Mechanism of hydrogen transfer in arsane generation by aqueous tetrahydridoborate: Interference effects of AuIII and other noble metals

► Arsane generation with aqueous tetrahydroborate in the presence of trace Au, Pd and Pt. ► Incorporation of hydrogen from the solvent into arsane. ► Au, Pd and Pt perturb the mechanism of hydrogen transfer from borane to As. ► Key-role played by metal-borane complex intermediates in the early stage of reaction.