Two new composite inorganic-organic materials from the copper/sulfate/4,4'-bipyridine family have been isolated and structurally characterized. The structure of the monovalent compound exhibits double chains in which the two parallel -Cu-bipy- chains are interconnected through sulfate bridges. The divalent polymer consists of two-dimensional interwoven networks that are stacked together by hydrogen bonding between the layers. (c) 2005 Elsevier B.V. All rights reserved.