Small Anions Research Articles

Effects of Alkyl Chain Length on Interfacial Structure and Differential Capacitance in Graphene Supercapacitors: A Molecular Dynamics Simulation Study

Supercapacitors with graphene electrodes are studied via molecular dynamics simulation. As an electrolyte, we consider three different room-temperature ionic liquids (RTILs), each of which is made up of the same anion BF4−, and different cations, 1-Cn(n=2,4,6)-3-methylimidazolium, respectively. We investigate how the alkyl chain length of the cation affects their interfacial structure and electrical properties for electric double layer capacitors. As a whole, cations and anions make layering structures between two parallel electrodes. Cations in the nearest layer orient predominantly in parallel to the electrode. Imidazolium rings of cations form π-stacking with graphene, then the alkyl chains of cations align parallel to the electrode. Differential capacitances in three RTILs are found to decrease with an increase of the magnitude of electrode potentials. The ion size and orientation affect both structure and capacitance behavior. The parallel orientations of cations become stronger with an increase of the alkyl chain length for the considered RTILs. The differential capacitance tends to decrease with raising the alkyl chain length over a wide range of the electrode potential. This is ascribed to a steric effect caused by larger cation size. It is also found that anodic capacitance is higher than cathodic one due to a higher screening efficiency by small anions, and an asymmetry in the peak of capacitance biased to the cathodic side becomes weaker as the alkyl chain length increases. Comparing electrode charge with ion numbers near the electrodes, with respect to their changes in response to the electrode potential, we find that the interfacial layer of the electrolyte mainly governs capacitive behavior of the systems.

Detection of recurrent fluorescence photons emitted from C4−

SynopsisWe detected recurrent fluorescence (RF) in the region of visible light emitted from small carbon cluster anions C4− and C6− stored in an electrostatic ion storage ring. The observed RF decay profile for C4− is consistent to our simulation under the assignment that the RF is associated with the C2∏g-X2∏u transition. In addition, observation of the RF at two different wavelengths suggests that the RF band is rather broad.

Eu(III)-functionalized In-MOF (In(OH)bpydc) as fluorescent probe for highly selectively sensing organic small molecules and anions especially for CHCl3 and MnO4−

A highly fluorescent metal–organic framework (In-MOF, In(OH)bpydc (bpydc=biphenyl-5,5′-dicarboxylate)) imparting additional luminescent Eu3+ ions has been synthesized for sensing organic molecules and anions, especially chloroform and MnO4−, both of them have a significant spectral response. This Eu3+-incorporated hybrid (In-MOF-Eu) has been fully characterized, which reveals large surface area, great pore size, favorable thermal stability, excellent luminescence as well as good fluorescence stability. On the one hand, the dual-emitting MOF hybrid exhibits a distinctly different response to the chloroform, one of which is almost unchanged, while the other intrinsic broad emission has a remarkable enhancement, leading to an obvious change in color; on the other hand, it also shows a high selectivity for detection of MnO4− because of the largest quenching effect on the luminescent emission, which results in a dark emission. This work represents a new approach for the fabrication of highly selective and sensitive probe for detection of chloroform and MnO4−, as it underlines the opportunity of MOFs with prominent optical properties to explore the existing target substance in the environment.

Formation of Fluorohydroxyapatite with Silver Diamine Fluoride

Silver diamine fluoride (SDF) is found to promote remineralization and harden the carious lesion. Hydroxyapatite crystallization is a crucial process in remineralization; however, the role of SDF in crystal formation is unknown. We designed an in vitro experiment with calcium phosphate with different SDF concentrations (0.38, 1.52, 2.66, 3.80 mg/mL) to investigate the effect of this additive on the nucleation and growth of apatite crystals. Two control groups were also prepared—calcium phosphate (CaCl2·2H2O + K2HPO4 in buffer solution) and SDF (Ag[NH3]2F in buffer solution). After incubation at 37 oC for 24 h, the shape and organization of the crystals were examined by bright-field transmission electron microscopy and electron diffraction. Unit cell parameters of the obtained crystals were determined with powder X-ray diffraction. The vibrational and rotational modes of phosphate groups were analyzed with Raman microscopy. The transmission electron microscopy and selected-area electron diffraction confirmed that all solids precipitated within the SDF groups were crystalline and that there was a positive correlation between the increased percentage of crystal size and the concentration of SDF. The powder X-ray diffraction patterns indicated that fluorohydroxyapatite and silver chloride were formed in all the SDF groups. Compared with calcium phosphate control, a contraction of the unit cell in the a-direction but not the c-direction in SDF groups was revealed, which suggested that small localized fluoride anions substituted the hydroxyl anions in hydroxyapatite crystals. This was further evidenced by the Raman spectra, which displayed up-field shift of the phosphate band in all the SDF groups and confirmed that the chemical environment of the phosphate functionalities indeed changed. The results suggested that SDF reacted with calcium and phosphate ions and produced fluorohydroxyapatite. This preferential precipitation of fluorohydroxyapatite with reduced solubility could be one of the main factors for arrest of caries lesions treated with SDF.

