Thispaper has investigated the coordination and supramolecular assemblies of alkali metal ions,cucurbit[5]uril(Q[5]),and[CdCl_(4)]^(2-)to confirm whether[CdCl_(4)]^(2-)can produce the“honeycomb effect”,induce coordi...Thispaper has investigated the coordination and supramolecular assemblies of alkali metal ions,cucurbit[5]uril(Q[5]),and[CdCl_(4)]^(2-)to confirm whether[CdCl_(4)]^(2-)can produce the“honeycomb effect”,induce coordination of alkali metal ions to Q[5],and form linear coordination polymers.In this work,the effect of alkali metal ions on the construction of Q[5]-Cd^(2+)ion system under acidic conditions was investigated.Five complexes were successfully obtained by solvent evaporation method.Among the five crystal structures obtained,it can be observed that the presence of[CdCl_(4)]^(2-)did not result in the complexation of alkali metal ions by the Q[5]molecule.Instead,a bowl-like Cd^(2+)@Q[5]complex was formed.Indeed,[CdCl_(4)]^(2-)did not produce the honeycomb effect but led to the formation of Q[5]-based honeycomb frameworks with hexagonal cellsoccupied by[CdCl_(4)]^(2-).The experimental results show that cadmium ion showed stronger ability to coordinate to Q[5]in HCl solution.展开更多
A new cucurbit[6]uril bridsed binuclear complex {[Gd（H2O）6]2[Q6（H2O）]}C16·4H2O, where Q6 represents cucurbit[6]uril, has been synthesized and characterized by X-ray diffraction. The crystal structure shows th...A new cucurbit[6]uril bridsed binuclear complex {[Gd（H2O）6]2[Q6（H2O）]}C16·4H2O, where Q6 represents cucurbit[6]uril, has been synthesized and characterized by X-ray diffraction. The crystal structure shows that the complex has an extended cucurbit[6]uril-bridged structure consisting of two gadolinium（Ⅲ） ions, in which each gadolinium（Ⅲ） ion is coordinated with two neighboring carbonylic oxygen atoms of Q6 and six oxygen atoms of water molecules that leans toward one side of the portal. One disordered guest water molecule resides in the Q6 molecule cavity and occupies two different positions. Hydrogen bonds assemble the complcx to threedimensional supramolecular structure.展开更多
In order to reduce the impact of CdS photogenerated electron-hole recombination on its photocatalytic performance,a narrow band gap semiconductor MoS_(2) and organic macromolecular cucurbit[n]urils(Q[n])were used to m...In order to reduce the impact of CdS photogenerated electron-hole recombination on its photocatalytic performance,a narrow band gap semiconductor MoS_(2) and organic macromolecular cucurbit[n]urils(Q[n])were used to modify CdS.Q[n]/CdS-MoS_(2)(n=6,7,8)composite photocatalysts were synthesized by hydrothermal method.Infrared spectroscopy,X-ray diffraction,X-ray photoelectron spectroscopy,field emission scanning electron microscopy,ultraviolet-visible and photoluminescence spectrum were used to characterize the structure,morphology and optical properties of the products,and the catalytic degradation of the solutions of methylene blue,rhodamine B and crystal violet by Q[n]/CdS-MoS_(2) composite catalyst was investigated.The results showed that the Q[n]played a regulatory role on the growth and crystallization of CdS-MoS_(2) particles,Q[n]/CdS-MoS_(2)(n=6,7,8)formed flower clusters with petal-like leaves,the flower clusters of petal-like leaves increased the surface area and active sites of the catalyst,the Q[n]/CdS-MoS_(2) barrier width decreased,the electron-hole pair separation efficiency was improved in the Q[6]/Cds-MoS_(2).Q[n]makes the electron-hole pair to obtain better separation and migration.The Q[6]/CdS-MoS_(2) and Q[7]/CdS-MoS2 have good photocatalytic activity for methylene blue,and the catalytic process is based on hydroxyl radical principle.展开更多
New fabrication method of nanostructures is of great importance for the applications of nanoscience and nanotechnology.This review summarizes cucurbit[n]uril(CB[n])-based nanostructure fabrication and modification app...New fabrication method of nanostructures is of great importance for the applications of nanoscience and nanotechnology.This review summarizes cucurbit[n]uril(CB[n])-based nanostructure fabrication and modification approaches.These strategies include the use of CB[n]s as building blocks and supramolecular crosslinkers to fabricate nanostructures,to surface modify nanostructures,and as gatekeepers to control the release of encapsulated cargo.These nanostructures are used for drug delivery,bioimaging,chemical sensing,catalysis and other applications.CB[n]s often play a vital role in the fabrication of these nanos-tructures,and the realization of the applications.展开更多
