Tetraalkylammonium Iodides Research Articles

Inorganic-Organic Hybrid Sulfide Solid Electrolytes Based on the Tetraalkylammonium Iodide-LiI-Li2S-P2S5 System

In this study, a series of novel inorganic-organic hybrid sulfide solid electrolytes was synthesized by doping Li7P2S8I with a selection of tetraalkylammonium iodides, including tetramethylammonium iodide (TMAI), tetraethylammonium iodide (TEAI), tetrapropylammonium iodide (TPAI), and tetrabutylammonium iodide (TBAI). The electrolytes were prepared in varying compositions, represented as (1−x) Li7P2S8I · x (TMAI, TEAI, TPAI, TBAI), where x values were adjusted to 0, 0.05, 0.1, and 0.2 (molar ratio) to assess their influence on the electrolyte properties. The hybrids exhibited predominantly amorphous structures. Tetraalkylammonium iodides with longer alkyl chains exhibited lower ionic conductivities. Mechanical characterization via indentation tests indicated that the incorporation of tetraalkylammonium iodides with longer alkyl chains reduced the elastic moduli of the composites. This study presents a methodological approach for modulating the structural and mechanical properties of sulfide solid electrolytes through strategic organic doping.

Determination of densities, apparent molar volume and apparent molar volume of transfer of some R4NI salt solutions in NMF-DMSO mixtures using magnetic float densitometer and then to study of ionic Interaction at 303.15 K

Binary solvent mixtures of different (%) compositions have been prepared at 303.15 K using tetra alkyl ammonium iodides (R 4 NI) of 0.02 M to 0.14 M to investigate inter ionic interaction, ion-ion and ion solvent interactions in NMF-DMSO solvent mixture containing large cations of tetra alkyl ammonium iodides (R 4 NI). The densities (ρ 0 ) of binary solvent mixtures and salt solutions have been measured by magnetic float densitometer. The apparent molar volume at infinite dilution ф v 0 , in the solvent mixtures, have been utilized to estimate the apparent molar volumes of transfer ∆ф v 0 (tr), for various tetra alkyl ammonium iodide salts (R 4 NI) from NMF-DMSO mixtures. The observed trend and variations of dielectric constant and density with different (%) composition of NMF – DMSO provide useful information about the structural interactions.

Influence of Tetra Alkyl Ammonium Cation on Thermo-Physical Properties of N,N-Dimethyl Formamide with 1,4-Dioxane at Different Temperatures

Ultrasonic technique, transport properties and related acoustical parameters of 1,4-dioxane and N,N-dimethyl formamide were prepared of different % compositions at variable temperatures using tetra alkyl ammonium iodide salts (R4NI) of 0.14 M, to investigate inter-ionic interactions, molecular interactions, molecular rearrangement, molecular association etc. The densities were measured by using magnetic float densitometer. Transport properties provide a deep and meaningful insight of various interactions taking place between the binary liquid mixtures with salts. We have observed the influence of small as well as large alkyl chain length (R4N+), and extract the information with respect to various kinds of intermolecular interactions such as dipole-dipole, dipole-induced dipole, solute-solvent, dispersive type and H-bonding interaction between the components. Such observations in the presence of specific molecular interactions of binary solutions and structural effects were analyzed on the basis of measured and derived thermo-dynamical parameters.

Synthesis and Structural Studies of Three‐Dimensional Supramolecular Motifs Derived from Neutral and Cationic Zinc Alkanesulfonates

The one‐pot reactions between anhydrous zinc acetate, diethyl or di‐n‐propyl sulfite, and tetraalkylammonium iodide (120 °C, 12 h) proceed through sulfur‐centered Arbuzov‐type rearrangement to afford [R14N]2[Zn(OSO2R)4] [R1, R = Et (1); R1 = nBu, R = nPr (2)] bearing alkanesulfonate groups bound to the metal center. The zincate salts 1 and 2 are used as precursors for the synthesis of neutral and cationic coordination complexes, namely, [Zn(OSO2Et)2(bipy)(dmso)2] (3; bipy = 4,4′‐bipyridine, dmso = dimethyl sulfoxide), [Zn(OSO2nPr)2(bipy)2]·dmso·H2O (4), [Zn(bipy)(H2O)4](OSO2Et)2 (5), [Zn(H2O)6](OSO2Et)2 (6), and [Zn(H2O)6](OSO2nPr)2 (7). X‐ray crystallographic studies of 3–7 reveal that the alkanesulfonate groups act as prolific H‐bond acceptors and assist the transformation of zero‐, one‐, or two‐dimensional coordination frameworks into three‐dimensional structural motifs.

