Electronic spectrum of the 2877 Å band of styrene: Rotational structure and transition moment

Abstract

Rotational fine structure in the 0-0 band of the 2877 Å transition of styrene is reported and analyzed by use of computer simulation techniques. The analysis allows determination of the changes in rotational constants upon excitation (Δ A = −0.00614 9 cm −1, Δ B = −0.00062 4 cm −1, Δ C = −0.00072 1 cm −1) and is consistent with a planar configuration in the excited state. The band is shown to be A-type, which confirms the π ∗ ← π nature of the electronic transition. The origin of the band was determined to be 34758.79 ± 0.05 cm −1.