The Experts below are selected from a list of 3318 Experts worldwide ranked by ideXlab platform
Feihe Huang - One of the best experts on this subject based on the ideXlab platform.
-
construction of a 2 Pseudorotaxane and a 3 Pseudorotaxane based on perbromoethylated pillar 5 arene pyridinium iodide ion pair recognition
Chemical Communications, 2019Co-Authors: Li Shao, Feihe HuangAbstract:Herein we report the preparation of a [2]Pseudorotaxane and a [3]Pseudorotaxane based on perbromoethylated pillar[5]arene/pyridinium iodide ion-pair recognition.
-
Construction of a [2]Pseudorotaxane and a [3]Pseudorotaxane based on perbromoethylated pillar[5]arene/pyridinium iodide ion-pair recognition.
Chemical communications (Cambridge England), 2019Co-Authors: Li Shao, Jiyong Liu, Bin Hua, Feihe HuangAbstract:Herein we report the preparation of a [2]Pseudorotaxane and a [3]Pseudorotaxane based on perbromoethylated pillar[5]arene/pyridinium iodide ion-pair recognition.
-
a dual thermoresponsive gemini type supra amphiphilic macromolecular 3 Pseudorotaxane based on pillar 10 arene paraquat cooperative complexation
Journal of the American Chemical Society, 2016Co-Authors: Xiaodong Chi, Li Shao, Jianzhuang Chen, Feihe HuangAbstract:Herein, first we report the preparation of a thermoresponsive [3]Pseudorotaxane from cooperative complexation between a water-soluble pillar[10]arene and a paraquat derivative in water. Then we successfully construct the first pillararene-based gemini-type supra-amphiphilic [3]Pseudorotaxane from the water-soluble pillar[10]arene and a paraquat-containing poly(N-isopropylacrylamide) based on this new molecular recognition motif in water. This macromolecular [3]Pseudorotaxane shows unique dual-thermoresponsiveness. Furthermore, it can self-assemble into polymeric vesicles at 37 °C in water. These vesicles can be further used in the controlled release of small molecules induced by cooling to 25 °C or heating to 60 °C.
-
Formation of a pillar[5]arene-based [3]Pseudorotaxane in solution and in the solid state
Chemical communications (Cambridge England), 2013Co-Authors: Lingyan Gao, Chengyou Han, Bo Zheng, Shengyi Dong, Feihe HuangAbstract:It was demonstrated that a novel [3]Pseudorotaxane could be separated by column chromatography during the synthesis of a copillar[5]arene. Single crystal X-ray analysis revealed that this [3]Pseudorotaxane consisted of the copillar[5]arene and its monomer in a molar ratio of 2 : 1.
-
n Pseudorotaxanes n 2 3 from self assembly of two cryptands and a 1 2 bis 4 pyridinium ethane derivative
European Journal of Organic Chemistry, 2012Co-Authors: Xuzhou Yan, Peifa Wei, Mingming Zhang, Xiaodong Chi, Feihe HuangAbstract:Efficient host–guest complexation and interesting self-assembled structures formed between two crown ether-based cryptands and a 1,2-bis(4-pyridinium)ethane derivative 3 are reported. By self-assembly of cis-dibenzo-24-crown-8-based cryptand 1 and guest 3, a [3]Pseudorotaxane was formed in solution, which further formed a supramolecular poly[3]Pseudorotaxane structure in the solid state driven by π-π stacking interactions. Meanwhile, a [2]Pseudorotaxane, obtained from self-assembly of a bis(m-phenylene)-32-crown-10-based cryptand 2 and guest 3, can form a supramolecular poly[2]Pseudorotaxane structure in the solid state. This difference in the binding model reflects the diversity of host–guest chemistry of crown ether-based cryptands. Furthermore, these host–guest recognition processes and self-assembled structures were fully characterized by 1H NMR, UV/Vis spectroscopy, electrospray ionization mass spectrometry, and single-crystal X-ray analysis. Interestingly, formation of the [3]Pseudorotaxane between cryptand 1 and guest 3 can be reversibly controlled by adding and removing potassium cations in acetone. This reversible complexation process provides a simple on/off mechanism that can be used in the construction of controllable molecular switches.
Haibo Yang - One of the best experts on this subject based on the ideXlab platform.
