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

作者：Zhao, Hui; Shen, Fang-Fang; Sun, Ji-Fu; Gao, Zhong-Zheng^*

来源：Inorganic Chemistry Communication, 2022, 141: 109536.

DOI：10.1016/j.inoche.2022.109536

• Cucurbit[8]uril
• Self-assembly
• Host-guest interaction
• Styrene group
• [2+2] photodimerization

he interaction of (E)-4-(4-(1-methyl-pyridinium)styryl)-1-methyl-pyridinium chloride (SMP) guest, with cucurbit [8]uril (CB[8]) host was characterized by H-1 NMR spectroscopy, electronic absorption, isothermal titration calorimetry (ITC), high-resolution electrospray mass spectrum and fluorescence spectroscopy. Experimental data indicated that the styryl group of SMP resides within the cavity of CB[8] in aqueous solution, generating a highly stable inclusion complex SMP@CB[8] with a host-guest binding ratio of 1:2. Isothermal titration calorimetry experiments showed that the complexation of the SMP guest with CB[8] were enthalpy and entropy driven, which benefits from ion dipole interactions between the guest SMP and the host CB[8]. What's more interesting is that the styryl units of supramolecular complexes can more easily undergo [2 + 2] photodimerization under the promotion of macrocyclic CB[8] when irradiated with visible light.