RESUMO
In the title compound, C(8)H(7)ClN(4)S(2), the thia-zole ring is essentially planar [r.m.s. deviation = 0.0011â (2)â Å] and conformation of the thia-zolidine ring is twisted on the C-C bond. The C=N bond has a Z configuration.
RESUMO
The crystallographic study of a partially hydrated form of cyclomaltoheptaose (beta-cyclodextrin, betaCD) is reported. C(42)H(70)O(35).7.5H(2)O; space group P2(1) with unit cell constants a=15.1667(5), b=10.1850(3), c=20.9694(7)A, beta=110.993(2) degrees ; final discrepancy index R=0.0760 for the 6181 observed reflections and 784 refined parameters. One water molecule is included in the cavity and distributed over two partially occupied positions, the other 6.5 waters distributed over eight positions are located as space-filler between the macrocycles. The crystal structure belongs to the cage-type, like that observed in Form I (betaCD.12H(2)O; Lindner, K; Saenger, W. Carbohydr. Res. 1982, 99, 103-115) and Form II (betaCD.11H(2)O; Betzel, C., et al. J. Am. Chem. Soc., 1984, 106, 7545-7567).
Assuntos
Modelos Moleculares , Água/química , beta-Ciclodextrinas/química , Cristalização , Cristalografia por Raios X , Ligação de Hidrogênio , Difração de Raios XRESUMO
The title compound, [Fe(C(5)H(5))(C(18)H(32)N)], was synthesized by the amination of ferrocenecarbaldehyde. In the complex, the two cyclo-penta-dienyl (Cp) rings are almost parallel with a dihedral angle of 1.36â (8)°, and are separated by a centroid-centroid distance of 3.299â (2)â Å. In the crystal, adjacent mol-ecules are linked into a one-dimensional supra-molecular structure via weak C-Hâ¯π inter-actions between the Cp ring H atom and the Cp ring.
RESUMO
In the title compound, C(12)H(14)N(2)O(2), the quinoxaline ring system and the C atoms of the methylene and methyl substituents lie on a mirror plane. The crystal packing is stabilized by weak π-π inter-actions [centroid-centroid distance = 3.680â (7)â Å].
RESUMO
A new soluble cyclodextrin derivative 6-O-(2-hydroxybutyl)-beta-cyclodextrin (6-HB-beta-CD) was prepared. Its molecular binding and recognition ability were investigated with the comparison of beta-cyclodextrin (beta-CD), 2-O-(2-hydroxypropyl)-beta-cyclodextrin (2-HP-beta-CD), 6-O-(2-hydroxypropyl)-beta-cyclodextrin (6-HP-beta-CD), and 2-O-(2-hydroxybutyl)-beta-cyclodextrin (2-HB-beta-CD). The relationship between the complex stability constants and the possible structures of inclusion compounds was discussed with the interaction of hosts and guests, including the weak hydrophobic interactions, the size/shape matching, the steric hindrance, and the hydrophilic property.
Assuntos
beta-Ciclodextrinas/química , beta-Ciclodextrinas/síntese química , Dicroísmo Circular , Compostos de Epóxi/química , Estrutura MolecularRESUMO
A new soluble cyclomaltoheptaose (cyclodextrin) derivative, 2-O-(2-hydroxybutyl)cyclomaltoheptaose [2-O-(2-hydroxybutyl)-beta-cyclodextrin, 2-HB-beta-CD], was prepared and studied as an efficient chiral selector in the separation of racemic mixtures of drugs by capillary electrophoresis (CE). Results showed that 2-HB-beta-CD could provide higher separating capability than that of beta-CD and the similarly substituted 2-HP-beta-CD.