Experimental and Computational Studies of the Reactions of N and O Atoms with Small Heterocyclic Anions.

The existence of heterocyclic aromatic anions in extraterrestrial environments, such as the upper atmosphere of Titan, has been recently confirmed by data from the Cassini spacecraft. Nitrogen and oxygen atoms are also common species in the ionospheres of planets and moons and in the interstellar medium. In the current work, we extend previous studies to explore the reactivity of five-membered ring aromatic anions that contain nitrogen, oxygen, or sulfur (deprotonated pyrrole, furan, and thiophene) with N and O atoms both experimentally and computationally. Furanide and thiophenide anions react with the N atom by associative electron detachment (AED). All three anions react with the O atom both by AED and by processes that form ionic products. The reaction of pyrrolide anion with the O atom generates only one ionic product C4H3NO-, corresponding to an O addition and H loss process. The corresponding process is observed as the major channel for the reaction of furanide anion with the O atom while other ionic products HCOO- and C2H- are also formed. The reaction of thiophenide with the O atom is more complex, and four ionic products are generated, of which three are sulfur-containing ions. The reaction mechanisms are studied theoretically by employing density functional theory calculations, and spin conversion is found to be critical for understanding some product distributions. This work provides insight into the rich gas-phase chemistry of aromatic ion-atom reactions, which are relevant to ionospheric and interstellar chemistry.

Luminescent coordination polymers based on a new resorcin[4]arene-functionalized tetracarboxylate: Highly selective luminescent detection of metal cations, anions and small organic molecules

Fluorescence-based probes have received considerable attention because of their superiority in high selectivity and sensitivity. In this work, two novel luminescent isostructural coordination polymers (CPs), namely, [Zn3(HL)2(DMF)2(H2O)2]·2H2O (1) and [Cd3(HL)2(DMF)2(H2O)2]·2H2O (2), were successfully prepared by using a new resorcin[4]arene-based tetracarboxylic acid H4L under solvothermal conditions. In 1 and 2, HL3- anions bridge four metal cations to form charming 2D double layer structures. Drastically, the highly selective and sensitive luminescent detection of small organic molecules, metal cations and anions, particularly of Fe3+, Cr2O72- and nitrobenzene, has been studied using 1 or 2 as a promising luminescent sensor.

Hydrogen Ion Role on the Reduction of Poly-(Neutral Red)

