A new oxamato-bridged heterotrinuclear NiIICuIINiII complex with irregular spin state structure: Synthesis, spectroscopy, crystal structure and magnetism

A new oxamato-bridged NiIICuIINiII species, [Ni(tacn)(H2O)]2[m-Cu(pba)](ClO4)2$6H2O 1, (tacnZ1,4,7-triazacyclononane; pbaZ1,3- propylenebis(oxamato)) has been synthesized and structurally as well as magnetically characterized. Complex 1 has a discrete trinuclear NiIICuIINiII structure: Two nickel(II) ions are bridged by [Cu(pba)]2K anion, macrocyclic ligand tacn works as terminal ligand of the nickel(II) center. The magnetic data of compound 1 was analyzed by means of H ZKJð SNi1$ SCuC S Ni2$ SCuÞCD½ S 2 z K1=3SðSC1Þ Cb½gNið SNi1C S Ni2ÞCgCu S Cu H leading to gCuZ2.19, gNiZ2.18, JZK112.8 cmK1, DZG4.31 cmK1. The parameters are compared with the similar complexes and the irregular spin state structure of complex 1 is also described here. q 2005 Elsevier B.V. All rights reserved.