Selected cis- and trans-3-fluorostyrene rotamers studied by two-color resonant two-photon mass-analyzed threshold ionization spectroscopy
Pei Ying Wu and Wen Bih Tzeng
Journal of Molecular Spectroscopy. 316, 72-78 (2015)
We applied two-color resonant two-photon ionization and mass-analyzed threshold ionization techniques to record the vibronic, photoionization efficiency, and cation spectra of the selected rotamers of 3-fluorostyrene. The adiabatic ionization energies of cis- and trans-3-fluorostyrene were determined to be 69 960 ± 5 and 69 856 ± 5 cm-1, respectively. Cation vibrations 10a, 15, 6b, and 12 of both rotamers have been found to have frequencies of 218, 404, 452, and 971 cm-1, respectively. This finding shows that the relative orientation of the vinyl group with respect to the F atom does not affect these vibrations of the 3-fluorostyrene cation. Our one-dimensional potential energy surface calculations support that the cis–trans isomerization of 3-fluorostyrene does not occur under the present experimental conditions.