Many azo compounds and their intermediates are toxic and have been linked to various health issues,representing a growing global problem.Molecular engineering for selective encapsulation of azobenzene compounds is cri...Many azo compounds and their intermediates are toxic and have been linked to various health issues,representing a growing global problem.Molecular engineering for selective encapsulation of azobenzene compounds is critical,given their significant use in smart materials and prevalence as environmental micropollutants released from the food and dye industries.However,the current host molecules catering to azobenzene compounds are mainly limited to cyclodextrins,pillar[n]arenes and cucurbit[n]urils,demonstrating a moderate affinity.This report describes that a novel 3,3'-bipyridinium-based cyclophane was capable of encapsulating anionic azobenzene compounds in water with high binding affinity and pH stability through electrostatic attraction-enhanced mechanism,surpassing the extensively reported supramolecular systems.1D&2D NMR experiments,UV-vis spectrum,X-ray crystallography and computational modeling were carried out to understand the host-vip complexation.It's worth noting that the tetracationic cyclophane exhibited good selective and anti-interference encapsulation properties in binary,ternary and seawater systems.Furthermore,upon UV/white light irradiation,the reversible conversion between(E)-4,4'-azobisbenzoate and(Z)-4,4'-azobisbenzoate triggers the dissociation/recomplexation of the host-vip complex within 3 min.This reversible photo-switchable(E)-disodium 4,4'-azobisbenzoateBPy-Box^(4+)supramolecular system holds promise for designing novel materials for extraction/release of azo compounds and other small smart materials.展开更多
Planar chiral cyclophanes are a type of structurally intriguing organic molecules,which have found increasingly applications in the field of biologically active compounds,asymmetric catalysis,and optically pure materi...Planar chiral cyclophanes are a type of structurally intriguing organic molecules,which have found increasingly applications in the field of biologically active compounds,asymmetric catalysis,and optically pure materials.As such,significant efforts in the development of new methods to build up enantioenriched cyclophanes in a precise manner have attracted increased attention in recent years.Among the plethora of reported synthetic strategies,catalytic enantioselective method has emerged as one of the most straightforward and efficient ways to deliver optically pure planar chiral cyclophanes.In this review,the recent progress in catalytic enantioselective reactions for the synthesis of planar chiral cyclophanes will be discussed,which would stimulate the research interest of chemists for the discovery of novel asymmetric strategies for the preparation of valuable and previously difficult-to-access chiral molecules.展开更多
Anion can be identified by pyromellitic imide-azacyclophane which is one of the host compounds.This article investigated the interaction between the host and organic pollution compounds.The host and other eight compou...Anion can be identified by pyromellitic imide-azacyclophane which is one of the host compounds.This article investigated the interaction between the host and organic pollution compounds.The host and other eight compounds were optimized by DFT（density functional theory） B3LYP/6-31G level and the energy of compounds was corrected using Boys-Bemardi method.On the basis of B3LYP/6-31G optimized geometries,the RDG function and sign（λ2（r））ρ（r） function values of space points were calculated,and color RDG isosurface map was drawn.3He chemical shift was calculated by the B3LYP/6-31G method.The results showed that the eight organic pollution molecules with the host one shaped stable configurations by hydrogen bonds,respectively.The stabilization energy of complexes 4 and 7 showed repulsion（steric effects） of cyclophane cage observably affecting the stability of the complexes.The location,intensity and the type of interaction in complex 1 were analyzed through color-filled RDG isosurface map.Aromaticity calculations showed that the weak interaction reduced the transverse induction ring current in the host rings,and deteriorated the aromaticity of compounds.展开更多
Three-residue cyclophane-forming enzymes(3-Cy FEs) are a group of radical S-adenosylmethionine(SAM)enzymes involved in the biosynthesis of ribosomally synthesized and posttranslationally modified peptides(Ri PPs). 3-C...Three-residue cyclophane-forming enzymes(3-Cy FEs) are a group of radical S-adenosylmethionine(SAM)enzymes involved in the biosynthesis of ribosomally synthesized and posttranslationally modified peptides(Ri PPs). 3-Cy FE catalyzes the crosslinking between an aromatic residue(Ω1) and a non-aromatic residue(X3) in a Ω1-X2-X3 motif to produce a cyclophane ring, a key step in the biosynthesis of the Ri PP natural product triceptide. In this study, we perform a genome-wide search for the Xye-type triceptides, showing these Ri PPs are likely class-specific and only present in gamma-proteobacteria. The 3-Cy FE Pau B from Photorhabdus australis exhibits a relaxed substrate specificity on the X3 position, but glycine in this position is not suitable for cyclophane formation. We also reconstituted the activity of Pau B in vitro,showing it produces the N-terminal cyclophane firstly, and then the C-terminal ring, whereas the middle cyclophane is produced in the last step.展开更多
