Cucurbit[6]uril-based multifunctional supramolecular assemblies: synthesis, removal of Ba() and fluorescence sensing of Fe()

• Published in: Dalton transactions : an international journal of inorganic chemistry Vol. 47; no. 11; pp. 3958 - 3964
• Main Authors: Zhang, Xiu-Du, Zhao, Yue, Chen, Kai, Wang, Peng, Kang, Yan-Shang, Wu, Hua, Sun, Wei-Yin
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 2018
• Subjects: Alkaline earth metals; Aromatic compounds; Assemblies; Assembly; Barium; Calcium; Fluorescence; Nitrobenzoic acid; Strontium
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c8dt00182k

A novel cucurbit[6]uril-based (Q[6]) supramolecular assembly {(NH 4 ) 2 ·Q[6]·(HDTNB) 2 ·2H 2 O} ( 1 ) with a three-dimensional (3D) framework structure was successfully constructed via outer-surface interactions between Q[6] and a flexible aromatic compound, 5,5′-dithiobis-(2-nitrobenzoic acid) (H 2 DTNB), as a structure-directing agent. It is interesting to find that assembly 1 can selectively capture Ba( ii ) cations among the common alkaline-earth metal ions of Mg( ii ), Ca( ii ), Sr( ii ) and Ba( ii ), resulting in the formation of an isomorphic 3D assembly {Ba(H 2 O) 2 Q[6]}·(HDTNB) 2 ( 2 ). Furthermore, both assemblies 1 and 2 exhibit the selective sensing of Fe( iii ) ions through fluorescence quenching, which has rarely been reported for Q[ n ]-based supramolecular assemblies. Supramolecular assemblies formed of cucurbit[6]uril and flexible aromatic compounds were achieved via outer-surface interactions, and show selective adsorption and sensing properties.