STUDY ON THE MULTIPLE RECOGNITION OF BETA -CYCLODEXTRIN DIMER BRIDGEDWITH 2 1,2-DIAMINOETHANE

The beta-cyclodextrin dimer (1, host) bridged two 1, 2-diaminoethane w as synthesized by using a regiospecific capping reagent (m-benzenedisu lfonyl chloride). The research we have done indicated that the dimer a nd Cu2+ ion formed a stable coordination compound (2, host). The evide nce that p-, m- or o-chlorophenol and p-, m- or o-chlorophenolate (gue sts) was included by beta-cyclodextrin, 1 and 2 respectively, comes fr om H-1 NMR spectroscopic studies performed on the host-guest inclusion compounds in D2O at 22 degrees C. Comparison of the formation constan ts of inclusion compounds revealed that there is a multiple recognitio n mechanism in existence between the host molecule (2) and the organic anion guest.