Novel Pillared Layer Structure of the Organically Templated Indium Phosphate [In₈(HPO₄)₁₄(H₂O)₆](H₂O)₅(H₃O)(C₃N₂H₅)₃

Abstract

An imidazole encapsulating indium phosphate with an In:P ratio of 4:7 and a new pillared layer structure has been synthesized under solvothermal conditions and characterized by single-crystal X-ray diffraction, 31 P CPMAS NMR, and thermogravimetric analysis. [Crystal data: [In 8 (HPO 4 ) 14 (H 2 O) 6 ](H 2 O) 5 (H 3 O)(C 3 N 2 H 5 ) 3, M r = 2686.72, trigonal, space group P −3 c 1 (No. 165), a =13.859(2) Å, c =19.186(8) Å, V = 3193(4) Å 3, Z = 2, R = 3.6%, R w = 3.7% (1650 observed data with I > 3σ( I ))]. The structure consists of layers assembled from InO 6 and InO 5 (OH 2 ) octahedra and PO 3 (OH) tetrahedra which are pillared through additional InO 6 octahedra to produce a three-dimensional framework. The framework contains a two-dimensional array of channels in which imidazolium cations, hydroxonium ions, and water molecules reside. Within the channels are 16-membered rings of alternating In and P polyhedra which have dimensions ∼8.6 × 9.7 Å.