Publications (9)10.64 Total impact
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Article: Host-guest complexes of a water soluble cucurbit[6]uril derivative with some dications of 1,ω-alkyldipyridines: 1H NMR and X-ray structures
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ABSTRACT: Interactions between a symmetrical tetramethyl-substituted cucurbit[6]uril (host: TMeQ[6]) and 1,ω-alkylenedipyridine (ω = 2, 4, 6, 8, 10) dicationic guests were investigated using 1H NMR spectroscopy and single crystal X-ray crystallography. In these inclusion complexes, combined cavity and portal binding in TMeQ[6] were observed, and the length of the bridged alkylene was found to play an important role not only in balancing the overall hydrophilic/hydrophobic interaction between the host and the guest, but also in defining the structure of the resulting inclusion complexes. For the guest 1,2-ethylenedipyridine (Edpy), TMeQ[6] includes a positively charged pyridine ring of Edpy to form an unsymmetrical inclusion complex; for the guest 1,4-butylenedipyridine (Bdpy), TMeQ[6] includes a positively charged pyridine ring of Bdpy, but the different competitive interactions in and between the related inclusion complexes could lead to a fast exchange between the hosts and guests. For the guests with longer bridge chains, such as 1,6-hexamethylenedipyridine (Hdpy) or 1,8-octylenedipyridine (Odpy), a stable pseudorotaxane inclusion complex is formed by combining the hydrophobic cavity and the outer portal dipole-ion interactions. However, for 1,10-decatylenedipyridine (Ddpy), the two TMeQ[6] host molecules include the two end pyridine rings of Ddpy and form a dumbbell inclusion complex.Science in China Series B Chemistry 04/2012; 52(4):475-482. · 1.20 Impact Factor -
Article: A new tripodal rhodamine B derivative as a highly selective and sensitive fluorescence chemosensor for copper(II)
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ABSTRACT: A new tripodal rhodamine B derivative 2 was designed and synthesized by tripodal trialdehyde and rhodamine B hydrazide for the first time. This derivative could be used as a fluorescent chemosensor for the selective and sensitive determination of copper(II) in Tris-HCl buffer and ethanol aqueous mixed media. Under the optimum conditions described herein, fluorescence enhancement at 557/577 nm was linearly related to the concentration of copper(II) in the range of 0.10 to 10.00×10−5 mol·L−1, with a correlation coefficient of R 2=0.9964 (n=15) and a detection limit of 1.129×10−7 mol·L−1 (the relative standard deviation for five repeated measurements at 4.00×10−5 mol·L−1 Cu(II) was 2.2%). The absorbance measurements at 557 nm were linearly related to the concentration of Cu(II) in the range of 0.50 to 25.00×10−5 mol·L−1, with a correlation coefficient of R 2=0.9948 (n=13) and a detection limit of 3.338×10−7mol·L−1.Science in China Series B Chemistry 04/2012; 52(4):523-528. · 1.20 Impact Factor -
Article: A novel rhodamine-based thiacalix[4]arene fluorescent sensor for Fe3+ and Cr3+
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ABSTRACT: The novel fluorescent sensor 1, which is comprised of two rhodamine B lactams as fluorophores that are 1,3-alternately linked to a thiacalix[4]arene, behaves as a highly sensitive ion-induced fluorescent sensor for Fe3+ and Cr3+. This compound was synthesized, and its recognition of metal ions was evaluated by fluorescence and absorption spectroscopy. The possible mechanism of Fe3+- and Cr3+-induced spirocycle opening of 1 leads to fluorescent and colorimetric enhancement, and these properties were investigated by spectroscopy, 1H NMR and IR. The stoichiometric ratios and association constants of the complexes between 1 and these ions have been measured and calculated, and showed that the presence of Fe3+ or Cr3+ induced sensor 1 to form a stable 1:1 complex. KeywordsFluorescent-Colorimetrical-Chemosensor-Rhodamine-Thiacalix[4]areneJournal of Inclusion Phenomena 04/2012; 68(1):139-146. · 1.89 Impact Factor -
Article: Direct coordination of metal ions to cucurbit[n]urils
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ABSTRACT: Cucurbit[n]urils (Q[n]) are promising ligands for the coordination of metal ions, metal complexes or clusters, and form various Q[n]-based complexes. Among the Q[n] complexes, those formed by direct coordination between Q[n]s and metal ions are particularly important. The direct coordination of metal ions to cucurbit[n]urils leads to the formation of Q[n]-based molecular capsules, tubular polymers and molecular bracelets, which could have nanoscale applications in drug delivery, molecular devices and new materials. Keywordsmetal ions-cucurbit[n]urils-direct coordination-molecular capsules-tubular polymers-molecular braceletsChinese Science Bulletin 04/2012; 55(32):3633-3640. · 1.32 Impact Factor -
Article: Synthesis of a symmetrical tetrasubstituted cucurbit[6]uril and its host-guest inclusion complex with 2,2 ′-bipyridine
