Density functional theory studies on IR spectra of the triphenylene derivatives : a scaled quantum mechanical force field approach

Abstract

Density functional theory, B3-LYP with the 6-31G* basis set was applied to study the structures and vibrational infrared spectra of triphenylene and the hexasubstituted triphenylene derivatives. The calculated force fields were scaled using the scaled quantum mechanical force field method. The predicted vibrational frequencies were compared with the experimental IR spectra (500-4000 cm -1 ). The spectra were interpreted and vibrational assignments were reported. This study shows that the scaled density functional force field approach enables, through the transferability of scale factors, good interpretation of vibrational spectra of large molecules.