2) A3Nb2Ti2P5S24
The new quinternary thoiphosphates, A3Nb2Ti2P5S24 (A = Rb, Cs) have been prepared with the use of halide fluxes and the crystal structure of the compound have been determined by single crystal X-ray diffraction methods. The compounds of A3Nb2Ti2P5S24 (A = Rb, Cs) have been synthesized and crystallize in space group C_2h^6-C2/c the monoclinic system with two formula units in a cell dimensions: a = 13.3326(4) Å, b = 27.3161 (7) Å, c = 11.7834 (4) Å, β = 116.1847 (9) °, V = 3851.1 (2) Å 3 for Rb3Nb2Ti2P5S24, a = 13.4219 (4) Å, b = 27.5078 (1) Å, c = 11.8079 (4) Å, β = 116.0479 (8) °, V = 3916.8 (2) Å3 for Cs3Nb2Ti2P5S24
The structure of the title compounds are composed of octahedral TiS6, tetrahedral PS4, and bicapped trigonal prismatic Nb2S12. The polyhedra form a three-dimensional framework by sharing S atoms. Two frameworks related by an inversion intertwined but there is no bonding interaction between them. The charge balance of the compound can be represented by the formula [A+]3[Nb4+]2[Ti4+]2[PS43-]5[S22-]2.
