP) Derivatives and the Correspondent Change in the Orbital Energy Levels in Different Solvents

The experimental UV and CV of five substituted 2-hydroxybenzophenones in solvents acetonitrile, n-dimethylformamide and dimethylsulfoxide are presented. Results obtained were used to determine their experimental highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) and the results were compared to their theoretical model. The derivatives with an electron withdrawing group (EWG) have more favourable reduction potential, electron affinity, lower dipole moment, lower LUMO and HOMO energy levels and longer absorption lambda(max)compared to those containing an electron donating group. Acetonitrile enhances the reduction potential especially for those of derivatives with EWG, leading to higher reduction potential compared to solvents DMF and DMSO.