Synthesis, crystal structure and magnetic behavior of two new binuclear complexes bridged by a pentadentate ligand:: [Ni2L2(NCS)2](ClO4)2 and [Ni2L2(NCO)2](ClO4)2 [L = pentadentate ligand]

Two new binuclear nickel(II) complexes [Ni2L2(NCS)(2)](ClO4)(2) (1) and [Ni2L2(NCO)(2)](ClO4)(2) (2), where L is a pentadentate Schiff base ligand derived from the reaction of 2 mol of 2-benzoyl pyridine and I mol of diethylene triamine, have been prepared and characterized. The structures of complexes 1 and 2 have been Studied by single crystal X-ray diffraction analysis. The structure analysis reveals that each nickel(II) center is coordinated in a distorted octahedral (NiN6) fashion consisting of three nitrogen atoms from one and two nitrogen atoms from other pentadentate ligand and the last one from terminal thiocyanato/cyanato ion. The variable temperature magnetic susceptibility of both compounds I and 2 have been studied and found a very weak magnetic interaction between two nickel(II) centers consistent with the structures (Ni (. . .) Ni distance of 5.809(1) Angstrom for 1 and 5.695(1) Angstrom for 2 with no suitable bridge or linkage to propagate magnetic interaction), (C) 2002 Elsevier Science Ltd. All rights reserved.