The A 2A1-X 2B1 transition of H2O+ in the near infrared region

Article abstract of DOI:10.1063/1.474326

A titanium sapphire laser spectrometer along with velocity modulation detection was used to record, between 12 000 and 13 400 cm^-1, the absorption spectrum of the A ²A₁-X ²B₁ electronic transition of H₂O⁺ produced in an ac glow discharge with a gas mixture of He/H₂O. The Σ(0,7,0)-(0,0,0) transition has been observed at 13 411 cm^-1 and revised rotational assignments are presented. The Δ(0,7,0)-(0,0,0) and Π(0,6,0)-(0,0,0) transitions have been observed for the first time, at 13 331 and 12 494 cm^-1, respectively. The vibrational assignment follows the vibrational numbering of Brommer et al. [J. Chem. Phys. 98, 5222 (1993)]. The rotational analysis was performed using the combination differences technique. Strong perturbations are observed, they are tentatively explained in term of rovibronic interactions. A set of effective molecular parameters has been obtained for each vibrational level of the A state. The values of the spin-orbit parameter are reported, they illustrate the vibronic coupling between the two electronic states.