Relevant bibliographies by topics / Anion / Journal articles

Journal articles on the topic 'Anion'

To see the other types of publications on this topic, follow the link: Anion.
Author: Grafiati
Published: 4 June 2021
Last updated: 11 March 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Anion.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Talanov, M. V., V. B. Shirokov, and V. M. Talanov. "Anion order in perovskites: a group-theoretical analysis." Acta Crystallographica Section A Foundations and Advances 72, no. 2 (January 29, 2016): 222–35. http://dx.doi.org/10.1107/s2053273315022147.

Full text
Abstract:
Anion ordering in the structure of cubic perovskite has been investigated by the group-theoretical method. The possibility of the existence of 261 ordered low-symmetry structures, each with a unique space-group symmetry, is established. These results include five binary and 14 ternary anion superstructures. The 261 idealized anion-ordered perovskite structures are considered as aristotypes, giving rise to different derivatives. The structures of these derivatives are formed by tilting ofBO6octahedra, distortions caused by the cooperative Jahn–Teller effect and other physical effects. Some derivatives of aristotypes exist as real substances, and some as virtual ones. A classification of aristotypes of anion superstructures in perovskite is proposed: theAXclass (the simultaneous ordering ofAcations and anions in cubic perovskite structure), theBXclass (the simultaneous ordering ofBcations and anions) and theXclass (the ordering of anions only in cubic perovskite structure). In most perovskites anion ordering is accompanied by cation ordering. Therefore, the main classes of anion order in perovskites are theAXandBXclasses. The calculated structures of some anion superstructures are reported. Comparison of predictions and experimentally investigated anion superstructures shows coherency of theoretical and experimental results.
APA, Harvard, Vancouver, ISO, and other styles
2

Wilkinson, Hazel S., and William T. A. Harrison. "Hexane-1,6-diammonium bis(dihydrogenarsenate): infinite anionic layers containing R 6 6(24) loops." Acta Crystallographica Section E Structure Reports Online 63, no. 3 (February 28, 2007): m902—m904. http://dx.doi.org/10.1107/s1600536807007672.

Full text
Abstract:
The title compound, C6H18N2 2+·2H2AsO4 −, contains a network of doubly protonated centrosymmetric hexane-1,6-diammonium cations and dihydrogenarsenate anions. These species interact by way of cation-to-anion N—H...O and anion-to-anion O—H...O hydrogen bonds, the latter leading to infinite sheets of the H2AsO4 − anions.
APA, Harvard, Vancouver, ISO, and other styles
3

Parthé, Erwin. "Crystal chemical information to be obtained from the bond-number equality concept." Acta Crystallographica Section B Structural Science 62, no. 2 (March 15, 2006): 335–37. http://dx.doi.org/10.1107/s0108768106003065.

Full text
Abstract:
Based on the bond-number equality concept an equation is derived for anion complexes of normal valence compounds with triangularly and/or tetrahedrally coordinated central atoms and anions having one, two, three and four bonds to central atoms: %Δ = 4 − (n/m′) × [2 − %A [1] + %A [3] + 2 × %A [4]]. %Δ is the ratio of the number of central atoms with triangular anion coordination to the sum of all central atoms in the anion complex. n/m′ is the ratio of the number of all A anions to the number of all central atoms C′ in the anion complex. %A [1] is the ratio of the number of anions with one bond to a central atom to the sum of all anions in the anion complex. %A [3] and %A [4] are defined accordingly. The equation can be used to formulate the possible crystal chemical formulae, which are characterized by partitions of central atoms and anions according to their bond numbers. Nitridosilicates and selected oxoborates are treated as examples of applications of the equation.
APA, Harvard, Vancouver, ISO, and other styles
4

Maslowska-Jarzyna, Krystyna, Maria L. Korczak, Jakub A. Wagner, and Michał J. Chmielewski. "Carbazole-Based Colorimetric Anion Sensors." Molecules 26, no. 11 (May 27, 2021): 3205. http://dx.doi.org/10.3390/molecules26113205.

Full text
Abstract:
Owing to their strong carbazole chromophore and fluorophore, as well as to their powerful and convergent hydrogen bond donors, 1,8-diaminocarbazoles are amongst the most attractive and synthetically versatile building blocks for the construction of anion receptors, sensors, and transporters. Aiming to develop carbazole-based colorimetric anion sensors, herein we describe the synthesis of 1,8-diaminocarbazoles substituted with strongly electron-withdrawing substituents, i.e., 3,6-dicyano and 3,6-dinitro. Both of these precursors were subsequently converted into model diamide receptors. Anion binding studies revealed that the new receptors exhibited significantly enhanced anion affinities, but also significantly increased acidities. We also found that rear substitution of 1,8-diamidocarbazole with two nitro groups shifted its absorption spectrum into the visible region and converted the receptor into a colorimetric anion sensor. The new sensor displayed vivid color and fluorescence changes upon addition of basic anions in wet dimethyl sulfoxide, but it was poorly selective; because of its enhanced acidity, the dominant receptor-anion interaction for most anions was proton transfer and, accordingly, similar changes in color were observed for all basic anions. The highly acidic and strongly binding receptors developed in this study may be applicable in organocatalysis or in pH-switchable anion transport through lipophilic membranes.
APA, Harvard, Vancouver, ISO, and other styles
5

Schefe, C. R., M. Watt, W. J. Slattery, and P. M. Mele. "Organic anions in the rhizosphere of Al-tolerant and Al-sensitive wheat lines grown in an acid soil in controlled and field environments." Soil Research 46, no. 3 (2008): 257. http://dx.doi.org/10.1071/sr07139.

Full text
Abstract:
Several sampling methods were investigated for the quantification of organic anions in the rhizosphere of Al-tolerant (ET8) and Al-sensitive (ES8) wheat plants in soil systems. Controlled environment studies used anion exchange membranes to collect rhizosphere organic anions (from root tips and mature regions of nodal roots) from ET8 and ES8 plants at the 6-leaf stage in a glasshouse environment. Using the anion exchange membranes, a selection of organic anions were detected on the tips and mature regions of roots, with ET8 and ES8 having similar rhizosphere organic anion profiles. The field experiment used 2 established methods of organic anion collection: rhizosphere soil and root washings. The ET8 and ES8 wheat lines had similar levels of organic anions, including malate, in the rhizosphere (using soil shaken from roots and root washings) at 3 sampling times (4 and 6 leaves, and flowering). The rhizosphere organic anions differed significantly from the bulk soil, with the concentration and range of organic anions in the rhizosphere decreasing towards flowering, presumably due to physiological changes in plant and root growth. This study used several techniques to investigate organic anion exudation by roots, with organic anions detected using all techniques. However, technical limitations of these techniques were recognised: (i) the lack of simultaneous exposure of root tips to both the anion exchange membrane and the chemical stimulant, e.g. Al3+; and (ii) the inability to derive the origin of organic anions measured in rhizosphere soil and root washings. The challenge for future soil-based organic anion research is to identify the dominant stress that has triggered an exudation response (i.e. Al toxicity, P deficiency), and to clearly differentiate between plant- and microbial-derived contributions to exudation.
APA, Harvard, Vancouver, ISO, and other styles
6

Sun, Jing, Qing Shan Li, Wei Hong, Biao Zhan, Guo Wei Wang, and Guang Zhong Xing. "The Two-Step Process for the Production of Anion Acrylic Fiber." Applied Mechanics and Materials 320 (May 2013): 615–18. http://dx.doi.org/10.4028/www.scientific.net/amm.320.615.

