Spectral, Electrochemical and Computational Investigations of Binding of n-(4-Hydroxyphenyl)-imidazole with p-Sulfonatocalixarene
The characteristics of host-guest complexation between p-sulfonated calix[n]arene (SCnA, n = 4, 6) and Vitamin K(3) (VK(3)) were investigated by fluorescence spectrometry and absorption spectrometry using methylene blue (MB) as a probe. Interaction with MB and SCnA led to an obvious decrease in fluorescence intensity of MB, accompanying with shifts of emission peaks. Absorption peaks also showed interesting changes; however, when VK(3) was added, fluorescence intensity and absorbance recovered and a slight and slow red shift was observed. The obtained results showed that the inclusion ability of p-sulphonated calix[n]arenes towards VK(3) was the order: p-sulphonated calixarene (SC6A) >p-sulphonated calixarene (SC4A). Relative mechanism was proposed to explain the inclusion process.