A combined experimental and theoretical study on p-sulfonatocalix[4]arene encapsulated 7-methoxycoumarin

作者：Ashwin Bosco Christin Maria Arputham; Baby Arulanandu Herculin Arun; Prakash Muthuramalingam^*; Hochlaf Majdi^*; Mareeswaran Paulpandian Muthu^*

来源：Journal of Physical Organic Chemistry, 2018, 31(4): e3788.

DOI：10.1002/poc.3788

• 7-methoxycoumarin
• computational calculations
• herniarin
• host-guest interaction
• p-sulfonatocalix[4]arene

Host-guest interactions are essential in chemistry, biology, medicine and environmental science. In this combined experimental and theoretical contribution, the encapsulation of 7-methoxycoumarin (herniarin, 7MC) with p-sulfonatocalix[4]arene (p-SC4) is studied using absorption and fluorescence spectroscopy, cyclic voltammetry and computational approaches. The 1:1 stoichiometry is confirmed using Job's plot. Our results show that the keto group of 7MC is the main source for electrochemical conversion of this complex. The excited state 7MC radiative decay is studied using time-correlated single photon counting technique. The computed UV-Vis absorption spectra for this complex at gas phase and solvent are online with the experimental spectra. Moreover, we determined the binding energy and the binding constant of the 7MC-p-SC4 complex. Density functional theory computations revealed that stabilization of the complex formed by p-SC4 and 7MC is due to weak noncovalent and dispersive types of interactions. A comparison with encapsulation of amino acids by p-SC4 is also conducted. Finally, we show that the flexibility of p-SC4 and the weak nature of its interaction with 7MC are on the origin of the reversibility of encapsulation, which is mandatory for applications such as drug delivery.

• 出版日期2018-4