TORSIONAL, VIBRATIONAL AND VIBRATION-TORSIONAL LEVELS IN THE S1 AND GROUND CATIONIC D0+ STATES OF PARA-FLUOROTOLUENE

The S$_{1}$ electronic state and ground state of the cation of textit{para}-fluorotoluene (textit{p}FT) have been investigated using resonance-enhanced multiphoton ionization (REMPI) spectroscopy and zero-kinetic-energy (ZEKE) spectroscopy.footnote{A. M. Gardner, W. D. Tuttle, L. Whalley, A. Claydon, J. H. Carter and T. G. Wright, textit{J. Chem. Phys.}, textbf{145}, 124307 (2016).} Here we focus on the low wavenumber region where a number of “pure” torsional, fundamental vibrational and vibration-torsional levels are expected; assignments of observed transitions are discussed, which are compared to results of published work on toluene (methylbenzene) from the Lawrance group.footnote{J. R. Gascooke, E. A. Virgo, and W. D. Lawrance textit{J. Chem. Phys.}, textbf{143}, 044313 (2015).} The similarity in the activity observed in the excitation spectrum of the two molecules is striking