Quinoxaline radical-bridged transition metal complexes with very strong antiferromagnetic coupling

Abstract

A new family of radical-bridged compounds, (Cp*₂Co)[M₂Cl₄(dpq)] (M = Fe (1), Co (2), Zn (3)), (dpq = 2,3-di(2-pyridyl)-quinoxaline) is reported. Magnetic studies, DFT and ab initio calculations reveal strong antiferromagnetic metal–radical interactions with coupling constants of J = −213.1 and −218.8 cm⁻¹ for 1 and 2, respectively.