Programming microscopic assembly mode to control macroscopic property is an attractive research objective.In particular,controlling molecular assembly to control fluorescence is of considerable interest for developing...Programming microscopic assembly mode to control macroscopic property is an attractive research objective.In particular,controlling molecular assembly to control fluorescence is of considerable interest for developing smart fluorescent materials.Herein,a color-tunable supramolecular emissive system was developed based on cucurbit[8]uril mediated host-guest assembly.Chemical designing for the molecular structures with minimized change resulted in different assembly modes and hence generating distinctive fluorescence,including green,yellow and orange with the addition of cucurbit[n]uril.Taking advantage of this feature,the advanced information encryption material(4D code)with multiple encryption levels and time-dependent encryption feature was developed.Such a code was dynamic on time scale,generating a series of 3D codes with time.The encrypted information only can be recognized by integrating time-coursed codes.This work provides a new insight for designing intelligent fluorescent materials for information encryption with high level of security.展开更多
Photoresponsive supramolecular systems have merited extensive attention for their applications in materials science and life science.Here,we synthesized a water-soluble stiff-stilbene molecular photoswitch,exhibiting ...Photoresponsive supramolecular systems have merited extensive attention for their applications in materials science and life science.Here,we synthesized a water-soluble stiff-stilbene molecular photoswitch,exhibiting outstanding photoisomerization reaction between its(E)-and(Z)-configurations upon irradiation at distinct light.The photoswitch can assemble with cucurbit[7]uril(CB[7])to form a superior fluorescent supramolecular complex(compared to the only guest)with excellent water solubility,which manifested dramatic photoluminescence enhancement caused by restriction of intramolecular rotation and remained good photochromic characteristics.Furthermore,introduction of CB[7]influence photoreaction quantum yield(Φ)of the stiff-stilbene,leading to reduction ofΦ_(E→Z) and increase ofΦ_(Z→E) of the stiff-stilbene.Importantly,the photoadjustable supramolecular assembly can act as a fluorescence switch,and the phototunable guest further selectively modulate G-quadruplex structure of Tel22 upon light irradiation or with addition of CB[7].The study provides a new simple way for accurately regulating photochromic properties of molecular switches and developing smart materials with potential applications in controlled modulation of G-quadruplex,targeted biological imaging and so on.展开更多
The binding interactions between 4-aminopyridine(4-AP) and a series of cucurbit[n]urils(Q[5], Q[6],TMe Q[6], Q[7], Q[8]) have been studied using1H NMR spectroscopy, UV–vis absorption spectroscopy,isothermal titration...The binding interactions between 4-aminopyridine(4-AP) and a series of cucurbit[n]urils(Q[5], Q[6],TMe Q[6], Q[7], Q[8]) have been studied using1H NMR spectroscopy, UV–vis absorption spectroscopy,isothermal titration calorimetry(ITC) and X-ray crystallography. The data indicates that the Q[5]@4-AP complex exhibits exo binding, which is not observed in the other four host-guest complexes. Furthermore,X-ray crystallography clearly reveals how the Q[n]s bind with 4-AP to form complexes, for example Q[5]forms an outer-surface complex, whilst Q[6], TMe Q[6] and Q[7] formed 1:1 host and guest type complexes, and Q[8] formed a stable 1:2 ternary complex due to its large cavity, which can accommodate two 4-AP molecules.展开更多
