Supramolecular self-assembly between symmetric tetramethyl cucurbit[6]uril and 1,2-Di(4-pyridyl)ethylene derivative.

In recent years, symmetrical α,α′,δ,δ′-tetramethyl-cucurbit[6]uril (TMeQ[6]) has attracted much attention from many researchers due to its interesting assembly pattern. Herein, we have investigated the host–guest interactions pattern of the symmetric TMeQ[6] with (E)-1-(5-carboxypentyl)-4-(2-(pyridin-4-yl)vinyl)pyridin-1-ium. (ECPP). Furthermore, their binding behaviors were investigated by ¹H NMR spectroscopy, MALDI-TOF mass spectrometry, isothermal titration calorimeter, fluorescence, and UV–vis spectrum. The results indicate that TMeQ[6] and ECPP form host–guest complexes in a host/guest molar ratio of 1:1. TMeQ[6] is bound with the vinylpyridine group of ECPP. In addition, TMeQ[6]-ECPP exhibits a high association constant Ka = (1.520 ± 0.58) × 10⁶ M⁻¹, ΔH = − 53.40 kJ/mol, ΔS = − 60 J/mol·K. which provides a promising foundation for potential studies of the assemblies. [ABSTRACT FROM AUTHOR]