Full text
Abstract:
This article describes the preparation process of the anion acrylic and its test. In this study, using natural mineral nanomaterials prepared anion additives, using a two-step prepared anion acrylic fiber. Has been tested, the anion acrylic the indicators are good, the anion release can reach 1430 anions / cm3, and can be widely used in clothing, textile, medical and other fields.
APA, Harvard, Vancouver, ISO, and other styles
7

Wilkinson, Hazel S., and William T. A. Harrison. "2-Methylpiperazinium bis(dihydrogenarsenate)." Acta Crystallographica Section E Structure Reports Online 63, no. 3 (February 28, 2007): m900—m901. http://dx.doi.org/10.1107/s1600536807008392.

Full text
Abstract:
The title compound, C5H14N2 2+·2H2AsO4 −, contains a network of centrosymmetric doubly protonated 2-methylpiperazinium cations, showing disorder of the methyl group, accompanied by dihydogenarsenate anions. The component species interact by way of cation-to-anion N—H...O and anion-to-anion O—H...O hydrogen bonds, the latter leading to infinite sheets of the H2AsO4 − anions containing R 6 6(24) supramolecular loops.
APA, Harvard, Vancouver, ISO, and other styles
8

Yamuna, Thammarse S., Jerry P. Jasinski, Manpreet Kaur, Brian J. Anderson, and H. S. Yathirajan. "5-(4-Fluorophenyl)-2H-pyrazol-1-ium 2,2,2-trifluoroacetate." Acta Crystallographica Section E Structure Reports Online 70, no. 4 (March 15, 2014): o429—o430. http://dx.doi.org/10.1107/s1600536814005200.

Full text
Abstract:
The title salt, C9H8FN2+·C2F3O2−, crystallizes with two independent cations (AandB) and two independent anions (CandD) in the asymmetric unit. In the cations, the dihedral angles between the benzene and pyrazolium rings are 23.7 (3)° in cationAand 1.8 (8)° in cationB. In the crystal, each anion links to the two cationsviaN—H...O hydrogen bonds, forming a U-shaped unit with anR44(14) ring motif. These U-shaped units stack along theaaxis and are linkedviaC—H...O and C—H...F hydrogen bonds, forming slabs lying parallel to (100). Within the slabs there are π–π interactions between the pyrazolium rings [inter-centroid distance = 3.6326 (15) Å] and between the benzene rings [inter-centroid distance = 3.7244 (16) Å]. In the anions, the F atoms of the trifluoromethyl groups are disordered over two sets of sites, with refined occupancy ratios of 0.58 (3):0.42, 0.540 (14):0.46 (14), and 0.55 (2):0.45 (2) for anionC, and 0.73 (5):0.27 (5), 0.63 (5):0.37 (5), and 0.57 (8):0.43 (8) for anionD.
APA, Harvard, Vancouver, ISO, and other styles
9

Li, Lei, Yu-Jian Hong, Dong-Yang Chen, Wang-Chuan Xiao, and Mei-Jin Lin. "Anion–π interactions in lithium–organic redox flow batteries." Chemical Communications 55, no. 16 (2019): 2364–67. http://dx.doi.org/10.1039/c8cc09834d.

Full text
Abstract:
The interactions between the electrolyte anions and electron-deficient redox-active organic molecules (anion–π interactions) have strong influences on the battery properties due to the anion–π-induced formation of radical anions or sandwich-like aggregates.
APA, Harvard, Vancouver, ISO, and other styles
10

Cervera, Maria, and Jordi Marquet. "Effects of superoxide anion generated from aromatic radical anions produced in nucleophilic aromatic photosubstitution reactions." Canadian Journal of Chemistry 76, no. 6 (June 1, 1998): 966–69. http://dx.doi.org/10.1139/v98-044.

Full text
Abstract:
Superoxide anion is generated from aromatic radical anions produced in nucleophilic aromatic photosubstitutions when the reactions are carried out in non-deoxygenated solutions of polar aprotic solvents. Superoxide anion thus generated displaces cyanide anion from acetonitrile and benzyl cyanide, ethoxide anion from ethyl acetate, and methanesulfenate anion from dimethyl sulfoxide. Hence, non-deoxygenated polar aprotic solvents should be avoided in nucleophilic aromatic photosubstitution reactions.Key words: superoxide, fluoride, nucleophilic aromatic photosubstitution.
APA, Harvard, Vancouver, ISO, and other styles
11

Sekine, Takashi, Hiroki Miyazaki, and Hitoshi Endou. "Molecular physiology of renal organic anion transporters." American Journal of Physiology-Renal Physiology 290, no. 2 (February 2006): F251—F261. http://dx.doi.org/10.1152/ajprenal.00439.2004.

Full text
Abstract:
Recent advances in molecular biology have identified three organic anion transporter families: the organic anion transporter (OAT) family encoded by SLC22A, the organic anion transporting peptide (OATP) family encoded by SLC21A ( SLCO), and the multidrug resistance-associated protein (MRP) family encoded by ABCC. These families play critical roles in the transepithelial transport of organic anions in the kidneys as well as in other tissues such as the liver and brain. Among these families, the OAT family plays the central role in renal organic anion transport. Knowledge of these three families at the molecular level, such as substrate selectivity, tissue distribution, and gene localization, is rapidly increasing. In this review, we will give an overview of molecular information on renal organic anion transporters and describe recent topics such as the regulatory mechanisms and molecular physiology of urate transport. We will also discuss the physiological roles of each organic anion transporter in the light of the transepithelial transport of organic anions in the kidneys.
APA, Harvard, Vancouver, ISO, and other styles
12

Salhany, James M. "Anion binding characteristics of the band 3 / 4,4'-dibenzamidostilbene-2,2'-disulfonate binary complex: Evidence for both steric and allosteric interactions." Biochemistry and Cell Biology 77, no. 6 (December 1, 1999): 543–49. http://dx.doi.org/10.1139/o99-061.

Full text
Abstract:
A novel kinetic approach was used to measure monovalent anion binding to better define the mechanistic basis for competition between stilbenedisulfonates and transportable anions on band 3. An anion-induced acceleration in the release of 4,4prime-dibenzamidostilbene-2,2prime-disulfonate (DBDS) from its complex with band 3 was measured using monovalent anions of various size and relative affinity for the transport site. The K1/2 values for anion binding were determined and correlated with transport site affinity constants obtained from the literature and the dehydrated radius of each anion. The results show that anions with ionic radii of 120-200 pm fall on a well-defined correlation line where the ranking of the K1/2 values matched the ranking of the transport site affinity constants (thiocyanate < nitrate equivalent to bromide < chloride < fluoride). The K1/2 values for the anions on this line were about 4-fold larger than expected for anion binding to inhibitor-free band 3. Such a lowered affinity can be explained in terms of allosteric site-site interactions, since the K1/2 values decreased with increasing anionic size. In contrast, iodide, with an ionic radius of about 212 pm, had a 10-fold lower affinity than predicted by the correlation line established by the smaller monovalent anions. These results indicate that smaller monovalent anions have unobstructed access to the transport site within the band 3 / DBDS binary complex, while iodide experiences significant steric hindrance when binding. The observation of steric hindrance in iodide binding to the band 3 / DBDS binary complex, but not in the binding of smaller monovalent anions, suggests that the stilbenedisulfonate binding site is located at the outer surface of an access channel leading to the transport site.Key words: band 3, anion transport, membrane protein structure, red cell membrane.
APA, Harvard, Vancouver, ISO, and other styles
13

Kim, Hee-Joon. "Assembly of Sn(IV)-Porphyrin Cation Exhibiting Supramolecular Interactions of Anion···Anion and Anion···π Systems." Molbank 2022, no. 4 (September 25, 2022): M1454. http://dx.doi.org/10.3390/m1454.