Four imidazole cyclophanes have been synthesized by the oxidation of bis-imidazoline with barium manganate followed by cyclization with 2,6-bis(bromomethyl) pyridine in the presence of NaH. All the compounds were iden...Four imidazole cyclophanes have been synthesized by the oxidation of bis-imidazoline with barium manganate followed by cyclization with 2,6-bis(bromomethyl) pyridine in the presence of NaH. All the compounds were identified by IR, (HNMR)-H-1, MS and elemental analysis.展开更多
Molecular recognition in water,the biological solvent,always receives significant research focus in supramolecular chemistry.The mechanisms of molecular recognition in water is key to comprehending biological processe...Molecular recognition in water,the biological solvent,always receives significant research focus in supramolecular chemistry.The mechanisms of molecular recognition in water is key to comprehending biological processes at the molecular level.Over the past five decades,supramolecular chemists have developed a vast array of synthetic receptors with highly diverse structures and recognition properties.Among them,cyclophanes represent an important family of macrocyclic receptors that have been extensively explored.The aromatic moieties in cyclophanes not only facilitate chemical modifications to impart water solubility but also enable forming hydrophobic cavities for vip inclusion in aqueous environments.Pioneered by Koga et al.,who reported the first inclusion complex of cyclophanes in water and solid state,numerous water-soluble cyclophanes,including derivatives of blue box,calixarenes,resorcinarenes,pillararenes,octopusarenes,biphenarenes,coronarenes,and naphthotubes,etc.,have been synthesized and subjected to investigation of the recognition capabilities in aqueous solutions.This review provides an overview of cyclophane receptors designed to bind organic vips in water.We categorize them into two classes based on the modifications made to their hydrophobic cavities:those with“exo-functionalized hydrophobic cavities”and those with“endo-functionalized hydrophobic cavities”.We introduce their distinctive features and discuss strategies to enhance recognition affinity and selectivity.This review aims to inspire the development of novel synthetic receptors with intriguing properties and foster practical applications of cyclophanes.展开更多
Stimuli-responsive macrocycles are of importance for synthetic chemistry and smart materials. In this manuscript, we report two novel organoborane cyclophanes, which were successfully synthesized by ruthenium-catalyze...Stimuli-responsive macrocycles are of importance for synthetic chemistry and smart materials. In this manuscript, we report two novel organoborane cyclophanes, which were successfully synthesized by ruthenium-catalyzed olefin metathesis. They are composed of one/two boron-doped helicene π-skeletons and flexible alkyl chain linkers, thus representing a new kind of non-conjugated organoborane macrocycles. Their cyclic structures and photophysical properties, as well as Lewis acidity were theoretically and experimentally investigated. Notably, two enantiomers in one single crystal are observed for one organoborane cyclophane, owning to the presence of helical π-framework in its cyclic structure. Moreover, their Lewis acid-base adducts may dissociate in the excited state and thus display intriguing photo-responsive fluorescence properties, which can be further modulated by temperature. This study thus provides a novel design strategy for non-conjugated organoborane macrocycles, which may promote the development of stimuli-responsive macrocyclic materials with fascinating properties.展开更多
Two o-carborane based tetraphenylethene(TPE)cationic cyclophanes O1.4PF_(6)and O2.4PF_(6)were syn thesized through an S_(N)2 reaction.Their structures were confirmed both possessing Z-shaped cavities in single crystal...Two o-carborane based tetraphenylethene(TPE)cationic cyclophanes O1.4PF_(6)and O2.4PF_(6)were syn thesized through an S_(N)2 reaction.Their structures were confirmed both possessing Z-shaped cavities in single crystal analysis.The optical properties of these macrocycles were systematically investigated using UV–vis spectroscopy and fluorescence techniques.It is worth noting that the introduction of a methoxy group to the TPE unit enables the synthesis of a near-infrared-emitting macrocycle O2.4PF_(6).The recogni tion behaviors of these two macrocycles towards nucleotides were investigated using various technique including fluorescence titration,UV–vis titration,and transmission electron microscopy(TEM).Interest ingly,these cyclophanes exhibited aggregation-induced emission(AIE)effects in water or under the in duction of nucleotides.展开更多
