Rydberg States of Styrene from VUV Absorption and REMPI Spectra

The VUV absorption spectrum of gas phase styrene has been remeasured and interpreted, taking into consideration the argon matrix-isolated styrene's spectrum and resonance-enhanced multiphoton ionization spectra (REMPI). Of particular interest was the detection of Rydberg states. Three Rydberg states with n = 3 were detected at 5.799 eV (delta = 0.74), 6.456 eV (delta = 0.40), and 6.5281 eV (delta = 0.35). Only the 6.5281-eV state has a strong REMPI signal and a well-defined vibrational structure. This Rydberg state has the same geometry as the ground state (planar styrene). The two origins of the ''benzenoid E(1u)'' valence state were detected at 5.986 and 6.161 eV and therefore the B-a-B-b splitting is 0.175 eV. (C) 1995 Academic Press Inc. Journal of Molecular Spectroscopy