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1.
Dr. Hui Guo Prof. Dominique Hourdet Dr. Alba Marcellan Dr. François Stoffelbach Dr. Joel Lyskawa Lieselot de Smet Aurélien Vebr Prof. Richard Hoogenboom Prof. Patrice Woisel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(6):1292-1297
The regulation of the concentration of a wide range of small molecules is ubiquitous in biological systems because it enables them to adapt to the continuous changes in the environmental conditions. Herein, we report an aqueous synthetic system that provides an orchestrated, temperature and pH controlled regulation of the complexation between the cyclobis(paraquat-p-phenylene) host ( BBox ) and a 1,5-dialkyloxynaphthalene ( DNP ) guest attached to a well-defined dual responsive copolymer composed of N-isopropylacrylamide as thermoresponsive monomer and acrylic acid as pH-responsive monomer. Controlled, partial release of the BBox , enabling control over its concentration, is based on the tunable partial collapse of the copolymer. This colored supramolecular assembly is one of the first synthetic systems providing control over the concentration of a small molecule, providing great potential as both T and pH chromic materials and as a basis to develop more complex systems with molecular communication. 相似文献
2.
Corbett PT Sanders JK Otto S 《Angewandte Chemie (International ed. in English)》2007,46(46):8858-8861
3.
M. Fernando Bravo Dr. Kalanidhi Palanichamy Milan A. Shlain Frank Schiro Yasir Naeem Prof. Dr. Mateusz Marianski Prof. Dr. Adam B. Braunschweig 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(51):11782-11795
Synthetic carbohydrate receptors (SCRs) that selectively recognize cell-surface glycans could be used for detection, drug delivery, or as therapeutics. Here we report the synthesis of seven new C2h symmetric tetrapodal SCRs. The structures of these SCRs possess a conserved biaryl core, and they vary in the four heterocyclic binding groups that are linked to the biaryl core via secondary amines. Supramolecular association between these SCRs and five biologically relevant C1-O-octyloxy glycans, α/β-glucoside ( α/β-Glc ), α/β-mannoside ( α/β-Man ), and β-galactoside ( β-Gal ), was studied by mass spectrometry, 1H NMR titrations, and molecular modeling. These studies revealed that selectivity can be achieved in these tetrapodal SCRs by varying the heterocyclic binding group. We found that SCR017 (3-pyrrole), SCR021 (3-pyridine), and SCR022 (2-phenol) bind only to β-Glc. SCR019 (3-indole) binds only to β-Man. SCR020 (2-pyridine) binds β-Man and α-Man with a preference to the latter. SCR018 (2-indole) binds α-Man and β-Gal with a preference to the former. The glycan guests bound within their SCR hosts in one of three supramolecular geometries: center-parallel, center-perpendicular, and off-center. Many host–guest combinations formed higher stoichiometry complexes, 2:1 glycan⋅SCR or 1:2 glycan⋅SCR , where the former are driven by positive allosteric cooperativity induced by glycan–glycan contacts. 相似文献
4.
Bin Tan Xiao-Dong Yang Li Sun Xiao-Ying Huang Jie Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(16):4136-4142
A flexible bipyridinium-linker-based porous host framework with electron-accepting pore surface, namely, [Zn2( L )(pmc)1.5] ⋅ 12 H2O ( 1 ; L⋅ Cl2=1,1′-[1,4-phenylene-bis(methylene)]bis(4,4′-bipyridinium) dichloride, H4pmc=pyromellitic acid) exhibits recognition of phenol and aromatic amine guests based on adsorbent–adsorbate charge-transfer interactions. Significantly, the resultant guest-encapsulated complexes 1@Guests can all be characterized by single-crystal X-ray diffraction. The host framework undergoes a reversible single crystal-to-single crystal transformation in response to the inclusion of different guests with flexible torsional motions of the hexagonal ring and the trapezoid-shaped bipyridinium groups. Such recognition can be visibly monitored and detected by obvious color changes. The host framework could also be recovered, and this suggested that guest sorption/desorption is reversible and that the host framework could be reused in potential applications. This work may provide an effective way to develop porous materials with special emphasis on applications involving guest recognition. 相似文献
5.
Sung Beom Seo Seungwon Lee Hae-Geun Jeon Prof. Dr. Kyu-Sung Jeong 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(26):10527-10531
As a synthetic model for intra-protein interactions that reinforce binding affinities between proteins and ligands, the energetic interplay of binding and folding was investigated using foldamer-based receptors capable of adopting helical structures. The receptors were designed to have identical hydrogen-bonding sites for anion binding but different aryl appendages that simply provide additional π-stacking within the helical backbones without direct interactions with the bound anions. In particular, the presence of electron-deficient aryl appendages led to dramatic enhancements in the association constant between the receptor and chloride or nitrate ions, by up to three orders of magnitude. Extended stacking within the receptor contributes to the stabilization of the entire folding structure of complexes, thereby enhancing binding affinities. 相似文献
6.
