Abstract:Three m-terphenyl ligands 2,6-Ar 2 C 6 H 3 -[Ar = 2,6-Me 2 C 6 H 3 (2,6-Xyl); 3,5-Me 2 C 6 H 3 (3,5-Xyl); 2,3,4,5,6-Me 5 C 6 (Pmp)] have been used to stabilise three series of two-coordinate Group 12 diaryl complexes; (2,6-Ar 2 C 6 H 3 ) 2 M [M = Zn, Cd, Hg; Ar = 2,6-Xyl 1-3; 3,5-Xyl 4-6; Pmp 7-9], where differing steric demands on the metal centres are imparted. These are the first homoleptic d-block complexes featuring any of these ligands. Complexes 1-9 have been characterised in solution and the solid state; the analysis of structural changes produced by differences in ligand properties is reported. In particular, complexes 4-6 show smaller C-M-C bond angles and contain secondary ligand interactions that are not seen in the analogous complexes 1-3 and 7-9. † Electronic supplementary information (ESI) available: Crystallographic data for complexes 1-9, molecular structures and crystallographic data for iodides 2,6-Ar 2 C 6 H 3 I (Ar = 2,6-Xyl, 3,5-Xyl, Pmp) and [2,

Low-coordinate m-terphenyl complexes are precatalysts for dehydrocoupling of dimethylamine–borane, where small changes in coordination environment effect significant mechanistic differences.