Benefiting from its bent molecular structure,3,6-pyridazinyl contained tetracationic cyclophane（1） is synthesized by template-directed method with high isolated yield up to 92%.This template-directed strategy is fur...Benefiting from its bent molecular structure,3,6-pyridazinyl contained tetracationic cyclophane（1） is synthesized by template-directed method with high isolated yield up to 92%.This template-directed strategy is further utilized to efficiently construct [2]rotaxane.展开更多
Two novel dithia[3.3]metacyclophanes substituted with ethynyl groups were synthesized as small-sized metacyclophanes from the corresponding brominated dithia-metacyclophanes via C-C bond formation reaction. These comp...Two novel dithia[3.3]metacyclophanes substituted with ethynyl groups were synthesized as small-sized metacyclophanes from the corresponding brominated dithia-metacyclophanes via C-C bond formation reaction. These compounds were characterized by using 1H NMR, mass spectrometry and elemental analyses. The exact structures were determined by using X-ray diffraction analyses. X-ray diffraction analysis results revealed that these compounds have anti conformations because of existence of intermolecular π-π interaction and some short contacts in the crystal. The long wavelength fluorescence was observed for one of the compound having a pyrene moiety in solid state because of the existence of the intermolecular π-π interaction between two pyrene units.展开更多
Dendritic cyclophane tetramer and octamer were prepared by aminolysis of succinimidyl ester derivative of tetraaza [6.1.6.1] paracyclophane with the corresponding poly(amidoamine) dendrimers as a scaffold, followed by...Dendritic cyclophane tetramer and octamer were prepared by aminolysis of succinimidyl ester derivative of tetraaza [6.1.6.1] paracyclophane with the corresponding poly(amidoamine) dendrimers as a scaffold, followed by removal of the protecting groups. The present cyclophane tetramer and octamer showed enhanced vip-binding affinities toward fluorescent vips such as 6-p-toluidinonaphthalene-2-sulfonate and 6-anilinonaphthalene-2-sulfonate, in comparison with those of monocyclic cyclophane, reflecting multivalency effects in macrocycles.展开更多
A cationic water-soluble cyclophane (1a) having a rhodamine moiety as a red-fluorescence fluorophore was prepared by reaction of a monoamine derivative of tetraaza[6.1.6.1]paracyclophane having three N-t-butoxycarbon...A cationic water-soluble cyclophane (1a) having a rhodamine moiety as a red-fluorescence fluorophore was prepared by reaction of a monoamine derivative of tetraaza[6.1.6.1]paracyclophane having three N-t-butoxycarbonyl-β-alanine residues with rhodamine B isothiocyanate, followed by removal of the protecting groups. The vip-binding behavior of 1a toward anionic vips such as dabsyl derivative and 4-(1-pyrene)butanoate was investigated by fluorescence spectroscopy. The results suggested the formation of host-vip complexes with a stoichiometric ratio of 1:1 and the binding constants (K) of the host-vip complexes were evaluated.展开更多
A water-soluble cyclophane (1) having poly(ethylene glycol) (PEG) moieties has been prepared from a tetraazide-functionalized cyclophane derivative and four poly(ethylene glycol) methyl ether acetylenes by Cu(I)-catal...A water-soluble cyclophane (1) having poly(ethylene glycol) (PEG) moieties has been prepared from a tetraazide-functionalized cyclophane derivative and four poly(ethylene glycol) methyl ether acetylenes by Cu(I)-catalyzed 1,3 dipolar cycloadditions (click chemistry). An analogous derivative having a pyrene moiety (2) was also prepared in a similar manner. The vip-binding behavior of 1 and 2 toward anionic vips such as 6-p-toluidinonaphthalene-2-sulfonate was investigated by fluorescence spectroscopy. The binding constants (K) of the host-vip complexes were evaluated.展开更多
A cationic branch-type cyclophane tetramer (1a) was synthesized by introducing three Boc-protected cyclophane derivatives into a N-acetylated tetraaza[6.1.6.1]paracy-clophane derivative as a core skeleton through DCC ...A cationic branch-type cyclophane tetramer (1a) was synthesized by introducing three Boc-protected cyclophane derivatives into a N-acetylated tetraaza[6.1.6.1]paracy-clophane derivative as a core skeleton through DCC condensation, followed by removal of the external Boc-protecting groups. Cationic cyclophane tetramer 1a exhibited a high affinity toward an anionic and hydrophobic fluorescent vip, TNS, with binding constant of 4.8 × 105 M-1. This value of 1a was about 80-fold larger than that of the corresponding monomeric cyclophane for the identical vip, reflecting multivalent effect on the vip binding. As for electrostatic recognition, the obtained binding constant of 1a was one order of magnitude larger than that of an analogous anionic cyclophane tetramer (1b) for the identical vip. These enhanced vip-binding abilities of 1a were easily evaluated by fluorescence titration experiments.展开更多