Study of the Influence of Alkyl Chain Cation Solvent Interactions on the Slope of ϕv v/s √C Curves in 1, 3-Butanediol-DMF Solvent Mixtures by Apparent Molar Volume Measurements

The concept of Frank's hypothesis (that is the effect of large tetra alkyl ammonium ions on the solvent structure, especially water, in the ion-ion and ion-solvent interactions) was found to be not applicable when water was replaced by one of the organic solvents e.g. Dimethyl formamide (DMF), in the solvent mixture, that is, if the study involves ion-ion and ion- solvent interactions in 1,5-pentane diol - DMF solvent mixture containing large cations of tetraalkyl ammonium iodides. The densities of binary solvent mixtures and salt solutions have been measured at 298.15 K by magnetic float densitometer. The apparent molar volumes at infinite dilution, ФV 0 , determined by ФV -values in the solvent mixtures, have been utilized to estimate the partial molar volumes of transfer, ΔФV 0 (tr), for various tetraalkyl ammonium iodide salts from DMF to 1,5-Pentane diol.

Enolization versus carbonylation at glassy carbon surface through cathodic means

The cathodic reduction of ω-bromomethylarylketones in aprotic organic solvents (such as propylene carbonate) containing tetraalkylammonium iodides achieved at smooth glassy carbon (GC) permits through a selective one-electron reduction, the scission of the CBr bond. Quite unexpectedly, the free radical thus formed is prior attached to the carbon surface in its enolic form (GCO(Ar)CCH2). Successive radical addition processes may lead to a redox polymer based on the one-electron oxidation of enol ethers. The average superficial enol concentration at the carbon surface (found to be about 2.5×10−8molcm−2) was assessed by the halogen index (iodine or bromine) via halogen addition to the double bonds followed by the micro-coulometric reduction of the resulting vicinal di-halo compounds.

A Study of Masson's Slope in Dioxane-Formamide Mixture by Magnetic Float Densitometer Using Tetra Alkyl Ammonium Iodides at 25 ºC

A Study of Masson's Slope in Dioxane-Formamide Mixture by Magnetic Float Densitometer Using Tetra Alkyl Ammonium Iodides at 25 ºC

Janus‐Like Squaramide‐Based Hosts: Dual Mode of Binding and Conformational Transitions Driven by Ion‐Pair Recognition

New tripodal squaramide-based hosts have been synthesised and structurally characterised by spectroscopic methods. In 2.5 % (v/v) [D(6)]DMSO in CDCl(3), compound 4 formed dimeric assemblies [log K(dim)=3.68(8)] as demonstrated by (1)H NMR spectroscopy and UV dilution experiments. AFM and SEM analyses revealed the formation of a network of bundled fibres, which indicates a preferential mechanism for aggregation. These C(3)-symmetric tripodal hosts exhibited two different and mutually exclusive modes of binding, each one easily accessible by simultaneous reorientation of the squaramide groups. In the first, a convergent disposition of the NH squaramide protons allowed the formation of an array of N-H⋅⋅⋅X(-) hydrogen bonds with anions. In the second mode, reorientation of carbonyl squaramide groups allowed multiple C=O⋅⋅⋅H interactions with ammonium cations. The titration of 4 with different tetraalkylammonium iodides persistently showed the formation of 1:1 complexes, as well as 1:2 and 1:3 complexes. The corresponding stoichiometries and binding affinities of the complexes were evaluated by multi-regression analysis. The formation of high-order complexes, supported by ROESY, NOESY and mass spectrometry experiments, has been attributed to the insertion of NR(4)I ion pairs between the carbonyl and NH protons of the squaramide groups located in adjacent arms of 4. The observed effects reflect the induction of significant conformational changes in the hosts, mainly in relation to the relative orientation of the squaramide groups adapting their geometries to incoming ion-pair complementary substrates. The results presented herein identify and fully describe two different modes of ion-pair recognition aimed at directing conformational transitions in the host, therefore establishing a base for controlling more elaborate movements of molecular devices through ion-pair recognition.

Free propargyl radical: Facile cathodic generation and covalent linkage to solid surfaces

The cathodic reduction of propargyl bromide in regular polar solvents such as N,N-dimethylformamide or acetonitrile (ACN) results in a two-electron scission of the C Br bond. In contrast to this, the use of solvents of higher dielectric permittivity like propylene carbonate (PC) containing tetraalkylammonium iodide as electrolyte permits the quasi instantaneous formation of the corresponding iodide that can be electrochemically cleaved in a different way. Using gold, platinum, palladium or copper under those conditions allows obtaining the propargyl radical at quite low potentials. Unexpectedly, glassy carbon (GC) as cathode material causes a neat splitting of two one-electron transfers (ET) usually observed for most of organic halides as a single two-electron step. A dense propargylation of these solid surfaces was noticed. The propargyl group surface coverage was checked by FTIR, by its derivatization with alkyl ferrocene using azide-yne click chemistry, and by bromine index (coulometric reduction of halogenated surface-grafted layers); its level was found to be (4–6) × 10 − 9 mol cm − 2 of the apparent starting electrode area.