Neutral Red (3-amino-7-dimethylamino-2-methylphenazine, abbreviated as NR) is a heterocyclic compound belonging to the phenazine family. Like its close relative Azure A, NR has been subject of much ongoing research [1] due to its biochemical (as dye for staining in histology) and chemical (as a pH indicator) relevance. Among other relevant functions, NR can be used as DNA-revealing dye by optical and electrochemical methods [2], for the evaluation of natural and synthetic biomaterials [3, 4], development of optical sensors [5], mediator of electro transfer in organic and bio-electrochemistry [6]. The first polymer of such a family, poly(thionine) was obtained by Albery et al. [7] and, since then, a whole lot of research has been devoted to polymer derivatives of NR and phenazine-like compounds. Their potential applications span from photogalvanic cells [8], batteries [9], bio-sensing [10], electrochromic systems [11], sensor of pH [12] and biosensors metal/PNR [13]. Indeed, the presence of the counter-anion A- becomes important. When no small anions (i.e. Cl-) are present, the electro-catalysis is favoured at basic pH. On the other hand, H2 is discharged at acidic pH, because the big counter-anions present in the Britton-Robinson buffer cannot pass through the polymer matrix. In other words, the proposed mechanisms above can be summarized as follows: PNR + 2e- + 2H+ ⇆ PNRH2 PNRH2 + 2 e- + 2 H+ ⇆ PNRH2 + H2 In order to retrieve reliable information about such redox processes and be able to tell “which is which”, derivative voltoabsorptometry was carried out on PNR films over the 2.18 to 8.95 pH range. Such an analytical method is a very useful tool in that UV-Vis absorptions are monitored as a function of a specific potential range. This, in turn, allows telling apart different contributions to the same redox peak(s) that may come from different phenomena. dA/dt changes against potential. During cycling of PNR at acidic pH, the most prominent changes were detected at 4 wavelengths: 418 nm, 587 nm, 745 nm, and 925 nm. In here, the current intensities and dA/dt are plotted against the potential window. The reduction-oxidation processes of the central ring on the NR molecule [14] absorbs at 418 and 578 nm, whereas the redox activity of the inter-monomer bond causes absorption at 745 and 925 nm. It can be inferred that, at acidic pH, the central ring is protonated and its reduction is easier (i.e. a lower potential is required); as the pH increases, the amount of protonated PNR decreases and its reduction becomes more difficult (i.e. the potential shifts to more negative values) till it becomes impossible or highly unlikely/not detectable. REFERENCES [1] R. Osborne. M. A. Perkins, Food Chem. Toxicol. 32 (1994) 133-142. [2] A. C. Allison, I. A. Magnus, M. R. Young, Nature 209 (1966) 874-878. [3] X. Zhong, J. Chen, B. Liu, Y. Xu, Y. Luang, J. Solid State Electrochem. 11 (2007) 463–468. [4] M. E. Ghica, C. M. A. Brett, Electroanalysis 18 (2006) 748 – 756. [5] G. Broncová, T. V. Shishkanova, P. Matejka, R. Volf, V. Král, Anal. Chim. Acta 511 (2004) 197–205. [6] M. M. Barsan, J. Klincar, M. Batic, C. M.A. Brett, Talanta 71 (2007) 1893–1900. [7] B. S. B. Salomi, C. K. Mitra, Biosens. Bioelectron. 22 (2007) 1825–1829. [8] J. C. Lamanna, K. A. McCracken, Anal. Biochem. 142 (1984) 117-125. [9] H. Heli, S. Z. Bathaie, M. F. Mousavi, Electrochim. Acta 51 (2005) 1108–1116. [10] G. Zhang, S. Shuang, C. Dong, D. Liu, M. M.F. Choi. J. Photoch. Photobio. B 74 (2004) 127–134. [11] Y. Ni, S. Dua, S. Kokot, Anal. Chim. Acta 584 (2007) 19–27. [12] D. Benito, J.J. García-Jareño, J. Navarro-Laboulais, F. Vicente, J. Electroanal. Chem. 446 (1998) 47. [13] J. Agrisuelas, J.J. Garcia-Jareño, P. Rivas, J.M. Rodriguez-Mellado, F. Vicente, Electrochim. Acta. 171 (2015) 165–175. [14] J. Agrisuelas, J.J. García-Jareño, D. Gimenez-Romero, F. Vicente, Electrochim. Acta. 55 (2010) 6128–6135. ACKNOWLEDGEMENTS Part of this work was supported by FEDER-CICyT CTQ2015-71794-R. Figure 1

A Comprehensive Study of the Intercalation Behavior of Anions from Ionic-Liquid Based Electrolytes into a Graphite Positive Electrode for Dual-Ion Batteries

