Study on the molecular recognitions of calix[n]arenes to 2,3-diaminonaphthalene by using fluorometric technique.

The molecular recognition properties of calixarenes to 2,3-diaminonaphthalene (DAN) were investigated. We found that the fluorescence emission of DAN has a blue shift after p-sulfonic sodium calix[4]arece (SSCA) was added to DAN. The proposed mechanism of the molecular recognition between SSCA and DAN indicates that DAN goes into the cavity of SSCA with the help of the hydrogen bonding between the amino group of DAN and sulphonyl group of SSCA. The inclusion ratios and inclusion constants of the host-guest complexes are determined by using the deduced equations.