Infrared Spectroscopy and Density Functional Theory Investigations of the Reactivity of Titanium Atoms with Carbon Monoxide and Water Isolated in Solid Argon: Sequential Evolution from Triplet to Singlet State

Thermally evaporated titanium atoms reacted with carbon monoxide and water in solid argon at 12 K to produce the HTiOH–CO and HTiOH–(CO)2 molecules, which were characterized using infrared spectroscopy on the basis of CO, Ti, and water concentration variations and of isotopic substitutions. The insertion product, HTiOH, resulting from the reaction of a titanium atom with a water molecule reacts with CO spontaneously to give the HTiOH–CO molecule, which in turn reacts with a second CO molecule to give HTiOH–(CO)2 The density functional theory calculations were performed to elucidate the geometrical and electronic structures and support the spectral assignments. The topological analysis of the charge density within the experimentally observed molecules allowed us to rationalize the coordination sphere as well as the electron pairing on the titanium center.