Free allyl radical: Catalytic generation and subsequent immobilization onto Au, Pd, Pt, and carbon cathodes

The cathodic reduction of allyl bromide (AllBr) in polar solvents of high dielectric constant containing tetraalkylammonium iodide at precious metals (Au, Pd, Pt, Rh) permits the one-electron scission of the C Br bond easily generating allyl radical. Glassy carbon (GC) used as cathode material also allows splitting the two one-electron transfers, usually observed with most of organic halides. A facile and dense allylation of several solid surfaces (in particular, at GC, Au and Pt) is obtained. The level of ethylenic moiety coverage was calculated by means of bromine and iodine indices (coulometric reduction of halogenated surface-grafted layers) and found to be between 1 and 6 × 10 −9 mol cm −2 of the original electrode area.

Ion-pair and triple-ion formation of some tetraalkylammonium iodides in n-hexanol and its binary mixtures with o-toluidine

The electrolytic conductivity of the tetraalkylammonium iodides, R 4NI (R = butyl to heptyl), has been studied in (0.00, 0.25, 0.50 and 0.75) mass fraction of o-toluidine (C 7H 9N) in n-hexanol (C 6H 14O) at T = 298.15 K. The limiting molar conductance Λ 0, association constants K A and the co-sphere diameter R for ion-pair formation in 0.00 and 0.25 mass fraction of solvent mixture have been evaluated using the Fuoss-equation. However, the deviation of the conductometric curves ( Λ versus c 1/2) from linearity for the electrolytes at 0.50 and 0.75 mass fraction of o-toluidine (C 7H 9N) in n-hexanol (C 6H 14O) indicates triple ion formation, and therefore the corresponding conductance data have been analyzed by the Fuoss–Kraus theory of triple ions. The observed values of the molar conductivity are explained by the ion-pairs (M + + X − ↔ MX) and triple-ions ( 2 M + + X - ↔ M 2 X + , M + + 2 X - ↔ MX 2 - ) formation. From the investigations, the following trend in conductance of the solvated salts has been observed: [Display omitted]

Study of the Influence of Alkyl Chain Cation‐Solvent Interactions on Water Structure in 1,3‐Butanediol‐Water Mixture by Apparent Molar Volume Data

The densities of 1,3‐butanediol‐water mixtures and some tetraalkylammonium iodide salt solutions in these solvent mixtures at different concentrations (0.02 M‐0.14 M) have been determined at 298.15 K using magnetic float densitometer technique. Then apparent molar volumes ΦV of the electrolytes in above solvent mixtures were calculated. The apparent molar volumes of transfer ∆ΦV° (tr) were also calculated and the ion‐ion / ion‐ solvent interactions are then discussed on the basis of changes in the Masson′s slope and apparent molar volumes of transfer data.

Nucleophilic cationization reagents.

Nucleophilic cationization reagents fitted with aminooxy groups are described. Practical syntheses of mono- and bis-aminooxy tetraalkylammonium iodides including N-hydroxyethyl-functionalized analogs are reported. An oximation example using one of the reagents is presented to illustrate their use in synthesis of cationic materials.

Ion association and solvation behavior of tetraalkylammonium iodides in binary mixtures of dichloromethane + N,N-dimethylformamide probed by a conductometric study

Precise measurements on electrical conductances of tetraalkylammonium iodides, R(4)NI (R = n-butyl to n-heptyl), in different mass% (0-100) of dichloromethane (DCM) + N,N-dimethylformamide (DMF) at 298.15 K have been performed. Limiting molar conductances (Λ(0)), association constants (K(A)) and co-sphere diameter (R) for ion-pair formation in the mixed solvent mixtures have been evaluated using the Fuoss conductance-concentration equation. However, the deviation of the conductometric curves (Λ versus √c) from linearity for the electrolytes in 100 mass% of DCM indicated triple ion formation, and therefore corresponding conductance data have been analyzed by the Fuoss-Kraus theory of triple ions. Limiting ionic molar conductances λ have been calculated by the reference electrolyte method along with a numerical evaluation of ion pair and triple ion formation constants (K(P)≈K(A) and K(T)). The results have been interpreted in terms of ion-solvent interactions and structural changes in the mixed solvents.

