Cw. Bauschlicher et al., INFRARED-SPECTRA OF PERDEUTERATED NAPHTHALENE, PHENANTHRENE, CHRYSENE, AND PYRENE, The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory, 101(13), 1997, pp. 2414-2422
Calculations are carried out using density functional theory (DFT) to
determine the harmonic frequencies and intensities of perdeuterated na
phthalene, phenanthrene, pyrene, and chrysene. We also report matrix-i
solation spectra for these four species. The theoretical and experimen
tal frequencies and relative intensities for the perdeuterated species
are in generally good agreement. The effect of perdeuteration is to r
educe the sum of the integrated intensities by a factor of about 1.75.
This reduction occurs for all vibrational motions, except for the wea
k low-frequency ring deformation modes. There is also a significant re
distribution of the relative intensities between the out-of-plane C-D
bands relative to those found for the out-of-plane C-H bands. The theo
retical isotopic ratios provide an excellent diagnostic of the degree
of C-H(C-D) involvement in the vibrational bands, allowing in most cas
es a clear distinction of the type of motion.