Developing efficient and stable electrocatalyst to hydrogen evolution reaction adaptable for electrolytes with different p H is a big challenge.In this work,a hierarchically structured ternary nanohybrid composed of f...Developing efficient and stable electrocatalyst to hydrogen evolution reaction adaptable for electrolytes with different p H is a big challenge.In this work,a hierarchically structured ternary nanohybrid composed of flower-like Ru nanoparticles,rigid macrocyclic cucurbit[6]uril(CB[6])and carboxylated multiwalled carbon nanotubes(MWCNTs)was successfully prepared by chemical wet method.Benefited by the structural merits of flower-like Ru nanoparticles exposed abundant active sites supported by the MWCNTs holding superior mass transport and electrons transfer ability as well as the existence of CB[6],the obtained catalyst exhibited outstanding HER activities with overpotentials of 27,37 and 70 m V at-10 m A/cm^(2) in alkaline,acidic,and neutral electrolytes,respectively.Under the same electrocatalytic operation conditions,the HER performance is comparable or superior to commercial Pt/C catalyst(47,27and 49 m V).Besides,chronopotentiometric and accelerated stability test also revealed its extraordinary stability,which could be further employed for electrocatalytic procedure in a broad pH range.展开更多
The binding behavior of cucurbit[8]uril(Q[8])and p-hydroxybenzoic acid(p-HBA)has been investigated using ^(1)H NMR titration experiments,UV-Vis absorption,isothermal titration calorimetry(ITC),and X-ray crystallograph...The binding behavior of cucurbit[8]uril(Q[8])and p-hydroxybenzoic acid(p-HBA)has been investigated using ^(1)H NMR titration experiments,UV-Vis absorption,isothermal titration calorimetry(ITC),and X-ray crystallography.Results revealed that the Q[8]can accommodate two p-HBA molecules to form a 1:2 host-guest inclusion complex in solution,namely(p-HBA)2@Q[8].From a poorly scattering crystal,we were able to identify two symmetry unique Q[8]rings,but with different p-HBA fillings.The structure can be represented as Q[8]+1.5 p-HBA,which gives Q[8]@(p-HBA)2∙Q[8]@p-HBA as the structural formula.This supramolecular structure was screened for its ability to capture iodine.The experimental results showed that the adsorption efficiency of the supramolecular organic framework material for iodine capture was 43.8%,with an equilibrium adsorption capacity of 223.3 mg/g.展开更多
文摘Thispaper has investigated the coordination and supramolecular assemblies of alkali metal ions,cucurbit[5]uril(Q[5]),and[CdCl_(4)]^(2-)to confirm whether[CdCl_(4)]^(2-)can produce the“honeycomb effect”,induce coordination of alkali metal ions to Q[5],and form linear coordination polymers.In this work,the effect of alkali metal ions on the construction of Q[5]-Cd^(2+)ion system under acidic conditions was investigated.Five complexes were successfully obtained by solvent evaporation method.Among the five crystal structures obtained,it can be observed that the presence of[CdCl_(4)]^(2-)did not result in the complexation of alkali metal ions by the Q[5]molecule.Instead,a bowl-like Cd^(2+)@Q[5]complex was formed.Indeed,[CdCl_(4)]^(2-)did not produce the honeycomb effect but led to the formation of Q[5]-based honeycomb frameworks with hexagonal cellsoccupied by[CdCl_(4)]^(2-).The experimental results show that cadmium ion showed stronger ability to coordinate to Q[5]in HCl solution.
基金supported by the National Natural Science Foundation of China(No.20471056)
文摘A new cucurbit[6]uril bridsed binuclear complex {[Gd（H2O）6]2[Q6（H2O）]}C16·4H2O, where Q6 represents cucurbit[6]uril, has been synthesized and characterized by X-ray diffraction. The crystal structure shows that the complex has an extended cucurbit[6]uril-bridged structure consisting of two gadolinium（Ⅲ） ions, in which each gadolinium（Ⅲ） ion is coordinated with two neighboring carbonylic oxygen atoms of Q6 and six oxygen atoms of water molecules that leans toward one side of the portal. One disordered guest water molecule resides in the Q6 molecule cavity and occupies two different positions. Hydrogen bonds assemble the complcx to threedimensional supramolecular structure.
