CRYOGENIC REACTIONS OF GALLIUM WITH MOLECULAR-HYDROGEN AND METHANE

The reactions of gallium with molecular hydrogen and methane have been investigated via FT-IR matrix isolation spectroscopy. It is found that excited atomic gallium reacts with H-2 to yield both GaH and GaH2, where GaH2 is identified as a bent molecule with a bond angle of 136 +/- 5-degrees. The dimer of gallium, Ga2, reacts spontaneously with H-2 to form Ga2(b-H)2 with two bridging hydrogens, which can be converted photoreversibly to Ga2(t-H)2 with two terminal hydrogens. The trimer of gallium, Ga3, has also been isolated and found to react with H-2. The reactions of Ga with CH4 have also been studied in Ar, Kr, and neat CH4 matrices. HGaCH3 was the only photoreaction product identified.