Tetraalkylammonium Iodides Research Articles

Initiating Properties of Benzoyl Peroxide–Tetraalkylammonium Iodide System in Radical Chain Oxidation Reactions

Tetraalkylammonium iodides have an initiating effect on benzoyl peroxide in the oxidation of cumene. The characteristics of the kinetics of this process in low temperature oxidation have been studied.

Hydration and association in solutions of tetraalkylammonium iodides

Conductivity, self-diffusion coefficient and viscosity were measured at 298 K for tetraalkylammonium iodides in aqueous solutions, 0.5 M urea solutions and mixtures of water with tert-butanol. The molar conductivity was analysed via the Fuoss–Hsia equation. The limiting molar conductivity, the separation of ions forming the ion pairs and the association constants were determined. In all studied systems the association of opposite ions was weak, but contact ion pairs were present. The hydrodynamic radii of ions, determined from the self-diffusion coefficients, were used to compute the dynamic hydration numbers. As expected, the dynamic hydration numbers were noticeably smaller than the static numbers, because they represented the water molecules located inside the R4N+ ions, between the alkyl chains. Addition of tert-butanol reduced the hydration of Me4N+ and, probably, Bu4N+ ions, but induced aggregation of Bu4N+ cations only.

Influence of electrolytes on the photovoltaic performance of organic dye-sensitized nanocrystalline TiO 2 solar cells

We have studied the influence of electrolytes on the photovoltaic performance of mercurochrome-sensitized nanocrystalline TiO 2 solar cells using LiI, LiBr, and tetraalkylammonium iodides as the electrolyte. Short-circuit photocurrent density ( J sc) and open-circuit photovoltage ( V oc) depended strongly on the electrolyte. J sc of 3.42 mA cm −2 and V oc of 0.52 V were obtained for the LiI electrolyte and J sc of 2.10 mA cm −2 and V oc of 0.86 V were obtained for the Pr 4NI electrolyte. This difference in photovoltaic performance was due to the change in the conduction band level of the TiO 2 electrode. Large V oc of 0.99 V was obtained for the LiBr electrolyte due to the large energy gap between the conduction band level of TiO 2 and the Br/Br 2 redox potential. Solar cell performance also depended strongly on organic solvent, suggesting that the physical properties of solvents such as Li ion conductivity and donor number affect photovoltaic performance.

The cathodic insertion of tetraalkylammonium iodides into palladium

The cathodic behavior of tetraalkylammonium iodides was studied at a polished palladium cathode in aprotic dimethylformamide (DMF). Coulometric and electrochemical quartz crystal microbalance analyses allowed to show the formation of phases, the stoichiometry of which was fully determined. The reversible insertion of tetraalkylammonium cations as well as the electrolyte into palladium was demonstrated.

Transport properties and battery performance studies of AgI–Ag 2O–Se 2O–P 2O 5 glass

Various compositions of silver-based quaternary superionic conducting (SIC) [AgI–Ag 2O–(SeO 2+P 2O 5)(SSP)] glasses were prepared by melt quenching technique. The X-ray diffraction (XRD) and conductivity studies were carried out to identify the amorphous nature and to select high ionic conducting composition of the SSP system for the fabrication of batteries. Solid-state primary batteries were fabricated using the 66.67%AgI–23.07%Ag 2O–10.26%(0.3SeO 2+0.7P 2O 5) (66SSP37) glass with different cathode materials [I:C, (I+C):SE and {(I+C)+SE}:T AAI, where I is Iodine, C is graphite, SE is solid electrolyte (SSP glass) and T AAI is tetraalkyl (methyl and butyl) ammoniumiodide]. The open circuit voltage (OCV), polarization and discharge characteristics were measured to estimate the lifetime of the batteries made up of SSP glass.

On the cathodic corrosion of platinum in the presence of iodides in dry aprotic solvents

Alkali and tetraalkylammonium iodides, generally used as electrolytes in analytical electrochemistry, were found to corrode platinum surfaces submitted to cathodic polarization. This phenomenon seems to be very general when aprotic dipolar solvents, carefully dried, are used. Thus, in dimethylformamide a slow reduction step implying platinum metal is observed and appears strongly dependent on the nature of the electrolyte cation. The corrosion process seems to be due to the concomitant insertion of cations and salts which leads to platinum clusters. Electroanalysis shows that corrosion (weight loss, surface holes and grain joins) may depend on both the potential applied to the metal and iodide salt concentration.

