One- and two-dimensional CdII coordination polymers incorporating organophosphinate ligands

Reaction of cadmium nitrate with diphenylphosphinic acid in dimethylformamide solvent yielded the one-dimensional coordination polymer catena-poly[[bis(dimethylformamide-kappa O)cadmium(II)]-bis(mu-diphenylphosphinato-kappa O-2:O')], [Cd(C12H10O2P)(2)(C3H7NO)(2)](n), (I). Addition of 4,4'-bipyridine to the synthesis afforded a two-dimensional extended structure, poly[[(mu-4,4'-bipyridine-kappa N-2:N') bis(mu-diphenylphosphinato-kappa O-2:O')cadmium(II)] dimethylformamide monosolvate], {[Cd(C12H10O2P)(2)(C10H8N2)]center dot C3H7NO}(n), (II). In (II), the 4,4'-bipyridine molecules link the Cd-II centers in the crystallographic a direction, while the phosphinate ligands link the Cd-II centers in the crystallographic b direction to complete a two-dimensional sheet structure. Consideration of additional pi-pi interactions of the phenyl rings in (II) produces a three-dimensional structure with channels that encapsulate dimethylformamide molecules as solvent of crystallization. Both compounds were characterized by single-crystal X-ray diffraction and FT-IR analysis.