A tetracationic macrocycle, namely ExBluebox^(4+),bearing two N-phenylene-bipyridinium units that arebridged in a face-to-face manner by two rigid linkerswas synthesized by using an electron-rich template.Compared to ...A tetracationic macrocycle, namely ExBluebox^(4+),bearing two N-phenylene-bipyridinium units that arebridged in a face-to-face manner by two rigid linkerswas synthesized by using an electron-rich template.Compared to the so-called Bluebox^(4+) first inventedby Stoddart, ExBluebox^(4+) reported here has an extendedcavity, allowing the recognition of vipswhose sizes exceed the inner cavity of Bluebox^(4+). Incomparison with the so-called Exbox^(4+) in which twopyridinium units are separated by a phenylene linker,the viologen dications in ExBluebox^(4+) remain intact.ExBluebox^(4+) demonstrates capabilities of recognizingvarious aromatic vips in both water and organicsolvent such as MeCN. By taking advantage of thedifference in binding affinities, the macrocycle dissolvedin water was able to separate pyrene fromperylene, this separation would otherwise be ratherdifficult due to pyrene and perylene’s similar physicalproperties such as their boiling points. In water,ExBluebox^(4+) can be recognized within the cavity ofcucurbit[10]uril (CB[10]), forming a complex ExBluebox^(4+)⊂ CB[10], driven by the hydrophobic effect andcation-dipole interactions. After encapsulated withinof CB[10], the vip recognition ability of ExBluebox^(4+)survived or even increased in water, allowingthe self-assembly of “Russian doll” structures in theform of vip ⊂ ExBluebox^(4+) ⊂ CB[10].展开更多
Photodynamic therapy(PDT)holds great promise for treating periodontitis,yet its clinical efficacy is limited by the lack of specificity of conventional photosensitizers toward pathogenic bacteria.Herein,we developed a...Photodynamic therapy(PDT)holds great promise for treating periodontitis,yet its clinical efficacy is limited by the lack of specificity of conventional photosensitizers toward pathogenic bacteria.Herein,we developed a targeted photosensitizer system using a host–vip supramolecular strategy to address this challenge.The design features a selenoviologen cyclophane(SeVB)host molecule that encapsulates a Porphyromonas gingivalis(P.gingivalis)-specific binding peptide(PQGPPQF,abbreviated PQ),forming the supramolecular complex SeVB⊃PQ.Leveraging the high affinity of PQ for P.gingivalis fimbriae,SeVB⊃PQ demonstrates exceptional bacterial targeting capability,achieving a colocalization coefficient of 0.669.Upon light activation,SeVB⊃PQ generates elevated intracellular reactive oxygen species while disrupting adenosine triphosphate synthesis in P.gingivalis,resulting in a 33.12%enhancement in antimicrobial activity compared to SeVB alone at 0.1μM.Beyond its direct bactericidal effects,SeVB⊃PQ-mediated PDT effectively restores subgingival microbiome homeostasis and attenuates microbial pathogenicity through metabolic modulation.In comparative studies with both SeVB and clinical-grade methylene blue(MB),SeVB⊃PQ demonstrated superior performance in mitigating inflammatory tissue damage and promoting periodontal regeneration.This targeted supramolecular platform not only advances PDT for periodontitis treatment but also provides a novel paradigm for the rational design of pathogen-selective photosensitizers.展开更多
The design and development of selective recognition and sensing systems for biologically important nucleoside triphosphates(NTPs)have attracted significant attention in recent years,owing to their critical roles in ce...The design and development of selective recognition and sensing systems for biologically important nucleoside triphosphates(NTPs)have attracted significant attention in recent years,owing to their critical roles in cellular processes.In this study,we report the synthesis of two tetraphenylethene-based tetraimidazolium cyclophanes(1 and 2)through a one-step S_(N)2 reaction.These cyclophanes are capable of recognizing NTPs by forming stable 1:1 host-vip complexes in aqueous solution.Of particular interest,cyclophane 1 demonstrates exceptional selectivity for guanosine triphosphate(GTP),distinguishing it from other nucleoside triphosphates such as ATP,CTP,and UTP.This selective recognition is accompanied by distinct and measurable fluorescence responses,which are significantly enhanced upon binding to GTp,enabling the potential for sensitive detection.This study highlights the potential of tetraphenylethene-based tetraimidazolium cyclophanes as a highly selective and sensitive sensor for GTP,offering new insights into the design of molecular systems for the recognition of biologically relevant nucleotides.展开更多
