The Experts below are selected from a list of 206097 Experts worldwide ranked by ideXlab platform
Feihe Huang - One of the best experts on this subject based on the ideXlab platform.
-
constructing adaptive photosensitizers via supramolecular modification based on pillararene host guest interactions
Angewandte Chemie, 2020Co-Authors: Li Shao, Feihe Huang, Bin Hua, Yutong Pan, Mengbin Wang, Bin LiuAbstract: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.
-
cyclic ether contaminant removal from water using nonporous adaptive pillararene crystals via host guest Complexation at the solid solution interface
Research (Washington D.C.), 2019Co-Authors: Yujuan Zhou, Kecheng Jie, Run Zhao, Feihe HuangAbstract:The removal of soluble cyclic ether contaminants, such as dioxane and THF, produced in industrial chemical processes from water is of great importance for environmental protection and human health. Here we report that nonporous adaptive crystals of perethylated pillar[5]arene (EtP5) and pillar[6]arene (EtP6) work as adsorbents for cyclic ether contaminant removal via Host-Guest Complexation at the solid-solution interface. Nonporous EtP6 crystals have the ability to adsorb dioxane from water with the formation of 1:2 Host-Guest Complex crystals, while EtP5 crystals cannot. However, both guest-free EtP5 and EtP6 crystals remove THF from water with EtP5 having a better capacity. This is because EtP5 forms a 1:2 Host-Guest Complex with THF via Host-Guest Complexation at the solid-solution interface while EtP6 forms a 1:1 Host-Guest Complex with THF. EtP6 also shows the ability to selectively remove dioxane from water even in the presence of THF. Moreover, the reversible transitions between nonporous guest-free EtP5 and EtP6 structures and guest-loaded structures make them highly recyclable.
-
supramolecular solid state microlaser constructed from pillar 5 arene based host guest Complex microcrystals
Journal of the American Chemical Society, 2018Co-Authors: Bin Hua, Li Shao, Wei Zhou, Zhaoliang Yang, Zhihua Zhang, Haiming Zhu, Feihe HuangAbstract:Herein we report a novel host–guest Complex single crystal material based on a pillar[5]arene (P5) and a laser dye trans-4-[p-(dimethylamino)styryl]-1-methylpyridinium iodide (DASP). Single crystal structure characterization shows that two P5 molecules act as a supramolecular nanocapsule for one isolated DASP molecule. This spatial confinement effectively restricts aggregation-caused quenching (ACQ) effects and other nonradiative channels (e.g., twisted intramolecular charge transfer), leading to high luminescent efficiency of the isolated DASP. Together with its regular shape and smooth surface, each 2P5⊃DASP microcrystal forms a Fabry-Perot (F–P) microcavity and produces a stable laser output with a high Q factor and a low threshold.
-
taco Complex templated highly regio and stereo selective photodimerization of a coumarin containing crown ether
Chemical Communications, 2017Co-Authors: Peifa Wei, Kecheng Jie, Haoze Wang, Feihe HuangAbstract:Preorientation of the terminal coumarins of a crown ether with the assistance of taco-type host–guest Complex formation promotes regio- and stereo-selectivity of coumarin photodimerization to give only the syn head-to-tail coumarin isomer.
-
redox responsive amphiphilic macromolecular 2 pseudorotaxane constructed from a water soluble pillar 5 arene and a paraquat containing homopolymer
ACS Macro Letters, 2015Co-Authors: Xiaodong Chi, Guping Tang, Feihe HuangAbstract:Here we report a redox-responsive host–guest Complex between a new water-soluble pillar[5]arene (WP5) and a paraquat derivative. Compared with the neutral form of the paraquat derivative that binds WP5 weakly, its dication form binds WP5 much more strongly. Furthermore, we utilize this new water-soluble redox-responsive molecular recognition motif to construct the first pillararene-based amphiphilic macromolecular [2]pseudorotaxane, which self-assembles into redox-responsive polymeric vesicles in water. Such pillararene-based supramolecular vesicles were further used to construct a drug delivery system to encapsulate and controlled release DOX·HCl, an anticancer drug. The uptake of these DOX·HCl-loaded supramolecular vesicles by cancer cells was studied with confocal laser scanning microscopy. Meanwhile, DOX·HCl-loaded supramolecular vesicles showed anticancer activity in vitro comparable to free DOX·HCl under the examined conditions.