Michael Heilmann Prof. Dr. Konrad Tiefenbacher 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(56):12900-12904
A molecular tweezer based on a glycoluril-derived framework bearing four phosphate groups was synthesized and shown to be capable of binding organic amines in aqueous solution. This work reports the Ka values for 30 complexes of this molecular tweezer and amine guests, determined by means of 1H NMR titrations. Both the hydrophobic cavity and the phosphate groups contribute to the binding. Bulkier molecules and molecules bearing negatively charged groups like carboxylates in amino acids bind less tightly due to a steric clash and coulombic repulsion. The narrow cavity and the strong ionic interactions of the phosphate groups with ammonium guests favor binding of aliphatic diamines. These binding properties clearly distinguish this system from structurally related molecular clips and tweezers. 相似文献
7.
Li Shao Yutong Pan Bin Hua Shidang Xu Guocan Yu Mengbin Wang Bin Liu Feihe Huang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(29):11877-11881
In order to promote the development of photodynamic therapy (PDT), undesired side effects like low tumor specificity and the “always-on” phenomenon should be avoided. An effective solution is to construct an adaptive photosensitizer that can be activated to generate reactive oxygen species (ROS) in the tumor microenvironment. Herein, we design and synthesize a supramolecular switch based on a host–guest complex containing a water-soluble pillar[5]arene ( WP5 ) and an AIEgen photosensitizer ( G ). The formation of the host–guest complex WP5 ⊃ G quenches the fluorescence and inhibits ROS generation of G . Benefitting from the pH-responsiveness of WP5 , the binding site between G and WP5 changes in an acidic environment through a shuttle movement. Consequently, fluorescence and ROS generation of the host–guest complex can be switched on at pH 5.0. This work offers a new paradigm for the construction of adaptive photosensitizers by using a supramolecular method. 相似文献
8.
Dr. Aldo C. Catalán Axel A. Loredo Dr. Ruy Cervantes Prof. Dr. Jorge Tiburcio 《ChemistryOpen》2022,11(6):e202200112
A pseudo-rotaxane is a host−guest complex composed of a linear molecule encircled by a macrocyclic ring. These complexes can be assembled by sliding the host over the guest terminal groups. If there is a close match between the molecular volume of the flanking groups on the guest and the cavity size of the macrocycle, the slipping might occur slowly or even become completely hindered. We have previously shown that it is possible to overcome the restraints imposed by steric effects on the sliding process by integrating electrostatic attractive interactions during the slipping step. In this work, we extend our electrostatically assisted slipping approach (EASA) to a new host−guest system featuring a flexible macrocyclic ring and a series of asymmetric guests containing a cyclic tertiary ammonium group. Compelling evidence for pseudo-rotaxane formation is presented, along with thermodynamic and kinetic data. Experimental results suggests that the higher conformational flexibility of 24-crown-8 significantly increases the sliding rate, compared with the more rigid dibenzo-24-crown-8, without affecting complex stability. Furthermore, by combining the EASA and macrocycle flexibility, we were capable to slip a large eight-membered cyclic group across the 24-crown-8 annulus, setting a new limit on the ring molecular size that can pass through a 24-membered crown ether. 相似文献
9.
10.
Zsolt Csók Tamás Kégl László Párkányi Ágnes Varga Sándor Kunsági-Máté László Kollár 《Supramolecular chemistry》2013,25(10):710-719
A wide variety of 2-methyl-resorcinol-based deepened cavitands were synthesised from readily available reagents in a four-step procedure with overall yields of up to 62%. A systematic variation of the rim was carried out by building up a flexible upper aromatic wall on the rigid cavitand platform through CH2, CH2O and CH2OCH2 spacers. These aromatic walls were further extended by a Suzuki cross-coupling reaction. Full characterisation of the synthesised cavitands was carried out. The solid-state structure of tetrakis(phenoxymethyl)cavitand was determined by X-ray crystallography. Gas-phase theoretical calculations for this molecule predict the presence of weak T-shaped interactions between the upper phenyl rings. The host–guest complex formation ability of two deepened cavitand hosts towards 4-chloro-benzotrifluoride was proved by photoluminescence method. 相似文献
11.
