End-on cyanate or end-to-end thiocyanate bridged dinuclear copper(II) complexes with a tridentate Schiff base blocking ligand: synthesis, structure and magnetic studies

Two dinuclear copper(II) complexes, [Cu-2(L)(2)(mu(1,1)-NCO)(2)] (1) and [Cu-2(L)(2)(mu 1,3NCS)(2)]center dot H2O center dot DMF (2), have been synthesized using a tridentate N2O donor Schiff base ligand (HL), [1((2-(ethylamino) ethylimino) methyl)naphthalen-2-ol], and characterized by elemental analysis, spectral study and X-ray crystallography. Both complexes are centrosymmetric dimers in which square pyramidal copper(II) centres are connected by pseudo-halides: end-on cyanate in 1 and end-to-end (EE) thiocyanate in 2. Variable temperature (2-300 K) magnetic susceptibility measurements indicate the presence of ferromagnetic exchange coupling between copper(II) centres in complex 1 (J = 0.97 cm(-1)), and antiferromagnetic exchange coupling in 2 (J = -0.6 cm(-1)).