Zur Kristallstruktur der Cyanoelpasolithe [N(CH3)4]2CsCo(CN)6 und [H3NCH3]2NaFe(CN)6 / Concerning the Crystal Structures of the Cyano-Elpasolites [N(CH3)4]2CsCo(CN)6 and [H3NCH3]2NaFe(CN)6

Abstract

Abstract Single crystals of the cyano complexes [N(CH3)4]2CsCo(CN)6 and [H3NCH3]2NaFe(CN)6 were prepared and their structures determined by X-ray methods. The cobalt compound is monoclinic, a =885.5(1), b = 892.6(2), c = 1259.9(5) pm, β = 90.29(4)°, space group I2/m, Z = 2; R1 = 0.048 for 861 independent reflections. The resulting average distances in the nearly undistorted octahedra are Co - C = 189.8, C - N = 114.1, Cs - N = 325.6 pm. The iron compound exhibits a cubic elpasolite type structure, a = 1105.2(1) pm, space group Fm 3m , Z = 4; R1 = 0.040 for 127 independent reflections; Fe - C = 193.4(6), Na - N = 247.7(8) pm. The orientation of the librating tetramethyl-ammonium group within the cages of the cobalt compound and the disorder of the monomethyl-ammonium cation around the special site (1/4, 1/4, 1/4) of the iron complex are discussed.