Riley J. Petersen Brett J. Rozeboom Dr. Shalisa M. Oburn Nolan J. Blythe Tanner L. Rathje Javier A. Luna Steven K. Kibby Emily A. O'Brien Kayleigh G. Rohr Joshua R. Carpenter Taylor L. Sanders Andrew M. Johnson Dr. Kristin M. Hutchins Prof. Scott K. Shaw Prof. Leonard R. MacGillivray Prof. Jay Wm. Wackerly 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(9):1928-1930
A novel macrocyclic host molecule was synthesized that forms in a single step from commercially available starting materials. The core of the macrocycle backbone possesses two quinone rings and, thus, it is redox-active. Host–guest binding involving the clip-shaped cavity indicates selective binding of pyridine N-oxides based on the electron density of and steric bulk around the anionic oxygen. 相似文献
12.
Kirmse W 《Angewandte Chemie (International ed. in English)》2005,44(17):2476-2479
13.
Dr. Masashi Yokoya Dr. Shinya Kimura Prof. Dr. Masamichi Yamanaka 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(18):5601-5614
Urea, which has both hydrogen bond acceptor and donor moieties, is an ideal structure for a supramolecular synthon. Various supramolecules having ureido group(s) have been widely developed. This article summarizes recent developments of urea derivatives that exhibit various functions: i) supramolecular capsules that form discrete urea–urea intermolecular hydrogen bonds, ii) supramolecular polymers that form continuous urea–urea intermolecular hydrogen bonds, iii) supramolecular gels that form continuous urea–urea intermolecular hydrogen bonds, iv) artificial host molecules based on the molecular recognition ability of the ureido group, and v) catalytic reactions developed by utilizing the molecular recognition ability of the ureido group. 相似文献
14.
Dr. Eunji Lee Hyunsoo Ryu Huiyeong Ju Seulgi Kim Dr. Ji-Eun Lee Prof. Jong Hwa Jung Prof. Shunsuke Kuwahara Prof. Mari Ikeda Prof. Yoichi Habata Prof. Shim Sung Lee 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(4):949-953
Some biological receptors change their shapes and rigidity by metalation to recognize substrates precisely via adaptive guest binding process. Herein we present a semi-flexible tricyclic host molecule whose conformation is rigidified by dimetalation to uptake organic guests selectively. Considering two metal binding sites and an empty space between them, pillar[5]-bis-thiacrown (L) was synthesized. The tricyclic host L forms a disilver(I) complex [Ag2L(NO3)2], with an Ag⋅⋅⋅Ag separation of 9.976 Å. Binding studies based on 1H NMR including 2D NOESY and DOSY experiments towards α,ω-dicyanoalkanes [CN(CH2)nCN, n=2–6, shortly C2–C6] demonstrated that the dimetalated L, Ag2L preferentially recognizes C2 over other guests than that of free L. Furthermore, the dimetalated the host only uptakes C2 in the presence of other guests. Crystal structures support the idea that the space between two silver(I) centers plays a decisive role on the selective guest binding forming an Ag-C2-Ag@L arrangement via the length-selective recognition. This work demonstrates the chemical example of the adaptive guest binding and presents a new perspective on the metallosupramolecules of pillararenes. 相似文献
15.
Dr. Dennis Larsen Prof. Dr. Sophie R. Beeren 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(48):11032-11038
Enzyme-mediated dynamic combinatorial chemistry combines the concept of thermodynamically controlled covalent self-assembly with the inherent biological relevance of enzymatic transformations. A system of interconverting cyclodextrins has been explored, in which the glycosidic linkage is rendered dynamic by the action of cyclodextrin glucanotransferase (CGTase). External factors, such as pH, temperature, solvent, and salinity are reported to modulate the composition of the dynamic cyclodextrin library. Dynamic libraries of cyclodextrins (CDs) could be obtained in wide ranges of pH (5.0–9.0), temperature (5–37 °C), and salinity (up to 7.5 m NaNO3), and with high organic solvent content (50 % by volume of ethanol), showing that enzyme-mediated dynamic systems can be robust and not limited to physiological conditions. Furthermore, it is demonstrated how strategic choice of reaction conditions can enhance template effects, in this case, to achieve highly selective production of α-CD, an otherwise challenging target due to competition from the structurally similar β-CD. 相似文献
16.