Efficient capture of radioactive iodine species is essential for nuclear accident preparedness and aqueous waste treatment,but remains a challenging task.Herein,a triangle imidazolium cyclophane is readily accessible ...Efficient capture of radioactive iodine species is essential for nuclear accident preparedness and aqueous waste treatment,but remains a challenging task.Herein,a triangle imidazolium cyclophane is readily accessible by Friedel-Crafts reaction from benzimidazole precursor,which behaves as an efficient absorbent to quickly capture iodine vapor and its aqueous solution with a maximum adsorption capacity of 3.54 g g^(-1),exceeding most known macrocycles.Moreover,after 30 cycles of reuse,the material still maintained an iodine adsorption efficiency of over 84%.Mechanism investigations revealed that the cationic nature of imidazolium cyclophanes along with the cavities of the materials were responsible for its excellent adsorption ability towards iodine species.展开更多
基金support by the National Natural Science Foundation of China(No.52473225)the Guangdong Basic and Applied Basic Research Foundation(No.2023A1515110262)。
文摘Many azo compounds and their intermediates are toxic and have been linked to various health issues,representing a growing global problem.Molecular engineering for selective encapsulation of azobenzene compounds is critical,given their significant use in smart materials and prevalence as environmental micropollutants released from the food and dye industries.However,the current host molecules catering to azobenzene compounds are mainly limited to cyclodextrins,pillar[n]arenes and cucurbit[n]urils,demonstrating a moderate affinity.This report describes that a novel 3,3'-bipyridinium-based cyclophane was capable of encapsulating anionic azobenzene compounds in water with high binding affinity and pH stability through electrostatic attraction-enhanced mechanism,surpassing the extensively reported supramolecular systems.1D&2D NMR experiments,UV-vis spectrum,X-ray crystallography and computational modeling were carried out to understand the host-vip complexation.It's worth noting that the tetracationic cyclophane exhibited good selective and anti-interference encapsulation properties in binary,ternary and seawater systems.Furthermore,upon UV/white light irradiation,the reversible conversion between(E)-4,4'-azobisbenzoate and(Z)-4,4'-azobisbenzoate triggers the dissociation/recomplexation of the host-vip complex within 3 min.This reversible photo-switchable(E)-disodium 4,4'-azobisbenzoateBPy-Box^(4+)supramolecular system holds promise for designing novel materials for extraction/release of azo compounds and other small smart materials.
基金financial support provided by Huanghuai University and Hangzhou Medical College.
文摘Planar chiral cyclophanes are a type of structurally intriguing organic molecules,which have found increasingly applications in the field of biologically active compounds,asymmetric catalysis,and optically pure materials.As such,significant efforts in the development of new methods to build up enantioenriched cyclophanes in a precise manner have attracted increased attention in recent years.Among the plethora of reported synthetic strategies,catalytic enantioselective method has emerged as one of the most straightforward and efficient ways to deliver optically pure planar chiral cyclophanes.In this review,the recent progress in catalytic enantioselective reactions for the synthesis of planar chiral cyclophanes will be discussed,which would stimulate the research interest of chemists for the discovery of novel asymmetric strategies for the preparation of valuable and previously difficult-to-access chiral molecules.
文摘Anion can be identified by pyromellitic imide-azacyclophane which is one of the host compounds.This article investigated the interaction between the host and organic pollution compounds.The host and other eight compounds were optimized by DFT（density functional theory） B3LYP/6-31G level and the energy of compounds was corrected using Boys-Bemardi method.On the basis of B3LYP/6-31G optimized geometries,the RDG function and sign（λ2（r））ρ（r） function values of space points were calculated,and color RDG isosurface map was drawn.3He chemical shift was calculated by the B3LYP/6-31G method.The results showed that the eight organic pollution molecules with the host one shaped stable configurations by hydrogen bonds,respectively.The stabilization energy of complexes 4 and 7 showed repulsion（steric effects） of cyclophane cage observably affecting the stability of the complexes.The location,intensity and the type of interaction in complex 1 were analyzed through color-filled RDG isosurface map.Aromaticity calculations showed that the weak interaction reduced the transverse induction ring current in the host rings,and deteriorated the aromaticity of compounds.
