Reversible Dihydrogen Activation and Catalytic H/D Exchange with Group 10 Heterometallic Complexes

Reaction of a hexagonal planar palladium complex featuring a [PdMg(3)H(3)] core with H(2) is reversible and leads to the formation of a new [PdMg(2)H(4)] tetrahydride species alongside an equivalent of a magnesium hydride co‐product [MgH]. While the reversibility of this process prevented isolation of [PdMg(2)H(4)], analogous [PtMg(2)H(4)] and [PtZn(2)H(4)] complexes could be isolated and characterised through independent syntheses. Computational analysis (DFT, AIM, NCIPlot) of the bonding in a series of heterometallic tetrahydride compounds (Ni–Pt; Mg and Zn) suggests that these complexes are best described as square planar with marginal metal‐metal interactions; the strength of which increases slightly as group 10 is descended and increases from Mg to Zn. DFT calculations support a mechanism for H(2) activation involving a ligand‐assisted oxidative addition to Pd. These findings were exploited to develop a catalytic protocol for H/D exchange into magnesium hydride and zinc hydride bonds.