Structure and vibrations of 2-fluoro-N-methylaniline in the S-0, S-1 and D-0 states: REMPI and MATI spectroscopy and theoretical calculations

摘要

Theoretical calculations predicted that there are only two stable conformers, trans and cis, for 2-fluoro-N-methylaniline (2FNMA) in the S-0, S-1 and D-0 states. Compared to the cis conformer, the trans one is more stable, and has a population more than 99% at room temperature. The optimized molecular skeleton of trans and cis 2FNMA are both non-planar in the S-0 state, but planar in the S-1 and D-0 states. The one-dimensional potential energy surface of 2FNMA in the S-0 state is obtained. The Resonance-enhanced two-photon ionization (R2PI) and Mass-analyzed threshold ionization (MATI) spectra of trans 2FNMA are obtained. The first electronic excitation energy (E-1) and the adiabatic ionization energy (LE) of trans 2FNMA are determined. The substitution effect on the molecular structures, transition energies and vibrations of 2FNMA are discussed. (C) 2017 Elsevier B.V. All rights reserved.