基金supported by grants from the National Key Research and Development Program (Nos. 2018YFA0900402 and 2021YFA0910501)the National Natural Science Foundation of China (Nos. 21822703, 21921003, and 32070050)+2 种基金the funding of Innovative research team of high-level local universities in Shanghaia key laboratory program of the Education Commission of Shanghai Municipality (No. ZDSYS14005)West Light Foundation of the Chinese Academy of Sciences (No. xbzgzdsys-202105)。
文摘Three-residue cyclophane-forming enzymes(3-Cy FEs) are a group of radical S-adenosylmethionine(SAM)enzymes involved in the biosynthesis of ribosomally synthesized and posttranslationally modified peptides(Ri PPs). 3-Cy FE catalyzes the crosslinking between an aromatic residue(Ω1) and a non-aromatic residue(X3) in a Ω1-X2-X3 motif to produce a cyclophane ring, a key step in the biosynthesis of the Ri PP natural product triceptide. In this study, we perform a genome-wide search for the Xye-type triceptides, showing these Ri PPs are likely class-specific and only present in gamma-proteobacteria. The 3-Cy FE Pau B from Photorhabdus australis exhibits a relaxed substrate specificity on the X3 position, but glycine in this position is not suitable for cyclophane formation. We also reconstituted the activity of Pau B in vitro,showing it produces the N-terminal cyclophane firstly, and then the C-terminal ring, whereas the middle cyclophane is produced in the last step.
文摘Four imidazole cyclophanes have been synthesized by the oxidation of bis-imidazoline with barium manganate followed by cyclization with 2,6-bis(bromomethyl) pyridine in the presence of NaH. All the compounds were identified by IR, (HNMR)-H-1, MS and elemental analysis.
基金supported by the National Natural Science Foundation of China(Nos.22271164,U20A20259)the Fundamental Research Funds for the Central Universitiesthe NCC Fund(No.NCC2020FH04).
文摘Molecular recognition in water,the biological solvent,always receives significant research focus in supramolecular chemistry.The mechanisms of molecular recognition in water is key to comprehending biological processes at the molecular level.Over the past five decades,supramolecular chemists have developed a vast array of synthetic receptors with highly diverse structures and recognition properties.Among them,cyclophanes represent an important family of macrocyclic receptors that have been extensively explored.The aromatic moieties in cyclophanes not only facilitate chemical modifications to impart water solubility but also enable forming hydrophobic cavities for vip inclusion in aqueous environments.Pioneered by Koga et al.,who reported the first inclusion complex of cyclophanes in water and solid state,numerous water-soluble cyclophanes,including derivatives of blue box,calixarenes,resorcinarenes,pillararenes,octopusarenes,biphenarenes,coronarenes,and naphthotubes,etc.,have been synthesized and subjected to investigation of the recognition capabilities in aqueous solutions.This review provides an overview of cyclophane receptors designed to bind organic vips in water.We categorize them into two classes based on the modifications made to their hydrophobic cavities:those with“exo-functionalized hydrophobic cavities”and those with“endo-functionalized hydrophobic cavities”.We introduce their distinctive features and discuss strategies to enhance recognition affinity and selectivity.This review aims to inspire the development of novel synthetic receptors with intriguing properties and foster practical applications of cyclophanes.
基金supported by the National Natural Science Foundation of China (Nos. 22175074, 21822507)。
文摘Stimuli-responsive macrocycles are of importance for synthetic chemistry and smart materials. In this manuscript, we report two novel organoborane cyclophanes, which were successfully synthesized by ruthenium-catalyzed olefin metathesis. They are composed of one/two boron-doped helicene π-skeletons and flexible alkyl chain linkers, thus representing a new kind of non-conjugated organoborane macrocycles. Their cyclic structures and photophysical properties, as well as Lewis acidity were theoretically and experimentally investigated. Notably, two enantiomers in one single crystal are observed for one organoborane cyclophane, owning to the presence of helical π-framework in its cyclic structure. Moreover, their Lewis acid-base adducts may dissociate in the excited state and thus display intriguing photo-responsive fluorescence properties, which can be further modulated by temperature. This study thus provides a novel design strategy for non-conjugated organoborane macrocycles, which may promote the development of stimuli-responsive macrocyclic materials with fascinating properties.
基金supported by the National Natural Science Foundation of China(No.22071025)the Joint Independent Innovation Fund of Tianjin University and Fuzhou University(No.TF2021-3)the Young and Middle-aged Teacher Education Research Project of Fujian Province(No.JAT210020)。
文摘Two o-carborane based tetraphenylethene(TPE)cationic cyclophanes O1.4PF_(6)and O2.4PF_(6)were syn thesized through an S_(N)2 reaction.Their structures were confirmed both possessing Z-shaped cavities in single crystal analysis.The optical properties of these macrocycles were systematically investigated using UV–vis spectroscopy and fluorescence techniques.It is worth noting that the introduction of a methoxy group to the TPE unit enables the synthesis of a near-infrared-emitting macrocycle O2.4PF_(6).The recogni tion behaviors of these two macrocycles towards nucleotides were investigated using various technique including fluorescence titration,UV–vis titration,and transmission electron microscopy(TEM).Interest ingly,these cyclophanes exhibited aggregation-induced emission(AIE)effects in water or under the in duction of nucleotides.