基金This work was supported by the National Natural Science Foundation of China(No.21871064)the National College Students’Innovative Training Program of China(No.2020053)+1 种基金the“Undergraduate Teaching Project”of Guizhou University(No.201936)the Student Research Training Foundation of Guizhou University,China(No.(2019)106).
文摘In order to reduce the impact of CdS photogenerated electron-hole recombination on its photocatalytic performance,a narrow band gap semiconductor MoS_(2) and organic macromolecular cucurbit[n]urils(Q[n])were used to modify CdS.Q[n]/CdS-MoS_(2)(n=6,7,8)composite photocatalysts were synthesized by hydrothermal method.Infrared spectroscopy,X-ray diffraction,X-ray photoelectron spectroscopy,field emission scanning electron microscopy,ultraviolet-visible and photoluminescence spectrum were used to characterize the structure,morphology and optical properties of the products,and the catalytic degradation of the solutions of methylene blue,rhodamine B and crystal violet by Q[n]/CdS-MoS_(2) composite catalyst was investigated.The results showed that the Q[n]played a regulatory role on the growth and crystallization of CdS-MoS_(2) particles,Q[n]/CdS-MoS_(2)(n=6,7,8)formed flower clusters with petal-like leaves,the flower clusters of petal-like leaves increased the surface area and active sites of the catalyst,the Q[n]/CdS-MoS_(2) barrier width decreased,the electron-hole pair separation efficiency was improved in the Q[6]/Cds-MoS_(2).Q[n]makes the electron-hole pair to obtain better separation and migration.The Q[6]/CdS-MoS_(2) and Q[7]/CdS-MoS2 have good photocatalytic activity for methylene blue,and the catalytic process is based on hydroxyl radical principle.
基金National Natural Science Foundation of China(No.21921003)for financial support.
文摘New fabrication method of nanostructures is of great importance for the applications of nanoscience and nanotechnology.This review summarizes cucurbit[n]uril(CB[n])-based nanostructure fabrication and modification approaches.These strategies include the use of CB[n]s as building blocks and supramolecular crosslinkers to fabricate nanostructures,to surface modify nanostructures,and as gatekeepers to control the release of encapsulated cargo.These nanostructures are used for drug delivery,bioimaging,chemical sensing,catalysis and other applications.CB[n]s often play a vital role in the fabrication of these nanos-tructures,and the realization of the applications.
基金supported by the National Natural Science Foundation of China(22025503,22220102004)the Shanghai Municipal Science and Technology Major Project(2018SHZDZX03)+3 种基金the Fundamental Research Funds for the Central Universitiesthe Programme of Introducing Talents of Discipline to Universities(B16017)the Science and Technology Commission of Shanghai Municipality(21JC1401700)the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study(SN-ZJU-SIAS-006)。
文摘Programming microscopic assembly mode to control macroscopic property is an attractive research objective.In particular,controlling molecular assembly to control fluorescence is of considerable interest for developing smart fluorescent materials.Herein,a color-tunable supramolecular emissive system was developed based on cucurbit[8]uril mediated host-guest assembly.Chemical designing for the molecular structures with minimized change resulted in different assembly modes and hence generating distinctive fluorescence,including green,yellow and orange with the addition of cucurbit[n]uril.Taking advantage of this feature,the advanced information encryption material(4D code)with multiple encryption levels and time-dependent encryption feature was developed.Such a code was dynamic on time scale,generating a series of 3D codes with time.The encrypted information only can be recognized by integrating time-coursed codes.This work provides a new insight for designing intelligent fluorescent materials for information encryption with high level of security.
基金We thank Top-Notch Talents Program of Henan Agricultural University(No.30501049)Project supported by the Science and Technology Department of Henan Province(No.212102310332)the Merit Funding for the Oversea Staff of Henan Province for financial support.
