W0205

Layered Silver Sulfonates: A New Class of Lamellar Solids. G.D. Enright, G.K. Shimizu, C. I. Ratcliffe, G.S. Rego, and J.A. Ripmeester, Steacie Institute for Molecular Sciences, National Research Council, Ottawa (ONT.), Canada

Crystallographic studies have shown that silver sulfonates form a class of infinite lamellar solids that are structurally analogous to zirconium phosphonates. What began as a crystal engineering project to synthesize functional framework materials has led to the discovery of this new class of layered compounds. A single crystal X-ray structure of a product revealed the silver p-toluenesulfonate starting material. Its structure consists of layers of SO₃ bridged Ag(I) centers with toluene groups directed into the interlayer region. A number of other new Ag sulfonate compounds have been synthesized. and characterized by X-ray diffraction. In particular single crystal structural studies of Ag benzenesulfonate and Ag trifluoromethanesulfonate have revealed a remarkably flat layer of hexagonally arranged Ag(I) centers with symmetric bridging SO₃ groups above and below. Calorimetry has shown these compounds to be stable to at least 200 C.

The crystals used in these studies are extremely thin plates that have been coated in oil to reduce solvent loss and add rigidity when placed in the cold stream. Extensive screening is necessary to find single crystals with well defined diffraction spots and reasonable rocking curves. A CCD diffractometer is invaluable for these studies.