Vibrational spectroscopic study of 2, 6- and 2, 7-dimethylnaphthalenes by Density functional theory.

Abstract

Fourier transform infrared and Fourier transform Raman spectra of 2, 6- and 2, 7-dimethylnaphthalenes in solid phase, have been investigated. The theoretical calculations of the vibrations of 2, 6- and 2, 7- dimethylnaphthalenes were performed by using density functional theory (DFT)-Beck3–Lee–Yang–Parr (B3LYP) levels with 6-31G* and 6- 311+G** basis sets. The complete assignments are performed on the basis of the potential energy distribution (PED) of the vibrational modes, calculated with scaled quantum mechanics method (SQM) by using MOLVIB program. The computational frequencies are in good agreement with the observed results. The comparisons between the observed and calculated frequencies are shown