Cyanato bridged binuclear nickel(II) and copper(II) complexes with pyridylpyrazole ligand: Synthesis, structure and magnetic properties

Binuclear cyanate bridged nickel(II) complex [Ni(L)(NCO)](2)(PF(6))(2) (1) and copper(II) complex [Cu(L) (NCO)](2)(PF(6))(2) (2), where L is N,N-bis(3,5-dimethylpyrazol-1-ylmethyl) aminomethylpyridine, a tetradentate N(4)-coordinated ligand have been synthesized and characterized by physicochemical method. The structures of complexes 1 and 2 have been studied by single crystal X-ray diffraction analysis. The structure analysis reveals that both nickel(II) and copper(II) center are coordinated in distorted octahedral fashion and coordination mode of cyanate ligand is end-to-end (mu-1,3) for complex 1 but it is double end-on (mu-1,1) mode for complex 2. The variable temperature magnetic susceptibility data, measured from 2 to 300 K, show weak antiferromagnetic interaction with J value -6.2(1) cm 1 for complex 1, whereas complex 2 has very weak ferromagnetic interaction with J value +0.5(1) cm 1. (C) 2011 Elsevier B.V. All rights reserved.