A novel cesium hydroxygallophosphate with a layered structure built up of rutile ribbons:: CsGa2(OH)2[(PO4)H(PO4)]

A new cesium gallophosphate, CsGa2(OH)(2)[(PO4)H(PO4)], with an original layer structure has been synthesized by hydrothermal route and characterized by single-crystal X-ray diffraction (R = 0.0344, R-w 0.0319). Its structure crystallizes in the monoctinic space group P2(1)/a with cell parameters a = 16.079(6) angstrom, b = 5.9873(12) angstrom, c = 4.5033(15) angstrom, beta = 93.36(4)degrees and Z = 2. It consists of [Ga(OH)PO4](infinity) layers built up of rutile ribbons interconnected through PO4 tetrahedra. The structure of CsGa2(OH)(2)[(PO4)H(PO4)] is closely related to those of (NH4)Ga(OH)PO4 and (en)Ga-2(OH)(2)(PO4)(2) (en = ethylenediamine [H3N(CH2)(2)NH3](2+)). The three structures differ mainly from each other by the relative positions and the spacing of the successive layers, which are governed by different hydrogen bonding modes between [Ga(OH)PO4](infinity) layers and the interleaved species. The title compound presents strong symmetric hydrogen bonds O-H-O which bridge two PO4 tetrahedra of two successive layers. As a consequence, the distance between the layers is significantly shorter than in the two other amine compounds. (c) 2006 Elsevier Inc. All rights reserved.