Crystal and molecular structure of tris(hexaamminerhodium(III)) tetrakis(trichlorostannato(II))(tetrachlorostannato(II)rhodate(I) hexachlorostannate(II) tetrahydrate

Abstract

The crystal and molecular structure of the title compound, [Rh(NH 3) 6] 3[Rh(SnCl 3) 4(SnCl 4)] [SnCl 6] · 4H 2O, has been determined by the single-crystal X-ray diffraction method. The compound crystallizes in the monoclinic system, space group P2 n with a = 16.581(2), b = 11.010(4), c = 16.024(2)Å, β = 90.76(1), and two molecules per unit cell. The structure was solved by Patterson's method and refined by the least-squares technique to give a final R factor of 0.031. The three cations, [Rh(NH 3) 6] 3+, are a regular octahedron with an average RhN bond length of 2.07 Å. The rhodium anion, [Rh(SnCl 3) 4(SnCl 4)] 5−, is a trigonal bipyramid with the two axial RhSn bonds, 2.493 Å in length, and the three equatorial bonds, 2.546, 2.540, and 2.540 Å. One of the three tin atoms in the equatorial trigonal plane forms a distorted trigonal bipyramid with two short SnCl bonds 2.384 Å in length and two long bonds, 2.733 Å. The other four tin atoms have a distorted tetrahedral arrangement with an average SnCl bond length of 2.42 Å. The tin anion, [SnCl 6] 4−, which is not coordinated to rhodium, forms extremely long SnCl bonds of 2.763, 2.800, and 2.893 Å in a distorted octahedral arrangement.