SYNTHESIS AND CRYSTAL-STRUCTURE OF TL(I)T L(III)(0.6)BI(III)(0.4)(CRO4)(2)

The crystal sructure of Tl(I)Tl(III)(0.6)Bi(III)(0.4)(CrO4)(2) was det ermined with a single crystal. The unit-cell is orthorhombic, space gr oup Pnma. The cell parameters are: alpha(Angstrom) = 14.652(2), b(Angs trom) = 5.7085(12), c(Angstrom) = 8.620(2), Z = 4, rho = 5.92 g cm(-3) The structure is isomorphous with Tl(I)Tl(III)(CrO4)(2) and was refin ed to the final factor R = 0.072 (R- w = 0.10), using 1434 independent reflections (I > 4 sigma(I)). A three-dimensional framework and, note worthy, trivalent bismuth atoms located in a quasi-regular octahedral surrounding, constitute the main features of the structure. (C) Academ ie des Sciences/Elsevier, Paris