Interpreting Disorder In [beta]-Cyclodextrin Inclusion Complexes: Methods, Results, And Their Implications. Tom J. Brett, Joanna L. Clark, Richard K. Shoemaker, Charles R. Ross II, and John J. Stezowski, Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304.

Crystallographic studies of cyclodextrin (cyclic oligomers of D-glucose) inclusion complexes are usually plagued by the disorder of guest molecules. This disorder is troublesome, but the correct interpretation reveals vital chemical information about the system of interest. Successful interpretation is helped along by the use of many complementary techniques.

We have been studying [beta]-cyclodextrin ([beta]-CD) inclusion complexes with photochemically reactive guest molecules in order to better understand the solid-state photochemical behavior of these systems. The crystallographic studies of these systems reveal much disorder present. In order to fully interpret this disorder, a number of methods have been applied to these systems. The methods utilized include crystallographic methods such as low temperature data collection and the analysis of graphics displayed electron density maps, and non-crystallographic methods such as molecular modeling techniques, solid-state NMR, and photochemical reaction outcomes. These methods and their application to the studies of systems of [beta]-CD inclusion complexes with propyl phenyl ketone, butyl phenyl ketone, benzoin methyl ether, and coumarin will be discussed, as will be their implication in the observed solid state photochemical behavior of the guest molecules.