-
supramolecular polymer cross linked by discrete tris 2 Pseudorotaxane metallacycles and its redox responsive behavior
Inorganic Chemistry, 2018Co-Authors: Xuqing Wang, Lijun Chen, Guangqiang Yin, Bo Jiang, Haibo YangAbstract:A new discrete hexagonal metallacycle M containing tris-[2]Pseudorotaxane moiety has been successfully designed and synthesized via coordination-driven self-assembly. The newly designed tris-[2]Pseudorotaxane metallacycle was well characterized with nuclear magnetic resonance and mass spectra analysis. Such tris-[2]Pseudorotaxane metallacycle M and pillar[5]arene dimer (PD) could further form a new family of cross-linked redox-responsive supramolecular polymer M⊃(PD)3 through a host–guest interaction. Interestingly, the polymer M⊃(PD)3 displayed redox-responsive behavior and showed tuned weight-average diffusion coefficients D upon redox stimuli, which is attributed to the changed coordination geometries of [Cu(phen)2]+ and [Cu(phen)2]2+ in such system.
-
Supramolecular Polymer Cross-Linked by Discrete Tris-[2]Pseudorotaxane Metallacycles and Its Redox-Responsive Behavior
2018Co-Authors: Xuqing Wang, Lijun Chen, Guangqiang Yin, Bo Jiang, Haibo YangAbstract:A new discrete hexagonal metallacycle M containing tris-[2]Pseudorotaxane moiety has been successfully designed and synthesized via coordination-driven self-assembly. The newly designed tris-[2]Pseudorotaxane metallacycle was well characterized with nuclear magnetic resonance and mass spectra analysis. Such tris-[2]Pseudorotaxane metallacycle M and pillar[5]arene dimer (PD) could further form a new family of cross-linked redox-responsive supramolecular polymer M⊃(PD)3 through a host–guest interaction. Interestingly, the polymer M⊃(PD)3 displayed redox-responsive behavior and showed tuned weight-average diffusion coefficients D upon redox stimuli, which is attributed to the changed coordination geometries of [Cu(phen)2]+ and [Cu(phen)2]2+ in such system
Xuqing Wang - One of the best experts on this subject based on the ideXlab platform.
-
supramolecular polymer cross linked by discrete tris 2 Pseudorotaxane metallacycles and its redox responsive behavior
Inorganic Chemistry, 2018Co-Authors: Xuqing Wang, Lijun Chen, Guangqiang Yin, Bo Jiang, Haibo YangAbstract:A new discrete hexagonal metallacycle M containing tris-[2]Pseudorotaxane moiety has been successfully designed and synthesized via coordination-driven self-assembly. The newly designed tris-[2]Pseudorotaxane metallacycle was well characterized with nuclear magnetic resonance and mass spectra analysis. Such tris-[2]Pseudorotaxane metallacycle M and pillar[5]arene dimer (PD) could further form a new family of cross-linked redox-responsive supramolecular polymer M⊃(PD)3 through a host–guest interaction. Interestingly, the polymer M⊃(PD)3 displayed redox-responsive behavior and showed tuned weight-average diffusion coefficients D upon redox stimuli, which is attributed to the changed coordination geometries of [Cu(phen)2]+ and [Cu(phen)2]2+ in such system.
-
Supramolecular Polymer Cross-Linked by Discrete Tris-[2]Pseudorotaxane Metallacycles and Its Redox-Responsive Behavior
2018Co-Authors: Xuqing Wang, Lijun Chen, Guangqiang Yin, Bo Jiang, Haibo YangAbstract:A new discrete hexagonal metallacycle M containing tris-[2]Pseudorotaxane moiety has been successfully designed and synthesized via coordination-driven self-assembly. The newly designed tris-[2]Pseudorotaxane metallacycle was well characterized with nuclear magnetic resonance and mass spectra analysis. Such tris-[2]Pseudorotaxane metallacycle M and pillar[5]arene dimer (PD) could further form a new family of cross-linked redox-responsive supramolecular polymer M⊃(PD)3 through a host–guest interaction. Interestingly, the polymer M⊃(PD)3 displayed redox-responsive behavior and showed tuned weight-average diffusion coefficients D upon redox stimuli, which is attributed to the changed coordination geometries of [Cu(phen)2]+ and [Cu(phen)2]2+ in such system
Xuzhou Yan - One of the best experts on this subject based on the ideXlab platform.
