The [2] pseudorotaxane of cucurbit[6]uril(CB[6]) with guest molecule 1,6-bis(imidazol-1-yl)hexane dihydrochloride(BIMH-Cl) made pBR322 DNA hydrolyzed efficiently in physiological environment. The cleavage mechanism wa...The [2] pseudorotaxane of cucurbit[6]uril(CB[6]) with guest molecule 1,6-bis(imidazol-1-yl)hexane dihydrochloride(BIMH-Cl) made pBR322 DNA hydrolyzed efficiently in physiological environment. The cleavage mechanism was proposed that was a cooperation process of the CB[6] molecule and the guest BIMH molecule. In this mechanism, the protonated imidazole might bind DNA via the electrostatic interactions and the CB[6] glycoluril carbonyl oxygen atoms activated a water molecule to attack the phosphorus atom.展开更多
A twin-axial hetero[5]pseudorotaxane was constructed based on 1-hexyl-4,40-bipyridinium guest 1 and cucurbit[8]uril（CB[8]）and a-cyclodextrin（a-CD）.In its structure,CB[8]included two bipyridinium units to realize t...A twin-axial hetero[5]pseudorotaxane was constructed based on 1-hexyl-4,40-bipyridinium guest 1 and cucurbit[8]uril（CB[8]）and a-cyclodextrin（a-CD）.In its structure,CB[8]included two bipyridinium units to realize the twin-axial mode,and the hexyl chain was threaded into the cavity of a-CD.The[5]pseudorotaxane contains two types of macrocyclic hosts while the single axial and twin axial modes co-exist in its structure.The transformation of[5]pseudorotaxane could be realized by the addition of acid and 2,6-dihydroxynaphthalene（HN）.展开更多
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
A water soluble negatively charged fluorescent 1,4-benzo-1,5-naphtho-36-crown-10-based host has been devised and synthesized.As shown by proton NMR,ESI mass spectrometry and UV-vis spectroscopy,it binds paraquat with ...A water soluble negatively charged fluorescent 1,4-benzo-1,5-naphtho-36-crown-10-based host has been devised and synthesized.As shown by proton NMR,ESI mass spectrometry and UV-vis spectroscopy,it binds paraquat with a 1:1 stoichiometry and an association constant of 4.50(±0.02) ×103 M-1 in water.Its complexation with paraquat in water was further investigated by fluorescence emission spectroscopy.The results revealed that when paraquat was added to the water solution of the host,the fluorescence emission of the host was quenched by the charge transfer between the crown ether host and paraquat guest.A similar bis-p-phenylene-34-crown-10-based host was synthesized as a contrasting host.Lacking the naphthalene unit,the second host binds paraquat with a 1:1 stoichiometry and a lower association constant,1.04(±0.04) ×103 M-1,in water.This demonstrated that the naphthalene unit could not only act as a strong fluorescence group but also improve the π-πstacking interactions between the host and guest.展开更多
Three novel calix[4]（aza）crown deravatives have been synthesized, including a new [2]pseudorotaxane in which calix[4]- azacrown behaves as a stopper, a novel ＇tren＇ type calix[4]azacrown and a novel ＇spiro＇ type...Three novel calix[4]（aza）crown deravatives have been synthesized, including a new [2]pseudorotaxane in which calix[4]- azacrown behaves as a stopper, a novel ＇tren＇ type calix[4]azacrown and a novel ＇spiro＇ type calix[4]azacrown containing moroholine unit. The structures of these compounds have been confirmed by NMR and MS.展开更多
Two new supramolecular architectures {（HC2O4）2^2- [C6H（18）N2^2＋ C（36）H（36）N（24）O（12）]} 12H2O（1） and{（C6H5SO3）22 [C6H（18）N22＋ C（36）H（36）N（24）O（12）]} 12H2O（2） were synthesized and character...Two new supramolecular architectures {（HC2O4）2^2- [C6H（18）N2^2＋ C（36）H（36）N（24）O（12）]} 12H2O（1） and{（C6H5SO3）22 [C6H（18）N22＋ C（36）H（36）N（24）O（12）]} 12H2O（2） were synthesized and characterized by singlecrystal X-ray diffraction, thermogravimetric analysis and X-ray powder diffraction. Compound 1contains infinite two dimensional（2D） L18（8）14（8）8（4） type anion–water aggregates [（HC2O4）4（H2O）（22）]^4- and results in the construction of sandwich-like three dimensional（3D） networks. In compound 2, honeycomb-like three dimensional（3D） networks are fabricated by one dimensional（1D）＂W＂-like T5（0）A2 type anion–water clusters [（C6H5SO3）（H2O）6]^-. These results indicate that anionic groups play a crucial role in modulating the structures of water clusters with their spatial structure and binding sites. In these two structures, the majority of interactions are O...H and H...H interactions on the Hirshfeld surface, which means that hydrogen bonding and hydrophobic interactions are the dominate drive forces in forming these supramolecular systems.展开更多
This paper reports the synthesis of a perylene-bridged bis(crown ether) through the condensation reaction between primary amine-armed dibenzo-24-crown-8 and 3,4,9,10-perylenetetracarboxylic dianhydride.Pseudorotaxane ...This paper reports the synthesis of a perylene-bridged bis(crown ether) through the condensation reaction between primary amine-armed dibenzo-24-crown-8 and 3,4,9,10-perylenetetracarboxylic dianhydride.Pseudorotaxane with a perylene moiety at the wheel and a fullerene unit in the middle of the axle was prepared,which was evidenced by 1H NMR and fluorescence experiments.Subsequent investigations show that the formation and disassociation of the pseudorotaxane can be controlled by the alternating addition of KPF6 and 18-crown-6,following the change of the florescence intensity of perylene.展开更多
文摘The [2] pseudorotaxane of cucurbit[6]uril(CB[6]) with guest molecule 1,6-bis(imidazol-1-yl)hexane dihydrochloride(BIMH-Cl) made pBR322 DNA hydrolyzed efficiently in physiological environment. The cleavage mechanism was proposed that was a cooperation process of the CB[6] molecule and the guest BIMH molecule. In this mechanism, the protonated imidazole might bind DNA via the electrostatic interactions and the CB[6] glycoluril carbonyl oxygen atoms activated a water molecule to attack the phosphorus atom.
