共查询到20条相似文献,搜索用时 31 毫秒
1.
Xin Wu Jennifer R. Small Alessio Cataldo Anne M. Withecombe Peter Turner Philip A. Gale 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(42):15286-15291
Synthetic anion transporters that facilitate transmembrane H+/Cl? symport (cotransport) have anti‐cancer potential due to their ability to neutralize pH gradients and inhibit autophagy in cells. However, compared to the natural product prodigiosin, synthetic anion transporters have low‐to‐modest H+/Cl? symport activity and their mechanism of action remains less well understood. We report a chloride‐selective tetraurea macrocycle that has a record‐high H+/Cl? symport activity similar to that of prodigiosin and most importantly demonstrates unprecedented voltage‐switchable transport properties that are linked to the lack of uniport activity. By studying the anion binding affinity and transport mechanisms of four other anion transporters, we show that the lack of uniport and voltage‐dependent H+/Cl? symport originate from strong binding to phospholipid headgroups that hampers the diffusion of the free transporters through the membrane, leading to an unusual H+/Cl? symport mechanism that involves only charged species. Our work provides important mechanistic insights into different classes of anion transporters and a new approach to achieve voltage‐switchability in artificial membrane transport systems. 相似文献
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3.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(24):6952-6956
A near‐infrared (NIR) polymethine dye ( 1 ), consisting of a cyclohepta[1,2‐b ;4,3‐b′ ]dithiophene and two phenol moieties, was synthesized. This dye exhibited pH‐responsive changes in its photophysical properties due to a two‐step acid–base equilibrium that produced a protonated cation ( 1H+ ) and an anion ( 1− ). While 1H+ showed an intense fluorescence in the red region of the visible spectrum, 1− exhibited a strong absorption in the NIR region. The tropylium ion character in 1H+ induces high pK a1 and pK a2 values for 1 . Moreover, a stable radical ( 1. ) was prepared, which showed a NIR absorption band with a maximum at circa 1600 nm. The cyclic voltammogram of 1. revealed a two‐step reversible redox process that produced 1− and the cation 1+ , which is different from 1H+ . These redox processes accompany drastic electrochromic changes in the vis–NIR region. Overall, 1 is susceptible to multiple interconversions between five forms, due to the multifaceted character of the cycloheptadithiophene skeleton. 相似文献
4.
Sheng‐Run Zheng Yue‐Peng Cai Xue‐Li Zhang Cheng‐Yong Su 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(11):o642-o644
The title compound, C16H16N5+·Cl− (nbbH+·Cl−), displays N—H⋯N, N—H⋯Cl and π–π interactions in the crystal packing. The Cl− anion is chelated by the nbbH+ cation via two N—H⋯Cl hydrogen bonds. Inter‐ion N—H⋯N and N—H⋯Cl hydrogen bonds link ions related by 21 screw axes into chains along the c axis. These chains are further linked by glide‐plane operations to generate a three‐dimensional network, which is additionally stabilized by interchain π–π interactions. 相似文献
5.
Maksymilian Chruszcz Marcin Cymborowski Anna Gawlicka‐Chruszcz Shoichi Yasukawa Joseph D. Ferrara Wladek Minor 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(12):o868-o871
The crystal structures of the title compounds, (S)‐1‐carboxy‐3‐(methylsulfanyl)propanaminium chloride, C5H12NO2S+·Cl−, and (S)‐1‐carboxy‐3‐(methylselanyl)propanaminium chloride, C5H12NO2Se+·Cl−, are isomorphous. The protonated l ‐methionine and l ‐selenomethionine molecules have almost identical conformations and create very similar contacts with the Cl− anions in the crystal structures of both compounds. The amino acid cations and the Cl− anions are linked viaN—H⋯Cl− and O—H⋯Cl− hydrogen bonds. 相似文献
6.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2018,130(17):4606-4610
An experimental study on protonation of simple weakly basic molecules (L) by the strongest solid superacid, H(CHB11F11), showed that basicity of SO2 is high enough (during attachment to the acidic H atoms at partial pressure of 1 atm) to break the bridged H‐bonds of the polymeric acid and to form a mixture of solid mono‐ LH+⋅⋅⋅An−, and disolvates, L−H+−L. With a decrease in the basicity of L=CO (via C), N2O, and CO (via O), only proton monosolvates are formed, which approach L−H+−An− species with convergence of the strengths of bridged H‐bonds. The molecules with the weakest basicity, such as CO2 and weaker, when attached to the proton, cannot break the bridged H‐bond of the polymeric superacid, and the interaction stops at stage of physical adsorption. It is shown here that under the conditions of acid monomerization, it is possible to protonate such weak bases as CO2, N2, and Xe. 相似文献
7.
