Effects of denticity and ligand rigidity on reactivity of copper complexes with cumyl hydroperoxide

Cu(II) complexes bearing N2/Py2 tetradentate ligands consisting of two pyridyl arms and a flexible ethyldiamine backbone, [(BPMEN)Cu(ClO4)(2)] (1), with rigid cyclohexyl backbone [(BPMCN)Cu(ClO4)(2)] (2), and substituted with bispyrrolidyl [(PDP)Cu(ClO4)(2)] (3), and Cu(II) complex bearing N2/Py3 pentadentate ligand, [(TPMEN)Cu(ClO4)(2)] (4), were synthesized and structurally characterized. Reactivity of 1-4 with cumyl hydroperoxide was investigated to study the effects of ligand rigidity and denticity on the mechanism of O-O bond cleavage. Results presented herein illustrate that 1-3 favors homolysis, however 4 showed little to almost no impact on O-O bond cleavage.