Sym-bis(benzimidazole)-2,2'-ethylene cations act as a new axle template for threading cucurbit[6]uril derivatives on,forming[2]pseudorotaxane and[3]pseudorotaxane.These new complexes have been studied using 1 H NMR...Sym-bis(benzimidazole)-2,2'-ethylene cations act as a new axle template for threading cucurbit[6]uril derivatives on,forming[2]pseudorotaxane and[3]pseudorotaxane.These new complexes have been studied using 1 H NMR,UV-vis absorption spectroscopy and X-ray analysis.Changes in the 1 H NMR spectra indicate that the two types of pseudorotaxane can be formed by varying the host concentration. UV-vis absorption titration experiments at different pH values demonstrate that interesting pK_a shifts of the bis-benzimidazole derivatives can be induced by the host-guest complexation.The associated constants were calculated to be 2.81×10^4 L/mol and 9.06×10^6 L/mol for the[2]pseudorotaxanes and |3]pseudorotaxanes,respectively.Furthermore,X-ray diffraction studies of the solid state structures provide unequivocal proof of the host concentration dependent pseudorotaxane,which is strongly in line with the evidences in solution.展开更多
Since the outer surface interaction of Q[n]s (OSIQ, including self-, anion- and aromatic-induced OSIQs) was proposed in 2014, it has become the most important research area in our group to construct various Q[n]-based...Since the outer surface interaction of Q[n]s (OSIQ, including self-, anion- and aromatic-induced OSIQs) was proposed in 2014, it has become the most important research area in our group to construct various Q[n]-based supramolecular frameworks via the OSIQ strategy. Herein, we report a novel supramolecular framework constructed using cucurbit[8]uril (Q[8]) and 4-sulfocalix[6]arene (SC[6]A). This Q[8]/SC[6]A-based supramolecular framework is a product via the perfect combination of self-, anion- and aromatic-induced OSIQs. This framework has the characteristics of easy preparation and high stability with the most important feature being the sequence selective capture of specific metal cations, such as common alkali- and alkaline earth metal ions, and renewability. Thus, this framework may be used in seawater desalination, potassium ion enrichment, radioactive cesium ion pollution source treatment, Gruinard's treatment or water softening and other applications.展开更多
基金supported by the National Natural Science Foundation of China(No,21272045)the Natural Science Foundation of Guizhou Province and Guizhou Universitythe "Chun-Hui" Funds of the Chinese Ministry of Education are gratefully acknowledged
文摘Sym-bis(benzimidazole)-2,2'-ethylene cations act as a new axle template for threading cucurbit[6]uril derivatives on,forming[2]pseudorotaxane and[3]pseudorotaxane.These new complexes have been studied using 1 H NMR,UV-vis absorption spectroscopy and X-ray analysis.Changes in the 1 H NMR spectra indicate that the two types of pseudorotaxane can be formed by varying the host concentration. UV-vis absorption titration experiments at different pH values demonstrate that interesting pK_a shifts of the bis-benzimidazole derivatives can be induced by the host-guest complexation.The associated constants were calculated to be 2.81×10^4 L/mol and 9.06×10^6 L/mol for the[2]pseudorotaxanes and |3]pseudorotaxanes,respectively.Furthermore,X-ray diffraction studies of the solid state structures provide unequivocal proof of the host concentration dependent pseudorotaxane,which is strongly in line with the evidences in solution.
基金National Natural Science Foundation of China(Nos. 21871064, 21601090, 21761007, 51663005)Science and Technology Plan Project of Guizhou Province (Nos. 20175788 and20185781)+1 种基金Basic Research Program of Shenzhen (No. JCYJ20190812151405298)Shenzhen Peacock Plan。
文摘Since the outer surface interaction of Q[n]s (OSIQ, including self-, anion- and aromatic-induced OSIQs) was proposed in 2014, it has become the most important research area in our group to construct various Q[n]-based supramolecular frameworks via the OSIQ strategy. Herein, we report a novel supramolecular framework constructed using cucurbit[8]uril (Q[8]) and 4-sulfocalix[6]arene (SC[6]A). This Q[8]/SC[6]A-based supramolecular framework is a product via the perfect combination of self-, anion- and aromatic-induced OSIQs. This framework has the characteristics of easy preparation and high stability with the most important feature being the sequence selective capture of specific metal cations, such as common alkali- and alkaline earth metal ions, and renewability. Thus, this framework may be used in seawater desalination, potassium ion enrichment, radioactive cesium ion pollution source treatment, Gruinard's treatment or water softening and other applications.