Amanda R. Buist Alan R. Kennedy 《Acta Crystallographica. Section C, Structural Chemistry》2016,72(2):155-160
Carbamazepine (CBZ) is well known as a model active pharmaceutical ingredient used in the study of polymorphism and the generation and comparison of cocrystal forms. The pharmaceutical amide dihydrocarbamazepine (DCBZ) is a less well known material and is largely of interest here as a structural congener of CBZ. Reaction of DCBZ with strong acids results in protonation of the amide functionality at the O atom and gives the salt forms dihydrocarbamazepine hydrochloride {systematic name: [(10,11‐dihydro‐5H‐dibenzo[b,f]azepin‐5‐yl)(hydroxy)methylidene]azanium chloride, C15H15N2O+·Cl−}, dihydrocarbamazepine hydrochloride monohydrate {systematic name: [(10,11‐dihydro‐5H‐dibenzo[b,f]azepin‐5‐yl)(hydroxy)methylidene]azanium chloride monohydrate, C15H15N2O+·Cl−·H2O} and dihydrocarbamazepine hydrobromide monohydrate {systematic name: [(10,11‐dihydro‐5H‐dibenzo[b,f]azepin‐5‐yl)(hydroxy)methylidene]azanium bromide monohydrate, C15H15N2O+·Br−·H2O}. The anhydrous hydrochloride has a structure with two crystallographically independent ion pairs (Z′ = 2), wherein both cations adopt syn conformations, whilst the two hydrated species are mutually isostructural and have cations with anti conformations. Compared to neutral dihydrocarbamazepine structures, protonation of the amide group is shown to cause changes to both the molecular (C=O bond lengthening and C—N bond shortening) and the supramolecular structures. The amide‐to‐amide and dimeric hydrogen‐bonding motifs seen for neutral polymorphs and cocrystalline species are replaced here by one‐dimensional polymeric constructs with no direct amide‐to‐amide bonds. The structures are also compared with, and shown to be closely related to, those of the salt forms of the structurally similar pharmaceutical carbamazepine. 相似文献
8.
Han Shen Ian M. Steele Richard F. Jordan 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(10):m405-m406
In the crystal structure of the title compound, [LiPd2Cl4(C12H12N2)2](C24F20B)·1.196CD2Cl2 or [{(Me2bipy)PdCl2}2(μ‐Li)]+·B(C6F5)4−·1.196CD2Cl2 (Me2bipy is 4,4′‐dimethyl‐2,2′‐bipyridine), an Li+ cation is stabilized by complexation with two (Me2bipy)PdCl2 units through weak Li—Cl interactions. This compound is thus a rare example of a complex that exhibits an arrested Cl− abstraction. 相似文献
9.
Jan Tillmann Hans‐Wolfram Lerner Michael Bolte 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(10):883-888
The crystal structures of four substituted‐ammonium dichloride dodecachlorohexasilanes are presented. Each is crystallized with a different cation and one of the structures contains a benzene solvent molecule: bis(tetraethylammonium) dichloride dodecachlorohexasilane, 2C8H20N+·2Cl−·Cl12Si6, (I), tetrabutylammonium tributylmethylammonium dichloride dodecachlorohexasilane, C16H36N+·C13H30N+·2Cl−·Cl12Si6, (II), bis(tetrabutylammonium) dichloride dodecachlorohexasilane benzene disolvate, 2C16H36N+·2Cl−·Cl12Si6·2C6H6, (III), and bis(benzyltriphenylphosphonium) dichloride dodecachlorohexasilane, 2C25H22P+·2Cl−·Cl12Si6, (IV). In all four structures, the dodecachlorohexasilane ring is located on a crystallographic centre of inversion. The geometry of the dichloride dodecachlorohexasilanes in the different structures is almost the same, irrespective of the cocrystallized cation and solvent. However, the crystal structure of the parent dodecachlorohexasilane molecule shows that this molecule adopts a chair conformation. In (IV), the P atom and the benzyl group of the cation are disordered over two sites, with a site‐occupation factor of 0.560 (5) for the major‐occupied site. 相似文献
10.
