scholarly journals Reaction Rates in Binary Mixed Solvents. IV

1968 ◽  
Vol 41 (4) ◽  
pp. 987-992 ◽  
Author(s):  
Yasuhiko Kondo ◽  
Yoshitoshi Honjo ◽  
Niichiro Tokura
Keyword(s):  
Mixed Solvents ◽  
Reaction Rates

scholarly journals Reaction Rates in Binary Mixed Solvents. II

1967 ◽  
Vol 40 (6) ◽  
pp. 1433-1438 ◽  
Author(s):  
Yasuhiko Kondo ◽  
Niichiro Tokura
Keyword(s):  
Mixed Solvents ◽  
Reaction Rates

scholarly journals Reaction Rates in Binary Mixed Solvents.

1969 ◽  
Vol 42 (6) ◽  
pp. 1708-1712 ◽  
Author(s):  
Yasuhiko Kondo ◽  
Toshiharu Kusaka ◽  
Niichiro Tokura
Keyword(s):  
Mixed Solvents ◽  
Reaction Rates

scholarly journals Reaction Rates in Binary Mixed Solvents. III

1967 ◽  
Vol 40 (6) ◽  
pp. 1438-1442 ◽  
Author(s):  
Yasuhiko Kondo ◽  
Niichiro Tokura
Keyword(s):  
Mixed Solvents ◽  
Reaction Rates

Solvent structure effects on solvated electron reactions in mixed solvents: Negative ions in 1-propanol–water and 2-propanol–water

1990 ◽  
Vol 68 (9) ◽  
pp. 940-946 ◽  
Author(s):  
Annesley Peiris Sedigallage ◽  
Gordon R. Freeman
Keyword(s):  
Mixed Solvents ◽  
Negative Ions ◽  
Liquid Structure ◽  
Reaction Rates ◽  
Effective Radius ◽  
Mutual Diffusion ◽  
Residual Effects ◽  
Coulombic Interaction ◽  
Bulk Fluid ◽  
Interaction Factor

In models of the kinetics of chemical reactions in solution the solvent is commonly assumed to be a uniform continuum. An example is the Smoluchowski–Debye–Stokes–Einstein equation for the rate constant k2 of a bimolecular reaction between charged or polar species: k2 = κRTfrr/1.5ηrd where κ = probability that a reactant encounter pair will react, R = gas constant, T = temperature, f = Coulombic interaction factor, rr = effective radius for reaction, η = solvent viscosity, and rd = effective radius for mutual diffusion. The equation is useful in evaluating effects of bulk-fluid properties on reaction rates. Residual effects are attributed to more specific solvent behaviour. Rate constants and activation energies E2 of reactions of solvated electrons [Formula: see text] with [Formula: see text] and [Formula: see text] ions vary with the composition of 1-propanol–water and 2-propanol–water mixed solvents. Plots of k2η/fT against solvent composition are nonlinear and change with solvent pair and with reactant pair. Measured molar conductivities Λ0(Li+, [Formula: see text]) and Λ0(2Li+, [Formula: see text]) indicate the solvent dependence of rd for the mutual diffusion of Li+ and [Formula: see text] or [Formula: see text]. The liquid structure influences both the rate of diffusion of the reactants and the probability of reaction of a reactant encounter pair.

scholarly journals Reaction Rates in Binary Mixed Solvents. VI. An Sn Ar Reaction in a Methanol-Acetonitrile Mixture

1971 ◽  
Vol 44 (9) ◽  
pp. 2548-2550 ◽  
Author(s):  
Yasuhiko Kondo ◽  
Kohei Uosaki ◽  
Niichiro Tokura
Keyword(s):  
Mixed Solvents ◽  
Reaction Rates

Solvent structure effects on solvated electron reactions with ions in 2-butanol/water mixed solvents

1991 ◽  
Vol 69 (5) ◽  
pp. 884-892 ◽  
Author(s):  
Sedigallage A. Peiris ◽  
Gordon R. Freeman
Keyword(s):  
Rate Constant ◽  
Pure Water ◽  
Mixed Solvents ◽  
Reaction Rates ◽  
Bimolecular Reaction ◽  
Activation Energies ◽  
Solvated Electron ◽  
Polar Species ◽  
Water Solvent ◽  
Alcohol Water

The Smoluchowski–Debye–Stokes–Einstein equation for the rate constant k2 of a bimolecular reaction between charged or polar species[Formula: see text]was used to evaluate effects of bulk solvent properties on reaction rates of solvated electrons with [Formula: see text] and [Formula: see text] in 2-butanol/water mixed solvents. To explain detailed effects it was necessary to consider more specific behavior of the solvent. Rate constants k2, activation energies E2, and pre-exponential factors A2 of these reactions vary with the composition of 2-butanol/water mixtures. The values of E2 were in general similar to activation energies of ionic conductance EΛ0 of the solutions, except for much higher values of E2 of [Formula: see text] in alcohol-rich solvents and of [Formula: see text] in pure water solvent. The solvent apparently participates chemically in the [Formula: see text] reaction, and the [Formula: see text] reaction is multistep. Rate constant and conductance measurements of thallium acetate solutions in 2-butanol containing zero and 10 mol% water were complicated by the formation of ion clusters larger than pairs. Key words: alcohol/water mixed solvents, ions, reaction kinetics, solvated kinetics, solvated electron, solvent effects.