The increasing demand for large scale energy storage capabilities causes a big field of research to make the battery systems safer and environmentally benign. A promising approach is the replacement of conventional volatile and highly flammable organic solvent-based electrolytes by ionic liquids (ILs) as the main component of the electrolyte. ILs exhibit excellent properties such as a broad electrochemical stability window, a high thermal stability, non-flammability and a high ionic conductivity.[1] A further prevention of pollution is the application of carbon-based, transition metal-free electrode materials. Recently, “dual-ion” and “dual-graphite” cells were introduced which are composed of a lithium-incorporating anode and an anion incorporating graphite-based cathode.[2][3] During charge the ions intercalate into the electrode active materials and are released back into the electrolyte during discharge (see Figure 1). Since the cathode potential reaches and may even exceed 5 V vs. Li/Li+, electrolytes that exhibit a high stability vs. oxidation are necessary. For that reason, ILs with their versatile properties were introduced and investigated. The state of the art electrolyte for this system is composed of a solution of lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) in N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (Pyr14TFSI). In order to increase the specific capacity of this system, one main strategy is to focus on the intercalation of smaller anions than TFSI into the graphite structure. In this context, the major challenge is the synthesis of ILs or mixtures of ILs with organic electrolytes consisting of small anions to provide an electrochemically stable electrolyte. Interestingly, not only the size and shape of the intercalated anions plays a major role in view of onset potential for anion uptake as well as discharge capacity. Instead, also more complex coherences such as ion association, self-aggregation of ions as well as solvent co-intercalation have to be taken into consideration. In this work, we investigate the electrochemical intercalation of anions with different shapes and sizes from IL based electrolytes into a graphite-based cathode. Against this background, the influence of side chain modifications within the anion structure as well as the influence of the used cation within the conductive salt (Li+/K+) on the intercalation behavior was studied using different electrochemical analysis techniques. Therefore, in this contribution we will give new insights to the question if the anion size is the main issue to tailor the reversible capacity for anion intercalation. Furthermore, the influence of lithium plating behavior in different electrolyte systems on the overall cell performance as well as the effect of adding small amounts of different additives such as foreign cations and different conductive salts into the baseline electrolyte is discussed. Figure 1: Schematic illustration of the operating principle of a "dual-ion cell”.[2] 1] A. Lewandowski, A. Swiderska-Mocek, Journal of Power Sources, 194 (2009) 601-609. [2] T. Placke, P. Bieker, S.F. Lux, O. Fromm, H.W. Meyer, S. Passerini, M. Winter, Zeitschrift für Physikalische Chemie, 226 (2012) 391-407. [3] K. Beltrop, P. Meister, S. Klein, A. Heckmann, M. Grünebaum, H.-D. Wiemhöfer, M. Winter, T. Placke, Electrochimica Acta, 209 (2016) 44-55. Figure 1

Theoretical insights into the interaction between RunPt13-n (n = 4, 7 and 9) clusters and [BMIM]+ based ionic liquids: Effect of anion

Density functional theory has been performed to systematically study the interactions between RunPt13-n (n=4, 7 and 9) clusters and [BMIM]+ based ionic liquids. Ionic liquids [BMIM][Br], [BMIM][BF4], [BMIM][PF6], [BMIM][CF3SO3], and [BMIM][NTf2] have different effects on the stability of Ru7Pt6. Ionic liquids with median size anions of PF6− and CF3SO3− can better improve the stability of Ru7Pt6 than those with the small anions of Br− and BF4− and large anion of NTf2−. Based on negative relaxation energies, the stabilities of Ru4Pt9, Ru7Pt6, and Ru9Pt4 are all enhanced after interacting with [BMIM][CF3SO3]. The stability enhanced degree is in agreement with the interaction strength. For Ru7Pt6–n{[BMIM][CF3SO3]} (n=1, 2, 3, 4), the interaction between ionic liquid and cluster plays the primary role in stabilizing the cluster in Ru7Pt6–[BMIM][CF3SO3]. With the increase of the number of [BMIM][CF3SO3], the role of the interaction in stabilizing the cluster is getting weaker, while the role of steric protection is getting more important.

Scientific Approach for a Cleaner Environment Using Ionic Liquids

Ionic liquids (ILs) are ionic compounds composed of a bulky organic cation and a smaller anion. The size mismatch leads to the low melting points relative to typical ionic compounds such as NaCl. ILs have become a very fruitful area of academic and industrial research primarily because of their beneficial and diverse properties. Ionic liquids characteristically have low vapor pressures, good solvency, high ionic conductivities, and good heat transfer properties. Our work on different combinations of cations and anions has led to a wide span of properties, such as acidity, water solubility, chemical reactivity, viscosity, melting points, etc. Further optimization of a property for a particular application was accomplished through synthesis and compositional variations. Ionic liquid compositions can be tailored to make them much greener than many traditional solvents and catalysts. Volatile organic compounds (VOCs) may cause air pollution and health issues. As a result industrial processes are looking for s...

