Mechanism for binding to the flexible cavity of permethylated?-cyclodextrin

摘要: The cavity of α-cyclodextrin (α-CDx) is too small to includeo-toluic acid (o-TA) while it filled byp-toluic (p-TA) form a relatively stable inclusion complex. Such strict selectivity ascribed rigid structure the α-CDx which stabilized by intramolecular hydrogen bonds between O(2) hydroxyl groups and O(3) adjacent glucopyranose units. Meanwhile, substrate hexakis (2,3,6-tri-O-methyl)-α-CDx (TMe-α-CDx) remains somewhat obscure because flexible nature its cavity. absence seems cause TMe-α-CDx leading an induced-fit type inclusion. structures complexes have been presented on basis the1H NMR data. thermodynamic parameters indicate that complexation witho-TA orp-TA entropically favorable process. TA with occur through dehydration from CO2H group situated at hydrophobic CDx dipole-dipole interaction has regarded as force dominates orientation polar guest molecule in