CuTiPS₅ – A New Structure Type with a Corrugated Layered Network Structure

The reaction of the binary sulfides TiS₂ and P₄S₁₀ with the elements Cu and S for 10 h at 750 °C and subsequent annealing at 550 °C for 21 d result in the novel compound CuTiPS₅, which crystallizes in the triclinic space group P1 with a = 6.8381(12), b = 6.9905(12), c = 14.612(3) Å, α = 90.057(6)°, β = 101.771(7)°, γ = 103.165(7)°, Z = 4, R₁ = 1.87 %, wR₂ = 4.74 % (all reflections) and represents the first quaternary copper titanium thiophosphate. The crystal structure contains ¹ _∞[Cu₂Ti₂(PS₄)₂S₂] chains built from TiS₆ octahedra and PS₄ and CuS₄ tetrahedra, which are connected by common edges and linked via common vertices to form layers. The anionic [TiPS₅]^– partial structure has been found previously, whereas the distinct 2D extension of the network is observed for the first time in compounds with such a MTiPS₅ composition. The structure resembles sections of the TiS₂ and Cu₃PS₄ structures, which were found in the reaction as by-products.