Vibrational motion in thiophosgene and related studies

Abstract

Over 300 second excitated state to ground state vibrational transitions have been located, measured and assigned by dispersed fluorescence spectroscopy. The energies of these transitions were also fit with a spectroscopic effective Hamiltonian. These spectra show high activity in the v_1 and v_4 modes which is expected due to their known high Frank-Condon activity. However, predicted activity in other modes, particularly v_2 and v_6was not observed, quite likely due to the poor resolution of the higher energy spectrum. This made low-lying lines difficult to assign, thus hindering assignments of progressions in the higher region of this spectra. A higher resolution spectrum is required. A torsional potential energy surface was also constructed for the 2-fluoroethanol molecule, in an attempt to make theoretical predictions and corroborate known experimental work on the molecule. This surface includes zero-point energy (ZPE) corrections, to see if it would lower the torsional barrier significantly. It did not. A computer program used to predict potential couplings in a tier model of IVR is also presented.