Full text
Abstract:
Trans-diaqua[meso-tetrakis(4-pyridyl)porphyrinato]Sn(IV) dinitrate complexes were assembled in a two-dimensional manner via hydrogen bonding between aqua ligands and pyridyl substituents. Interestingly, this supramolecular assembly was accompanied by unconventional noncovalent interactions, such as anion···anion and anion···π interactions, which were confirmed by X-ray crystallographic analysis. Two nitrate anions close to 2.070 Å were constrained in a confined space surrounded by four hydrogen-bonded Sn(IV)-porphyrin cations. The nitrate anion was also 3.433 Å away from the adjacent pyrrole ring, and the dihedral angle between the two mean planes was estimated to be 7.39°. The preference of the anion···π interaction was related to the electron-deficient π-system owing to the high-valent Sn(IV) center and cationic nature of the porphyrin complex. These two unconventional noncovalent interactions played an important role in the formation of a one-dimensional array with pairs of Sn(IV)-porphyrin cation and nitrate anion.
APA, Harvard, Vancouver, ISO, and other styles
14

Kellum, J. A., R. Bellomo, D. J. Kramer, and M. R. Pinsky. "Hepatic anion flux during acute endotoxemia." Journal of Applied Physiology 78, no. 6 (June 1, 1995): 2212–17. http://dx.doi.org/10.1152/jappl.1995.78.6.2212.

Full text
Abstract:
We sought to determine the role the liver might play in the regulation of anion-cation balance during both stable baseline conditions and acute endotoxemia. Ten pentobarbital sodium-anesthetized dogs were instrumented at laparotomy with ultrasonic flow probes around the left renal artery, portal vein, and hepatic artery, and catheters were inserted into the hepatic vein, portal vein, pulmonary artery, left renal vein, and abdominal aorta. Measurements were obtained from each site at baseline and 30-45 min after the intravenous infusion of endotoxin. The total anion flux across the liver was calculated from the strong-ion difference. At baseline, the liver removed anions from the circulation (-0.34 meq/min). With early endotoxemia, however, the liver switched to the release of anions (0.12 meq/min; P = 0.0046). After endotoxin administration, the gut, which was neutral at baseline, began to take up anions (-0.47 meq/min; P = 0.008). Anion flux across the lung and kidney was unchanged. We conclude that in the dog the liver, which removes anions at baseline, switches to release anions during early endotoxemia and may be a major site of acid production in early sepsis.
APA, Harvard, Vancouver, ISO, and other styles
15

Li, Qing Shan, and Ming Shuang Xu. "Preparation and Functionality Research of Anion Functional Fabrics." Advanced Materials Research 178 (December 2010): 216–19. http://dx.doi.org/10.4028/www.scientific.net/amr.178.216.

Full text
Abstract:
In order to provide scientific proof to anion functional fabrics application research in textile domain, in this article, anion functional fabrics were prepared, the anion generating capacity was determined and the effect of anion fabrics and mice BLA after exercise were first studied. The anion generating capacity shows that: due to the adding of anion function powders to function fabrics, the anion amount released by function fabrics is apparently higher than common fabrics. Washing can not significantly reduce the anion amount of function fabrics releasing. These can indicate that the function fabrics can release anion stable and lasting. The determination of mice’s BLA after swimming showed that Compared to common fabrics, functional fabrics have significant difference (P<0.05). The anions of functional fabrics releasing can reduce animals BLA after exercise and help to eliminate exercise-induced muscle fatigue.
APA, Harvard, Vancouver, ISO, and other styles
16

Smith, Stephen S., Erich D. Steinle, Mark E. Meyerhoff, and David C. Dawson. "Cystic Fibrosis Transmembrane Conductance Regulator." Journal of General Physiology 114, no. 6 (November 29, 1999): 799–818. http://dx.doi.org/10.1085/jgp.114.6.799.

Full text
Abstract:
The cystic fibrosis transmembrane conductance regulator (CFTR) Cl channel exhibits lyotropic anion selectivity. Anions that are more readily dehydrated than Cl exhibit permeability ratios (PS/PCl) greater than unity and also bind more tightly in the channel. We compared the selectivity of CFTR to that of a synthetic anion-selective membrane [poly(vinyl chloride)–tridodecylmethylammonium chloride; PVC-TDMAC] for which the nature of the physical process that governs the anion-selective response is more readily apparent. The permeability and binding selectivity patterns of CFTR differed only by a multiplicative constant from that of the PVC-TDMAC membrane; and a continuum electrostatic model suggested that both patterns could be understood in terms of the differences in the relative stabilization of anions by water and the polarizable interior of the channel or synthetic membrane. The calculated energies of anion–channel interaction, derived from measurements of either permeability or binding, varied as a linear function of inverse ionic radius (1/r), as expected from a Born-type model of ion charging in a medium characterized by an effective dielectric constant of 19. The model predicts that large anions, like SCN, although they experience weaker interactions (relative to Cl) with water and also with the channel, are more permeant than Cl because anion–water energy is a steeper function of 1/r than is the anion–channel energy. These large anions also bind more tightly for the same reason: the reduced energy of hydration allows the net transfer energy (the well depth) to be more negative. This simple selectivity mechanism that governs permeability and binding acts to optimize the function of CFTR as a Cl filter. Anions that are smaller (more difficult to dehydrate) than Cl are energetically retarded from entering the channel, while the larger (more readily dehydrated) anions are retarded in their passage by “sticking” within the channel.
APA, Harvard, Vancouver, ISO, and other styles
17

Yan, Liwei, Ankur Saha, Wei Zhao, Jennifer F. Neal, Yusheng Chen, Amar H. Flood, and Heather C. Allen. "Recognition competes with hydration in anion-triggered monolayer formation of cyanostar supra-amphiphiles at aqueous interfaces." Chemical Science 13, no. 15 (2022): 4283–94. http://dx.doi.org/10.1039/d2sc00986b.

Full text
APA, Harvard, Vancouver, ISO, and other styles
18

Kovanda, František, Eva Kovácsová, and David Koloušek. "Removal of Anions from Solution by Calcined Hydrotalcite and Regeneration of Used Sorbent in Repeated Calcination-Rehydration-Anion Exchange Processes." Collection of Czechoslovak Chemical Communications 64, no. 9 (1999): 1517–28. http://dx.doi.org/10.1135/cccc19991517.

Full text
Abstract:
Synthetic hydrotalcite calcined at 350-550 °C was used for the removal of arsenate, chromate, and vanadate ions from water solutions. The initial anion concentrations were 0.002 mol l-1. The sorption isotherms were measured at 20 °C and at neutral pH. The Langmuir adsorption isotherm was used for the sorption capacity evaluation. The ability of the calcined hydrotalcite to remove the anions from solution decreased in the order of vanadate - arsenate - chromate. The hydrotalcite calcined at 450 °C exhibited the best sorption ability for all the anions. The sorbed anions were released by anion exchange in a carbonate-containing solution and the hydrotalcite after subsequent calcination was used again for the removal of anions. The repeating cycles calcination-rehydration-anion exchange gradually reduced the adsorption capacity of the hydrotalcite. The sorption capacity decreased by 50% after the first two cycles but it did not change significantly in the subsequent cycles. When chromate anions were adsorbed, the decrease in sorption capacity was not observed during repeated calcination-rehydration-anion exchange cycles. The change in the sorption capacity was influenced by the ability of calcined hydrotalcite to regenerate the layered crystal structure during the rehydration process.
APA, Harvard, Vancouver, ISO, and other styles
19

Franz, Jan, and Francesco Antonio Gianturco. "Investigation of rotational state-changing collisions of C2N− ions with helium." Proceedings of the International Astronomical Union 15, S350 (April 2019): 443–44. http://dx.doi.org/10.1017/s1743921319007580.

