Syntheses and Structures of Layered Copper( II ) Diphosphonates with Mixed Ligands

This paper describes the syntheses and crystal structures of two new copper( II ) diphosphonates with mixed ligands: [Cu 3 (hedpH) 2 (4,4′‐bipy)(H 2 O) 2 ]·2H 2 O ( 1 ) and [Cu 3 (hedpH) 2 (4,4′‐azpy)(H 2 O) 2 ]·1.6H 2 O ( 2 ) (hedp = 1‐hydroxyethylidenediphosphonate, 4,4′‐bipy = 4,4′‐bipyridine, 4,4′‐azpy = 4,4′‐azobispyridine). Both adopt a two‐dimensional layer structure containing neutral ladder‐like chains of {Cu 3 (hedpH) 2 (H 2 O) 2 } n linked by 4,4′‐bipy or 4,4′‐azpy ligands. The adjacent layers are held together by strong hydrogen bonds, thus generating a three‐dimensional network with rectangular shaped channels. The lattice water is found in these channels. The magnetic properties of compounds 1 and 2 have also been investigated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)