ON THE CONSTITUTION OF OXORUTHENATES(VI) .1. ON THE STRUCTURE OF CS2[RUO4]

By heating of well ground mixtures of the oxides [Cs2O2, RuO2, Cs:Ru = 2.2:1, Pd-tube, 800-degrees-C, 31 d] dark-green orthorhombic single crystals of Cs2RuO4 have been prepared for the first time: space group Pnma (No. 62); a = 851.20(11), b = 647.50(11), c = 1145.75(17) pm, is isostructural to beta-K2SO4. The structure was determined by four-circle diffractometer data [MoK-alphaBAR, 977 from 984 I(o)(hkl), R = 5.8%, R(W) = 2.8%], parameters see text. The Madelung Part of Lattice Energy, MAPLE, the Effective Coordination Numbers, ECoN and the charge distribution have been calculated and discussed.