REACTIONS OF PULSED-LASER ABLATED AL ATOMS WITH H-2 - INFRARED-SPECTRA OF ALH, ALH2, ALH3, AND AL2H2 SPECIES

Pulsed laser evaporated Al atoms were reacted with H-2 in excess argon during condensation at 10 K. Matrix infrared spectra, deuterium subst itution, and ab initio calculations identified AlH, AlH2, AlH3, and se veral Al2H2 species. The spectra are complicated by H-2 complexes with the major products. Activation energy for these reactions was provide d by hyperthermal aluminum atoms from the laser ablation process. Abso rptions for AlH3 increased markedly on photolysis, which facilitated t heir identification.