Reactions of aluminum, gallium, and indium (M) atoms with phosphine: Generation and characterization of the species M center dot PH3, HMPH2, and H2MPH

Upon deposition of Al, Ga, or In atoms (M) together with phosphine in a sol id argon matrix, metal atom complexes M . PH3 are formed. Photolysis of the matrices at lambda = 436 nm results in the tautomerization of the adduct s pecies to the insertion products HMPH2 and H2MPH. In addition, PH is formed from the reactions with Ga and In, with HMPH2 being its most likely precur sor. Further photolysis into the absorption maximum of HMPH2 near 550 nm re sults in decomposition of HMPH2 with partial re-formation of the adduct M . PH3 and further buildup of PH. H2MPH is photostable under these conditions but suffers decomposition under the action of UV light (200 less than or e qual to lambda less than or equal to 400 nm). All the molecules have been i dentified by their IR spectra, the assignments being attested by the effect s of deuteration and also by comparison either with the vibrational propert ies anticipated by density functional theory (DFT) calculations or with tho se of known, related molecules. The resulting analysis is elaborated for th e light it sheds on the structures and properties of the new molecules and on the mechanisms of the reactions affording, or disposing of, them.