Monroe, Jeffrey C.Landee, Christopher P.Rademeyer, MelanieTurnbull, Mark M.2021-05-112021-05-112020-03Monroe, J.C., Landee, C.P., Rademeyer, M. et al. 2020, 'Copper(II) halide salts with 1-(4 '-Pyridyl)-Pyridinediium', Inorganics, vol. 8, no. 3, art. 18, pp. 1-11.2304-6740 (online)10.1021/ja00234a010http://hdl.handle.net/2263/79821The compounds [1,40 -bipyridine]-1,10 -diium [CuCl4] (1) and [1,40 -bipyridine]-1,10 -diium [CuBr4] (2) were prepared and their crystal structures and magnetic properties are reported. The compounds are isomorphous and crystallize in the monoclinic space group C2/c. The cation crystallizes in a two-fold disordered fashion with the terminal nitrogen and carbon atoms exhibiting 50% occupancies. This results in a crystal packing arrangement with significant hydrogen bonding that is very similar to that observed in the corresponding 4,40 -bipyridinediium complexes. Temperature dependent magnetic susceptibility measurements and room temperature EPR spectroscopy indicate the presence of very weak antiferromagnetic exchange. The data were fit to the Curie–Weiss law and yielded Weiss constants of −0.26(5) K (1) and −1.0(1) K (2).en© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.Cu(II)MagnetismEPRPyridine-based compoundArticle