基金the National Basic Research Program of China (973 Program, No. 2011CB932500)the National Natural Science Foundation of China (Nos. 20932004 and 91227107) for fnancial support
文摘A twin-axial hetero[5]pseudorotaxane was constructed based on 1-hexyl-4,40-bipyridinium guest 1 and cucurbit[8]uril（CB[8]）and a-cyclodextrin（a-CD）.In its structure,CB[8]included two bipyridinium units to realize the twin-axial mode,and the hexyl chain was threaded into the cavity of a-CD.The[5]pseudorotaxane contains two types of macrocyclic hosts while the single axial and twin axial modes co-exist in its structure.The transformation of[5]pseudorotaxane could be realized by the addition of acid and 2,6-dihydroxynaphthalene（HN）.
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supported by the National Natural Science Foundation of China(20774086 and 20834004)National Basic Research Program (2009CB930104)the SRF for ROCS,SEM(J20080410)
文摘A water soluble negatively charged fluorescent 1,4-benzo-1,5-naphtho-36-crown-10-based host has been devised and synthesized.As shown by proton NMR,ESI mass spectrometry and UV-vis spectroscopy,it binds paraquat with a 1:1 stoichiometry and an association constant of 4.50(±0.02) ×103 M-1 in water.Its complexation with paraquat in water was further investigated by fluorescence emission spectroscopy.The results revealed that when paraquat was added to the water solution of the host,the fluorescence emission of the host was quenched by the charge transfer between the crown ether host and paraquat guest.A similar bis-p-phenylene-34-crown-10-based host was synthesized as a contrasting host.Lacking the naphthalene unit,the second host binds paraquat with a 1:1 stoichiometry and a lower association constant,1.04(±0.04) ×103 M-1,in water.This demonstrated that the naphthalene unit could not only act as a strong fluorescence group but also improve the π-πstacking interactions between the host and guest.
基金Thanks for the support of the National Natural Science Foundation of China （No. 20376059）.
文摘Three novel calix[4]（aza）crown deravatives have been synthesized, including a new [2]pseudorotaxane in which calix[4]- azacrown behaves as a stopper, a novel ＇tren＇ type calix[4]azacrown and a novel ＇spiro＇ type calix[4]azacrown containing moroholine unit. The structures of these compounds have been confirmed by NMR and MS.
基金the financial support by the National Natural Science Foundation of China(Nos.21202037and 21401044)Doctor Fund of Henan University of Technology(No.2013BS066)
文摘Two new supramolecular architectures {（HC2O4）2^2- [C6H（18）N2^2＋ C（36）H（36）N（24）O（12）]} 12H2O（1） and{（C6H5SO3）22 [C6H（18）N22＋ C（36）H（36）N（24）O（12）]} 12H2O（2） were synthesized and characterized by singlecrystal X-ray diffraction, thermogravimetric analysis and X-ray powder diffraction. Compound 1contains infinite two dimensional（2D） L18（8）14（8）8（4） type anion–water aggregates [（HC2O4）4（H2O）（22）]^4- and results in the construction of sandwich-like three dimensional（3D） networks. In compound 2, honeycomb-like three dimensional（3D） networks are fabricated by one dimensional（1D）＂W＂-like T5（0）A2 type anion–water clusters [（C6H5SO3）（H2O）6]^-. These results indicate that anionic groups play a crucial role in modulating the structures of water clusters with their spatial structure and binding sites. In these two structures, the majority of interactions are O...H and H...H interactions on the Hirshfeld surface, which means that hydrogen bonding and hydrophobic interactions are the dominate drive forces in forming these supramolecular systems.
基金supported by the National Basic Research Program of China (973 Program) (2006CB932900)the National Natural Science Foundation of China (20932004 and 20772063)
文摘This paper reports the synthesis of a perylene-bridged bis(crown ether) through the condensation reaction between primary amine-armed dibenzo-24-crown-8 and 3,4,9,10-perylenetetracarboxylic dianhydride.Pseudorotaxane with a perylene moiety at the wheel and a fullerene unit in the middle of the axle was prepared,which was evidenced by 1H NMR and fluorescence experiments.Subsequent investigations show that the formation and disassociation of the pseudorotaxane can be controlled by the alternating addition of KPF6 and 18-crown-6,following the change of the florescence intensity of perylene.
