Magnetic chains formed from tetra-coordinate Co(II) complexes

Two tetra-coordinate Co(II) complexes, [CoCl2(bzfupy)2] and [CoCl2(p-tol)2] with N-donor ligands, are apparently mononuclear systems. The magnetic susceptibility at low temperature attains a maximum which is a fingerprint of the exchange interaction. The exchange coupling constant fitted to a model of 1D-magnetic chain yields J/hc = −0.50 cm−1 and −0.57 cm−1, respectively. The magnetic interaction is mediated by the π-π stacking in the first complex, and the short Cl…Cl contacts in the second.