Harri Sopo Reijo Sillanp 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(7):o386-o388
In the title compound, C30H48NO3+·Cl−·H2O, the cation acts with a water molecule as a chloride ion receptor. The chloride ion forms three strong intramolecular hydrogen bonds. The water molecule forms both an intramolecular bridge between one phenol H atom and the chloride ion, and an intermolecular link to the aliphatic alcohol O atom. Weak intermolecular C—H...Cl and C—H ...O hydrogen bonds provide additional packing interactions. 相似文献
11.
Si‐Si Feng Li‐Ping Lu Shu‐Xia Wang Li Li Miao‐Li Zhu 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(3):m105-m108
The title compound, [FeCl2(C24H21N7)]Cl·C2H5OH·2H2O, comprises an [FeCl2(C24H21N7)]+ cation, a Cl− anion, an ethanol molecule and two water molecules. The cations are linked by π–π and C—H⋯π interactions into one‐dimensional tapes, and hydrogen bonding between the cations, Cl− anions, and ethanol and water molecules links these tapes into a three‐dimensional network. 相似文献
12.
Sndor L. Bek David Urmann Andrea Lakatos Clemens Glaubitz Martin U. Schmidt 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(3):o144-o148
Nimustine hydrochloride [systematic name: 4‐amino‐5‐({[N‐(2‐chloroethyl)‐N‐nitrosocarbamoyl]amino}methyl)‐2‐methylpyrimidin‐1‐ium chloride], C9H14ClN6O2+·Cl−, is a prodrug of CENU (chloroethylnitrosourea) and is used as a cytostatic agent in cancer therapy. Its crystal structure was determined from laboratory X‐ray powder diffraction data. The protonation at an N atom of the pyrimidine ring was established by solid‐state NMR spectroscopy. 相似文献
13.
Dubravka Matkovi‐alogovi Zora Popovi Vesna Trali‐Kulenovi Livio Racan Grace Karminski‐Zamola 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(4):o190-o191
The title compound, C8H8N3S+·Cl−·2H2O, has been synthesized and characterized both spectroscopically and structurally. The structure consists of 1,3‐benzothiazole‐6‐carboxamidinium cations, chloride anions and water molecules, all interconnected by hydrogen bonds into a three‐dimensional network. The 1,3‐benzothiazole moiety is inclined to the 6‐amidine group by 36.71 (9)°. 相似文献
14.
Delphine Firley Bernard Fraisse Fatima Zouhiri Anne Spasojevi‐de Bir Didier Desmaële Jean D'Angelo Nour Eddine Ghermani 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(3):o154-o157
Both 7‐carboxylato‐8‐hydroxy‐2‐methylquinolinium monohydrate, C11H9NO3·H2O, (I), and 7‐carboxy‐8‐hydroxy‐2‐methylquinolinium chloride monohydrate, C11H10NO3+·Cl−·H2O, (II), crystallize in the centrosymmetric P space group. Both compounds display an intramolecular O—H⋯O hydrogen bond involving the hydroxy group; this hydrogen bond is stronger in (I) due to its zwitterionic character [O⋯O = 2.4449 (11) Å in (I) and 2.5881 (12) Å in (II)]. In both crystal structures, the HN+ group participates in the stabilization of the structure via intermolecular hydrogen bonds with water molecules [N⋯O = 2.7450 (12) Å in (I) and 2.8025 (14) Å in (II)]. In compound (II), a hydrogen‐bond network connects the Cl− anion to the carboxylic acid group [Cl⋯O = 2.9641 (11) Å] and to two water molecules [Cl⋯O = 3.1485 (10) and 3.2744 (10) Å]. 相似文献
15.