Ion Pair and Triple Ion Formation by Some Tetraalkylammonium Iodides in Binary Mixtures of Carbon Tetrachloride + Nitrobenzene

Electrical conductances of tetraalkylammonium iodides, R4NI (R = butyl to heptyl), in different mass % (20 to 80) of carbon tetrachloride (CCl4) + nitrobenzene (PhNO2) have been measured at 298.15 K. Limiting molar conductances Λ0, association constants KA, and cosphere diameter R for ion pair formation in the mixed solvent mixtures have been evaluated using the Lee−Wheaton conductivity equation. However, the deviation of the conductometric curves (Λ versus √c) from linearity for the electrolytes in 80 mass % of CCl4 + PhNO2 indicated triple ion formation, and therefore corresponding conductance data have been analyzed by the Fuoss−Kraus theory of triple ions. Limiting ionic molar conductances λ0± have been calculated by the reference electrolyte method along with a numerical evaluation of ion pair and triple ion formation constants (KP ≈ KAand KT); the results have been discussed in terms of solvent properties and configurational theory.

Ion-Pair and Triple-Ion Formation by Some Tetraalkylammonium Iodides in Binary Mixtures of 1,4-Dioxane + Tetrahydrofuran

Electrical conductances of tetraalkylammonium iodides, R4NI (R = pentyl to heptyl) have been measured at 298.15 K in low-permittivity mixtures of 1,4-dioxane (ε = 2.21) and tetrahydrofuran (ε = 7.58). Minima in the conductometric curves (Λ versus √c) were observed for electrolyte concentrations dependent upon both the electrolyte and the binary solvent mixture. The conductance data have been analyzed by the Fuoss−Kraus theory of triple ions. A numerical evaluation of ion-pair and triple-ion formation constants (KP and KT) was made, and the results have been discussed in terms of a molecular scale model.

1,2,3‐Dithiazole Chemistry in Heterocyclic Synthesis

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1,2,3-Dithiazole chemistry in heterocyclic synthesis

The chemistry of various 5H-1,2,3-dithiazoles is investigated with emphasis on assisted ring opening and ring closure reactions leading to new heterocycles. Thus on treatment with catalytic tetraalkylammonium iodide N-(2-chloropyrid-3-yl)and N-(4-chloropyrid-3-yl)-4-chloro-1,2,3dithiazol-5H-imines 19 and 20 give thiazolo[5,4-b]pyridine-2-carbonitrile 16 and thiazolo[4,5-c]pyridine-2-carbonitrile 17 respectively. Similar treatment of bisdithiazoles 29 and 30 afford high yielding routes to 1,3,4-thiadiazole-2,5-dicarbonitrile 31 and thiazole-2,4,5tricarbonitrile 32 respectively. N-(Pyrid-3-yl)-4-chloro-1,2,3-dithiazol-5H-imine 36 reacts with secondary alkylamines to give as main product pyrido[2,3-d]pyrimidines 37 and several minor byproducts including a deep green quinoidal 2,2’-bithiazole 40. Dithiazolylidenacetonitriles 43 react with either anhydrous HBr or tetraalkylammonium chloride to afford a series of 3-halo-4substituted-isothiazole-5-carbonitriles 45 and 52 respectively. The reactions of dithiazoles 43 with tetraalkylammonium chloride are complicated owing to the formation of isothiazolopentathiepin-8-carbonitrile 53, isothiazolodithiin-4,5,7-tricarbonitrile 54, tetracyanothiophene 56 and an unidentified compound 55 whose possible structures are proposed. The mechanistic rationales for the formation of the identified products are proposed.

Mechanism of the hydrolysis of N-aryliminotriphenylphosphoranes

The initiating effect of the benzoyl peroxide—tetraalkylammonium iodide system in the low-temperature liquid-phase oxidation of cumene at 313 K is studied. The reaction proceeds by a nonbranching-chain radical mechanism. At the initial stage, the kinetics of the process is described by a first-order equation. The parameters of the kinetic equation are determined at various substrate concentrations and component proportions in the initiating system. Addition to the reaction mixture of benzoic acid, cumene hydroperoxide, and iodine in amounts that can accumulate during the reaction produces only a slight effect on the oxidation rate.

Electrochemical Pumping of DMF Electrolyte Solutions across Membranes

Electrolysis of (dimethylformamide) (DMF) solutions containing tetraalkylammonium iodide salts and dissolved iodine in a two-compartment cell separated by a Nafion membrane results in transfer of solution volume between the two compartments. The pumping process was reversible and the rate, which ranged from 20 to 50 μL/min, was controlled by the cell current. The volume of solution pumped was significantly greater than what is predicted from the apparent molar volumes of the species involved in the electrolysis and from the charge passed. The additional volume is attributed to migration-assisted solvent flow across the membrane separator. Comparison of pumping results for a series of Nafion materials indicated that the solvent flow was related to the number of solvent molecules per ion-exchange site in the membrane. Pumping occurred with and against small external pressures up to 0.1 atm. Analysis of apparent molar ionic volumes indicates that the electrode reaction, contributes little to the observed volume change. Instead, the pumping is associated almost entirely with the apparent molar ionic volume of tetraalkylammonium ions and migration-assisted flow of DMF. © 2004 The Electrochemical Society. All rights reserved.