Synthesis and crystal structure of Cu4TiS4: A novel chalcogenide with tetrahedrally coordinated titanium

Article abstract of DOI:10.1016/S0925-8388(96)02363-8

Dark red single crystals of Cu₄TiS₄ were prepared by reacting an intimate mixture of Cu₂S, Ti and S at 500°C. Cu₄TiS₄ is tetragonal, space group I42m with a = 5.448(1) A, c = 10.565(2) A, Z = 2. The crystal structure is of a new type. It was determined from diffractometer data and refined to a conventional R of 0.024 for 132 F_os and 17 variables. The crystal structure is based on a cubic close packing of chalcogen with Cu and Ti in tetrahedral interstices. This results in a three-dimensional framework of vertex sharing CuS₄ tetrahedra which are connected with the almost regular TiS₄ tetrahedra through common edges. The bond lengths are d(Ti-S) = 2.278 A and d(Cu-S) = 2.333 to 2.351 A.