AL(2P)(SIH4) COMPLEX AND PHOTOREVERSIBLE OXIDATIVE ADDITION REDUCTIVE ELIMINATION-REACTION AL(2P)(SIH4) REVERSIBLE SIH3ALH .2. AL(2P)(SIH4) REVERSIBLE SIH3ALH REACTION

Brief 400-nm photolysis of 1:10 silane/argon matrices containing monatomically isolated aluminum results in the formation of the insertion product silylaluminum hydride (SiH3AlH), most likely via an oxidative addition mechanism. The techniques of UV-vis, EPR, and infrared spectroscopy enabled the identification and characterization of this molecule. The photolytic generation of this species paralleled the formation of methylaluminum hydride (CH3AlH) studied previously in our laboratory. EPR spectral simulations and ab initio self-consistent-field molecular orbital (SCF MO) calculations were employed to help in the characterization of silylaluminum hydride. The EPR spectral parameters extracted from the raw data via the computer simulations, along with subsequently calculated atomic orbital spin densities, determined that the molecule was a bent, orthorhombic species. The SCF MO calculated bond angle at the Al atom was shown to be 118.80-degrees. Secondary photolysis of the aluminum/silane matrix sample resulted in the conversion of the insertion product back to that of the ground-state complex most likely by a reductive elimination mechanism.