Mass analyzed threshold ionization of phenol centre dot CO: Intermolecular binding energies of a hydrogen-bonded complex

摘要

[Phenol centre dot CO]~+ was studied using a combination of two-color resonant zero kinetic energy (ZEKE) spectroscopy and mass analyzed threshold ionization (MATI) spectroscopy to investigate the interaction of the CO ligand with a hydrogen-bonding cation. Vibrational progressions were observed in three intermolecular modes, the in-plane bend (42 cm~(-1)), stretch (130 cm~(-1)), and in-plane wag (160 cm~(-1)), and are consistent with a planar hydrogen-bonded structure where the CO bonds through the carbon atom to the phenol OH group. Dissociation energies for the S_0, S_1, and D_0 states were determined as 659 +- 20, 849 +- 20, and 2425 +- 10 cm~(-1), respectively. The cationic and neutral dissociation energies of the phenol centre dot CO complex are considerably stronger than those of phenol centre dot N_2, demonstrating the extent to which the larger quadrupole of CO affects the strength of binding.