Structure, spectroscopic and magnetic properties of a novel 1-D coordination copper(II) polymer containing BIMAM ligand [BIMAM = bis(imidazol-2-yl)methylaminomethane] and μ-1,3 squarato bridges

This paper reports the synthesis and complete characterization (structural, spectroscopic and magnetic) of [Cu(HBI-MAM)Cl(C4O4)(n)] (.) (H2O)(n) [BIMAM = bis(imidazol-2-yl)methylaminomethane]. This compound is made of infinite chains - running along c axis - built from [CuCl(HBIMAM)](+) units bridged together by mu-O-1, O-3-bis(monodentate) squarate anions. Non-covalent interactions (H-bonds and pi-pi) drive the build-up of an infinite three-dimensional array. The coordination polyhedron about the copper(II) ion is distorted square pyramidal. The EPR spectrum is indicative of a d(z2-x2) ground state for the Cu(II) ions with significant contribution of d(z2). Magnetic susceptibility measurements in the range 1.8-260K show weak antiferromagnetic exchange interactions (2J = -3.5(1) cm(-1)). The observed magnetic behaviour is discussed in terms of the crystal structure and compared with that observed in related copper(II) complexes containing mu-O-1, O-3-squarato bridges. (c) 2006 Elsevier B.V. All rights reserved.