A new lanthanum titanium oxysulfide, La(16)Ti(5)S(17+x)O(17), with x = 0.75 (9).

The title compound, hexadecalanthanum pentatitanium heptadecasulfide heptadecaoxide, La(16)Ti(5)S(17+x)O(17) [x = 0.75 (9)], has been obtained as a by-product in the preparation of new oxychalcogenide compounds in the La/Ti/Ag/S/O system. La(16)Ti(5)S(17+x)O(17) crystallizes in the tetragonal system (space group I4/m) and is isostructural with Nd(16)Ti(5)S(17)O(17). The structure of the title compound consists of an [La(2)S(2)] rock-salt-type framework, which delimits [001] square channels containing two types of chains of corner-sharing Ti(O,S)(6) octahedra. These chains are connected through La(O,S)(n) polyhedra.