Structural diversity by mixing chalcogen atoms in the chalcophosphate system K/In/P/Q (Q = S, Se).

The new thiophosphate salt K(4)In(2)(PS(4))(2)(P(2)S(6)) (1), the selenophosphate salts K(5)In(3)(mu(3)-Se)(P(2)Se(6))(3) (2), K(4)In(4)(mu-Se)(2)(P(2)Se(6))(3) (3), and the mixed seleno-/thiophosphate salt K(4)In(4)(mu-Se)(P(2)S(2.36)Se(3.64))(3) (4) are described. For the first time, a structurally different outcome of a chalcophosphate reaction was observed when sulfur and selenium are mixed, for example, by the use of K(2)S/P(2)Se(5)/S/In instead of K(2)Se/P(2)Se(5)/Se/In or K(2)S/P(2)S(5)/S/In. In compounds 1-4 indium atoms exist in a variety coordination environments. While in 1, indium is octahedrally coordinated, in 2-4 tetrahedral, trigonal-bipyramidal, and octahedral coordination environments are found for indium atoms. This remarkable structural diversity possibly is a reason, why particularly indium chalcophosphate flux reactions often produce a large variety of compounds at intermediate temperatures. In the mixed seleno-/thiophosphate salt K(4)In(4)(mu-Se)(P(2)S(2.36)Se(3.64))(3) (4) most of the chalcogen sites around the tetrahedrally coordinated P atoms show mixed S/Se occupancy. There is, however, a preference for Se binding to In ions and S binding to potassium ions.