Organically templated linear and layered cadmium sulfates

By reacting cadmium salts with H<SUB>2</SUB>SO<SUB>4</SUB> in the presence of organic amines or directly with amine sulfates under hydrothermal conditions, it has been possible to prepare three linear cadmium sulfates of linarite topology, with the compositions [H<SUB>3</SUB>N(CH<SUB>2</SUB>)<SUB>2</SUB>NH<SUB>3</SUB>]<SUB>2</SUB>[CdCl<SUB>2</SUB>(SO<SUB>4</SUB>)][SO<SUB>4</SUB>]·H<SUB>2</SUB>O, I, [HN(CH<SUB>2</SUB>)<SUB>6</SUB>NH][CdBr<SUB>2</SUB>(SO<SUB>4</SUB>)], II, [HN(CH<SUB>2</SUB>)<SUB>6</SUB>NH][CdCl<SUB>2</SUB>(SO<SUB>4</SUB>)], III. A layered cadmium sulfate of composition [H<SUB>3</SUB>N(CH<SUB>2</SUB>)<SUB>3</SUB>NH<SUB>3</SUB>][Cd<SUB>2</SUB>(H<SUB>2</SUB>O)<SUB>2</SUB>(SO<SUB>4</SUB>)<SUB>3</SUB>], IV, has also been obtained. These sulfates are the first examples of a family of organically templated metal sulfates with interesting structural features. In the linarite chains, the CdX<SUB>4</SUB>O<SUB>2</SUB> (X=Cl, Br) octahedron shares two trans-edges to form an [Mφ<SUB>4</SUB>] (φ=anionic ligand) chain decorated by the SO<SUB>4</SUB> tetrahedron that adopts a staggered arrangement on either side of the chain. IV is constructed by the fusion of four-membered ring ladders involving edge sharing between the sulfate tetrahedron and metal octahedron. IV appears to be the first member of a family of organically templated metal sulfates containing an octahedral-tetrahedral 2D net wherein the sulfate tetrahedron is connected at all four corners