Characterization of solid-state batteries using a silver selenoarsanate glass system

Abstract The highest conducting composition of the silver selenoarsanate (SSA) compound was prepared by a melt-quenching method and its glassy nature was confirmed by X-ray diffraction. Primary cells with the configuration: anode (Ag+(solid electrolyte, SE))/SE glass (SSA)/cathode ((iodide, I)+(graphite, C)+SE+(tetra-alkylammonium iodide, TAAI)) were fabricated. Their characteristics were examined in order to estimate the life time. In particular, a study was made of the open-circuit voltage (OCV), polarization and discharge behaviour of three different sets of primary batteries made up of SSA glassy compound with various cathode materials.

Fabrication and characterization of silver-based solid-state primary batteries

Solid-state primary batteries are fabricated using the highest conducting composition of AgIAg 2O-(SeO 2 + V 2O 5) (SSV) quarternary glassy compound with different cathode materials such as I:C, (I + C): SE, and [( I + C) + SE]: T AAI = 9:1 (I: iodide; C: graphite; SE: solid electrolyte; T AAI : tetraalkyl ammonium iodide, and A : methyl, ethyl and butyl). Various sets of batteries are fabricated with the following configuration: anode/glassy solid electrolyte/cathode. The performance of the batteries made up of SSV glass is evaluated in terms of the measured open-circuit voltage, polarization and discharge characteristics.

Intermediate range structure of organic-inorganic mixed superionic conductor glasses: AgI and tetraalkylammonium iodides

Intermediate range structures of organic-inorganic mixed superionic conductor glasses were investigated by low-angle neutron diffraction and small-angle neutron scattering (SANS) experiments. Significant small angle scatterings were observed in the glasses composed of AgI-CsI-deuterized-tetramethylammonium iodides. The fractal dimension D f was estimated from the plot of the log I(q) vs. Log q; it was 0.39 above q c and 2.8 below, where q c was a cross-over wavelength of q c ∼ 0.02−0.05 A ̊ − 1 . This result strongly supports the existence of percolation clusters in the organic-inorganic mixed superionic conductor glasses, which has been expected from ionic conductivity measurements.

Properties of organic cations that lead to the structure-direction of high-silica molecular sieves

A variety of new organic structure-directing agents (SDA's) are synthesized and used for the synthesis of high-silica molecular sieves. The hydrophobicity and rigidity of these new and other previously known SDA's are evaluated in terms of their phase transfer behavior from water to chloroform and the number of tertiary and quaternary connectivities, respectively. It is found that the phase transfer behavior of the organic cation SDA's is best measured when they are in their iodide form, in that the greatest ability for discrimination between differences in hydrophobicity is possible in this form of the salt. The phase transfer behavior of numerous SDA's shows the same trend as that of simple tetraalkylammonium iodides with respect to the correlation between C/N + values and percent transferred. The phase transfer results are correlated to the ability for structure-direction in molecular sieve synthesis. It is difficult to obtain a molecular sieve when using extremely hydrophobic SDA's. For hydrophobic, monocationic SDA's, introduction of a second charge into the molecule decreases the hydrophobicity and allows for structure-direction in molecular sieve synthesis. Thus, SDA's with intermediate hydrophobicity are found to be most useful for high-silica molecular sieve synthesis. In terms of SDA geometry, bulky, rigid molecules with limited conformational variability result in near unique formation of a great variety of new high-silica molecular sieves. The use of relatively flexible molecules with a minimum diameter of approximately 5 Å gives more than one molecular sieve.

Solid-state batteries using silver-based glassy materials

A new, fast ion-conducting, silver seleno molybdate (SSM), glassy electrolyte has been synthesized. Solid-state primary cells of the design anode/solid electrolyte/cathode have been fabricated with the highest conducting composition of the SSM glass as the solid electrolyte. The polarization and discharge characteristics of the cells are studied with different compositions of the cathode material. The effect of adding the solid electrolyte and tetraalkylammonium iodide (alkyl = methyl, butyl) to the cathode on the cell performance is investigated. The cell parameters are evaluated and the results are compared with a cell of the type Ag/AgI/(iodine + graphite) (I + C) that is fabricated using polycrystalline AgI as the solid electrolyte.

