The use of the isokinetic relationship and molecular mechanics to investigate molecular interactions in inclusion complexes of cyclodextrins

Abstract

The formation of 1:1 inclusion complexes of α- and β-cyclodextrin with various compounds in aqueous medium has been investigated for the isokinetic behavior. The included compounds fall clearly into definite groups, showing that the isokinetic behavior, when based on proper statistical methods, can be used as a tool for the interpretation and dissection of different interaction and reaction mechanisms in similar chemical reactions. Theoretical free energies, enthalpies and entropies of the formation of the inclusion complexes are calculated using the "rigid molecule approximation" of the molecular mechanics approach. The calculated results are in good agreement with the experimental values. The orientations of the embedded guest molecules in cyclodextrins obtained from the calculations are in agreement with experimental findings. The classification of the guest molecules can be explained in terms of different interaction energies. © 1989.