The rotationally resolved infrared spectrum of TiO and its isotopologues

In this study, we present the ro-vibrationally resolved gas-phase spectrum of the diatomic molecule TiO around 1000 cm(-1). Molecules were produced in a laser ablation source by vaporizing a pure titanium sample in the atmosphere of gaseous nitrous oxide. Adiabatically expanded gas, containing TiO, formed a supersonic jet and was probed perpendicularly to its propagation by infrared radiation from quantum cascade lasers. Fundamental bands of 46-50TiO and vibrational hotbands of (TiO)-Ti-48 are identified and analyzed. In a mass-independent fitting procedure combining the new infrared data with pure rotational and electronic transitions from the literature, a Dunham-like parameterization is obtained. From the present data set, the multi-isotopic analysis allows to determine the spin-rotation coupling constant c and the BornOppenheimer correction coefficient DTiU10 for the first time. The parameter set enables to calculate the BornOppenheimer correction coefficients Delta(Ti)(U02) and Delta(O)(U02). In addition, the vibrational transition moments for the observed vibrational transitions are reported. (C) 2021 Elsevier Inc. All rights reserved.