基金the financial support of NNSF of China(Nos.21402069 and 21361011)the Project of Jiangxi Provincial Education Department(No.GJJ14264)
文摘Benefiting from its bent molecular structure,3,6-pyridazinyl contained tetracationic cyclophane（1） is synthesized by template-directed method with high isolated yield up to 92%.This template-directed strategy is further utilized to efficiently construct [2]rotaxane.
文摘Two novel dithia[3.3]metacyclophanes substituted with ethynyl groups were synthesized as small-sized metacyclophanes from the corresponding brominated dithia-metacyclophanes via C-C bond formation reaction. These compounds were characterized by using 1H NMR, mass spectrometry and elemental analyses. The exact structures were determined by using X-ray diffraction analyses. X-ray diffraction analysis results revealed that these compounds have anti conformations because of existence of intermolecular π-π interaction and some short contacts in the crystal. The long wavelength fluorescence was observed for one of the compound having a pyrene moiety in solid state because of the existence of the intermolecular π-π interaction between two pyrene units.
文摘Dendritic cyclophane tetramer and octamer were prepared by aminolysis of succinimidyl ester derivative of tetraaza [6.1.6.1] paracyclophane with the corresponding poly(amidoamine) dendrimers as a scaffold, followed by removal of the protecting groups. The present cyclophane tetramer and octamer showed enhanced vip-binding affinities toward fluorescent vips such as 6-p-toluidinonaphthalene-2-sulfonate and 6-anilinonaphthalene-2-sulfonate, in comparison with those of monocyclic cyclophane, reflecting multivalency effects in macrocycles.
文摘A cationic water-soluble cyclophane (1a) having a rhodamine moiety as a red-fluorescence fluorophore was prepared by reaction of a monoamine derivative of tetraaza[6.1.6.1]paracyclophane having three N-t-butoxycarbonyl-β-alanine residues with rhodamine B isothiocyanate, followed by removal of the protecting groups. The vip-binding behavior of 1a toward anionic vips such as dabsyl derivative and 4-(1-pyrene)butanoate was investigated by fluorescence spectroscopy. The results suggested the formation of host-vip complexes with a stoichiometric ratio of 1:1 and the binding constants (K) of the host-vip complexes were evaluated.
文摘A water-soluble cyclophane (1) having poly(ethylene glycol) (PEG) moieties has been prepared from a tetraazide-functionalized cyclophane derivative and four poly(ethylene glycol) methyl ether acetylenes by Cu(I)-catalyzed 1,3 dipolar cycloadditions (click chemistry). An analogous derivative having a pyrene moiety (2) was also prepared in a similar manner. The vip-binding behavior of 1 and 2 toward anionic vips such as 6-p-toluidinonaphthalene-2-sulfonate was investigated by fluorescence spectroscopy. The binding constants (K) of the host-vip complexes were evaluated.
文摘A cationic branch-type cyclophane tetramer (1a) was synthesized by introducing three Boc-protected cyclophane derivatives into a N-acetylated tetraaza[6.1.6.1]paracy-clophane derivative as a core skeleton through DCC condensation, followed by removal of the external Boc-protecting groups. Cationic cyclophane tetramer 1a exhibited a high affinity toward an anionic and hydrophobic fluorescent vip, TNS, with binding constant of 4.8 × 105 M-1. This value of 1a was about 80-fold larger than that of the corresponding monomeric cyclophane for the identical vip, reflecting multivalent effect on the vip binding. As for electrostatic recognition, the obtained binding constant of 1a was one order of magnitude larger than that of an analogous anionic cyclophane tetramer (1b) for the identical vip. These enhanced vip-binding abilities of 1a were easily evaluated by fluorescence titration experiments.
基金supported by the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study(grant no.SN-ZJU-SIAS-006)the support from the Leading Innovation Team grant from the Department of Science and Technology of Zhejiang Province(grant no.2022R01005)+1 种基金the Natural Science Foundation of Zhejiang Province(grant no.LZ24B020002)the National Natural Science Foundation of China(grant no.22273082).
