CHIRAL SENSORS BASED ON LIPOPHILIC CYCLODEXTRINS - INTERROGATION OF ENANTIOSELECTIVITY BY COMBINED NMR, STRUCTURAL CORRELATION AND ELECTRODE RESPONSE STUDIES

Potentiometric chiral sensors based on 'per'-O-octyl-alpha-cyclodextrin have been devised for the ephedrinium ion. Electrode response studies, varying the structure of the host cyclodextrin and of the guest beta-arylammonium ion, combined with NMR measurements on the diastereoisomeric complexes have led to the formulation of a working model defining the structural origins of enantioselection in which the C-methyl substituent, beta to the aryl ring, acts as a stereo-differentiating group, and residual hydroxy groups in the cyclodextrin dagger are needed.