Fixation of both O2 and CO2 from air by a crystalline palladium complex bearing N-heterocyclic carbene ligands.

Crystals of the two-coordinate palladium(0) complex 1 bearing the new N-heterocyclic carbene ligand, ITmt, directly and rapidly fixed both O2 and CO2 from air to produce the corresponding palladium(II) peroxocarbonate complex 2. The present reaction consists of dioxygenation of the palladium(0) complex 1 to the palladium(II) peroxo complex 3 and the subsequent CO2 insertion to produce the peroxocarbonate complex 2. Reaction of the crystals of 1 with air was monitored by microscopic IR spectroscopy to confirm the sequence of the two-step solid-state reaction. The unique reactivity of solid 1 toward air was explained in terms of the structural features of the carbene ligand, ITmt.