Ba2CoCl6: Synthese, kristallstruktur und spektroskopische Eigenschaften

Abstract

Single crystals of Ba2CoCl6 were obtained from the binary chlorides BaCl2 and CoCl2 in sealed silica ampoules applying the Bridgman technique. According to the X-ray single crystal structure determination, Ba2CoCl6 crystallizes with the monoclinic crystal system (P21/n, Z = 4, a = 914.1(1), b = 811.4(1), c = 1279.7(2) pm, β= 90.22(2)°). The structure contains conedgial double octahedra, [Co2Cl10]6-, and extra Cl- anions. These are connected via nine-coordinate Ba2+ cations. Investigations of the absorption properties of the blue Ba2CoCl6 show a high-spin ground state. The absorption spectrum is comparable to that of CoCl2.