High-lying Rydberg states of vinyl bromide studied by two-photon resonant ionization spectroscopy

High-lying Rydberg states of vinyl bromide at 70 000–79 500 cm−1 have been investigated using 2 + 1 resonance-enhanced multiphoton ionization (REMPI) spectroscopy. Seven Rydberg series, including one s, three p, two d, and one f, have been identified from fitting the term values of observed electronic states to Rydberg formula rendering the ionization energy of 79 194 ± 17 cm−1 (9.819 ± 0.002 eV). All of the seven series converge to the same ionization-energy limit, corresponding to the ground state of vinyl bromide cation. The adiabatic ionization energy of vinyl bromide determined from this study is in excellent agreement with the values reported recently by other methods.