Towards a chromatographic similarity index to establish localised quantitative structure-retention relationships for retention prediction. II Use of Tanimoto similarity index in ion chromatography

Quantitative Structure-Retention Relationships (QSRR) are used to predict retention times of compounds based only on their chemical structures encoded by molecular descriptors. The main concern in QSRR modelling is to build models with high predictive power, allowing reliable retention prediction for the unknown compounds across the chromatographic space. With the aim of enhancing the prediction power of the models, in this work, our previously proposed QSRR modelling approach called “federation of local models” is extended in ion chromatography to predict retention times of unknown ions, where a local model for each target ion (unknown) is created using only structurally similar ions from the dataset. A Tanimoto similarity (TS) score was utilised as a measure of structural similarity and training sets were developed by including ions that were similar to the target ion, as defined by a threshold value. The prediction of retention parameters (a- and b-values) in the linear solvent strength (LSS) model in ion chromatography, log k=a – blog[eluent], allows the prediction of retention times under all eluent concentrations. The QSRR models for a- and b-values were developed by a genetic algorithm-partial least squares method using the retention data of inorganic and small organic anions and larger organic cations (molecular mass up to 507) on four Thermo Fisher Scientific columns (AS20, AS19, AS11HC and CS17). The corresponding predicted retention times were calculated by fitting the predicted a- and b-values of the models into the LSS model equation. The predicted retention times were also plotted against the experimental values to evaluate the goodness of fit and the predictive power of the models. The application of a TS threshold of 0.6 was found to successfully produce predictive and reliable QSRR models (Qext(F2)2>0.8 and Mean Absolute Error<0.1), and hence accurate retention time predictions with an average Mean Absolute Error of 0.2min.

Eight-coordinate fluoride in a silicate double-four-ring

Fluoride, nature's smallest anion, is capable of covalently coordinating to eight silicon atoms. The setting is a simple and common motif in zeolite chemistry: the box-shaped silicate double-four-ring (D4R). Fluoride seeks its center. It is the strain of box deformation that keeps fluoride in the middle of the box, and freezes what would be a transition state in its absence. Hypervalent bonding ensues. Fluoride's compactness works to its advantage in stabilizing the cage; chloride, bromide, and iodide do not bring about stabilization due to greater steric repulsion with the box frame. The combination of strain and hypervalent bonding, and the way they work in concert to yield this unusual case of multiple hypervalence, has potential for extension to a broader range of solid-state compounds.

Syntheses, crystal structures, and magnetic properties of a family of heterometallic octanuclear [Cu6Ln2] (Ln = Dy(iii), Tb(iii), Ho(iii), Er(iii), and Gd(iii)) complexes

Five novel [Cu6Ln2] complexes were synthesized, wherein LnIII ions are seven-coordinate and coordinated by one triethanolamine and three di-2-pyridyl ketone ligands, without coordinated solvent molecules and small anions.

Below the 12-vertex: 10-vertex carborane anions as non-corrosive, halide free, electrolytes for rechargeable Mg batteries

The development of practical Mg based batteries is limited by the lack of a library of suitable electrolytes. Recently a 12-vertex closo-carborane anion based electrolyte has been shown to be the first electrolyte for Mg based batteries, which is both non-corrosive and has high electrochemical stability (+3.5 V vs. Mg0/2+). Herein we show that smaller 10-vertex closo-carborane anions also enable electrolytes for Mg batteries. Reduction of the trimethylammonium cation of [HNMe31+][HCB9H91-] with elemental Mg yields the novel magnesium electrolyte [Mg2+][HCB9H91-]2. The electrolyte displays excellent electrochemical stability, is non-nucleophilic, reversibly deposits and strips Mg, and is halide free. This discovery paves the way for the development of libraries of Mg electrolytes based on more cost effective 10-vertex closo-carborane anions.

