Synthesis, structure and magnetic properties of two end-on double azido bridged nickel(II) dinuclear entities incorporating N,N,N-coordinating tridentate reduced Schiff base ligands
摘要:
Complexes of the general formula [Ni2L2(mu(1.1)-N-3)(2)(N-3)(2)] have been synthesised in good yields by reacting Ni(NO3)(2)center dot 6H(2)O with L in the presence of excess of sodium azide in methanol at room temperature. Here L is N,N-bis(2-pyridylmethyl)amine (L-1) and N-(2-pyridylmethyl)-N',N'-diethylethylenediamine (L-2). The X-ray structures of both compounds reveal that the N,N,N coordinating reduced Schiff bases are ligated facially. The Ni-N-azido-Ni angle is similar to 100 degrees and the Ni center dot center dot center dot Ni separation is similar to 3.2 angstrom. The variable temperature magnetic susceptibility measurements of the two complexes show ferromagnetic behavior. (c) 2005 Elsevier Ltd. All rights reserved.