Martin Pley

Cs2K2[Pt12O8(SO4)12] : A new oxide-sulfate with the cluster anion [Pt12O8(SO4)12]4-

Single crystals of Cs2K2[Pt12O8(SO4)12] (R3̄, Z = 3, a = 1198.9(3), c = 2768.9(9) pm, Rall = 0.1154) were obtained by the reaction of Cs2[Pt(NO2)4], K2[Pt(NO2)4] and conc. sulfuric acid at 400 °C in a sealed glass ampoule. The compound contains the cluster anion [Pt12O8(SO4)12]4−. It consists of six Pt26+ dumbbell shaped cations that are linked by eight oxide ions and twelve sulfate anions to form a distorted Pt12 icosahedron. The arrangement of the cluster anions in the crystal structure provides two voids for the cations. The larger one is occupied by the Cs+ ions while the K+ ions reside in the smaller one. For the Cs+ ions the coordination number is 15 while the K+ ions have a coordination number of 13.