Retention prediction of low molecular weight anions in ion chromatography based on quantitative structure-retention relationships applied to the linear solvent strength model

Quantitative Structure-Retention Relationships (QSRRs) represent a popular technique to predict the retention times of analytes, based on molecular descriptors encoding the chemical structures of the analytes. The linear solvent strength (LSS) model relating the retention factor, k to the eluent concentration (log k=a−blog [eluent]), is a well-known and accurate retention model in ion chromatography (IC). In this work, QSRRs for inorganic and small organic anions were used to predict the regression parameters a and b in the LSS model (and hence retention times) for these analytes under a wide range of eluent conditions, based solely on their chemical structures. This approach was performed on retention data of inorganic and small organic anions from the “Virtual Column” software (Thermo Fisher Scientific). These retention data were recalibrated via a “porting” methodology on three columns (AS20, AS19, and AS11HC), prior to the QSRR modeling. This provided retention data more applicable on recently produced columns which may exhibit changes of column behavior due to batch-to-batch variability. Molecular descriptors for the analytes were calculated with Dragon software using the geometry-optimized molecular structures, employing the AM1 semi-empirical method. An optimal subset of molecular descriptors was then selected using an evolutionary algorithm (EA). Finally, the QSRR models were generated by multiple linear regression (MLR). As a result, six QSRR models with good predictive performance were successfully derived for a- and b-values on three columns (R2>0.98 and RMSE<0.11). External validation showed the possibility of using the developed QSRR models as predictive tools in IC (Qext(F3)2>0.7 and RMSEP<0.4). Moreover, it was demonstrated that the obtained QSRR models for the a- and b-values can predict the retention times for new analytes with good accuracy and predictability (R2 of 0.98, RMSE of 0.89min, Qext(F3)2 of 0.96 and RMSEP of 1.18min).

Theoretical Investigation of the Te4Br2 Molecule in Ionic Liquids

Material synthesis in ionic liquids, at or near room temperature, is currently a subject of immense academic interest. In order to illuminate molecular‐level details and the underlying chemistry, we carried out molecular simulations of a single Te4Br2 molecule dissolved in the ionic liquid 1‐ethyl‐3‐methylimidazolium chloride, as well as in the ionic liquid mixed with aluminum chloride. Although the ethyl side chain is much too short to show detailed microheterogeneity, significant structuring with the small chloride anions is seen in case of the pure ionic liquid. In the case of the mixture, formation of larger anionic clusters is distinctly observed and analyzed. Due to the tendency of ionic liquids to dissociate, there is a pronounced shift to elongated Te–Br distances in both investigated solvents. However, only in the AlCl3‐containing liquid, we observe the reaction of the open chain‐like Te4Br2 molecule to a closed square‐like Te4Br+ and AlCl3Br– ion. The molecular arrangement of the [Te4]2+ unit shows negligible deviation from that in the experimental crystal structure.

Revised and Extended Values for Self-Diffusion Coefficients of 1-Alkyl-3-methylimidazolium Tetrafluoroborates and Hexafluorophosphates: Relations between the Transport Properties.

Earlier measurements of the self-diffusion coefficients of 1-alkyl-3-methylimidazolium (or [RMIM], R = alkyl) tetrafluoroborates and hexafluorophosphates have been revised and extended to 90 °C. The main changes are to DS+ and DS- for [HMIM][PF6] ([C6C1Im][PF6]) and DS- for [OMIM][BF4] ([C8C1Im][BF4]). New atmospheric pressure self-diffusion, density, and conductivity data are provided for [HMIM][BF4] ([C6C1Im][BF4]). Velocity cross-correlation, distinct diffusion, and Laity resistance coefficients have been calculated. There is no evidence for ion association. A new relation between the Nernst-Einstein deviation parameter (Δ) and resistance coefficients (rij) is derived; Δ tends toward 0.5 when the like-ion rii are much smaller than the unlike-ion rij, i.e., when the counterion interactions dominate. [OMIM]+ ion salts approach this limit. Stokes-Einstein-Sutherland and Walden plots overlap almost quantitatively for [BF4]-, [PF6]-, and Cl- salts with a common [RMIM]+ cation. That is, in thermodynamic states that have the same viscosity, the salt molar conductivities and hence ionic electrical mobilities of, say, [BMIM][BF4] and [BMIM][PF6] are almost equal, as are the corresponding Brownian or diffusive mobilities, (DSi/RT), for the cation, and also for these three small anions.