-
n Pseudorotaxanes n 2 3 from self assembly of two cryptands and a 1 2 bis 4 pyridinium ethane derivative
European Journal of Organic Chemistry, 2012Co-Authors: Xuzhou Yan, Peifa Wei, Mingming Zhang, Xiaodong Chi, Feihe HuangAbstract:Efficient host–guest complexation and interesting self-assembled structures formed between two crown ether-based cryptands and a 1,2-bis(4-pyridinium)ethane derivative 3 are reported. By self-assembly of cis-dibenzo-24-crown-8-based cryptand 1 and guest 3, a [3]Pseudorotaxane was formed in solution, which further formed a supramolecular poly[3]Pseudorotaxane structure in the solid state driven by π-π stacking interactions. Meanwhile, a [2]Pseudorotaxane, obtained from self-assembly of a bis(m-phenylene)-32-crown-10-based cryptand 2 and guest 3, can form a supramolecular poly[2]Pseudorotaxane structure in the solid state. This difference in the binding model reflects the diversity of host–guest chemistry of crown ether-based cryptands. Furthermore, these host–guest recognition processes and self-assembled structures were fully characterized by 1H NMR, UV/Vis spectroscopy, electrospray ionization mass spectrometry, and single-crystal X-ray analysis. Interestingly, formation of the [3]Pseudorotaxane between cryptand 1 and guest 3 can be reversibly controlled by adding and removing potassium cations in acetone. This reversible complexation process provides a simple on/off mechanism that can be used in the construction of controllable molecular switches.
-
a chemical responsive bis m phenylene 32 crown 10 2 7 diazapyrenium salt 2 Pseudorotaxane
Chemical Communications, 2012Co-Authors: Xuzhou Yan, Peifa Wei, Mingming Zhang, Feihe HuangAbstract:A chemical-responsive bis(m-phenylene)-32-crown-10/2,7-diazapyrenium salt [2]Pseudorotaxane was prepared. It was found to form a supramolecular poly[2]Pseudorotaxane in the solid state driven by π–π stacking interactions.
-
A chemical-responsive bis(m-phenylene)-32-crown-10/2,7-diazapyrenium salt [2]Pseudorotaxane
Chemical communications (Cambridge England), 2012Co-Authors: Xuzhou Yan, Peifa Wei, Mingming Zhang, Feihe HuangAbstract:A chemical-responsive bis(m-phenylene)-32-crown-10/2,7-diazapyrenium salt [2]Pseudorotaxane was prepared. It was found to form a supramolecular poly[2]Pseudorotaxane in the solid state driven by π–π stacking interactions.
-
[2]Pseudorotaxanes based on the recognition of cryptands to vinylogous viologens.
Organic letters, 2011Co-Authors: Xuzhou Yan, Peifa Wei, Mingming Zhang, Xiaodong Chi, Jiyong Liu, Feihe HuangAbstract:Host–guest complexation between two crown ether-based cryptands and two vinylogous viologens has been studied. Formation of [2]Pseudorotaxanes from a dibenzo-24-crown-8-based cryptand and these vinylogous viologens can be reversibly controlled by adding and removing potassium cation in acetone. Furthermore, the complexation between a bis(m-phenylene)-32-crown-10-based cryptand and a vinylogous viologen exhibits a high association constant, 1.18 × 106 M–1 in acetone, and leads to the formation of a supramolecular poly[2]Pseudorotaxane in the solid state.
J. Fraser Stoddart - One of the best experts on this subject based on the ideXlab platform.
-
Kinetically controlled self-assembly of Pseudorotaxanes on crystallization.
Organic letters, 2006Co-Authors: Brian H. Northrop, Saeed J. Khan, J. Fraser StoddartAbstract:Mixing of equimolar amounts of cyclobis(paraquat-p-phenylene) (CBPQT4+) with a bis-4-methylphenyl ether (MPE twice) of a 1,5-dioxynaphthalene (DNP) derivative in MeCN/CH2Cl2 (3:1) results in the formation of a [2]Pseudorotaxane which, on crystallization, yields a [4]Pseudorotaxane in the solid state that is stabilized by multiple [C−H···F] interactions: a mixture of the same components in a 1:3 ratio affords a crystalline [2]Pseudorotaxane after vapor diffusion of methyl-tert-butyl ether into a solution of these components in MeCN/CH2Cl2 (3:1).
-
In the twilight zone between [2]Pseudorotaxanes and [2]rotaxanes.
