An inclusion complex of cucurbit[7]uril with benzimidazolyl benzyl viologen exhibits fluorescence and photochromic properties

• Published in: Physical chemistry chemical physics : PCCP Vol. 24; no. 42; pp. 2593 - 25936
• Main Authors: Wang, Qin, Guo, Jun-Zhuo, Luo, Dan, Ye, Ming-Fu, Lin, Rui-Lian, Sun, Wen-Qi, Liu, Jing-Xin
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 02.11.2022
• Subjects: Carbonyls; Electron transfer; Fluorescence; Host-guest materials; Inclusion complexes; Oxygen atoms; Photochromism; Supramolecular compounds
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/d2cp03516b

In order to investigate the photochromic mechanism of photochromic materials based on supramolecular host-guest systems, we designed and synthesized a unique viologen derivative (benzimidazolyl benzyl viologen, guest 1 ·Cl 3 ), which does not contain oxygen atoms. The binding interaction of guest 1 3+ with host cucurbit[7]uril (Q[7]) was investigated by various techniques. The obtained supramolecular host-guest complex 1 3+ @Q[7] exhibits interesting fluorescence emission and reversible photochromism. The ESR and XPS experimental data suggest that the photochromic process of the complex 1 3+ @Q[7] comes from the electron transfer from the carbonyl O atoms of the host Q[7] to the bipyridinium N atoms of the guest 1 3+ . A self-assembled supramolecular inclusion complex of Q[7] with benzimidazolyl benzyl viologen exhibits interesting fluorescence emission and reversible photochromism.