Full text
Abstract:
AbstractThe cross sections for rotational inelastic collisions between atoms and a molecular anion can be very large, if the anion has a dipole moment. This makes molecular anions very efficient in cooling atomic gases. We address rotational inelastic collisions of Helium atoms with the molecular anion C2N–. Here we present preliminary calculations of the potential energy surface.
APA, Harvard, Vancouver, ISO, and other styles
20

González-Ruiz, Víctor, Ángel Cores, M. Mar Caja, Vellaisamy Sridharan, Mercedes Villacampa, M. Antonia Martín, Ana I. Olives, and J. Carlos Menéndez. "Fluorescence Sensors Based on Hydroxycarbazole for the Determination of Neurodegeneration-Related Halide Anions." Biosensors 12, no. 3 (March 14, 2022): 175. http://dx.doi.org/10.3390/bios12030175.

Full text
Abstract:
The environmental presence of anions of natural origin or anthropogenic origin is gradually increasing. As a tool to tackle this problem, carbazole derivatives are an attractive gateway to the development of luminescent chemosensors. Considering the different mechanisms proposed for anion recognition, the fluorescence properties and anion-binding response of several newly synthesised carbazole derivatives were studied. Potential anion sensors were designed so that they combined the native fluorescence of carbazole with the presence of hydrogen bonding donor groups in critical positions for anion recognition. These compounds were synthesised by a feasible and non-expensive procedure using palladium-promoted cyclodehydrogenation of suitable diarylamine under microwave irradiation. In comparison to the other carbazole derivatives studied, 1-hydroxycarbazole proved to be useful as a fluorescent sensor for anions, as it was able to sensitively recognise fluoride and chloride anions by establishing hydrogen bond interactions through the hydrogen atoms on the pyrrolic nitrogen and the hydroxy group. Solvent effects and excited-state proton transfer (ESPT) of the carbazole derivatives are described to discard the role of the anions as Brönsted bases on the observed fluorescence behaviour of the sensors. The anion–sensor interaction was confirmed by 1H-NMR. Molecular modelling was employed to propose a mode of recognition of the sensor in terms of complex stability and interatomic distances. 1-hydroxycarbazole was employed for the quantitation of fluoride and chloride anions in commercially available medicinal spring water and mouthwash samples.
APA, Harvard, Vancouver, ISO, and other styles
21

Schifferer, Lukas, Martin Stinglhamer, Kirandeep Kaur, and Olga García Macheño. "Halides as versatile anions in asymmetric anion-binding organocatalysis." Beilstein Journal of Organic Chemistry 17 (September 1, 2021): 2270–86. http://dx.doi.org/10.3762/bjoc.17.145.

Full text
Abstract:
This review intends to provide an overview on the role of halide anions in the development of the research area of asymmetric anion-binding organocatalysis. Key early elucidation studies with chloride as counter-anion confirmed this type of alternative activation, which was then exploited in several processes and contributed to the advance and consolidation of anion-binding catalysis as a field. Thus, the use of the halide in the catalyst–anion complex as both a mere counter-anion spectator or an active nucleophile has been depicted, along with the new trends toward additional noncovalent contacts within the HB-donor catalyst and supramolecular interactions to both the anion and the cationic reactive species.
APA, Harvard, Vancouver, ISO, and other styles
22

Gonfa, G., M. A. Bustam, T. Murugesan, Z. Man, and M. I. Abdul Mutalib. "Thermophysical Properties of Ionic Liquid with Thiocyanate and Dicynamide Anions." Key Engineering Materials 594-595 (December 2013): 953–57. http://dx.doi.org/10.4028/www.scientific.net/kem.594-595.953.

Full text
Abstract:
In this work, density and viscosity of ionic liquids with dicynamide and thiocyanate anion were obtained. The thermal expansion coefficient values were obtained from the experimental density values. The density and viscosity of the ionic liquids depends on the nature of the cations. The density of the ionic liquids increases in the order of [BMIM]+ < [AMI+ < [BzMI+ < [HEMI+ for dicynamide anion. Both for thiocyanate and dicynamide anions the viscosity values increase in the order of [BMI+ < [AMI+ < [BMI+ < [HEMI+. Moreover, viscosity values of ionic liquids with dicynamide anions are less than their corresponding thiocyanate anion.
APA, Harvard, Vancouver, ISO, and other styles
23

Flood, Amar H. "Creating molecular macrocycles for anion recognition." Beilstein Journal of Organic Chemistry 12 (March 31, 2016): 611–27. http://dx.doi.org/10.3762/bjoc.12.60.

Full text
Abstract:
The creation and functionality of new classes of macrocycles that are shape persistent and can bind anions is described. The genesis of triazolophane macrocycles emerges out of activity surrounding 1,2,3-triazoles made using click chemistry; and the same triazoles are responsible for anion capture. Mistakes made and lessons learnt in anion recognition provide deeper understanding that, together with theory, now provides for computer-aided receptor design. The lessons are acted upon in the creation of two new macrocycles. First, cyanostars are larger and like to capture large anions. Second is tricarb, which also favors large anions but shows a propensity to self-assemble in an orderly and stable manner, laying a foundation for future designs of hierarchical nanostructures.
APA, Harvard, Vancouver, ISO, and other styles
24

Bali, Atul, and Roopa Naik. "Pseudo Metabolic Acidosis in the Setting of Hypertriglyceridemia: A Case Report." Internal Medicine – Open Journal 4, no. 1 (December 31, 2020): 1–2. http://dx.doi.org/10.17140/imoj-4-111.

Full text
Abstract:
Low serum bicarbonate, with or without an elevated anion gap, can indicate metabolic acidosis. High anion gap metabolic acidosis is due to the unmeasured anions. Hypertriglyceridemia can also be associated with spuriously low serum bicarbonate levels due to lab interference. We present a 44-year-old woman who presented with anion gap metabolic acidosis in the presence of severe hypertriglyceridemia
APA, Harvard, Vancouver, ISO, and other styles
25

Xie, Huifang, and Ming Wah Wong. "Computational Design of Thiourea-based Cyclophane Sensors for Small Anions." Australian Journal of Chemistry 65, no. 3 (2012): 303. http://dx.doi.org/10.1071/ch11389.

Full text
Abstract:
The host–guest binding properties of a tri-thiourea cyclophane receptor (1) with several common anions have been investigated using density functional theory (DFT) and molecular dynamics calculations. Receptor 1 is predicted to be an effective receptor for binding small halogen and Y-shaped (NO3– and AcO–) anions in the gas phase, cyclohexane and chloroform. The calculated order of anion binding affinity for the receptor 1 in chloroform is F– > Cl– > AcO– > NO3– >Br– > H2PO4– > HSO4–. The binding free energies are strongly influenced by a dielectric solvent medium. The structures of the receptor–anion complexes are characterized by multiple (typically 6) hydrogen bonds in all cases. The overall binding affinity of various anions is determined by the basicity of anion, size and shape of the binding site, and solvent medium. Explicit chloroform solvent molecular dynamics simulations of selected receptor–anion complexes reveal that the anions are strongly bound within the binding pocket via hydrogen-bonding interactions to all the receptor protons throughout the simulation. A sulfur analogue of receptor 1 (2), with a larger central cavity, is shown to be a more effective sensor than 1 for small anions. Two different approaches to develop the thiourea-based cyclophane receptor into a chromogenic sensor were examined.
APA, Harvard, Vancouver, ISO, and other styles
26

Brown, J. C., R. K. Packer, and M. A. Knepper. "Role of organic anions in renal response to dietary acid and base loads." American Journal of Physiology-Renal Physiology 257, no. 2 (August 1, 1989): F170—F176. http://dx.doi.org/10.1152/ajprenal.1989.257.2.f170.

