title: Synthesis and structure of pillared molybdates and tungstates with framework layers.
abstract: Six new layered lanthanide molybdate and tungstate phases pillared by either naphthalenedisulfonate (NDS) or fumarate anions have been synthesized hydrothermally and structurally characterized. Five of these materials, [Nd(H(2)O)MoO(4)](2)[2,6-NDS] (1), [Nd(H(2)O)MoO(4)](2)[1,5-NDS] (2), [La(H(2)O)WO(4)](2)[1,5-NDS] (3), [La(H(2)O)WO(4)](2)[2,6-NDS] (4), and [Ce(H(2)O)MoO(4)](2)[fumarate] (6), have a closely related cationic inorganic layer structure which comprises a bilayer of polyhedra leading to the formation of a framework layer containing small, inaccessible pores. These layers are pillared by the organic anions which also bridge between the lanthanide cations within the layers. In the La/WO(4)/2,6-NDS system, a second polymorph, [La(2)(H(2)O)(2)W(2)O(8)][2,6-NDS] (5), is observed. In this compound, the tungstate anions have dimerized, forming W(2)O(8)(4-). This dimer is unique and comprises two square-based pyramidal tungsten centers which are opposed to each other.
authors: Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, UK.
authors: Jennifer L
authors: JL
authors: Nicholls
authors: Sarah E
authors: SE
authors: Hulse
authors: Samantha K
authors: SK
authors: Callear
authors: Graham J
authors: GJ
authors: Tizzard
authors: Richard A
authors: RA
authors: Stephenson
authors: Michael B
authors: MB
authors: Hursthouse
authors: William
authors: W
authors: Clegg
authors: Ross W
authors: RW
authors: Harrington
authors: Andrew M
authors: AM
authors: Fogg