SYNTHESIS AND CRYSTAL-STRUCTURES OF LITHIUM AND POTASSIUM HEXANITRORTHENATES(II)

A procedure for preparing Li-4[Ru(NO2)(6)]. 12H(2)O and K-4[Ru(NO2)(6) ] is described We have carried out an X-ray diffraction study of polyc rystals (DRON-UM1 diffractometer, R = 192 mm, CuKalpha radiation, Ni f ilter) and single crystals (CAD-4 automatic diffractometer, MoKalpha r adiation, graphite monochromator, omega/2 theta scan mode). Crystal da ta for Li-4[Ru(NO2)(6)]. 12H(2)O are a 11.749(9), c = 16.807(12) Angst rom, space group I (4) over bar, V = 2320.0 Angstrom(3), Z = 4, d(calc ) = 1.778 g/cm(3); for K-4[Ru(NO2)(6)]: a = 8.595(1) Angstrom; alpha = 53.23(2)degrees, space group R (3) over bar, V = 367.0 Angstrom(3), Z = 1, d(calc) = 2.414 g/cm(3). The structures are composed of [Ru(NO2) (6)](4-) complex anions, alkaline metal cations, and crystallization w ater molecules. In both compounds, the coordination polyhedra of Ru ar e nearly regular octahedra formed by nitrite nitrogen atoms. The Ru-N bond lengths are 2.054-2.102 Angstrom. The NO2 groups have virtually t he same geometric characteristics: the N-O distances are within 1.196- 1.316 Angstrom and the O-N-O angles are 112.9-117.4 degrees. The coord ination environment of alkaline metals by oxygen atoms is discussed.