Full text
Abstract:
Bicarbonate is formed when organic anions are oxidized systemically. Therefore, changes in organic anion excretion can affect systemic acid-base balance. To assess the role of organic anions in urinary acid-base excretion, we measured urinary excretion in control rats, NaHCO3-loaded rats, and NH4Cl-loaded rats. Total organic anions were measured by the titration method of Van Slyke. As expected, NaHCO3 loading increased urine pH and decreased net acid excretion (NH4+ + titratable acid - HCO3-), whereas NH4Cl loading had the opposite effect. Organic anion excretion was increased in response to NaHCO3 loading and decreased in response to NH4Cl loading. We quantified the overall effect of organic ion plus inorganic buffer ion excretion on acid-base balance. The amounts of organic anions excreted by all animals in this study were greater than the amounts of NH4+, HCO3-, or titratable acidity excreted. In addition, in response to acid and alkali loading, changes in urinary organic anion excretion were 40-50% as large as changes in net acid excretion. We conclude that, in rats, regulation of organic anion excretion can contribute importantly to the overall renal response to acid-base disturbances.
APA, Harvard, Vancouver, ISO, and other styles
27

Griffin, M. Pamela. "Role for anions in pulmonary endothelial permeability." Journal of Applied Physiology 83, no. 2 (August 1, 1997): 615–22. http://dx.doi.org/10.1152/jappl.1997.83.2.615.

Full text
Abstract:
Griffin, M. Pamela. Role for anions in pulmonary endothelial permeability. J. Appl. Physiol. 83(2): 615–622, 1997.—β-Adrenergic stimulation reduces albumin permeation across pulmonary artery endothelial monolayers and induces changes in cell morphology that are mediated by Cl− flux. We tested the hypothesis that anion-mediated changes in endothelial cells result in changes in endothelial permeability. We measured permeation of radiolabeled albumin across bovine pulmonary arterial endothelial monolayers when the extracellular anion was Cl−, Br−, I−, F−, acetate (Ac−), gluconate (G−), and propionate (Pr−). Permeability to albumin ( P albumin) was calculated before and after addition of 0.2 mM of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX), which reduces permeability. In Cl−, the P albumin was 3.05 ± 0.86 × 10−6 cm/s and fell by 70% with the addition of IBMX. The initial P albumin was lowest for Pr− and Ac−. Initial P albumin was higher in Br−, I−, G−, and F− than in Cl−. A permeability ratio was calculated to examine the IBMX effect. The greatest IBMX effect was seen when Cl− was the extracellular anion, and the order among halide anions was Cl− > Br− > I− > F−. Although the level of extracellular Ca2+ concentration ([Ca2+]o) varied over a wide range in the anion solutions, [Ca2+]odid not systematically affect endothelial permeability in this system. When Cl− was the extracellular anion, varying [Ca2+]ofrom 0.2 to 2.8 mM caused a change in initial P albumin but no change in the IBMX effect. The anion channel blockers 4-acetamido-4′-isothiocyanotostilbene-2,2′-disulfonic acid (0.25 mM) and anthracene-9-carboxylic acid (0.5 mM) significantly altered initial P albumin and the IBMX effect. The anion transport blockers bumetanide (0.2 mM) and furosemide (1 mM) had no such effects. We conclude that extracellular anions influence bovine pulmonary arterial endothelial permeability and that the pharmacological profile fits better with the activity of anion channels than with other anion transport processes.
APA, Harvard, Vancouver, ISO, and other styles
28

Franciolini, F., and W. Nonner. "A multi-ion permeation mechanism in neuronal background chloride channels." Journal of General Physiology 104, no. 4 (October 1, 1994): 725–46. http://dx.doi.org/10.1085/jgp.104.4.725.

Full text
Abstract:
Unitary current/voltage relationships of background Cl channels of rat hippocampal neurons were determined for varied gradients and absolute concentrations of NaCl. The channels revealed permeabilities for both Cl and Na ions. A hyperlinear increase of unitary conductance, observed for a symmetrical increase of salt concentration from 300 and 600 mM, indicated a multi-ion permeation mechanism. A variety of kinetic models of permeation were tested against the experimental current/voltage relationships. Models involving a pore occupied by mixed complexes of up to five ions were necessary to reproduce all measurements. A minimal model included four equilibrium states and four rate-limiting transitions, such that the empty pore accepts first an anion and then can acquire one or two cation/anion pairs. Three transport cycles are formed: a slow anion cycle (between the empty and single-anion states), a slow cation cycle (between the one- and three-ion states), and a fast anion cycle (between the three- and five-ion states). Thus, permeant anions are required for cation permeation, and several bound anions and cations promote a high rate of anion permeation. The optimized free-energy and electrical charge parameters yielded a self-consistent molecular interpretation, which can account for the particular order in which the pore accepts ions from the solutions. Although the model describes the mixed anion/cation permeability of the channel observed at elevated concentrations, it predicts a high selectivity for Cl anion at physiological ionic conditions.
APA, Harvard, Vancouver, ISO, and other styles
29

Lochmann, Christine, Thomas F. M. Luxford, Samanta Makurat, Andriy Pysanenko, Jaroslav Kočišek, Janusz Rak, and Stephan Denifl. "Low-Energy Electron Induced Reactions in Metronidazole at Different Solvation Conditions." Pharmaceuticals 15, no. 6 (June 2, 2022): 701. http://dx.doi.org/10.3390/ph15060701.

Full text
Abstract:
Metronidazole belongs to the class of nitroimidazole molecules and has been considered as a potential radiosensitizer for radiation therapy. During the irradiation of biological tissue, secondary electrons are released that may interact with molecules of the surrounding environment. Here, we present a study of electron attachment to metronidazole that aims to investigate possible reactions in the molecule upon anion formation. Another purpose is to elucidate the effect of microhydration on electron-induced reactions in metronidazole. We use two crossed electron/molecular beam devices with the mass-spectrometric analysis of formed anions. The experiments are supported by quantum chemical calculations on thermodynamic properties such as electron affinities and thresholds of anion formation. For the single molecule, as well as the microhydrated condition, we observe the parent radical anion as the most abundant product anion upon electron attachment. A variety of fragment anions are observed for the isolated molecule, with NO2− as the most abundant fragment species. NO2− and all other fragment anions except weakly abundant OH− are quenched upon microhydration. The relative abundances suggest the parent radical anion of metronidazole as a biologically relevant species after the physicochemical stage of radiation damage. We also conclude from the present results that metronidazole is highly susceptible to low-energy electrons.
APA, Harvard, Vancouver, ISO, and other styles
30

Zhou, Benhua, and Hongxia Liu. "Tetrakis(4-chloroanilinium) hexachloridostannate(IV) dichloride." Acta Crystallographica Section E Structure Reports Online 68, no. 6 (May 19, 2012): m782. http://dx.doi.org/10.1107/s1600536812021666.

Full text
Abstract:
The asymmetric unit of the title compound, (C6H7ClN)4[SnCl6]Cl2, comprises two 4-chloroanilinium cations, half of an [SnCl6]2− anion and a Cl− anion. The SnIV atom, located on a special position on a twofold rotation axis, exhibits an octahedral environment. In the crystal, molecules are linked by N—H...Cl hydrogen bonds between the 4-chloroanilinium cations, [SnCl6]2− anions and Cl− anions.
APA, Harvard, Vancouver, ISO, and other styles
31

Zhang, Jian, Bin Zhou, Zhen-Rong Sun, and Xue-Bin Wang. "Photoelectron spectroscopy and theoretical studies of anion–π interactions: binding strength and anion specificity." Physical Chemistry Chemical Physics 17, no. 5 (2015): 3131–41. http://dx.doi.org/10.1039/c4cp04687k.

Full text
APA, Harvard, Vancouver, ISO, and other styles
32

Li, WK, J. Baker, and L. Radom. "Rearrangement of the Fulminate Anion (CNO-) to the Cyanate Anion (OCN-). Possible Intermediacy of the Oxazirinyl Anion." Australian Journal of Chemistry 39, no. 6 (1986): 913. http://dx.doi.org/10.1071/ch9860913.

