Abstract
A series of copper halide complexes have been prepared employing 2-pyridone as a ligand. The compounds [CuBr2(2-pyridone)2]2 (1), [CuCl2(2-pyridone)2]2 (2), [CuCl2(2-pyridone)]2 (3), [CuCl2(2-pyridone)3] (4), and [CuCl2·2H2O]2[(2-pyridone)2] (5) were prepared and their structures and magnetic properties studied. Compounds 1 and 2 are dimeric species with the Cu(II) ions bridged by a pair of O-atoms from 2-pyridone molecules. Compound 3 is also a dimer, but in this case bridged by a pair of chloride ions. Only compound 4 is monomeric with fairly well isolated copper(II) ions, while compound 5 is a coordination polymer with the Cu(II) ions linked into chains via pairs of bridging chloride ions. Analysis of the magnetic data reveals that 1 and 2 exhibit significant antiferromagnetic interactions, while 4 is very weakly antiferromagnetic. Compounds 3 and 5 show weak ferromagnetic interactions. Data for 1 and 2 were fit to the antiferromagnetic dimer model with a Curie–Weiss correction to account for interdimer interactions: 1, J=−41.7(1)K, θ=−0.8(1)K; 2, J=−38.2(1)K, θ=−0.7(1)K. Data for 3 were fit to the ferromagnetic dimer model with a Curie–Weiss correction for interdimer interactions:); 2, J=9.4(6), θ=−3.2(3). Interactions in both 4 and 5 were sufficiently weak that data were fit only to the Curie–Weiss expression resulting in θ-values of −0.50(7) and 0.58(4)K respectively.