Pt. Snee et al., Ultrafast infrared studies of the reaction mechanism of silicon-hydrogen bond activation by eta(5)-CpV(CO)(4), J PHYS CH A, 103(49), 1999, pp. 10426-10432
The photochemical Si-H bond activation reaction by the group VB, d(4) organ
ometallic compound eta(5)-CpV(CO)(4) (Cp = C5H5) has been studied in neat t
riethylsilane under ambient conditions, The spectral evolutions of the meta
l-bended CO stretching bands were monitored from 300 fs to 800 ps following
UV photolysis using femtosecond pump-probe spectroscopic methods. The reac
tive intermediates observed on the ultrafast time scale were also studied u
sing density functional theory as well as ab initio quantum chemical modeli
ng. It was found that photolysis of vanadium tetracarbonyl resulted in the
formation of tricarbonyls in either the singlet or triplet electronic state
following CO loss. The subsequent reaction was partitioned into two pathwa
ys by the initial solvation of the tricarbonyls through the Si-H bond or an
ethyl group of the solvent molecule. Knowledge of the elementary reaction
steps including changes in molecular morphology and electronic multiplicity
allowed a comprehensive description of the chemical reactivity.