Full text
Abstract:
The rearrangement of the fulminate anion (CNO-) to the cyanate anion (OCN-) has been examined by using high-level ab initio molecular orbital calculations which include a diffuse-function-augmented polarization basis set and electron correlation incorporated at the full fourth-order Moller-Plesset level (MP4). The reaction is predicted to be exothermic by 275 kJ mol-1. Our best calculations indicate theinvolvement of a metastable cyclic oxazirinyl anion intermediate. However, this lies in an extremely shallow potential well and, in contrast to the predictions of semiempirical calculations, is unlikely to have more than a fleeting existence. The fulminate and cyanate anions are calculated to be stable with respect to electron loss and stable with respect to intramolecular rearrangement; accordingly, both should be observable gas-phase species.
APA, Harvard, Vancouver, ISO, and other styles
33

Maeda, Hiromitsu, and Yohei Haketa. "Charge-by-charge assemblies based on planar anion receptors." Pure and Applied Chemistry 83, no. 1 (November 12, 2010): 189–99. http://dx.doi.org/10.1351/pac-con-10-09-34.

Full text
Abstract:
This critical overview proposes a new concept, a charge-by-charge assembly, which consists of alternately stacked positively and negatively charged species, by introducing examples of planar anionic structures in the solid state. The preparation of planar organic anions is not easy; however, complexation of planar anion receptor molecules with inorganic anions is found to be an efficient strategy for constructing them. As suitable motifs, dipyrrolyldiketone boron complexes exhibit various receptor–anion complexes and charge-by-charge assemblies in the solid state. The concept discussed here can be applied to useful soft materials as well as crystals by modifying the anion receptors and cations.
APA, Harvard, Vancouver, ISO, and other styles
34

Martínez-Aguirre, Mayte A., Diego Martínez Otero, Magali L. Álvarez-Hernández, Teresa Torres-Blancas, Alejandro Dorazco-González, and Anatoly K. Yatsimirsky. "Anion and sugar recognition by 2,6-pyridinedicarboxamide bis-boronic acid derivatives." Heterocyclic Communications 23, no. 3 (June 27, 2017): 171–80. http://dx.doi.org/10.1515/hc-2017-0054.

Full text
Abstract:
AbstractTwo 2,6-pyridinedicarboxamide derivatives containing arylboronic acid fragments were prepared and fully characterized including X-ray crystal diffraction analysis of a pinacol ester. These compounds are potential bifunctional receptors for sugars and anions. Acid dissociation and stability constants for complexation of both receptors with glucose and fructose were determined by potentiometric titrations in aqueous DMSO. Also, binding of alizarin red S indicator was studied spectrophotometrically and a highly sensitive detection of fructose by an indicator displacement assay was proposed. Complexation with anions was studied by 1H NMR titrations in DMSO-d6. Binding of acetate anion occurs only via hydrogen bonding to OH groups of boronic acid fragments and does not affect signals of NH protons but chloride anion induces large shift of the signals of NH protons and small shifts of the signals of OH groups. This behavior makes possible anion discrimination based on preference in the type of binding site rather than simply on anion basicity as is typical for majority of neutral hydrogen bonding anion receptors.
APA, Harvard, Vancouver, ISO, and other styles
35

Shen, Chen, Guo-Ping Yong, Cong Zhang, and Ya Feng. "Anion-controlled morphologies and photophysical features of organic microcrystals by solid-phase anion exchange reactions." RSC Advances 6, no. 12 (2016): 10162–67. http://dx.doi.org/10.1039/c5ra24123e.

Full text
APA, Harvard, Vancouver, ISO, and other styles
36

Jian, Fang Fang, E. Liu, and Jun Ying Ma. "Interesting fluorine anion water clusters [F−·(H2O)n] in metal complex crystals." CrystEngComm 20, no. 27 (2018): 3849–57. http://dx.doi.org/10.1039/c8ce00532j.

Full text
Abstract:
Three crystalline complexes containing fluorine anion water cluster were reported. The fluoride anions and water molecules are H-bonded to each other in an alternating fashion within the fluoride–water hybrid cluster, where a fluoride anion plays the important role.
APA, Harvard, Vancouver, ISO, and other styles
37

Akaike, N., N. Inomata, and T. Yakushiji. "Differential effects of extra- and intracellular anions on GABA-activated currents in bullfrog sensory neurons." Journal of Neurophysiology 62, no. 6 (December 1, 1989): 1388–99. http://dx.doi.org/10.1152/jn.1989.62.6.1388.

Full text
Abstract:
1. Kinetic properties of gamma-aminobutyric acid (GABA)-gated inward and outward anion currents were investigated in the frog sensory neurons perfused internally and externally with various anions with the use of a rapid concentration-jump (termed as 'concentration-clamp') technique. 2. Extracellular Br- [( Br-]o) shifted the dose-response curves of GABA-induced inward anion currents to the left without affecting the maximum values, whereas [Cl-]o, [I-]o, [No3-]o, [HCOO-]o, and [CH3COO-]o altered the rate of desensitization differently without shifting the GABA dose-response curves, indicating that the kinetics of desensitization phase are affected differently by various extracellular anions. 3. [CH3COO-]o suppressed the maximum current of the dose-response curve of the GABA-induced inward ICl without affecting Kd. 4. Both activation and desensitization phases of GABA-induced ICl consisted of fast and slow components, respectively. [Br-]o, [I-]o, and [NO3-]o significantly prolonged the slow desensitization component, whereas both [HCOO-]o and [CH3COO-]o shortened it. The fast desensitization and the fast and slow activation components were also affected by these foreign anions. 5. GABA dose-response curves of inward currents carried by various intracellular anions (Cl-, Br-, NO3-, I-, SCN-, HCOO-, F-, CH3COO-, CH3CH2COO-, BrO3-, and ClO3-) while keeping a constant [Cl-]o had a constant Kd value but different saturating maximum currents. There were no marked differences among their current kinetics except in the case of SCN-, indicating that the current kinetics is not affected by replacing intracellular Cl- [( Cl-]i) with various foreign anions. 6. The configuration and amplitude of GABA-gated outward anion currents at a constant [Cl-]i reflected the extracellular action of individual anions on the anion-binding site of GABA receptor associated with the anion-selective channel. 7. The relative conductances of the various anions, calculated from the maximum peak currents in dose-response curves of the GABA-induced inward anion currents at a constant [Cl-]o, was in the sequence: I- greater than Br- greater than or equal to NO3- greater than ClO3- greater than SCN- greater than or equal to Cl- greater than HCOO- greater than BrO3- greater than CH3COO- greater than F- greater than CH3CH2COO-.(ABSTRACT TRUNCATED AT 400 WORDS)
APA, Harvard, Vancouver, ISO, and other styles
38

Alekov, Alexi K., and Christoph Fahlke. "Channel-like slippage modes in the human anion/proton exchanger ClC-4." Journal of General Physiology 133, no. 5 (April 13, 2009): 485–96. http://dx.doi.org/10.1085/jgp.200810155.

Full text
Abstract:
The ClC family encompasses two classes of proteins with distinct transport functions: anion channels and transporters. ClC-type transporters usually mediate secondary active anion–proton exchange. However, under certain conditions they assume slippage mode behavior in which proton and anion transport are uncoupled, resulting in passive anion fluxes without associated proton movements. Here, we use patch clamp and intracellular pH recordings on transfected mammalian cells to characterize exchanger and slippage modes of human ClC-4, a member of the ClC transporter branch. We found that the two transport modes differ in transport mechanisms and transport rates. Nonstationary noise analysis revealed a unitary transport rate of 5 × 105 s−1 at +150 mV for the slippage mode, indicating that ClC-4 functions as channel in this mode. In the exchanger mode, unitary transport rates were 10-fold lower. Both ClC-4 transport modes exhibit voltage-dependent gating, indicating that there are active and non-active states for the exchanger as well as for the slippage mode. ClC-4 can assume both transport modes under all tested conditions, with exchanger/channel ratios determined by the external anion. We propose that binding of transported anions to non-active states causes transition from slippage into exchanger mode. Binding and unbinding of anions is very rapid, and slower transitions of liganded and non-liganded states into active conformations result in a stable distribution between the two transport modes. The proposed mechanism results in anion-dependent conversion of ClC-type exchanger into an anion channel with typical attributes of ClC anion channels.
APA, Harvard, Vancouver, ISO, and other styles
39

Wysokiński, Rafał, Mariusz Michalczyk, Wiktor Zierkiewicz, and Steve Scheiner. "Anion–anion and anion–neutral triel bonds." Physical Chemistry Chemical Physics 23, no. 8 (2021): 4818–28. http://dx.doi.org/10.1039/d0cp06547a.