Chemistry (Weinheim an der Bergstrasse Germany), 2003Co-Authors: Jan O. Jeppesen, Scott A. Vignon, J. Fraser StoddartAbstract:A [2]Pseudorotaxane, based on a semi-dumbbell-shaped component containing asymmetrically substituted monopyrrolotetrathiafulvalene and 1,5-dioxynaphthalene recognition sites for encirclement by cyclobis(paraquat-p-phenylene) and with a "speed bump" in the form of a thiomethyl group situated between the two recognition sites, has been self-assembled. This supramolecular entity is a mixture in solution of two slowly interconverting [2]Pseudorotaxanes, one of which is on the verge of being a [2]rotaxane at room temperature, allowing it to be isolated by employing flash column chromatography. These two [2]Pseudorotaxanes were both characterized in solution by UV/Vis and 1 H NMR spectroscopies (1D and 2D) and also by differential pulse voltammetry. The spectroscopic and electrochemical data reveal that one of the complexes behaves wholly as a [2]Pseudorotaxane, while the other has some [2]rotaxane character to it. The kinetics of the shuttling of cyclobis(paraquat-p-phenylene) between the monopyrrolotetrathiafulvalene and the 1,5-dioxynaphthalene recognition sites have been investigated at different temperatures. The shuttling processes, which are accompanied by detectable color changes, can be monitored using UV/Vis and 1 H NMR spectroscopies; the spectroscopic data have been employed in the determination of the rate constants, free energies of activation, enthalpies of activation, and the entropies of activation for the translation of cyclobis(paraquat-p-phenylene) between the two recognition sites.
-
X-ray Crystallographic Studies on the Noncovalent Syntheses of Supermolecules
Structural Chemistry, 1999Co-Authors: Matthew C. T. Fyfe, J. Fraser Stoddart, David J. WilliamsAbstract:An approach to the supramolecular syntheses of discrete multicomponent aggregates of noncovalently bound molecules, i.e., supermolecules, is described. This approach involved the careful analysis of X-ray crystal structures so as to permit a gradual increase in superstructural complexity. Many elaborate supermolecules were synthesized noncovalently from dialkylammonium-containing cations and crown ethers, following the initial observation that the dibenzylammonium ion threads through dibenzo[24]crown-8 to generate a singly stranded, singly encircled [2]Pseudorotaxane, principally as a result of $$[{\text{N}}^{\text{ + }} - {\text{H}} \cdot \cdot \cdot {\text{O}}]$$ and $$[{\text{C}} - {\text{H}} \cdot \cdot \cdot {\text{O}}]$$ hydrogen bond formation. The scope of the fundamental recognition motif obtained from this initial observation was then broadened, through the use of thread-like ions with multiple dialkylammonium centers and/or larger crown ethers, so that multiply stranded and/or multiply encircled Pseudorotaxanes could be prepared. Cations bearing both dialkylammonium and crown ether recognition sites were also used for the nocovalent synthesis of a discrete daisy chain supermacrocycle and the basic recognition motif was combined with other motifs for the production of a wide range of novel superarchitectures. As a greater understanding of the noncovalent interactions governing the self-assembly of the complex superarchitectures was acquired, new protocols for the noncovalent syntheses of doubly docked Pseudorotaxanes and interwoven supramolecular bundles, including a supramolecular analogue of the photosynthetic special pair, were developed. The discovery that anions can play a prominent role in the solid-state self-assembly of some of the supermolecules was a valuable spinoff of the research.
-
Interwoven supramolecular arrays via the noncovalent polymerization of Pseudorotaxanes
Coordination Chemistry Reviews, 1999Co-Authors: Matthew C. T. Fyfe, J. Fraser StoddartAbstract:Abstract This review describes how the noncovalent polymerization of Pseudorotaxanes—inclusion complexes in which thread-like molecules or ions interpenetrate macrorings’ central cavities without the formation of a mechanical bond—leads to the production of interwoven supramolecular arrays in the solid state. The noncovalent synthesis of these polymeric supramolecular architectures requires the independent and simultaneous operation of at least two different orthogonal recognition algorithms, viz. a threading algorithm, for the formation of the Pseudorotaxane, and a noncovalent polymerization algorithm, that permits interPseudorotaxane association in the crystal. The information required for the operation of these orthogonal recognition algorithms is preprogrammed into the covalent frameworks of the interwoven supramolecular arrays’ precursors. Several different types of intermolecular interactions have been employed by crystal engineers for the noncovalent synthesis of interwoven supramolecular arrays in the solid state, in particular, metal–ligand, π – π stacking and hydrogen bonding interactions.
-
Doubly Docked Pseudorotaxanes
Chemistry - A European Journal, 1998Co-Authors: Peter R. Ashton, J. Fraser Stoddart, Matthew C. T. Fyfe, M.‐victoria Martínez‐díaz, Stephan Menzer, Cesare Schiavo, Andrew J. P. White, David J. WilliamsAbstract:The snug fit of two suitably spaced dialkylammonium centers within the cavity of the macrocyclic polyether bis-p-phenylene[34]crown-10 (BPP34C10) generates [2]Pseudorotaxanes in which each cationic ammonium center “docks” with one of the macrocycle's two polyether loops (right), for the most part by means of hydrogen bonds. One such doubly docked [2]Pseudorotaxane forms the basis of a prototypical chromophoric supramolecular switch triggered by alterations to the surrounding pH.
