The crystal structure of the hydrated cyano complexes NMe4MnII[(Mn, Cr)(III)(CN)(6)] center dot 3 H2O and NMe4Cd[M-III(CN)(6)] center dot 3 H2O (M-III = Fe, Co): Compounds related to Prussian Blue [German]

摘要

The crystal structures of the isotypic tetragonal compounds (space group I4, Z = 10) NMe4MnII [(Mn, Cr)(III)(CN)(6)] . 3 H2O (a = 1653.2(4), c = 1728.8(6) pm), NMe4Cd[Fe(CN)(6)] . 3 H2O (a = 1642.7(1), c = 1733.1(1) pm) and NMe4Cd[Co(CN)(6)] . 3 H2O (a = 1632.1(2), c = 1722.4(3) pm) were determined by X-rays. They exhibit perpendicular to c cyanobridged layers of octahedra [M-III(CN)(6)] and [(MN4)-N-II(OH2)2], which punctually are interconnected also parallel to c to yield altogether a spaceous framework. The M-II atoms at the positions linking into the third dimension are only five-coordinated and form square pyramids [(MN5)-N-II] with angles N-M-II-N near 104 degrees and distances of Mn-N: 1 x 214, 4 x 219 pm; Cd-N: 1 x 220 resp. 222, 4 x 226 resp. 228 pm. Further details and structural relations within the family of Prussian Blue are reported and discussed. [References: 29]