Full text
Abstract:
TrCl4− (Tr = Al, Ga, In, Tl) anion is able to engage in complexes with two Lewis bases: neutral NH3 or the CN− anion through a triel bond. Complexation leads to two types of geometries: axial and equatorial.
APA, Harvard, Vancouver, ISO, and other styles
40

Fortenberry, R. C. "Theoretical Electronic and Rovibrational Studies for Anions of Interest to the DIBs." Proceedings of the International Astronomical Union 9, S297 (May 2013): 344–48. http://dx.doi.org/10.1017/s1743921313016098.

Full text
Abstract:
AbstractThe dipole-bound excited state of the methylene nitrile anion (CH2CN−) has been suggested as a candidate carrier for a diffuse interstellar band (DIB) at 803.8 nm. Its corresponding radical has been detected in the interstellar medium (ISM), making the existence for the anion possible. This work applies state-of-the-art ab initio methods such as coupled cluster theory to reproduce accurately the electronic excitations for CH2CN− and the similar methylene enolate anion, CH2CHO−. This same approach has been employed to indicate that 19 other anions may possess electronically excited states, five of which are valence in nature. Concurrently, in order to assist in the detection of these anions in the ISM, work has also been directed towards predicting vibrational frequencies and spectroscopic constants for these anions through the use of quartic force fields (QFFs). Theoretical rovibrational work on anions has thus far included studies of CH2CN−, C3H−, and is currently ongoing for similar systems.
APA, Harvard, Vancouver, ISO, and other styles
41

Zhang, Jian-Feng, Bo Wan, Wen Liu, and Qian Shi. "Diaquadi-μ-formato-bis{μ-2,2′-[propane-1,3-diylbis(nitrilomethanylylidene)]diphenolato}cadmium(II)dinickel(II) dihydrate." Acta Crystallographica Section E Structure Reports Online 68, no. 8 (July 28, 2012): m1122—m1123. http://dx.doi.org/10.1107/s1600536812029583.

Full text
Abstract:
In the centrosymmetric title compound, [CdNi2(C17H16N2O2)2(HCOO)2(H2O)2]·2H2O, The NiIIcation is chelated by a 2,2′-[propane-1,3-diylbis(nitrilomethanylylidene)]diphenolate (salpn) anion, and further coordinated by a formate anion and a water molecule in a distorted NiN2O4octahedral geometry. The CdIIcation, located on an inversion center, is coordinated by four deprotonated hydroxy groups from two salpn anions and two carboxylate O atoms from formate anions in a distorted octahedral geometry. Both formate and salpn anions bridge the Cd and Ni cations, forming a trinuclear complex. Within the salpn anion, the benzene rings are twisted to each other at a dihedral angle of 61.46 (18)°. Intermolecular O—H...O hydrogen bonding is present in the crystal structure. The lattice water molecule is disorder over two positions with an occupancy ratio of 0.75:0.25.
APA, Harvard, Vancouver, ISO, and other styles
42

Rudiuk, Vitalii V., Anna M. Shaposhnyk, Vyacheslav M. Baumer, Igor A. Levandovskiy, and Svitlana V. Shishkina. "Salts of 4-[(benzylamino)carbonyl]-1-methylpyridinium and iodide anions with different cation:iodine stoichiometric ratios." Acta Crystallographica Section E Crystallographic Communications 77, no. 12 (November 2, 2021): 1219–23. http://dx.doi.org/10.1107/s2056989021011300.

Full text
Abstract:
The two iodide salts, 4-[(benzylamino)carbonyl]-1-methylpyridinium iodide–iodine (2/1), C14H15N2O+·I−·0.5I2, I, and 4-[(benzylamino)carbonyl]-1-methylpyridinium triiodide, C14H15N2O+·I3 −, II, with different cation:iodine atoms ratios were studied. Salt I contains one cation, one iodide anion and half of the neutral I2 molecule in the asymmetric unit (cation:iodine atoms ratio is 1:2). Salt II contains two cations, one triiodide anion (I 3 −) and two half triiodide anions (cation:iodine atoms ratio is 1:3). The NH group forms N—H...I hydrogen bonds with the I− anion in the crystal of I or N—H...O hydrogen bonds in II where only triiodide anions are present.
APA, Harvard, Vancouver, ISO, and other styles
43

Diop, Mouhamadou Birame, Libasse Diop, Laurent Plasseraud, and Thierry Maris. "Crystal structure of 2-methyl-1H-imidazol-3-ium aquatrichlorido(oxalato-κ2O,O′)stannate(IV)." Acta Crystallographica Section E Crystallographic Communications 71, no. 5 (April 22, 2015): 520–22. http://dx.doi.org/10.1107/s2056989015005988.

Full text
Abstract:
The tin(IV) atom in the complex anion of the title salt, (C4H7N2)[Sn(C2O4)Cl3(H2O)], is in a distorted octahedral coordination environment defined by three chlorido ligands, an oxygen atom from a water molecule and two oxygen atoms from a chelating oxalate anion. The organic cation is linked through a bifurcated N—H...O hydrogen bond to the free oxygen atoms of the oxalate ligand of the complex [Sn(H2O)Cl3(C2O4)]−anion. Neighbouring stannate(IV) anions are linked through O—H...O hydrogen bonds involving the water molecule and the two non-coordinating oxalate oxygen atoms. In combination with additional N—H...Cl hydrogen bonds between cations and anions, a three-dimensional network is spanned.
APA, Harvard, Vancouver, ISO, and other styles
44

McCarty, Nael A., and Zhi-Ren Zhang. "Identification of a region of strong discrimination in the pore of CFTR." American Journal of Physiology-Lung Cellular and Molecular Physiology 281, no. 4 (October 1, 2001): L852—L867. http://dx.doi.org/10.1152/ajplung.2001.281.4.l852.

Full text
Abstract:
The variety of methods used to identify the structural determinants of anion selectivity in the cystic fibrosis transmembrane conductance regulator Cl− channel has made it difficult to assemble the data into a coherent framework that describes the three-dimensional structure of the pore. Here, we compare the relative importance of sites previously studied and identify new sites that contribute strongly to anion selectivity. We studied Cl−and substitute anions in oocytes expressing wild-type cystic fibrosis transmembrane conductance regulator or 12-pore-domain mutants to determine relative permeability and relative conductance for 9 monovalent anions and 1 divalent anion. The data indicate that the region of strong discrimination resides between T338 and S341 in transmembrane 6, where mutations affected selectivity between Cl− and both large and small anions. Mutations further toward the extracellular end of the pore only strongly affected selectivity between Cl− and larger anions. Only mutations at S341 affected selectivity between monovalent and divalent anions. The data are consistent with a narrowing of the pore between the extracellular end and a constriction near the middle of the pore.
APA, Harvard, Vancouver, ISO, and other styles
45

Kruszynski, Rafal, and Dariusz Wyrzykowski. "Tetrabutylammonium bromotrichloroferrate(III)." Acta Crystallographica Section E Structure Reports Online 62, no. 5 (April 11, 2006): m994—m996. http://dx.doi.org/10.1107/s1600536806012402.