Solvent effects on the reactivity of solvated electrons with organic solutes in 1-butylamine–water mixtures

1996 ◽  
Vol 74 (3) ◽  
pp. 300-306 ◽  
Author(s):  
Yixing Zhao ◽  
Gordon R. Freeman
Keyword(s):  
Solvent Effects ◽  
Rate Constants ◽  
Pure Water ◽  
Strong Dependence ◽  
Mixed Solvents ◽  
Reaction Rates ◽  
Organic Solutes ◽  
Rich Region ◽  
Water Solvent ◽  
Solvent Molecules

The values of the rate constants of the reactions of es− with the efficient scavengers nitrobenzene and acetone are ≥ 2 × 106 m3 mol−1 s−1 in the whole range of 1-butylamine–water mixtures at 298 K; the reaction rates in the mixed solvents vary approximately as the solvent fluidity. In pure butylamine at 298 K, k2(es− + nitrobenzene) = 84 × 106 m3 mol−1 s−1 and k2(es− + acetone) = 7.3 × 106 m3 mol−1 s−1. The values of the rate constants of the reactions of es− with the inefficient scavengers phenol and toluene are < 2 × 105 m3 mol−1 s−1 in the whole range of 1-butylamine–water mixtures at 298 K and have a maximum at 50 mol% water and a minimum at 99 mol% water. In pure 1-butylamine at 298 K, k2(es− + phenol) = 1.0 × 104 m3 mol−1 s−1 and k2(es− + toluene) = 0.28 × 104 m3 mol−1 s−1. The reaction rates with inefficient scavengers show strong dependence on the solvent composition and selective solvation of electron and scavenger. In the amine-rich region (0–30 mol% water), the rate constants increase with the increase of viscosity, indicating the chemical participation of solvent molecules in the reaction. In the water-rich region from 50 to 99 mol% water, the decrease of the rate constants indicates the nonhomogeneous solvation of the electrons by water and of the organic solutes by 1-butylamine. From 99 mol% to pure water the rate constant increases rapidly, which we attribute to insufficient 1-butylamine to coat the phenol or toluene molecules. The variation of the activation energies E2 for the efficient scavengers, 14–27 kJ mol−1, are similar to the variation of Eη in the mixed solvents. The values of E2 for the inefficient scavengers are from 15 to 38 kJ mol−1 for phenol and from 6 to 21 kJ mol−1 for toluene. Both k2 and E2 for the inefficient scavenger reactions show a correlation with the temperature coefficient −dEAmax/dT of the optical absorption of es− in the mixed solvents, but the reason is obscure. Key words: 1-butylamine–water solvent, solvated electron, organic solutes, reactivity, solvent effects.

Solvent structure effects on solvated electron reactions in mixed solvents: positive ions in 1-propanol/water and 2-propanol/water

1991 ◽  
Vol 69 (1) ◽  
pp. 157-166 ◽  
Author(s):  
Sedigallage A. Peiris ◽  
Gordon R. Freeman
Keyword(s):  
Pure Water ◽  
Mixed Solvents ◽  
Reaction Rates ◽  
Mutual Diffusion ◽  
Residual Effects ◽  
Solvated Electron ◽  
Bulk Fluid ◽  
Positive Ions ◽  
Water Solvent ◽  
Alcohol Water

In models of the kinetics of chemical reactions in solution the solvent is commonly assumed to be a uniform continuum. An example is the Smoluchowski–Debye–Stokes–Einstein equation for the rate constant k2 of a bimolecular reaction between charged or polar species:[Formula: see text]where κ is the probability that a reactant encounter pair will react, R is the gas constant, T is the temperature, f is a factor that reflects the effect of electrostatic interaction between the reactants on their probability of attaining the closeness of approach rr at which reaction occurs, η is the solvent viscosity, and rd is the effective radius of the reactant entities for mutual diffusion. The equation is useful in evaluating effects of bulk fluid properties on reaction rates. Residual effects are attributed to more specific solvent behaviour.Rate constants k2, activation energies E2, and pre-exponential factors A2 of reactions of solvated electrons [Formula: see text] with [Formula: see text] [Formula: see text] and [Formula: see text] ions vary with the composition of 1-propanol/water and 2-propanol/water mixed solvents. Plots of k2η/fT against solvent composition are nonlinear and change with the solvent pair and with reactant pair. Measured molar conductivities [Formula: see text] [Formula: see text] [Formula: see text] and [Formula: see text] indicate that the values of rd for the mutual diffusion of the cations and anions have a minimum near 90 mol% water, and that the values in pure propanol-1 or −2 (150–190 pm) are larger than those in pure water solvent (26 pm for [Formula: see text] 70 pm for the metal ions). The liquid structure influences both the rate of diffusion and the probability of reaction of a reactant encounter pair. Key words: alcohol/water mixed solvents, positive ions, reaction kinetics, solvated electron, solvent effects.

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