Structural variation in cerium aryloxide complexes templated by hemilabile K+–amine interactions
A series of complexes with the formula K[Ce(OAr)(bdmmp)3] (Ar = –C6H5 (–Ph), –C10H7 (–Naph), –2,4-tBu-C6H3 (–dtbp) and –2,6-Ph-C6H3 (–dpp)) and K[Ce(OAr)2(bdmmp)2] (Ar = –2,6-iPr-C6H3 (–dipp)) (bdmmp = (bis(dimethylamino)methyl-4-phenolate)) are presented. The complexes were obtained through metathesis and protonolysis reactions from K[Ce(OTf)(bdmmp)3] or K[Ce(OtBu)(bdmmp)3] respectively. X-ray diffraction studies provide insight into the effect of the steric profile of the aryloxide ligand on perturbing the templating effect of the K+ ion with the pendent tertiary amine groups of the bdmmp− ligands. Characterization of the various aryloxide derivatives through cyclic voltammetry and variable temperature 1H NMR studies demonstrate the impact of the substituents on the solution dynamics and redox properties. Additionally, an unusual example of a terminal cerium(III) hydroxide complex was isolated and characterized in solid state and in solution using the bdmmp framework.