Structure and Magnetic Properties of a Trinuclear Copper(II) Complex with Bridging Carboxy-Phenyl Nitronyl Nitroxides

Abstract

A new complex {(NITPBAH)2[Cu(hfac)2]3} 1 derived from carboxy-phenyl-substituted nitronyl nitroxide radical (NITPBAH) and Cu(hfac)2(H2O)2 (NITPBAH = 2-(4-carboxy-phenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, hfac = hexafuoroacetylacetonato) has been synthesized as well as characterized structurally and magnetically. The single-crystal X-ray diffraction analyses indicated that the complex {(NITPBAH)2[Cu(hfac)2]3} 1 consists of trinuclear five-spin molecule system. Each NITPBAH ligand is bound to two copper atoms with its two oxygen atoms from ONCNO group. Copper atoms display two different coordination types. The central copper atom lies on an inversion center and is six-coordinated in an elongated octahedron using two hfac molecules and two oxygen atoms of ONCNO group from two different NITPBAH ligands. Two terminal copper atoms are five-coordinated in a distorted square-pyramidal environment formed by two hfac molecules and one oxygen atom of ONCNO group from one NITPBAH ligand. The magnetic susceptibility study of the complex {(NITPBAH)2[Cu(hfac)2]3} 1 shows strong antiferromagnetic interactions between Cu(II) ion and NITPBAH radical ligand.