Structural Chemistry of Several Compounds Elucidated by Single Crystal X-Ray Diffraction.

Abstract

The single crystal X-ray diffraction structure of four compounds have been determined. Crystals of bis((mu)-acetato-O:O')-bis 4'-nitro-2'-(2-pyridyl)phenyl-N dipalladium (II), (PdC(,13)H(,10) N(,2) O(,4))(,2), are monoclinic, space group I 2/c, with lattice constants: a = 14.300(3)(ANGSTROM), b = 9.939(1)(ANGSTROM), c= 18.822(2)(ANGSTROM), (beta) = 91.01(3)(DEGREES). The structure was solved by the heavy atom technique, and full-matrix least squares refinement resulted in a final R-value of 0.029, Rw = 0.050. The molecule has a folded conformation with Pd---Pd = 2,822(6)(ANGSTROM). Crystals of pseudo penta-O-acetyl-(beta)-D,L-Glucopyranose are monoclinic, space group P2(,1)/c, a = 11.580(2)(ANGSTROM), b = 8.276(1)(ANGSTROM), c = 22.031(2)(ANGSTROM), (beta) = 104.33(1)(DEGREES). The structure was solved by direct methods and refined to a final R value of 0.049 and Rw of 0.054. The pseudo-glucose ring has nearly a ('4)C(,1) conformation with O(61) in the gg position. Ba (Pt(,x), Ni(,1-x))(CN)(,4) .4H(,2)O crystallizes in space group C2/c with lattice constants: a = 12.209(2)(ANGSTROM), b = 13.752(2)(ANGSTROM), c = 6.638(1)(ANGSTROM) and (beta) = 107.76(1)(DEGREES). The disordered structure consists of columns of M(CN)(,4)('2-) groups (M = Pt and Ni) stacked along the c axis with M-M distance of 3.319(1)(ANGSTROM). Planes of these groups are tilted by 4.1(1)(DEGREES) from the c axis. The CN('-) ligands are found to be staggered with NC - M - M - CN torsion angles ranging from 42(DEGREES) to 48(DEGREES). The Ba('2+) ion has a ten fold coordination of bicapped square antiprismatic geometry. The crystal structure refined to R = 0.0469, Rw = 0.0699, and X = 0.59. 2,5-anhydro-(1,3,4,6-O-('2)H(,4))-D-Mannitol crystallizes in space group P2(,1)2(,1)2(,1) with a = 7.876(1)(ANGSTROM), b = 8.561(1)(ANGSTROM), c = 11.443(1)(ANGSTROM). The molecule does not have the expected C(,2) symmetry: the ring C - O bonds are unequal in length, and the conformation is slightly distorted from the ideal ('4)T(,3) configuration.