ANALYSIS OF THE CONFORMATIONAL BEHAVIOR OF PERFUNCTIONALIZED BETA-CYCLODEXTRINS .1. EVIDENCE FOR INSERTION OF ONE OF THE RIM SUBSTITUENTS INTO THE CYCLODEXTRIN CAVITY IN ORGANIC-SOLVENTS

Several functionalized beta-cyclodextrins have been shown to exhibit c onformational isomerism. The analysis of the conformational behaviour of several derivatives strongly suggests that a slow exchange occurs b etween C-7 and C-1 conformers, the C-1 probably involving insertion of one of the primary rim substituents in the cyclodextrin cavity. The s ignificance of the structural features of cyclodextrin substituents fo r the occurrence of conformational isomerism is examined. The relevanc e of the use of cyclodextrins for the design of molecular devices is d iscussed.