Full text
Abstract:
The Fe3+ centre in the complex anion of the title compound, [(C4H9)4N][FeBrCl3], is surrounded by three chloride anions and one bromide anion. The Br atom in [FeBrCl3]− is disordered, replacing Cl atoms. The Fe and N atoms lie on a twofold rotation axis.
APA, Harvard, Vancouver, ISO, and other styles
46

Ohya, Junichi, Hiroyuki Sango, and Etsuo Sakai. "Immobilization Reaction of Chromate Ion Using Ca4Al2(OH)12·Cl2·4H2O." Key Engineering Materials 617 (June 2014): 24–27. http://dx.doi.org/10.4028/www.scientific.net/kem.617.24.

Full text
Abstract:
Hydrocalmite-like hydrate is one of calcium aluminate hydrated products. This hydrate has a layer structure and the principal layer, which is similar to calcium hydroxide define alternate with interlayer including divalent anions and water molecules. Their anions are able to react with outer anions by anion-exchange reaction. In this study, anion-exchange reaction between hydrocalmite-like hydrate including chloride anion (Ca4Al2(OH)12·Cl2·4H2O, Cl-HC) and chromate anion (CrO42-) is examined. CrO42- is immobilized in various hydrated forms, which are varied with an increasing in the additive ratio of CaCrO4 to Cl-HC. As the additive ratio of CaCrO4 to Cl-HC is below 1.0 in molar, Ca4Al2(OH)12·CrO4·nH2O (n=6 or 8, CrO4-HC) is formed. In this case, the concentration of chromate ion in solution is less than 1.0 ×10-3 mol·dm-3 and over 99% of chromium immobilize in solid phase. However, when the additive ratio of CaCrO4 is over 1.0, ettringite type hydrate including CrO42- (Ca6Al2(OH)12·3CrO4 ·26H2O) is generated and over 10 % of chromium is eluted from the solid phase.
APA, Harvard, Vancouver, ISO, and other styles
47

Reiss, Guido J., and Martin van Megen. "Two New Polyiodides in the 4,4´-Bipyridinium Diiodide/Iodine System." Zeitschrift für Naturforschung B 67, no. 1 (January 1, 2012): 5–10. http://dx.doi.org/10.1515/znb-2012-0102.

Full text
Abstract:
The reaction of bipyridine with hydroiodic acid in the presence of iodine gave two new polyiodide-containing salts best described as 4,4´-bipyridinium bis(triiodide), C10H10N2[I3]2, 1, and bis(4,4´-bipyridinium) diiodide bis(triiodide) tris(diiodine) solvate dihydrate, (C10H10N2)2I2[I3]2 · 3 I2 ·2H2O, 2. Both compounds have been structurally characterized by crystallographic and spectroscopic methods (Raman and IR). Compound 1 is composed of I3 − anions forming one-dimensional polymers connected by interionic halogen bonds. These chains run along [101] with one crystallographically independent triiodide anion aligned and the other triiodide anion perpendicular to the chain direction. There are no classical hydrogen bonds present in 1. The structure of 2 consists of a complex I144− anion, 4,4´-bipyridinium dications and hydrogen-bonded water molecules in the ratio of 1 : 2 : 2. The I144− polyiodide anion is best described as an adduct of two iodide and two triiodide anions and three diiodine molecules. Two 4,4´-bipyridinium cations and two water molecules form a cyclic dimer through N-H· · ·O hydrogen bonds. Only weak hydrogen bonding is found between these cyclic dimers and the polyiodide anions.
APA, Harvard, Vancouver, ISO, and other styles
48

Dey, Sandeep Kumar, Sonam Kumari, Sonal Mandrekar, Shashank N. Mhaldar, Sarvesh S. Harmalkar, and Christoph Janiak. "Revisiting salicylidene-based anion receptors." RSC Advances 11, no. 58 (2021): 36850–58. http://dx.doi.org/10.1039/d1ra07677a.

Full text
Abstract:
Salicylidene Schiff bases undergo imine bond hydrolysis in the presence of halides and oxo-anions in aprotic media, raising fundamental questions on the applicability of salicylidene-based receptors as anion sensors.
APA, Harvard, Vancouver, ISO, and other styles
49

Savastano, Matteo, Celeste García-Gallarín, Claudia Giorgi, Paola Gratteri, Maria Dolores López de la Torre, Carla Bazzicalupi, Antonio Bianchi, and Manuel Melguizo. "Solid State and Solution Study on the Formation of Inorganic Anion Complexes with a Series of Tetrazine-Based Ligands." Molecules 24, no. 12 (June 16, 2019): 2247. http://dx.doi.org/10.3390/molecules24122247.

Full text
Abstract:
Four molecules (L1–L4) constituted by an s-tetrazine ring appended with two identical aliphatic chains of increasing length bearing terminal morpholine groups were studied as anion receptors in water. The basicity properties of these molecules were also investigated. Speciation of the anion complexes formed in solution and determination of their stability constants were performed by means of potentiometric (pH-metric) titrations, while further information was obtained by NMR and isothermal titration calorimetry (ITC) measurements. The crystal structures of two neutral ligands (L3, L4) and of their H2L3(ClO4)2∙2H2O, H2L4(ClO4)2∙2H2O, H2L3(PF6)2, and H2L3(PF6)2∙2H2O anion complexes were determined by single crystal X-ray diffraction. The formation of anion–π interactions is the leitmotiv of these complexes, both in solution and in the solid state, although hydrogen bonding and/or formation of salt-bridges can contribute to their stability. Evidence of the ability of these ligands to form anion–π interactions is given by the observation that even the neutral (not-protonated) molecules bind anions in water to form complexes of significant stability, including elusive OH− anions.
APA, Harvard, Vancouver, ISO, and other styles
50

Shafei, Gamal M. S. El, and Afaf A. Zahran. "Structural and Textural Properties of Perchlorated and Persulphated Mixed (Hydr)Oxides of Zirconium and Titanium." Adsorption Science & Technology 20, no. 8 (October 2002): 707–22. http://dx.doi.org/10.1260/026361702321104219.

Full text
Abstract:
Perchlorated and persulphated mixed hydroxides of zirconium and titanium were prepared by coprecipitation and impregnation in aqueous HClO4 or (NH4)2S2O8 solutions of 0.05, 0.10, 0.20 and 0.40 M concentrations. An alternate sequence of impregnation followed by calcination or vice versa was conducted and the samples obtained studied using XRD, FT-IR, pyridine titration and low-temperature (–196°C) nitrogen adsorption methods. XRD indicated that the presence of titanium stabilized the tetragonal modification of zirconia and almost completely prevented the usual tetragonal → monoclinic transformation upon calcination at 650°C. Both S2O82– and ClO4− anions at their lowest concentration level (0.05 M) partially retarded the crystallization which occurred upon calcination at 650°C in their absence. However, the two anions showed different effects. Whereas the perchlorate anion prevented the formation of a crystalline titania phase (anatase) to a greater extent than that of crystalline zirconia, the persulphate anion showed the opposite effect. Complete inhibition was observed with both anions at a concentration of 0.4 M. This effect was attributed to adsorption of the anions on the hydroxy species of zirconium and titanium formed initially, as demonstrated by IR spectroscopy which showed that the anions were of lower symmetry, viz. C2v, due to their bonding to the hydroxy species. Calcination at 650°C caused the material formed initially to lose virtually all its initial high surface area because of crystallization. The prevention of crystallization by added anions was reflected in the retention of a relatively high surface area even after calcination at 650°C. The recorded difference in the interactions of the anions with the hydroxy species formed initially was also reflected in the texture of the anion-modified solids. The protecting influence of the ClO4− anion increased with its increasing concentration in the system, whereas the corresponding effect with the S2O82– anion increased up to 0.10 M concentration and then decreased at higher concentrations.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the bibliographies on the topic 'Anion' for other source types:
Dissertations / Theses Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography