Spectroscopic investigations and crystal structure from synchrotron powder data of the inclusion complex of beta-cyclodextrin with atenolol.

Inclusion complexes of atenolol with beta-cyclodextrin (beta-CD) in aqueous solution have been investigated with 1H NMR and UV-vis spectroscopy. The stoichiometry of this inclusion complex was established to be equimolar (1:1) and its stability constant was determined by UV-vis spectroscopy. The crystal structure of the beta-CD-atenolol (1:1) inclusion compound has been solved from synchrotron powder diffraction data using direct-space search techniques.

Structures of tetrabromothiophene and tetrabromoselenophene: the influence of the heteroatom on the heterophene packing.

The crystal structures of C(4)Br(4)S and C(4)Br(4)Se have been determined from X-ray powder diffraction data, using direct-space search techniques. In the case of C(4)Br(4)S two crystalline phases occur, a stable orthorhombic and a metastable monoclinic phase. For the orthorhombic phase two different structural models were found that fit the experimental data equally well.

Structure of C15-, C17- and C19-mono-acid beta-triacylglycerols.

The crystal structures of beta-1,2,3-tris(pentadecanoyl)glycerol (beta-C15C15C15), beta-1,2,3-tris(heptadecanoyl)glycerol (beta-C17C17C17) and beta-1,2,3-tris(nonadecanoyl)glycerol (beta-C19C19C19) have been determined from high-resolution X-ray powder diffraction data. Grid search and Rietveld refinement have been used to determine and refine the structures, respectively. As in beta-1,2,3-tris(tridecanoyl)glycerol (beta-C13C13C13) and the even-numbered mono-acid triacylglycerols, all three odd-numbered monoacid triacylglycerols crystallize in space group P1 with Z = 2 in an asymmetric tuning-fork conformation and have a lateral acyl chain packing resulting in a layered structure.