Die Schichtstruktur des hydratisierten Tetramethylammoniummangan(II)- hexacyanochromats(III), NMe4MnCr(CN)6 · 4H2O / The Layer Structure of the Hydrated Tetramethylammoniummanganese(II)- hexacyanochrom ate(III), NMe4MnCr(CN )6 · 4H2O

Abstract

The crystal structure of the orthorhombic compound NMe4MnCr(CN)6-4H:0 has been determined (a = 1496.5, b = 783.8, c = 1727.0 pm, space group Pnma. Z = 4, = 0.06 for 2018 independent reflections). The structure consists of puckered layers formed by Cr(CN)6 3- octahedra (average Cr-C = 207.5 pm, C-N = 114.4 pm), which are two-dimensionally linked via cyano bridges Cr-CN-Mn to trans-dihydrated Mn(H2O)2+ cations (Mn-O = 219.3 pm. Mn-N = 224.4 pm). Between the layers, which are separated by disordered tetramethylammonium ions and additional water molecules, a hydrogen bridge O-H···N is formed by two of the four terminal ligands. The structure found is intermediate between the framework arrangement of CsMnCr(CN)6 and the chain structure of NMe4MnM(CN)8-8H2O. Some further relations are discussed.