Structural characterization, spectral and magnetic properties of isothiocyanate nickel(II) complexes with furopyridine derivatives

The nickel(II) complexes [Ni(Ln)4 (NCS)2], where L1 = furo[3,2-c]pyridine, L2 = 2-methylfuro[3,2-c]pyridine, L3 = 2,3-dimethylfuro[3,2-c]pyridine, L4 = benzo[4,5]furo[3,2-c]pyridine and L5 = isoquinoline, have been prepared and characterized by structural, spectroscopic and magnetic methods. The structures of the all complexes are formed by isolated molecules. The Ni(II) ions are six-coordinate, the equatorial planes are formed by four N-donor heterocycles whereas the isothiocyanate groups coordinate in the axial positions. The magnetism of the complexes exhibits a zero-field splitting, the magnitude of which correlates with the distortion degree of the coordination polyhedra.