Novel copper materials based on the self assembly of organophosphonic acids and bidentate amines

The hydrothermal synthesis and crystal structure of seven new supramolecular, heterocyclic adducts of copper organophosphonates are presented. Compounds 1 - 4, [CuX(D)(2)][C6H5P(O)(OH)(2)] [C6H5P(O)(2)(OH)], where D = 1,10-phenanthroline (phen) and X = Cl (1), Br (2), I (3), and NCS (4), are ionic in nature and possess a monoclinic structure, with the copper(II)-halide bond lying along a two-fold crystallographic axis. The crystals exhibit an alternating, lamellar structure in which 1-D 'ribbons' of [CuX(phen)(2)](+) cations are interleaved with 2-D 'sheets' of anionic [C6H5P(O)(OH)(2)][C6H5P(O)(2)(OH)](-) dimers. The ribbons are associated through pi-pi bonding of the heterocyclic rings, and the acid sheets through a combination of p - p bonding of the aromatic rings, and hydrogen-bonding between the P=O and P-OH of neighbouring acid dimers. Analogous derivatives have also been prepared by the reaction of [Cu(phen)(2)] Br with benzylphosphonic acid ( 5), [Cu(2,2'-bipy)(2)] I with phenylphosphonic acid ( 6) and [ Cu( phen) 2] I with phenylsulfonic acid ( 7). These complexes did not produce crystals suitable for single-crystal analysis. However, compounds (5) and (7) are thought to have similar structures to 1 - 4, whilst compound ( 6) has a different ( 2 : 2 : 3) ratio of copper : phosphonate : amine. Thus the supramolecular structure is robust for phenyl- and benzyl-phosphonic acids, with Cl, Br, I and NCS copper( II) phen complexes, and slightly varied by the presence of phenylsulfonic acid, but is not observed in the presence of 2,2'-bipy.