IR and Raman studies, and DFT quantum chemical calculations of the vibrational levels for α-4-methylbenzophenone

Polarized IR and Raman spectra of the oriented α-4-methylbenzophenone (C14H12O) single crystal have been measured. The assignment of the vibrational modes has been performed on the basis of quantum chemical calculations. The B3LYP/6-31G(d,p) quantum model and PED contributions have been applied in the discussion of the results. The dichroic behavior of several lines is analyzed and discussed in their relation to the results of QCC calculations and factor group analysis. The stimulated Raman spectrum of the crystal studied has been recorded. It has been shown that the ν(CH)ϕ symmetric Ag vibration at 3065 cm−1 participates efficiently in the stimulated effect and it could be used as a promoting mode of a new laser Raman material based on the 4-methylbenzophenone crystal.