Synthesis and structure determination of a new layered compound: V2P4S13

V2P4S13 was prepared from the elements taken in stoichiometric proportions and heated in an evacuated Pyrex tube for 10 days at 450°C. The crystal symmetry is triclinic, space group P1¯ with the parameters: a = 9.112(1) Å, b = 9.680(1) Å, c = 11.620(1) Å, α = 72.15(1)°, β = 110.82(1)°, γ = 110.13(1)°, V = 879.5(1) Å3, and Z = 2. The structure was solved from 3052 independent reflections and 173 parameters, the least-squares refinement yielding R = 0.033. The building units of the structure are made up of two distorted (VS6) octahedra and four distorted (PS4) tetrahedra sharing edges to form (V2P4S16) groups. These share sulfur atoms through their four (PS4) tetrahedra with the same neighbor groups. Infinite (V2P4S13) planes parallel to (101) are thus obtained, with no bonds other than van der Waals' ones between them. Within the slabs, the layered phase presents the following average distances: dV-S = 2.471(1) Å, dP-S = 2.050(1) Å, dV-V = 3.715(2) Å. From the various oxydation states of the atoms, the developed formula can be written VIII2PV4S−II13. The phase is semiconducting and magnetic susceptibility measurements show a Curie behavior with the occurrence of high spin d2 vanadium. Antiferromagnetic ordering is observed below 10 K.