Fixation of Both O<sub>2</sub> and CO<sub>2</sub> from Air by a Crystalline Palladium Complex Bearing <i>N-</i>Heterocyclic Carbene Ligands

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