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

Two tetra-coordinate Co(II) complexes, [CoCl 2 (bzfupy) 2 ] and [CoCl 2 (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.