Crystal structure and chemistry of a complex indium phosphate framework material, (ethylenediammonium)In{sub 3}P{sub 3}O{sub 12}(OH){sub 2}

The chemistry and structure of a novel indium phosphate material (RIPS-4), (H{sub 3}NCH{sub 2}CH{sub 2}NH{sub 3})In{sub 3}-P{sub 3}O{sub 12}(OH){sub 2}, are described. RIPS-4 was synthesized using ethylene diamine as a structure-directing organic agent. The X-ray crystal structure was determined from a 12 Multiplication-Sign 12 Multiplication-Sign 42 {mu}m{sup 3} crystal in space group C2/m with a=18.662(4) A, b=6.600(2) A, c=12.573(3) A and {beta}=120.92(1) Degree-Sign . The structure consists of a complex edge- and vertex-shared open framework of InO{sub 6} octahedra and PO{sub 4} tetrahedra enclosing cavities occupied by ethylenediamonium ions. One set of octahedra share opposing edges to form chains along the b-axis matching the structural unit in rutile (TiO{sub 2}). This rutile edge-shared chain has its projecting oxygen atoms shared with the vertexes of either a PO{sub 4} tetrahedron or a second type of InO{sub 6} octahedron. The O atoms are 2-connected, each to one In and one P, except for two protonated O atoms (hydroxyl groups) that connect to two and three In atoms, giving three- and four-coordinate O atoms, respectively. - Graphical abstract: The unique topology contains an unusual 4-connected oxygen atom (O{sub 1}) in a complex edge- and vertex-shared open framework of InO{sub 6} octahedra (blue) and PO{sub 4} tetrahedra (yellow) that encloses cavities occupied by ethylenediammonium ions. Highlights: Black-Right-Pointing-Pointer The structure has a unique open-framework topology. Black-Right-Pointing-Pointer The framework contains an unusual 4-connected oxygen atom. Black-Right-Pointing-Pointer Hydrogen bonds hold the ethylenediammonium ions in the cavities.