Donal H. Macartney - One of the best experts on this subject based on the ideXlab platform.
-
cucurbit 7 uril host guest Complexes of the histamine h2 receptor antagonist ranitidine
Organic and Biomolecular Chemistry, 2008Co-Authors: Ruibing Wang, Donal H. MacartneyAbstract:The macrocyclic host cucurbit[7]uril forms very stable Complexes with the diprotonated (K(CB[7])(1) = 1.8 x 10(8) dm(3) mol(-1)), monoprotonated (K(CB[7])(2) = 1.0 x 10(7) dm(3) mol(-1)), and neutral (K(CB[7])(3) = 1.2 x 10(3) dm(3) mol(-1)) forms of the histamine H(2)-receptor antagonist ranitidine in aqueous solution. The Complexation behaviour was investigated using (1)H NMR and UV-visible spectroscopy as a function of pH and the pK(a) values of the guest were observed to increase (DeltapK(a1) = 1.5 and DeltapK(a2) = 1.6) upon Host-Guest Complex formation. The energy-minimized structures of the Host-Guest Complexes with the cationic guests were determined and provide agreement with the NMR results indicating the location of the CB[7] over the central portion of the guest. The inclusion of the monoprotonated form of ranitidine slows the normally rapid (E)-(Z) exchange process and generates a preference for the (Z) isomer. The formation of the CB[7] Host-Guest Complex greatly increases the thermal stability of ranitidine in acidic aqueous solution at 50 degrees C, but has no effect on its photochemical reactivity.
-
cucurbit 7 uril host guest Complexes of the histamine h2 receptor antagonist ranitidine
Organic and Biomolecular Chemistry, 2008Co-Authors: Ruibing Wang, Donal H. MacartneyAbstract:The macrocyclic host cucurbit[7]uril forms very stable Complexes with the diprotonated (KCB[7]1 = 1.8 × 108 dm3 mol−1), monoprotonated (KCB[7]2 = 1.0 × 107 dm3 mol−1), and neutral (KCB[7]3 = 1.2 × 103 dm3 mol−1) forms of the histamine H2-receptor antagonist ranitidine in aqueous solution. The Complexation behaviour was investigated using 1H NMR and UV–visible spectroscopy as a function of pH and the pKa values of the guest were observed to increase (ΔpKa1 = 1.5 and ΔpKa2 = 1.6) upon host–guest Complex formation. The energy-minimized structures of the host–guest Complexes with the cationic guests were determined and provide agreement with the NMR results indicating the location of the CB[7] over the central portion of the guest. The inclusion of the monoprotonated form of ranitidine slows the normally rapid (E)–(Z) exchange process and generates a preference for the (Z) isomer. The formation of the CB[7] host–guest Complex greatly increases the thermal stability of ranitidine in acidic aqueous solution at 50 °C, but has no effect on its photochemical reactivity.
-
Cucurbit[7]uril stabilization of a diarylmethane carbocation in aqueous solution
Tetrahedron Letters, 2008Co-Authors: Ruibing Wang, Donal H. MacartneyAbstract:Abstract The stability of the 4,4′-bis(dimethylamino)diphenylmethane carbocation is significantly enhanced in aqueous solution by its inclusion in the cucurbit[7]uril host cavity. The formation of the host–guest Complex (KCB[7] = 2.0 × 104 M−1) shifts the carbinol–carbocation equilibrium, maximizing the formation of the intensely blue carbocation to 90% at pH 5.2.
Ruibing Wang - One of the best experts on this subject based on the ideXlab platform.
-
Inclusion Complexes of coumarin in cucurbiturils.