O-Hydroxyethylation of 1,1-dihydroperfluorinated alcohols

A convenient transformation of 1,1-dihydroperfluorinated alcohols into O-hydroxyethyl derivatives (R FCH 2OCH 2CH 2OH) is described in which ethylene carbonate is utilized as the alkylating agent. Tetraalkylammonium iodides and trialkylamines are effective catalysts.

Ultrasonic interferometric study of the solutions of tetraalkylammonium iodides in dimethylsulphoxide at 40, 50 and 60°C

An ultimate study of ion-solvent interaction has been carried out in the solutions of tetraalkylammonium iodides (R 4NI; where R = C 1 to n-C 6) in dimethylsulphoxide at 40, 50 and 60°C. The study reveals that the R 4N + cations remain more or less secluded in this solvent as found in other non-aqueous solvents like sulpholane and ethylene carbonates.

Kinetics and mechanism of transesterification of phenyl salicylate

AbstractThe first‐order rate constants, k1, obtained for methanolysis and ethanolysis of phenyl salicylate (PSH) in aqueous mixed solvents, fit to a relationship: k1 = A1 · [ROH]T/(1 + A2[ROH]T) where A1 and A2 are the unknown parameters and [ROH]T is the total concentration of alkanol. It is proposed that the alkanolysis of PSH involves the preequilibrium formation of monomeric ROH from polymeric (ROH)n, followed by an intramolecular general base‐catalysed nucleophilic attack by monomeric ROH on the carbonyl carbon of the ester. In the mixed solvents containing alkanol and MeCN, the k1 – [ROH]T profiles obtained in the presence of K+ ions are different from those obtained in the presence of Na+ ions which could be attributed to the cation‐induced changes in the alkanol structure. Negative KCl salt effect has been observed on methanolysis of PSH, while it is essentially unaffected by the presence of tetraalkylammonium iodide salts (R4NI). The rates of ethanolysis of PSH have been found to increase with increase in [R4NI] and this increase becomes more pronounced with increasing hydrophobic surface area of R4NI. The rate constants for methanolysis of PSH in aqueous mixed solvents containing 80% MeOH (v/v) are independent of [ŌH] within the [ŌH] range of 0.01 to 0.15 M. The rate of methanolysis could not be detected within ca. 47 h in mixed solvents containing 96% HeOH (3.8% MeCN and 0.2% H2O), 80% MeOH (19.8% MeCN and 0.2% H2O), and 0.022 M HCl. It is concluded that for efficient transesterification, PSH should exist in ionized form. The reaction of PSH with MeOH is ca. 400 times faster than that with t‐BuOH which could be ascribed to the most likely steric effect. The values of ΔH* and ΔS* obtained for methanolysis and ethanolysis are essentially independent of [ROH] within the ROH content of 20% to 96% for MeOH and 50% to 96% for EtOH. The effect of organic co‐solvent on rate of hydrolysis of PSH could be explained in terms of organic co‐solvent‐induced water polarization.

Solubilities of inorganic salts and tetraalkylammonium iodides in sulfolane at several temperatures

SohbMes of some common salts and t e t r a d k y l a m lodtdes (R,NI) In sublane have been determined at dlfferent temperatures. In general, solubl#tles of dkaH metal haJldes are In the order Iodides > bromldeo > chlorides. The sdub#nles of R4NI salts Increase wHh gmwlng alkyl chaln from Me,NI to n-Bu,NI. Enthalph of rdutkn of sparingly soluble haHder have been estimated from the sdublklty data and are used to evaluate the sohation enthalpies ln studying the sdute-wlvent lnteradlon In sultolane.

Synthesis of bis (Tetraalkylammonium) Sulphates

Abstract Bis (tetraalkylammonium) sulphates, (R4N)2SO4 (R = Me, Et, Prn, Bun and Penn), have been synthesized by persulphate oxidation of the respective tetraalkyl ammonium iodides in aqueous solution. The compounds thus prepared were characterized from the analytical, cryoscopic and spectroscopic data.

