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.