Comparative analysis of high-resolution spectra of naphthalene and its methyl-substituted derivatives cooled in a supersonic jet

We have carried out a comparative analysis of fine-structure fluorescence excitation and fluorescence spectra of naphthalene, 2,6-and 2,7-dimethylnaphthalene, and 2-methylnaphthalene molecules cooled in a supersonic jet. We have shown that both the frequencies and the intensities of most of the lines in the spectra of these molecules are correlated. Such a correlation facilitates interpretation of the spectra in the case when it is difficult to calculate the transition intensities and when lines corresponding to vibrations of different symmetry have close frequencies. For the considered molecules, a preliminary assignment of the lines in the fine-structure spectra is refined. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 3, pp. 336–340, May–June, 2007.