Orientational dynamics of β-cyclodextrin inclusion complexes

被引：73

作者：

Balabai, N ^{[1
]}

Linton, B ^{[1
]}

Napper, A ^{[1
]}

Priyadarshy, S ^{[1
]}

Sukharevsky, AP ^{[1
]}

Waldeck, DH ^{[1
]}

机构：

[1] Univ Pittsburgh, Dept Chem, Pittsburgh, PA 15260 USA

来源：

JOURNAL OF PHYSICAL CHEMISTRY B | 1998年 / 102卷 / 48期

关键词：

D O I：

10.1021/jp982756e

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The structure and dynamics of organic dye molecules included in beta-cyclodextrin are studied using spectroscopic measurements and theoretical models. The effect of the charge and the size of the guest molecule on the properties of the host-guest complex is probed by comparing complexes formed with three different chromophores: resorufin (anion), oxazine-118 (cation), and oxazine-725 (cation) in aqueous solutions of cyclodextrin. The binding is characterized using absorption and calorimetry titrations. The structure of the complexes is analyzed by molecular modeling using empirical force field and semiempirical quantum theory calculations. Time-resolved polarization spectroscopy is used to investigate the rotational dynamics of different chromophores bound to beta-cyclodextrin. Internal motion of the guest and overall rotational tumbling of the complex are observed for resorufin and oxazine-118. Modeling the internal motion of the chromophore as diffusion in a cone provides the mean square diffusion angle inside the cavity. It is found that the relative host-guest size determines the character of intermolecular host-guest dynamics.

引用

页码：9617 / 9624

页数：8

共 55 条

[1] A TEST OF CONTINUUM MODELS FOR DIELECTRIC FRICTION - ROTATIONAL DIFFUSION OF PHENOXAZINE DYES IN DIMETHYLSULFOXIDE [J].