'CLOSEST PACKINGS' LAW IN CRYSTAL STRUCTURES OF NEW Rh(III) COMPLEXES. N.V. Podberezskaya, G.V. Romanenko, Institute of Inorganic Chemistry Sib. Branch RAS, Novosibirsk, Russia

Crystal structures of two novel coordination Rh(III) compounds were determined (SYNTEX P2₁, MoK, /2-scan, 3deg.250) : cubic [Co(en)₃][Rh(NO₂)₆]*3H₂O, en=C₂H₈N₂ (I) (a=16.540(5) Å, V=4525(2) ų, Pa3, Z=8, D_c=1.974 g[[dotaccent]]cm^-3, 589 unique I_hkl > 2_I, R=0.0905) and triclinic Na[Rh(acac)₂Cl₂]*H₂O, acac=C₅H₇O₂^- (II) (a = 12.616(6), b = 8.411(4), c = 8.499(4) Å, (=108.37(4), (= 95.47(4), (= 110.45(4)[[ordmasculine]], V = 780.3 ų, P1(-), Z = 2, D_c=1.758 g[[dotaccent]]cm^-3, 1200 unique I_hkl >2_I, R=0.0463). In I, the joint packing of the complex cations, anions and water molecules presents the stacking after the three-layered closest packing with the combination of NaCl and CaF₂ structure types; in II, the complex anions produce the stacking after the hexagonal closest packing with Na⁺ and H₂O located in its cavities. The presence of organic ligands in the composition of the complexes does not contradict our understanding of packing rules for inorganic coordination compounds in the description of complex cations and anions as the quasi-spheric particles of the R_ef radius.

I II