T. Vijay T. Narasimhamurthy H. S. Yathirajan R. S. Rathore P. Nagaraja 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(1):o36-o38
In the crystal structure of the title salt, C7H7Cl2N2O2+·Cl−, the chloride anions participate in extensive hydrogen bonding with the aminium cations and indirectly link the molecules through multiple N+—H⋯Cl− salt bridges. There are two independent molecules in the asymmetric unit, related by a pseudo‐inversion center. The direct intermolecular coupling is established by C—H⋯O, C—H⋯Cl and C—Cl⋯Cl− interactions. A rare three‐center (donor bifurcated) C—H⋯(O,O) hydrogen bond is observed between the methylene and nitro groups, with a side‐on intramolecular component of closed‐ring type and a head‐on intermolecular component. 相似文献
16.
Zdenk Trvní
ek Igor Popa Karel Doleal 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(9):o662-o664
The title compound, C13H14N5O+·Cl−, belongs to the group of aromatic cytokinins. These compounds affect a variety of important physiological processes in plants and animals as well as in bacteria, including cell division, differentiation and senescence. The structure consists of a 6‐(4‐methoxybenzylamino)purinium cation and a Cl− anion. The cation moiety exists as the N3‐protonated N7 tautomer. The cation contains nearly planar benzene and purine ring systems, with a dihedral angle of 77.46 (5)°. The crystal structure is stabilized by Namino—H⋯Npurine hydrogen bonds connecting two adjacent molecules, thus forming centrosymmetric dimers. 相似文献
17.
Horst Schmidt Bernhard Euler Wolfgang Voigt Gerhard Heide 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(9):i57-i59
The title compound, lithium magnesium chloride heptahydrate, LiCl·MgCl2·7H2O, was analyzed in 1988 by powder X‐ray diffraction [Emons, Brand, Pohl & Köhnke (1988). Z. Anorg. Allg. Chem. 563 , 180–184] and a monoclinic crystal lattice was determined. In the present work, the structure was solved from single‐crystal diffraction data. A trigonal structure was found, exhibiting a network structure of Mg(H2O)6 octahedra and Li(H2O)Cl3 tetrahedra connected by H...Cl hydrogen bonds. The [Li(H2O)]+ unit is coordinated by distorted edge‐connected Cl− octahedra. 相似文献
18.
Xing‐Chen Yan Yu‐Hua Fan Cai‐Feng Bi Xia Zhang Zhong‐Yu Zhang 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(1):61-65
The contributions of the amino and imino resonance forms to the ground‐state structures of 2‐amino‐4‐methylpyridinium nitrate, C6H9N2+·NO3−, and the previously reported 2‐amino‐5‐methylpyridinium nitrate [Yan, Fan, Bi, Zuo & Zhang (2012). Acta Cryst. E 68 , o2084], were studied using a combination of IR spectroscopy, X‐ray crystallography and density functional theory (DFT). The results show that the structures of 2‐amino‐4‐methylpyridine and 2‐amino‐5‐methylpyridine obtained upon protonation are best described as existing largely in the imino resonance forms. 相似文献
19.
Jürgen Brüning Dragica Podgorski Edith Alig Jan W. Bats Martin U. Schmidt 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(3):o111-o113
Single crystals of the anhydrous form of the title compound {systematic name: 1‐[3‐(dimethylcarbamoyl)‐3,3‐diphenylpropyl]‐4‐hydroxy‐4‐(4‐chlorophenyl)piperidin‐1‐ium chloride}, C29H34ClN2O2+·Cl−, were obtained by diffusion of acetone into a solution in 2‐propanol. In the structure, N—H...Cl− and O—H...Cl− hydrogen bonds connect neighbouring molecules and chloride anions to form chains along the c‐axis direction. Neighbouring chains along the b‐axis direction are connected by intermolecular C—H...Cl− contacts, defining layers parallel to the (100) planes. The layers are connected by weak intermolecular C—H...Cl interactions only, which may account for the plate‐like shape of the crystals. 相似文献
20.
Jürgen Brüning Alexander Peters Jan W. Bats Martin U. Schmidt 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(1):o1-o4
Single crystals of the title compound, C9H10N3O3+·Cl−·H2O, were obtained by recrystallization from hydrochloric acid. The cations stack along the crystallographic a direction. The 2,3‐dioxo‐1,4‐dihydroquinoxaline group shows a significant deviation from planarity [r.m.s. deviation from the best plane = 0.063 (2) Å]. Hydrogen bonding links the cations, chloride anions and water molecules to form an extended three‐dimensional architecture. 相似文献