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ABSTRACT: Synthesis of a symmetrical tetrasubstituted cucurbit[6]uril has been achieved by using the diether of dimethylglycoluril (1) and the dimmer of glycoluril (2). The structure of the symmetrical tetramethylcucurbit[6]uril (TMeQ[6]) has been determined by single crystal X-ray diffraction, 1H NMR spectroscopy and ESMS. The 1H NMR spectra of 2,2′-bipyridine added to TMeQ[6] reveal that the host-guest inclusion complex was easily formed.Chinese Science Bulletin 04/2012; 49(11):1111-1116. · 1.32 Impact Factor -
Article: Host-guest complexes of cucubit[8]uril with phenanthrolines and some methyl derivatives
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ABSTRACT: The host-guest relationship between cucurbit[8]uril, phenanthrolines and some methyl substituted 1,10-phenanthrolines has been investigated by using 1H NMR spectroscopy and fluorescence spectroscopy. The results showed that phenanthrolines as molecular guests bind in the cavity and portal of cucurbit[8]uril in a ratio of 2:1 (guest to host). The phenanthroline isomers 1,10-,1,7- and 4,7- showed red shifts between 47 and 108 nm and pronounced increases in fluorescent intensity. These same isomers produced inclusion complexes with cucur-bit[8]uril which had moderate to fast exchange rates on the 1H NMR time scale. The methyl substituted 1,10-phenanthrolines studied gave stable inclusion complexes in a ratio of 2:1 which showed slow exchange rates. These guests formed п-п stacked pairs which were cavity bound but also partly protruded from only one portal forming unsymmetrical host-guest complexes. In addition, these п-п stacked pairs formed orientation isomers within the confines of the cucur-bit[8]uril cavity.Science in China Series B Chemistry 06/2005; 48(4):305-314. · 1.20 Impact Factor -
Article: Interaction of host-guest complexes of cucurbit[ n ] urils with double probe guests
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ABSTRACT: Three guests with two moiety probes for different Cucurbit[n = 6-8]urils have been synthesized. They are N-(2-methylenethiophen)-adamataneamine, N-(2-methylene pyrrole)-adamataneamine and N-(2-methylenefurfuran)-adamataneamine. The probes are methyle-nepyridyl typically for Q[6] and adamataneamine typically for Q[7]. The host-guest complexes of Cucurbit[n = 6-8]urils with these guests have been investigated by using NMR techniques and ESMS method. Also, thermoanalysis has been used for exploring relationship of enthalpy and stability of the host-guest complexes.Science in China Series B Chemistry 01/2004; 47(4):301-310. · 1.20 Impact Factor -
Article: NMR study on self-assembled cage complex of hexamethylenetetramine and cucurbit[n]urils
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ABSTRACT: Self-assembled complexes between cage compounds cucurbit[n = 5–8]urils and hexamethylenetetramine were studied by using NMR techniques. Experimental results reveal that hexamethylenetetramine can lid cucurbit [5] uril to forming self-assembled capsules in which nothing is encapsulated yet; the cavity of the cucurbit[7]uril can accommodate a hexamethylenetetramine molecule to form a selfassembled host-guest inclusion. Moreover, both the cavity interaction of the cucurbit[7]uril with hexamethylenetetramine·HCl and the portal interaction of the dipole carbonyl of the cucurbit[7]uril with hexamethylenetetramine·HCl lead to form self-assembled capsules in which the hexamethylenetetramine·HCl are encapsulated in the hexamethylenetetramine·HCl “lidded” cucurbit[7]uril. Although the structures of the portal and cavity to cucurbit[5]uril are similar, there is no obvious interaction between decamethylcucurbit[5]uril and hexamethylenetetramine, and also between cucurbit [6]uril or cucurbit[8]uril and hexamethylenetetramine.Chinese Science Bulletin 11/2003; 48(24):2694-2697. · 1.32 Impact Factor -
Article: Synthesis of partially methyl substituted cucurbit[n]urils with 3a-methyl-glycoluril
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ABSTRACT: Two partially methyl substituted cucurbituril, PMeQ[5] and HMeQ[6], were synthesized from 3a-methyl-glycoluril. They were characterized by 1H NMR, ES-MS and single crystal X-ray diffraction. Ab initio calculations showed that each isolated methyl substituted cucurbit[n]uril is the most stable form among its all possbile isomers. One of the remarkable properties of these two partially substituted cucurbituril is their high solubility in the commonly used solvents such as water, methanol, and DMSO.Journal of Molecular Structure. 875:442-446.
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Institutions
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2012
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Guizhou University
- Key Laboratory of Macrocyclic and Supramolecular Chemistry of Guizhou Province
Guiyang, Guizhou Sheng, China
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