Conductance-Viscosity Studies on Some Moderately Concentrated Nonaqueous Electrolyte Solutions from −50° to 125°C

Rebagay, T.V.; Casteel, Jerry F.; Sears, Paul G.

doi:10.1149/1.2401992

Cited by 10 publications

(7 citation statements)

References 13 publications

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“…Changes in the electrolyte concentration, therefore, should not change the effective size of the ferrocene ions. For a range of organic solvents, however, an increase in the concentration of the supporting electrolyte increases the viscosity of the solutions. − Therefore, a decrease in C TBATFB can result in a substantial increase in the diffusion coefficient of ferrocene. , For ferrocenium ions in dilute solutions, on the other hand, the electrostatic effects can overcome the viscosity-induced modulation of their diffusion properties. , A decrease in C TBATFB can impede the mass transport of the charged ferrocenioum ions due to a lack of electrostatic screening in diluted electrolyte solutions. The corollary of these effects, indeed, will be a decrease in D Fc + / D Fc with dilution of the supporting electrolyte.…”

Section: Resultsmentioning

confidence: 99%

“…For a range of organic solvents, however, an increase in the concentration of the supporting electrolyte increases the viscosity of the solutions. [20][21][22] Therefore, a decrease in C TBATFB can result in a substantial increase in the diffusion coefficient of ferrocene. 22,23 For ferrocenium ions in dilute solutions, on the other hand, the electrostatic effects can overcome the viscosity-induced modulation of their diffusion properties.…”

Section: Resultsmentioning

confidence: 99%

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Electrochemical Oxidation of Ferrocene: A Strong Dependence on the Concentration of the Supporting Electrolyte for Nonpolar Solvents

et al. 2009

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The estimation of the driving force for photoinduced charge-transfer processes, using the Rehm-Weller equation, requires the employment of redox and spectroscopic quantities describing the participating electron donor and acceptor. Although the spectroscopic data are usually obtained from diluted solutions, the redox potentials are most frequently obtained from electrochemical measurements conducted in concentrated electrolyte solutions. To correct for the differences in the media, in which the various types of measurements are conducted, a term, based on the Born equation for solvation energy of ions, is introduced in the Rehm-Weller equation. The Born correction term, however, requires a prior knowledge of the dielectric constants of the electrolyte solutions used for the redox measurements. Because of limited information for such dielectrics, the values for the dielectric constants of electrolyte solutions are approximated to the values of the dielectric constants of the corresponding neat solvents. We examined the validity of this approximation. Using cyclic voltammetry, we recorded the first one-electron oxidation potential of ferrocene for three different solvents in the presence of 1-500 mM supporting electrolyte. The dielectric constants for some of the electrolyte solutions were extracted from fluorescence measurements of a dimethylaminonaphthalimide chromophore that exhibits pronounced solvatochromism. The dielectric constants of the concentrated electrolyte solutions correlated well with the corresponding oxidation potentials. The dependence of the oxidation potential of ferrocene on the electrolyte concentration for different solvents revealed that the abovementioned approximation in the Born correction term indeed introduces a significant error in the estimation of the charge-transfer driving force from redox data collected using relatively nonpolar solvents.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Electrochemical Oxidation of Ferrocene: A Strong Dependence on the Concentration of the Supporting Electrolyte for Nonpolar Solvents

et al. 2009

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“…The deviations for fitting ~] and • data for the PC systems to Eq. [4] and [5] are somewhat larger than those resulting from parallel analyses of data for DMF systems discussed previously (1). This is explained in major part by greater temperature coefficients for ~] and A and experimentally less precise determinations on the PC salt solutions.…”

Section: = Exp(a + P/t + ~/T 2 + 5/t 3 + ~/T 4)mentioning

confidence: 75%

“…The equipment and other procedural details are described in the preceding article (1). All determinations were made in duplicate or triplicate with very good precision except in six cases of conductance or viscosity determinations at the lowest temperatures where differences as great as 1% were observed.…”

Section: Methodsmentioning

confidence: 99%

Conductance‐Viscosity Studies on Some Moderately Concentrated Nonaqueous Electrolyte Solutions from −50° to 125°C: II . Solutions of ,, and in Propylene Carbonate

Casteel

Angel

Mcneeley

et al. 1975

J. Electrochem. Soc.

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Matching conductance, viscosity, and density data at 25 ~ intervals between --50 ~ and 125~ have been determined and analyzed for moderately concentrated solutions Of three quaternary ammonium halides in propylene car-bon~te. Detailed results are presented for the fitting of experimental data as functions of molal concentration and temperature to appropriate equations by computer least squares procedures. Calculated results related to moles of solvent displaced per mole of solute and also apparent molal volumes indicate the lack of significant ion-solvent interactions in the solutions of the quaternary ammonium salts in propylene carbonate. Additionally, conductance-viscosity products and activation energies of viscous flow and conductance have been calculated and discussed. Throughout the broadly varying experimental conditions over the 175~ range, the conductances of the three salts have been found to be iairly closely proportional to the fluidity, or reciprocal of the viscosity, of the medium.Conductances and viscosities of moderately concentrated solutions of Bu4NI, KSCN, and NH4Br in N,Ndimethylformamide from --50 ~ to 125~ were dealt with in the first article in this series (1). As a supplementary, parallel investigation on other nonaqueous electrolyte solutions over the unusually broad 175~ range, the present conductance-viscosity study relates to solutions of three quaternary ammonium halides in propylene carbonate, a solvent which like DMF has received much attention during the last 15-20 years.Propylene carbonate or 4-methyl-l,3-dioxolan-2-F -~ I one,H3C--CH--CH2--O--C=O, symbolized by PC, is a commercially available cyclic ester which has become established as a promising electrolytic solvent (2). It has a liquid range extending from --49 ~ to 241~ and is a good solvent for most quaternary ammonium salts, selected alkali metal salts, and organic compounds. PC as a dipolar, aprotic liquid has the following physical properties at 25~ dielectric constant, 64.9 (3) ; viscosity, 2.513 eP (4) ; density, 1.1995 gcm -~ (5); dipole moment, 4.94 debyes (6); Kirkwood correlation factor, 1.01 (3).Other studies dealing with conductances and viscosities of both dilute and concentrated solutions of electrolytes in PC have been reported or summarized (2, 4, 7-i0), but none of these have significantly overlapped with the scope of this work. The quaternary ammoium salts were selected primarily because they were found to be among the most soluble common salts in PC at --50~ The major objective of this study, other than obtaining extensive and valuable new data, was

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“…The purity of the amides was determined by vapor phase chromatography, and the conductivity of aqueous amide solutions was checked by the method described previously (10).…”

Section: Methodsmentioning

confidence: 99%

Correlation of Dielectric Constant and Solubilizing Properties of Tetramethyldicarboxamides

Rebagay

DeLuca

1976

Journal of Pharmaceutical Sciences

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Conductance-Viscosity Studies on Some Moderately Concentrated Nonaqueous Electrolyte Solutions from −50° to 125°C

Cited by 10 publications

References 13 publications

Electrochemical Oxidation of Ferrocene: A Strong Dependence on the Concentration of the Supporting Electrolyte for Nonpolar Solvents

Electrochemical Oxidation of Ferrocene: A Strong Dependence on the Concentration of the Supporting Electrolyte for Nonpolar Solvents

Conductance‐Viscosity Studies on Some Moderately Concentrated Nonaqueous Electrolyte Solutions from −50° to 125°C: II . Solutions of ,, and in Propylene Carbonate

Correlation of Dielectric Constant and Solubilizing Properties of Tetramethyldicarboxamides

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