James M. Stewart

THE CRYSTAL STRUCTURE OF TRANS-BIS(8-AMINOQUINOLINE)AQUAZINC(II) TETRACHLOROZINCATE(II)

Abstract The crystal structure of trans-bis(8-aminoquinoline)aquazinc(II) tetrachlorozincate(II), [Zn(C9H8)2H2O, ZnCl4], monoclinic C2/c, a = 11.234, b = 10.8527, c = 19.025 A, β = 108.43°, Z = 4, has been determined with X-ray (MoKα) diffractometer data. The structure was solved by direct methods and refined with full-matrix least-squares to R = 0.041. The cation and anion lie on a crystallographic dyad. The anion has the expected tetrahedral configuration. The structure of the cation is roughly halfway between the limiting trigonal bipyramid and square pyramid five-coordinate geometries. The structure is rationalized on the basis of the bite of the 8-aminoquinoline, and the electronegativities of the two nitrogen atoms and water oxygen atom.

The crystal and molecular structure of 3-methyl-3-pyrazolin-5-one

The crystal structure of 3-methyl-3-pyrazolin-5-one (C4H6N20) has been determined by X-ray diffraction as a model for the pyrazolin-5-one compounds. The space group is P2a/a. Cell dimensions are a= 10.520 (3), b=6.499 (2), c= 8.052 (1)/~, fl= 114.45 (1) °, Z=4, D~= 1.299 (1) g.cm-3. Three-dimensional X-ray data were collected using Mo Ka radiation. The structure was solved using statistical methods of phase determination, and refined by the full-matrix least-squares method to R= 0.071 (unit weights). Hydrogen-bonded layers are found parallel to the ab plane. The predominant tautomer is established as 3-methyl-3-pyrazolin-5-one. A comparison of structures based on data gathered by moving-crystal moving-counter and stationary-crystal stationary-counter methods shows no significant differences in bond lengths and angles calculated from atomic parameters refined on either set of data.

The X-ray crystal structure of the antimalarial and antileprotic drug, 4,4′-diaminodiphenyl sulphone

The crystal structure of the important antimalarial and antileprotic drug, 4,4′-diaminodiphenyl sulphone (“Dapsone”), has been determined.

Synthesis and structure of a molybdenum(0) compound containing a stable nine-membered chelate ring

NN′-Bis(diphenylphosphinomethyl)-NN′- dimethylethylenediaminetetracarbonylmolybdenum contains a stable nine-membered chelate ring with the phosphorus atoms co-ordinated to molybdenum in cis-positions and the nitrogen atoms unco-ordinated.