A combined electron paramagnetic resonance (EPR) and density functional theory (DFT) investigation of the N, N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexane-diamino cobalt(II) complex was undertaken. This complex displays remarkable selectivity for the hydrolytic kinetic resolution of epoxides after activation with a suitable acid. The EPR data show that the complex possesses a vertical bar yz,(2)A(2)> ground state. The nitrogen and proton hyperfine, and nitrogen nuclear-quadrupole values, obtained from HYSCORE experiments, could be interpreted using complementary DFT results. Addition of acetic acid to the cobalt(II) complex under a N-2 atmosphere, resulted in the formation of new high-spin and low-spin Co(II) species, the latter possessing a vertical bar z(2),(2)A(1)> ground state. (C) 2008 Elsevier B.V. All rights reserved.