Cucurbit[8]uril-controlled [2 + 2] photodimerization of styrylpyridinium molecule

Complexation of (E)-4-(4-(1-methyl-pyridinium)styryl)-1-methyl-pyridinium chloride (SMP) guest and cucurbit[8]uril (CB[8]) host depending on the host-guest interactions which was characterized by 1H NMR spectroscopy, electronic absorption, isothermal titration calorimetry, high-resolution electrospray mass spectrum and fluorescence spectroscopy. What’s more interesting is that the styryl units in supramolecular complexes can more easily undergo [2 + 2] photodimerization under the promotion of macrocyclic CB[8] when irradiated with visible light.