TlIn5S6: ein neues, gemischtvalentes ternäres Chalkogenid und sein kristallchemisches Umfeld

Abstract

Abstract We report about synthesis and crystal structure of the new ternary mixed valence compound TlIn5S6, which crystallizes in the monoclinic system, space group P21/m with the lattice constants a = 8.7960(5) Å, b = 3.9129(3) Å, c = 17.458(2) Å, β = 94.71(1)°, (Z = 2). The threedimensional atomic arrangement can be explained in terms of the formulation Tl+([In2]4+)2(In3+)(S2−)6, implying the simultaneous existence of Tl+ and In3+ besides two distinct In2 4+-dumb bells with covalent bonding between In-atoms in different crystallographic surroundings. This structural principle corresponds to the already known solid In6S7, characterized by the formulation In+[In2]4+(In3+)3(S2−)7. In addition the paper contains information about the structurally related compounds In4X3(X = Se, Te), In5S4, In6X7(X = S, Se), M7Te10 (M = Al, Ga, In) and M3Te4 (M = Ga, In) which were poorly characterized up to now.