Photoreversible hydrogen migration system in a solid argon matrix formed by the reaction of methyl fluoride with laser-ablated titanium atoms

The photoreversible system of titanium methylidene and methyltitanium fluoride complexes has been formed by the reaction of methyl fluoride and laser-ablated Ti atoms and isolated in a solid argon matrix. There are two major groups of absorptions based on broad-band irradiation and annealing behavior. The increase of group I is accompanied by the decrease of group II on photolysis with UV light (240 nm < lambda < 380 nm) and the reverse with visible light (lambda > 530 nm). The methylidene CH2=TiHF and methyltitanium fluoride CH3-TiF are responsible for these absorptions, and the photochemical interconversion occurs via alpha-H migration between carbon and titanium atoms. The methylidene complex appears to be stabilized by an agostic hydrogen interaction. Absorptions for the higher coordinated (CH3)(2)TiF2 complex are observed to increase on UV irradiation and on annealing where CH3TiF spontaneously adds CH3F.