Hybrid organometallic compounds of gallium: UV excimer laser photochemistry of Ga( t-C 4H 9) n(CH 3) 3- n ( n = 0, 1, 2, 3)

Abstract

The gas-phase ultraviolet (UV) excimer laser induced photolysis of the gallium-alkyls Ga( t-C 4H 9) n (CH 3) 3- n ( n = 0, 1, 2, 3) was studied, using photolysis wavelenghts of 308, 248 and 193 nm. The photofragments Ga, GaH and GaCH 3 were detected by laser ionization time-of-flight mass spectroscopy, while the hydrocarbon products CH 4, C 2H 6, HC(CH 3) 3 and H 2C=C(CH 3) 2 were identified using Fourier transform infrared (FTIR) spectroscopy. The formation of the GaH photofragment, and a high olefin-to-alkane product ratio, for Ga( t-C 4H 9) 2(CH 3) and Ga( t-C 4H 9) 3 is interpreted to indicate a β-hydrogen elimination process. However, β-hydrogen elimination only occurs after fission of the weakest Ga-C bond, thus no β-hydride elimination is observed for Ga( t-C 4H 9)(CH 3) 2.