ABSTRACT

Fluorescence spectroscopy and time-resolved study have successfully explored the impact of supramolecular assembly, cucurbit[6]uril (CB6) on the dynamics of proton transfer in 2-(4’-pyridyl) benzimidazole (4-PBI). It has been observed that the guest molecules are capable of binding in three different states of protonation: cation C, tautomer T, and neutral N. While the acid–base equilibria is altered by the host molecule in the ground and excited states. Binding modes of the dye molecule with cucurbit[6]uril have been investigated by proton NMR spectroscopy. The binding of the guest with the supramolecular host is further confirmed by Quantum chemical calculations. The current study successfully recognises how the convoluted acid–base equilibria of dye molecule (4-PBI) are affected by cucurbit[6]uril (CB6) supramolecular assembly upon complexation.

摘要

荧光光谱和时间分辨研究成功探索了超分子组装葫芦[6]脲（CB6）对2-（4'-吡啶基）苯并咪唑（4-PBI）中质子转移动力学的影响。已经观察到客体分子能够在三种不同的质子化状态下结合：阳离子 C、互变异构体 T 和中性 N。而酸碱平衡被基态和激发态的主体分子改变。已经通过质子核磁共振光谱研究了染料分子与葫芦[6]脲的结合模式。客体与超分子主体的结合通过量子化学计算得到进一步证实。目前的研究成功地认识到染料分子 (4-PBI) 的复杂酸碱平衡如何受到葫芦[6]脲 (CB6) 超分子组装在络合时的影响。