Organic & biomolecular chemistry, 2009Co-Authors: Ruibing Wang, David Bardelang, Mélanie Waite, Konstantin A. Udachin, Donald M. Leek, Christopher I. Ratcliffe, John A. RipmeesterAbstract:Coumarin was found to form stable inclusion Complexes with cucurbiturils. In the presence of cucurbit[7]uril (CB[7]), 1 : 1 inclusion Complexes were observed in aqueous solution, as monitored by (1)H NMR and UV-visible absorption spectroscopies, and further supported by ab initio calculations, whereas with cucurbit[8]uril (CB[8]) a solid phase 1 : 2 host : guest Complex was found in a single crystal X-ray diffraction structure determination.
-
cucurbit 7 uril host guest Complexes of the histamine h2 receptor antagonist ranitidine
Organic and Biomolecular Chemistry, 2008Co-Authors: Ruibing Wang, Donal H. MacartneyAbstract:The macrocyclic host cucurbit[7]uril forms very stable Complexes with the diprotonated (KCB[7]1 = 1.8 × 108 dm3 mol−1), monoprotonated (KCB[7]2 = 1.0 × 107 dm3 mol−1), and neutral (KCB[7]3 = 1.2 × 103 dm3 mol−1) forms of the histamine H2-receptor antagonist ranitidine in aqueous solution. The Complexation behaviour was investigated using 1H NMR and UV–visible spectroscopy as a function of pH and the pKa values of the guest were observed to increase (ΔpKa1 = 1.5 and ΔpKa2 = 1.6) upon host–guest Complex formation. The energy-minimized structures of the host–guest Complexes with the cationic guests were determined and provide agreement with the NMR results indicating the location of the CB[7] over the central portion of the guest. The inclusion of the monoprotonated form of ranitidine slows the normally rapid (E)–(Z) exchange process and generates a preference for the (Z) isomer. The formation of the CB[7] host–guest Complex greatly increases the thermal stability of ranitidine in acidic aqueous solution at 50 °C, but has no effect on its photochemical reactivity.
-
cucurbit 7 uril host guest Complexes of the histamine h2 receptor antagonist ranitidine
Organic and Biomolecular Chemistry, 2008Co-Authors: Ruibing Wang, Donal H. MacartneyAbstract:The macrocyclic host cucurbit[7]uril forms very stable Complexes with the diprotonated (K(CB[7])(1) = 1.8 x 10(8) dm(3) mol(-1)), monoprotonated (K(CB[7])(2) = 1.0 x 10(7) dm(3) mol(-1)), and neutral (K(CB[7])(3) = 1.2 x 10(3) dm(3) mol(-1)) forms of the histamine H(2)-receptor antagonist ranitidine in aqueous solution. The Complexation behaviour was investigated using (1)H NMR and UV-visible spectroscopy as a function of pH and the pK(a) values of the guest were observed to increase (DeltapK(a1) = 1.5 and DeltapK(a2) = 1.6) upon Host-Guest Complex formation. The energy-minimized structures of the Host-Guest Complexes with the cationic guests were determined and provide agreement with the NMR results indicating the location of the CB[7] over the central portion of the guest. The inclusion of the monoprotonated form of ranitidine slows the normally rapid (E)-(Z) exchange process and generates a preference for the (Z) isomer. The formation of the CB[7] Host-Guest Complex greatly increases the thermal stability of ranitidine in acidic aqueous solution at 50 degrees C, but has no effect on its photochemical reactivity.
-
Cucurbit[7]uril stabilization of a diarylmethane carbocation in aqueous solution
Tetrahedron Letters, 2008Co-Authors: Ruibing Wang, Donal H. MacartneyAbstract:Abstract The stability of the 4,4′-bis(dimethylamino)diphenylmethane carbocation is significantly enhanced in aqueous solution by its inclusion in the cucurbit[7]uril host cavity. The formation of the host–guest Complex (KCB[7] = 2.0 × 104 M−1) shifts the carbinol–carbocation equilibrium, maximizing the formation of the intensely blue carbocation to 90% at pH 5.2.
Xiaodong Chi - One of the best experts on this subject based on the ideXlab platform.