文摘A tetracationic macrocycle, namely ExBluebox^(4+),bearing two N-phenylene-bipyridinium units that arebridged in a face-to-face manner by two rigid linkerswas synthesized by using an electron-rich template.Compared to the so-called Bluebox^(4+) first inventedby Stoddart, ExBluebox^(4+) reported here has an extendedcavity, allowing the recognition of vipswhose sizes exceed the inner cavity of Bluebox^(4+). Incomparison with the so-called Exbox^(4+) in which twopyridinium units are separated by a phenylene linker,the viologen dications in ExBluebox^(4+) remain intact.ExBluebox^(4+) demonstrates capabilities of recognizingvarious aromatic vips in both water and organicsolvent such as MeCN. By taking advantage of thedifference in binding affinities, the macrocycle dissolvedin water was able to separate pyrene fromperylene, this separation would otherwise be ratherdifficult due to pyrene and perylene’s similar physicalproperties such as their boiling points. In water,ExBluebox^(4+) can be recognized within the cavity ofcucurbit[10]uril (CB[10]), forming a complex ExBluebox^(4+)⊂ CB[10], driven by the hydrophobic effect andcation-dipole interactions. After encapsulated withinof CB[10], the vip recognition ability of ExBluebox^(4+)survived or even increased in water, allowingthe self-assembly of “Russian doll” structures in theform of vip ⊂ ExBluebox^(4+) ⊂ CB[10].
基金supported by the National Natural Science Foundation of China(22175138,22201228,22205172,52203240,82170927)the Guangdong Basic and Applied Basic Research Foundation(2023A1515110346)We thank the Interdisciplinary Training Program for Doctoral Candidates of Xi’an Jiaotong University(IDT2026).
文摘Photodynamic therapy(PDT)holds great promise for treating periodontitis,yet its clinical efficacy is limited by the lack of specificity of conventional photosensitizers toward pathogenic bacteria.Herein,we developed a targeted photosensitizer system using a host–vip supramolecular strategy to address this challenge.The design features a selenoviologen cyclophane(SeVB)host molecule that encapsulates a Porphyromonas gingivalis(P.gingivalis)-specific binding peptide(PQGPPQF,abbreviated PQ),forming the supramolecular complex SeVB⊃PQ.Leveraging the high affinity of PQ for P.gingivalis fimbriae,SeVB⊃PQ demonstrates exceptional bacterial targeting capability,achieving a colocalization coefficient of 0.669.Upon light activation,SeVB⊃PQ generates elevated intracellular reactive oxygen species while disrupting adenosine triphosphate synthesis in P.gingivalis,resulting in a 33.12%enhancement in antimicrobial activity compared to SeVB alone at 0.1μM.Beyond its direct bactericidal effects,SeVB⊃PQ-mediated PDT effectively restores subgingival microbiome homeostasis and attenuates microbial pathogenicity through metabolic modulation.In comparative studies with both SeVB and clinical-grade methylene blue(MB),SeVB⊃PQ demonstrated superior performance in mitigating inflammatory tissue damage and promoting periodontal regeneration.This targeted supramolecular platform not only advances PDT for periodontitis treatment but also provides a novel paradigm for the rational design of pathogen-selective photosensitizers.
基金supported by the National Natural Science Foundation of China(Nos.22301241 and 22371229)the Shaanxi Fundamental Science Research Project for Chemistry and Biology(22JHQ073).
文摘The design and development of selective recognition and sensing systems for biologically important nucleoside triphosphates(NTPs)have attracted significant attention in recent years,owing to their critical roles in cellular processes.In this study,we report the synthesis of two tetraphenylethene-based tetraimidazolium cyclophanes(1 and 2)through a one-step S_(N)2 reaction.These cyclophanes are capable of recognizing NTPs by forming stable 1:1 host-vip complexes in aqueous solution.Of particular interest,cyclophane 1 demonstrates exceptional selectivity for guanosine triphosphate(GTP),distinguishing it from other nucleoside triphosphates such as ATP,CTP,and UTP.This selective recognition is accompanied by distinct and measurable fluorescence responses,which are significantly enhanced upon binding to GTp,enabling the potential for sensitive detection.This study highlights the potential of tetraphenylethene-based tetraimidazolium cyclophanes as a highly selective and sensitive sensor for GTP,offering new insights into the design of molecular systems for the recognition of biologically relevant nucleotides.
基金supported by the National Natural Science Foundation of China(22271060)the Department of Chemistry,Fudan UniversityNingxia University。
文摘Efficient capture of radioactive iodine species is essential for nuclear accident preparedness and aqueous waste treatment,but remains a challenging task.Herein,a triangle imidazolium cyclophane is readily accessible by Friedel-Crafts reaction from benzimidazole precursor,which behaves as an efficient absorbent to quickly capture iodine vapor and its aqueous solution with a maximum adsorption capacity of 3.54 g g^(-1),exceeding most known macrocycles.Moreover,after 30 cycles of reuse,the material still maintained an iodine adsorption efficiency of over 84%.Mechanism investigations revealed that the cationic nature of imidazolium cyclophanes along with the cavities of the materials were responsible for its excellent adsorption ability towards iodine species.