Versatile organic iodide melts and glasses with high mole fractions of LiI: Glass transition temperatures and electrical conductivities

Noting the high σ o of LiI + LiPS 3 glasses we have explored the properties of salt melts in which all anions are iodide. To obtain these, various low-melting tetraalkylammonium iodides, TAAI's, which may vitrify with up to 70 mo1% LiI, have been synthesized. Some mixtures may remain liquid at room temperature indefinitely. Electrical conductances do not attain the room temperature values of the inorganic LiI glasses though may reach −10 −3 S cm −1 at 100°C. The organic cations introduce many possibilities for structural manipulation, and may also be polymerized. Preliminary polymerization and conductivity results are reported. The investigation has suggested an important principle (the counter-polarization principle) distinguishing high alkali conductivity in salt or polymer solutions on the one hand and glassy solid electrolytes on the other.

Specific adsorption of tetra-alkyl ammonium iodide at the mercury—solution interface and the influence of the double-layer structure on the kinetics of zinc ions

The effect of adsorption of tetra-alkyl ammonium iodide at the dme has been examined with Faradaic impedance measurements. The differential capacitance of mercury in the salt solutions of the type R 4NI, where R is CH 3, C 2H 5 and n-C 3H 7 at 25°C as a function of polarization is measured. The parameters of the electrocapillary maximum, E max and σ max, are evaluated. By comparing the differential capacitance curves with those observed in other aqueous salt solutions of the same concentration and assumed to exhibit specific adsorption, it is shown that the cation is specifically adsorbed and that adsorption increases from tetra-methyl to tetra-ethyl to tetra-propyl salts. On the anodic limb of the capacity curve it is assumed that there is simultaneous specific adsorption of cations and anions. The anions thus form bridges between the cations and the mercury surface. The apparent standard rate constant K s for the discharge of Zn(II)/Zn(Hg) in 1 M NaClO 4 was found to decrease in the presence of the quaternary cations and accelerated by iodide only. This phenomena is similar to that observed with the hydrogen evolution reaction at the mercury electrode and is opposite of those observed with anions of the persulphate type.

ChemInform Abstract: SOLUTE‐SOLVENT INTERACTIONS IN ION‐PAIR EXTRACTION OF TETRAALKYLAMMONIUM IODIDES. 3. THE ROLE OF RELATIVE PERMITTIVITY AND SOLUBILITY PARAMETER IN NITROBENZENE‐TETRACHLOROMETHANE MIXTURES AT 25°C

Chemischer InformationsdienstVolume 14, Issue 34 Article ChemInform Abstract: SOLUTE-SOLVENT INTERACTIONS IN ION-PAIR EXTRACTION OF TETRAALKYLAMMONIUM IODIDES. 3. THE ROLE OF RELATIVE PERMITTIVITY AND SOLUBILITY PARAMETER IN NITROBENZENE-TETRACHLOROMETHANE MIXTURES AT 25°C E. IWAMOTO, E. IWAMOTOSearch for more papers by this authorH. OHMORI, H. OHMORISearch for more papers by this authorY. YAMAMOTO, Y. YAMAMOTOSearch for more papers by this author E. IWAMOTO, E. IWAMOTOSearch for more papers by this authorH. OHMORI, H. OHMORISearch for more papers by this authorY. YAMAMOTO, Y. YAMAMOTOSearch for more papers by this author First published: August 23, 1983 https://doi.org/10.1002/chin.198334081AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume14, Issue34August 23, 1983 RelatedInformation

Solute-Solvent Interactions in Ion Pair Extraction of Tetraalkylammonium Iodides. II. The Effect of Hydration of Iodide in Organic Solvents on the Extraction Constant

Abstract Solubilities of tetraalkylammonium iodides Et4NI, Pr4NI, and Bu4NI in nitrobenzene, in water, and in their mutually saturated solvents, and of Pr4NI in 1,1-dichloroethane and in its water saturated solvent were measured at 25 °C. Conductances of Et4NI, Pr4NI, and Bu4NI in nitrobenzene and Bu4NI in 1,1-dichloroethane, 1,2-dichloroethane, and dichloromethane have also been measured at 25 °C. A small amount of water in organic solvents increases the solubilities of the salts roughly twice those in pure solvents and decreases the association constants around 15% while a small amount of organic solvent in water gives a slight effect. Effects of mutual saturation of water and organic solvent on extraction equilibria of R4NI were discussed in terms of the selective hydration of the iodide.