Diverse Cooperative Reactivity at a Square Planar Aluminium Complex and Catalytic Reduction of CO 2 .

The use of a sterically demanding pincer ligand to prepare an unusual square planar aluminium complex is reported. Due to the constrained geometry imposed by the ligand scaffold, this four-coordinate aluminium centre remains Lewis acidic and reacts via differing metal-ligand cooperative pathways for activating ketones and CO 2 . It is also a rare example of a single-component aluminium system for the catalytic reduction of CO 2 to a methanol equivalent at room temperature.