Vibrational spectroscopy and quantum chemical studies of 1,6,7,12,13,18-hexaazatrinaphthylene and related compounds

The spectral properties of 1,6,7,12,13,18-hexaazatrinaphthylene (HATN) and a number of related compounds are modeled using density functional theory, B3LYP. The calculations predict the frequencies with mean absolute deviation of 6 cm(-1) and there is little improvement on going to basis sets larger than 6-31 G(d). The substituent effects on the observed spectra are modeled effectively in both frequency shifts and relative intensities. The electronic properties may be predicted using TD-DFT and these are in very good agreement, in terms of transition energies and intensities, with the experimental data.