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 SnO4 units, in addition to the trigonal-pyramidal SnO3 units. The connectivity between the SnO3, SnO4, and PO4 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(PO4)(2)(OH)](-). 0.5[(NH3)(CH2)(6)(NH3)](+): monoclinic, a = 9.315(2) Angstrom, b = 16.806(1) Angstrom, c = 9.513(3) Angstrom, beta = 1.1.1..03(1)degrees, V = 1390.0(5), Z = 4, M = 622.13(1), D-calc = 2.973 g cm(-3), Mo K alpha, R-F = 0.039. Crystal data for compound II, [Sn-3(PO4)(2)(OH)](-). 0.5[(NH3)(CH2)(8)(NH3)](+): orthorhombic, a 10.390(1) Angstrom, b=16.087(1) Angstrom, c = 18.717(1) Angstrom, V = 2849.3(1), Z = 4, M = 636.16(1), D-calc = 2.595 g cm(-3), Mo K alpha, R-F = 0.07.