"MOLECULAR STRUCTURE, SPECTROSCOPIC (FT-IR, FTRAMAN) AND HOMO–LUMO ANALYSES OF SOME ACNE VULGARIS DRUGS "

The FT-IR and FT-Raman spectra for salicylic acid and benzoyl peroxide have been recorded in the range 4000– 400 cm−1. DFT (B3LYP/6-311++G(d,p)) calculations have been performed giving energies, optimized structures, harmonic vibrational frequencies, IR intensities and Raman activities. The computed vibrational frequencies have been scaled and compared with corresponding experimental FT-IR and FT-Raman values. The differences between the observed and scaled wave number values for most of the fundamentals are very small. The calculated HOMO– LUMO energies show that charge transfer occurs in the molecules.