Spectral, Electrochemical and Computational Investigations of Binding of n-(4-Hydroxyphenyl)-imidazole with p-Sulfonatocalix[4]arene.

The interaction of n-(4-hydroxyphenyl)-imidazole with p-sulfonatocalix[4]arene is studied using fluorescence technique. The quenching of fluorescence intensity explains the efficiency of binding via binding constant and quenching constant. The excited state lifetime of n-(4-hydroxyphenyl)-imidazole is decreased upon interaction with p-sulfonatocalix[4]arene. The cyclic voltametric studies emphasized the interaction of n-(4-hydroxyphenyl)-imidazole with p-sulfonatocalix[4]arene. Quantum chemical calculations are carried out to study the interactions as well as charge transfer between the host and the guest upon complexation. The simulations revealed that the n-(4-hydroxyphenyl)-imidazole interacts with p-sulfonatocalix[4]arene with horizontal orientation with in the p-sulfonatocalix[4]arene cavity.