Novel Open-Framework Tin(II) Phosphate Materials Containing Sn−O−Sn Linkages and Three-Coordinated Oxygens

Two new open-framework tin(II) phosphate materials have been synthesized hydrothermally and their structures elucidated by single-crystal X-ray diffraction. These materials exhibit an entirely new building motif, unknown in phosphate-based materials, viz., vertex-sharing truncated square-pyramidal SnO 4 units, in addition to the trigonal-pyramidal SnO 3 units. The connectivity between the SnO 3, SnO 4, and PO 4 units is such that Sn−O−Sn linkages are observed for the first time. The networking creates three-coordinated oxygens in the structure. Crystal data for compound I, [Sn 3 (PO 4 ) 2 (OH)] - ·0.5[(NH 3 )(CH 2 ) 6 (NH 3 )] +: monoclinic, a = 9.315(2) Å, b = 16.806(1) Å, c = 9.513(3) Å, β = 111.03(1)°, V = 1390.0(5), Z = 4, M = 622.13(1), D calc = 2.973 g cm - 3, Mo Kα, R F = 0.039. Crystal data for compound II, [Sn 3 (PO 4 ) 2 (OH)] - ·0.5[(NH 3 )(CH 2 ) 8 (NH 3 )] +: orthorhombic, a = 10.390(1) Å, b = 16.087(1) Å, c = 18.717(1) Å, V = 2849.3(1), Z = 4, M = 636.16(1), D calc = 2.595 g cm - 3, Mo Kα, R F = 0.07.