100 nm Thin‐Film Solid‐Composite Electrolyte for Lithium‐Ion Batteries

A thin‐film composite electrolyte (CE) with thickness of only 100 nm is fabricated for the first time. The conductivity of the solid electrolyte is 2 × 10−7 S cm−1 which corresponds to a cell resistance of only 50 Ω cm2 at this thickness. The electrolyte is composed of a nanoporous thin film, a lithium salt, and a polymer, and is fabricated by a two‐step approach. First, a porous SiOxCyHz film is deposited on the electrode substrate, then the porous structure is filled with a polyethylene glycol (PEG)‐LiX mixture by spin‐coating. The filling ratio of the mesoporous SiOxCyHz is as high as 90% with less than 1% remaining porosity, as determined from ellipsometric porosimetry. The effect of the anion, X−, of the LiX salt as well as the molecular weight of the PEG on the Li+ ion conductivity of the CE is investigated. The CE with smaller anion and with lower molecular weight PEG yields the highest conductivity. A functional Li/CE/TiO2 battery is built for demonstration purposes.

Benzopyrimido-pyrrolo-oxazine-dione CFTR inhibitor (R)-BPO-27 for antisecretory therapy of diarrheas caused by bacterial enterotoxins.

Secretory diarrheas caused by bacterial enterotoxins, including cholera and traveler's diarrhea, remain a major global health problem. Inappropriate activation of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel occurs in these diarrheas. We previously reported that the benzopyrimido-pyrrolo-oxazinedione (R)-BPO-27 inhibits CFTR chloride conductance with low-nanomolar potency. Here, we demonstrate using experimental mouse models and human enterocyte cultures the potential utility of (R)-BPO-27 for treatment of secretory diarrheas caused by cholera and Escherichia coli enterotoxins. (R)-BPO-27 fully blocked CFTR chloride conductance in epithelial cell cultures and intestine after cAMP agonists, cholera toxin, or heat-stable enterotoxin of E. coli (STa toxin), with IC50 down to ∼5 nM. (R)-BPO-27 prevented cholera toxin and STa toxin-induced fluid accumulation in small intestinal loops, with IC50 down to 0.1 mg/kg. (R)-BPO-27 did not impair intestinal fluid absorption or inhibit other major intestinal transporters. Pharmacokinetics in mice showed >90% oral bioavailability with sustained therapeutic serum levels for >4 h without the significant toxicity seen with 7-d administration at 5 mg/kg/d. As evidence to support efficacy in human diarrheas, (R)-BPO-27 blocked fluid secretion in primary cultures of enteroids from human small intestine and anion current in enteroid monolayers. These studies support the potential utility of (R)-BPO-27 for therapy of CFTR-mediated secretory diarrheas.-Cil, O., Phuan, P.-W., Gillespie, A. M., Lee, S., Tradtrantip, L., Yin, J., Tse, M., Zachos, N. C., Lin, R., Donowitz, M., Verkman, A. S. Benzopyrimido-pyrrolo-oxazine-dione CFTR inhibitor (R)-BPO-27 for antisecretory therapy of diarrheas caused by bacterial enterotoxins.

Ruthenium Tetrazole Based Electroluminescent Device: Key Role of Counter Ions for Light Emission Properties

Light-emitting electrochemical cells (LECs), thanks to their simple device structure and the tunable emission wavelength of the light-emitting layer, are emerging as a class of electrochemical device candidate for the development of next-generation solid-state lighting. The possibility to tune on-demand the energy levels of Ruthenium(II) polypyridyl complexes, makes them ideal candidates as light-emitting layer. However, the optimization of the latter is not trivial and several issues, such as charge injection and electron and hole transport, have still to be solved to enhance the LEC performances. Here, we demonstrate how the exploitation of small counter anion (BF4-) enhances the light emission performance of ruthenium tetrazole complexes in light-emitting diodes. In comparison with neutral ruthenium tetrazole complexes, cationic Ru tetrazole ones, containing BF4- ion, show a reduction of turn-on voltage from7 to 5 V, at high luminous efficiency (1.49 cd/A) and applied voltage of 12 V, and a twofold improvement of the luminance. Moreover, complexes containing BF4- counter ion show better stability of luminance over time than other complexes without counter ion.