Reactions of beryllium atoms with hydrogen. Matrix infrared spectra of novel product molecules

Article abstract of DOI:10.1021/ja00078a057

Beryllium atoms formed by pulsed laser ablation have been codeposited with gaseous mixtures of hydrogen diluted in argon (concentrations varied from 25:1 to 100:1) onto a substrate at 10 K. Infrared spectroscopy on the reaction mixture identified six novel product molecules - BeH, BeH₂, BeBeH, HBeBeH, HBeHBeH, and HBe(H)₂-BeH. Assignments of infrared absorption bands were made on the basis of broad-band photolysis and annealing behavior, isotopic substitutions, and ab initio calculations performed at the MBPT(2) level. The major products initially are BeH (1970.0 cm^-1) and the previously unobserved BeH₂ molecule (v₃ = 2159.1 cm^-1, v₂ = 697.9 cm-1) with formation of the three dimers HBeBeH, HBeHBeH, and HBe(H)₂BeH at the expense of the initial reaction products upon annealing of the matrix to 30 K. The former dimer involves a stable Be-Be bond, and the latter dimers incorporate bridging hydrogen atoms. The new Be₂H molecule (2013.7, 540.0 cm^-1) is a minor product in these experiments, which exhibits a stronger Be-Be bond than Be₂.