Tuning the Electronic Properties of Tetravalent Cerium Complexes via Ligand Derivatization

Abstract

Molecular cerium complexes are of interest due to their remarkable redox and photophysical properties. We have investigated the ligand tunability of the electronic structure and properties of cerium(IV) complexes with functionalized tetradentate N2O2-donor ligands: [CeIV(LtBu)2] (1), [CeIV(LH)2] (2) and [CeIV(LNO2)2] (3), where H2LtBu = bis(2-hydroxy-3,5-di-tert-butylbenzyl)(2-pyridylmethyl)amine, H2LH = bis(2-hydroxybenzyl)(2-pyridylmethyl)amine and H2LNO2 = bis(2-hydroxy-5-nitrobenzyl)(2-pyridylmethyl)amine. These compounds all exhibit a quasi-reversible one-electron reduction to cerium(III), with the redox potential correlating with the electron donor-acceptor characteristics of the ligan..