title: Crystal structure of a cyclomaltoheptaose-4-hydroxybiphenyl inclusion complex.
abstract: The crystal structure of the inclusion complex of cyclomaltoheptaose (beta-cyclodextrin) with 4-hydroxybiphenyl was determined by single-crystal X-ray diffraction at 150K. The complex contains two cyclomaltoheptaose molecules, two 4-hydroxybiphenyl molecules, one ethanol molecule and fifteen water molecules in the asymmetric unit, and could be formulated as [2(C(42)H(70)O(35)).2(C(12)H(10)O).(C(2)H(6)O).15(H(2)O)]. It crystallized in the triclinic space group P1 with unit cell constants a=15.257(3), b=15.564(3), c=15.592(2)A, alpha=104.485(15) degrees , beta=101.066(14) degrees , gamma=104.330(17) degrees , V=3,343.6(10)A(3). In the crystal lattice, two beta-cyclodextrins form a head-to-head dimer jointed through hydrogen bonds. Two 4-hydroxybiphenyls were included in the dimer cavity with their hydroxyl groups protruding from two primary hydroxyl sides of the cyclodextrin molecules. The guest 4-hydroxybiphenyl molecules linked into a chain via a combination of an O-Hcdots, three dots, centeredO hydrogen bond and face-to-face pi-pi stacking of the phenyl rings. The crystal structure supports the calculation results indicating that the 2:2 inclusion complex formed by beta-cyclodextrin and 4-hydroxybiphenyl is the energetically favored structure.
authors.affiliation: School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, PR China.
authors.forename: En-Ju
authors.initials: EJ
authors.lastname: Wang
authors.forename: Zier
authors.initials: Z
authors.lastname: Yan
authors.forename: Jiwen
authors.initials: J
authors.lastname: Cai
mesh_terms: D001713:Biphenyl Compounds / Q000737:chemistry*; D018360:Crystallography, X-Ray; D019281:Dimerization; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D001713:Biphenyl Compounds; D047392:beta-Cyclodextrins; C019046:4-phenylphenol; C031215:betadex