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The crystal structures of the isomorphic tetragonalcompounds NMe4MnFe(CN)6 ·8 H2O (a = 1067.0, c = 1056.8 pm ) and NMe4Mn2(CN)6 · 8 H2O (a = 1066.9, c = 1064.1 pm ), space group P4/n, Z = 2 , were determined (R = 0 .03). The structure is built up from slightly distorted M(CN)63− octahedra and square planar Mn(H2O)42+ cations, stacked one upon the other in nearly eclipsed positions to form cyanobridged chains - Mn -NC -Mm -CN -along [001]. The average distances in the compounds are: Fe -C = 193.8 (Mn -C -199.3) pm, C -N = 114.7 (114.7 ) pm , Mn -N = 220 .2 (218 .2) pm, Mn -O = 218 .8 (218 .5) pm. The differences of bridge lengths are discussed, as well as the orientation and contact distances of the tetramethylammonium cations. These and additional crystal water, forming H -bonded(H2O)4 rings, occupy positions in the center of elpasolite- like sub cells, which result from O -H ··· N bridging between different chains. Some further relations to the structures of elpasolite and prussian blue are pointed out.

Am Secosteroid (I), einem wichtigen Zwischenprodukt bei Steroidsynthesen, werden Möglichkeiten zur stereospezifischen Reduktion der l4‐Ketogruppe untersucht.