A study of the magnetic properties of copper(II) pyrazinamide complexes

Abstract
The magnetic susceptibilities of the compounds [Cu(pyzA)2Cl2], [Cu(pyzA)2Br2], and [{Cu(pyzA)2(ClO4)2}n](where pyzA = pyszine-2-carboxamide) were measured between 1.7 and 280 K. The perchlorate complex exhibits Curie–Weiss behaviour to low temperatures. The susceptibilities of the halide complexes maximize at 17 K for the chloride and at ca. 31 K for the bromide. The experimental results are described by the Heisenberg model for a one-dimensional chain exhibiting antiferromagnetic interactions. Consistent with i.r. observations reported previous to this work, the observed susceptibilities of the halide complexes are indicative of a halogen-bridged infinite-chain structure for these species.