The crystal structure of the inclusion complex of cyclomaltoheptaose (β-cyclodextrin) with 4-tert-butyltoluene (original) (raw)

1992, Carbohydrate Research

The crystal of the 1: 1 complex of 4-tert-butyltoluene with cyclo?altoheptaose (/3-cyclodextrin, PCD) is triclinic Pl with a = 15.562(2), b = 15.564(4), c = 15.835(3) A, cy = 102.11(2), p = 102.15(l), y = 103.64(2)", V= 3505(l) A3, and Z= 2. The two independent PCD molecules in the asymmetric unit form a dimer by hydrogen bonding involving HO-3, which accommodates two molecules of the guest. The hydrophobic guests are enclosed completely in the j3CD cavities with the tert-butyl groups in the hydrophobic region beneath the primary hydroxyl groups. The aromatic rings have two orientations and their toluene methyl moieties could not be located but were calculated to be at the interface of the two monomers. The dimers form channels along the c axis. The inter-dimer space is filled with 17 molecules of water distributed over 25 sites. A dense network of hydrogen bonds is formed, involving the @CD hydroxyl groups and water molecules. Correspondence to: Dr. I.M. Mavridis, Institute of Physical Chemistry, NCSR Demokritos, Aghia Paraskevi 153.10, Athens, Greece. 0008-6215/92/$05.00 0 1992 -Elsevier Science Publishers B.V. All rights reserved 2 I.M. Mauri&, E. Hadjoudis/Carbohydr. Res. 229 (1992) l-15 EXPERIMENTAL