Li2Pt3Se4 : a new lithium platinum selenide with jagueite-type crystal structure by multianvil high-pressure/high-temperature synthesis

The monoclinic lithium platinum selenide Li2Pt3Se4 was obtained via a multianvil high-pressure/high-temperature route at 8 GPa and 1200 degrees C starting from a stoichiometric mixture of lithium nitride, selenium, and platinum. The structure of the ternary alkali metal-transition metal-selenide was refined from single-crystal X-ray diffractometer data: P2(1)/c (no. 14), a = 525.9(2), b = 1040.6(2), c = 636.5(2) pm, beta = 111.91(1)degrees, R1 = 0.0269, wR2 = 0.0569 (all data) for Li2Pt3Se4. Furthermore, the iso-structural mineral phases jagueite (Cu2Pd3Se4) and chrisstanleyite (Ag2Pd3Se4) were reinvestigated in their ideal stoichiometric ratio. The syntheses of the mineral phases were also carried out under multianvil conditions. Single-crystal data revealed a hitherto not described structural disorder of the transition metal atoms.