Amido analogues of zincocenes and cadmocenes

Abstract

The synthesis and characterisation of low-coordinate zinc and cadmium complexes of the sterically demanding 1,3,6,8-tetra-tert-butylcarbazol-9-yl ligand (^tBu₄carb⁻) are reported. (^tBu₄carb)₂M (M = Zn 1; M = Cd 2) are the first examples of formally two-coordinate bis-carbazol-9-yl complexes of the Group 12 metals and 2 is the first crystallographically characterised two-coordinate amido complex of cadmium. The structure and bonding within these complexes are explored via a combination of X-ray crystallography and DFT calculations. The solid state structures for these zinc and cadmium complexes differ greatly from each other; not only do the steric demands of the peripheral tert-butyl substituents in these systems act to inhibit solvent coordination, but they also influence the coordination geometry around the metal centres.