Resonance-enhanced multiphoton ionization (REMPI) spectroscopy of the 35Cl and 37Cl isotopomers of p-chloroanisole

摘要

The geometric structures and vibrations of p-chloroanisole isotopomers in the first electronically excited state were studied by mass-analyzed resonance-enhanced two-photon ionization spectroscopy and by theoretical calculations. The band origins of the S1 ← S0 electronic transitions of 35Cl and 37Cl isotopomers were found to be equivalent at 34 859 ± 3 cm-1. Assignments of the observed vibrational bands of the two isotopomers were made mainly based on the CIS/cc-PVDZ calculations and on conformity with the available data in the literature. Although the general spectral features of these two isotopomers are similar, the frequencies of some vibrational modes are different. This frequency shift partially depends on the degree of involvement of the chlorine atom in the molecular vibrations.