Röntgenstrukturuntersuchungen an Elpasolith-verwandten Hexacyanokomplexen [N(CH3)4]2A[M(CN)6] (A = Rb, Tl; M = Cr, Fe) / X-Ray Structure Investigations of Elpasolite Related Hexacyano Complexes [N(CH3)4]2A[M(CN)6] (A = Rb, Tl; M = Cr, Fe)

Abstract

Abstract Single crystals were prepared and X -ray structure determinations performed of the hexagonal com pounds (R3̄m, Z = 3) [N(CH3)4]2RbCr(CN)6 (a = 895.9, c = 2176.4 pm), [N (CH3)4],TlCr(CN)6 (a = 894.0, c = 2168.4 pm), [N(CH3)4],RbFe(CN)6 (a = 886.7, c = 2149.9 pm ) and of monoclinic [N(CH3)4]2TlFe(CN)6 (C2/c, Z = 4; a = 1511.4, b = 884.8, c = 1525.9 pm , β = 110.0°). The structure of the hexagonal complexes is closely related to that of cubic elpasolites, showing, however, orientational disorder of the tetramethylammonium groups. Within the monoclinic TIFe-compound this group has fixed orientation, which makes some of the Fe-CN-Tl bridges bent, contrary to the linear M-CN -A array within the hexagonal compounds. Details and relations are discussed with respect to similar hexacyano complexes.