Synthesis, crystal structure and magnetic properties of a cyclic dimer of [{Co(hfac)2}·BNOt-Bu]2

Abstract We prepared new metal-organic radical complex of cyclic dimer, [{Co(hfac) 2 }·BNO t- Bu ] 2 . This molecule is a good example for comparing quantitative magnetic interactions with polymeric molecule-based magnets consisting of Co ion and π -conjugated polyradical. We discuss about its crystal structure and magnetic property. This compound behaves as a paramagnetic compound with S =1. There are four 1 2 spins of bisnitroxide and two 3 2 spins of cobalt. Two spins of BNO radical are interacted ferromagnetically and intermolecular magnetic interactions of Co-ion are antiferromagnetic. Therefore, this compound has two 1 2 spins interacting ferromagnetically. An estimated Curie constant is 2.162 emu K/Oe mol and g eff value is 2.854.