Quantum Mechanical Study on the Effect of Solvent in the Properties of Benzophenone

The effect of solvents on spectroscopic properties of benzophenone is analyzed using DFT/6-311G method. The data on effect of solvents is used to estimate excited state dipole moment using the theoretically determined ground state dipole moment. The excited state dipole moment determined by different methods is compared and analysed. The excited state dipole moment of benzophenone is found to be greater than its corresponding ground state counterpart and, ground and excited state dipole moments are almost perpendicular to each other. The study was aimed to study the energy, molecular structure, vibrational spectra, HOMO-LUMO analysis dipole moment. The wavelength and intensity absorption bands are both affected when a molecule is solvent environment. This is due to unequal perturbation of the ground state and exited state. The vibrational frequencies determined experimentally were compered with the DFT calculation on which was obtained theoretically employing the 6-311G (Dd,p) bassis set method for the optimized geometry of the benzophenone. Benzophenone, an aromatic ketone (diphenylketone), is an important compound in organic photochemistry and perfumery as well as in organic synthesis. It used as a consistent of synthetic perfumes and as starting material for manufacture of dyes, pesticides and drugs. It can act as optical filters or deactivate substrate molecules that have been excited by light for the protection polymer and organic substances. Benzophenone is produced by copper-catalyzed oxidation of diphenylmethane with air.

Keywords: Benzophenone, Gaussian, Basis set, DFT, B3LYP, HOMO, LUMO.