Reactions of methane with titanium atoms:: CH3TIH, CH2=TiH2, agostic bonding, and (CH3)2TiH2

Laser-ablated titanium atoms react with methane to form the insertion product CHOH, which undergoes a reversible photochemical (x-H transfer to give the methylidene complex CH2=TiH2. On annealing a second methane activation occurs to produce (CH3)(2)TiH2. These molecules are identified from matrix infrared spectra by isotopic substitution (CH4, (CH4)-C-13, CD4, CH2D2) and comparison to DFT frequency calculations. The computed planar structure for singlet ground-state CH2=TiH2 shows CH2 distortion and evidence for agostic bonding (H-C-Ti, 91.4 degrees), which is supported by the spectra for CHD=TiHD.