-
redox responsive amphiphilic macromolecular 2 pseudorotaxane constructed from a water soluble pillar 5 arene and a paraquat containing homopolymer
ACS Macro Letters, 2015Co-Authors: Xiaodong Chi, Guping Tang, Feihe HuangAbstract:Here we report a redox-responsive host–guest Complex between a new water-soluble pillar[5]arene (WP5) and a paraquat derivative. Compared with the neutral form of the paraquat derivative that binds WP5 weakly, its dication form binds WP5 much more strongly. Furthermore, we utilize this new water-soluble redox-responsive molecular recognition motif to construct the first pillararene-based amphiphilic macromolecular [2]pseudorotaxane, which self-assembles into redox-responsive polymeric vesicles in water. Such pillararene-based supramolecular vesicles were further used to construct a drug delivery system to encapsulate and controlled release DOX·HCl, an anticancer drug. The uptake of these DOX·HCl-loaded supramolecular vesicles by cancer cells was studied with confocal laser scanning microscopy. Meanwhile, DOX·HCl-loaded supramolecular vesicles showed anticancer activity in vitro comparable to free DOX·HCl under the examined conditions.
-
per hydroxylated pillar 6 arene synthesis x ray crystal structure and host guest Complexation
Organic Letters, 2012Co-Authors: Xiaodong Chi, Xuzhou Yan, Feihe Huang, Weixiang Chen, Jiyong Liu, Yong Yao, Junli HouAbstract:A per-hydroxylated pillar[6]arene was prepared. Single-crystal X-ray analysis demonstrated that its molecules are arranged in an up-to-down manner to form infinite channels in the solid state. Its host–guest Complexation with a series of bispyridinium salts in solution was further investigated. It was found that the per-hydroxylated pillar[6]arene could form a 1:1 Complex with paraquat in acetone with an association constant of 2.2 × 102 M–1. This Complex is a [2]pseudorotaxane as shown by its crystal structure, which is the first pillar[6]arene-based host–guest Complex crystal structure.
-
a cationic water soluble pillar 5 arene synthesis and host guest Complexation with sodium 1 octanesulfonate
Chemical Communications, 2011Co-Authors: Fei Xiang, Chengyou Han, Xiaodong Chi, Zeper Abliz, Weixiang Chen, Feihe HuangAbstract:By the introduction of trimethylammonium groups at both upper and lower rims, a cationic water-soluble pillar[5]arene was prepared, which forms a stable 1:1 host–guest Complex with sodium 1-octanesulfonate in water.
Ayhan S. Demir - One of the best experts on this subject based on the ideXlab platform.
-
proline calixarene thiourea host guest Complex catalyzed enantioselective aldol reactions from nonpolar solvents to the presence of water
ChemInform, 2014Co-Authors: Ezgi Demircan, Serkan Eymur, Ayhan S. DemirAbstract:A combination of a thiourea tagged calixarene and L-proline is disclosed as catalyst for the aldol condensation of cyclohexanone and aromatic aldehydes.
-
proline calixarene thiourea host guest Complex catalyzed enantioselective aldol reactions from nonpolar solvents to the presence of water
Tetrahedron-asymmetry, 2014Co-Authors: Ezgi Demircan, Serkan Eymur, Ayhan S. DemirAbstract:A proline–calix[4]arene thiourea host–guest Complex catalyzed intermolecular aldol reaction of aromatic aldehydes with cyclohexanone has been developed. The anti-configured products were obtained in good yields and with high enantioselectivities. The reaction is proposed to work via a modified Houk–List model, where the carboxylate part of the proline constitutes as a supramolecular system with the thiourea. The outcome of the study indicates the influence of the calix[4]arene thiourea on both the reactivity and selectivity in a non-polar reaction medium, even in the presence of water at moderate temperatures.
-
Synthesis of a bipyridine-derived achiral thiourea trifluoromethanesulfonic acid salt and its application as an additive in organocatalytic asymmetric reactions
Tetrahedron Letters, 2013Co-Authors: Ayhan S. Demir, Sinan BascekenAbstract:Abstract The host–guest Complex of a proline–thiourea bipyridine trifluoromethanesulfonic acid salt can catalyze organocatalytic asymmetric reactions such as aldol, Michael, and Mannich in polar protic medium with high stereoselectivities. The privileged bipyridine backbone and the thiourea motif are essential to the activity and enantioselectivity through hydrogen bonding interactions.