文摘Photoresponsive supramolecular systems have merited extensive attention for their applications in materials science and life science.Here,we synthesized a water-soluble stiff-stilbene molecular photoswitch,exhibiting outstanding photoisomerization reaction between its(E)-and(Z)-configurations upon irradiation at distinct light.The photoswitch can assemble with cucurbit[7]uril(CB[7])to form a superior fluorescent supramolecular complex(compared to the only guest)with excellent water solubility,which manifested dramatic photoluminescence enhancement caused by restriction of intramolecular rotation and remained good photochromic characteristics.Furthermore,introduction of CB[7]influence photoreaction quantum yield(Φ)of the stiff-stilbene,leading to reduction ofΦ_(E→Z) and increase ofΦ_(Z→E) of the stiff-stilbene.Importantly,the photoadjustable supramolecular assembly can act as a fluorescence switch,and the phototunable guest further selectively modulate G-quadruplex structure of Tel22 upon light irradiation or with addition of CB[7].The study provides a new simple way for accurately regulating photochromic properties of molecular switches and developing smart materials with potential applications in controlled modulation of G-quadruplex,targeted biological imaging and so on.
基金supported by the Innovation Program for Highlevel Talents of Guizhou Province (No. 2016-5657)the University of Hull for support。
文摘The binding interactions between 4-aminopyridine(4-AP) and a series of cucurbit[n]urils(Q[5], Q[6],TMe Q[6], Q[7], Q[8]) have been studied using1H NMR spectroscopy, UV–vis absorption spectroscopy,isothermal titration calorimetry(ITC) and X-ray crystallography. The data indicates that the Q[5]@4-AP complex exhibits exo binding, which is not observed in the other four host-guest complexes. Furthermore,X-ray crystallography clearly reveals how the Q[n]s bind with 4-AP to form complexes, for example Q[5]forms an outer-surface complex, whilst Q[6], TMe Q[6] and Q[7] formed 1:1 host and guest type complexes, and Q[8] formed a stable 1:2 ternary complex due to its large cavity, which can accommodate two 4-AP molecules.
基金the financial support from the National Key R&D Program of China(Nos.2017YFA0206802,2018YFA0704502)the National Natural Science Foundation of China(NSFC,No.22033008)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(No.2021ZZ103)。
文摘Developing efficient and stable electrocatalyst to hydrogen evolution reaction adaptable for electrolytes with different p H is a big challenge.In this work,a hierarchically structured ternary nanohybrid composed of flower-like Ru nanoparticles,rigid macrocyclic cucurbit[6]uril(CB[6])and carboxylated multiwalled carbon nanotubes(MWCNTs)was successfully prepared by chemical wet method.Benefited by the structural merits of flower-like Ru nanoparticles exposed abundant active sites supported by the MWCNTs holding superior mass transport and electrons transfer ability as well as the existence of CB[6],the obtained catalyst exhibited outstanding HER activities with overpotentials of 27,37 and 70 m V at-10 m A/cm^(2) in alkaline,acidic,and neutral electrolytes,respectively.Under the same electrocatalytic operation conditions,the HER performance is comparable or superior to commercial Pt/C catalyst(47,27and 49 m V).Besides,chronopotentiometric and accelerated stability test also revealed its extraordinary stability,which could be further employed for electrocatalytic procedure in a broad pH range.
基金supported by the Science and Technology Projects of Guizhou Province,China(No.ZK[2023]General 040).
文摘The binding behavior of cucurbit[8]uril(Q[8])and p-hydroxybenzoic acid(p-HBA)has been investigated using ^(1)H NMR titration experiments,UV-Vis absorption,isothermal titration calorimetry(ITC),and X-ray crystallography.Results revealed that the Q[8]can accommodate two p-HBA molecules to form a 1:2 host-guest inclusion complex in solution,namely(p-HBA)2@Q[8].From a poorly scattering crystal,we were able to identify two symmetry unique Q[8]rings,but with different p-HBA fillings.The structure can be represented as Q[8]+1.5 p-HBA,which gives Q[8]@(p-HBA)2∙Q[8]@p-HBA as the structural formula.This supramolecular structure was screened for its ability to capture iodine.The experimental results showed that the adsorption efficiency of the supramolecular organic framework material for iodine capture was 43.8%,with an equilibrium adsorption capacity of 223.3 mg/g.