Dr. Laure-Elie Carloni Dr. C. Grazia Bezzu Prof. Dr. Davide Bonifazi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(71):16179-16200
Two-dimensional (2D) porous networks are of great interest for the fabrication of complex organized functional materials for potential applications in nanotechnologies and nanoelectronics. This review aims at providing an overview of bottom-up approaches towards the engineering of 2D porous networks by using biomacromolecules, with a particular focus on nucleic acids and proteins. The first part illustrates how the advancements in DNA nanotechnology allowed for the attainment of complex ordered porous two-dimensional DNA nanostructures, thanks to a biomimetic approach based on DNA molecules self-assembly through specific hydrogen-bond base pairing. The second part focuses the attention on how polypeptides and proteins structural properties could be used to engineer organized networks templating the formation of multifunctional materials. The structural organization of all examples is discussed as revealed by scanning probe microscopy or transmission electron microscopy imaging techniques. 相似文献
17.
Cassandra C. Shaffer Dr. Wenqi Liu Dr. Allen G. Oliver Dr. Bradley D. Smith 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(2):751-757
A new supramolecular paradigm is presented for reliable capture and co-precipitation of haloauric acids (HAuX4) from organic solvents or water. Two classes of acyclic organic compounds act as complementary receptors (tectons) by forming two sets of directional non-covalent interactions, (a) hydrogen bonding between amide (or amidinium) NH residues and the electronegative X ligands on the AuX4−, and (b) electrostatic stacking of the electron deficient Au center against the face of an aromatic surface. X-ray diffraction analysis of four co-crystal structures reveals the additional common feature of proton bridged carbonyls as a new and predictable supramolecular design element that creates one-dimensional polymers linked by very short hydrogen bonds (CO⋅⋅⋅OC distance <2.5 Å). Two other co-crystal structures show that the amidinium-π⋅⋅⋅XAu interaction will reliably engage AuX4− with high directionality. These acyclic compounds are very attractive as co-precipitation agents within new “green” gold recovery processes. They also have high potential as tectons for controlled self-assembly or co-crystal engineering of haloaurate composites. More generally, the supramolecular paradigm will facilitate the design of next-generation receptors or tectons with high affinity for precious metal square planar coordination complexes for use in advanced materials, nanotechnology, or medicine. 相似文献
18.
Dr. Kohei Takahashi Shunsuke Shimo Dr. Emanuel Hupf Junichi Ochiai Christina A. Braun Dr. William Torres Delgado Letian Xu Prof. Dr. Gang He Prof. Dr. Eric Rivard Prof. Dr. Nobuharu Iwasawa 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(36):8479-8483
Guest-controlled diastereoselective self-assembly of a diboryltellurophene and a chiral tetrol bearing an indacene backbone was achieved to give either hetero- or homochiral macrocyclic boronic esters, selectively. The heterochiral isomer (hetero-[2+2]Te) exhibited a higher inclusion ability for electron-deficient aromatic guests, leading to effective quenching of phosphorescence from the diboryltellurophene moieties. The reported macrocycles collectively represent a promising arene sensing approach based on phosphorescence. 相似文献
19.
Rubi A. Luna-Ixmatlahua Dr. Anayeli Carrasco-Ruiz Dr. Ruy Cervantes Prof. Dr. Alberto Vela Prof. Dr. Jorge Tiburcio 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(62):14042-14047
The use of the electrostatic stoppers concept in the field of mechanically interlocked molecules is reported; these stoppers are chemically sensitive end groups on a linear guest molecule that allows for the conversion of a pseudo-rotaxane species into a rotaxane complex by a change in the medium acidity. The chemical stimulus causes the appearance of negative charges on both ends of the linear component, passing from cationic to anionic, and causing a significant ring-to-axle electrostatic repulsion. This phenomenon has two different and simultaneous effects: 1) destabilizes the complex as a consequence of confining an anionic ring into an anionic axle, and 2) increases the dissociation energy barrier, thus impeding ring extrusion. This newly formed metastable rotaxane species is resistant to solvent and temperature effects and performs as a two-state degenerated molecular shuttle in solution. 相似文献
20.
Dr. Flora L. Thorp-Greenwood Dr. Mark J. Howard Dr. Lars T. Kuhn Prof. Michaele J. Hardie 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(14):3536-3540
Cryptophanes with flexible linkers derived from (±)-tris-(4-formyl-phenyl)-cyclotriguaiacylene with either bisoxydi(ethylamine) or bis(aminopropyl)ether were isolated as single crystals, the crystal structures of which showed the proposed, but previously uncharacterised, out-in conformation, in which both cyclotriguaiacylene fragments adopt a crown conformation with one crown sitting inside the other. The usual cage-like out-out conformation of the cryptophanes was observed when crystals were dissolved upon heating, and the molecules collapsed back to the out-in isomers over time. In contrast, a cryptophane also derived from (±)-tris-(4-formyl-phenyl)-cyclotriguaiacylene but with rigid dibenzalhydrazine linkers was isolated as the more usual out-out isomer. 相似文献