A Ni0(η2‑(Si–H))(η2‑H2) Complex That Mediates Facile H Atom Exchange between Two σ‑Ligands

σ-adduct complexes of low-valent, late first-row metal complexes are highly unusual, and this is particularly true of d10 systems. We have discovered a nickel/phosphine/silyl system that undergoes reaction with H2 in solution to generate a species best described as Ni0(η2-(Si–H))­(η2-H2) on the basis of multinuclear NMR studies. Theoretical calculations suggest that the Ni center facilitates H atom exchange between the η2-(Si–H) and η2-H2 ligands via interconversion with a higher valent NiII isomer. This exchange is exploited in the selective, catalytic deuteration of exogenous silanes.