ISSN:
0538-8066
Keywords:
Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The kinetics of the substitution reactions of Fe(CN)5H2O3- ion with a series of nitrogen and sulfur containing heterocycles were studied in aqueous media. In the presence of excess ligand, varied over a large range of concentrations, second-order rate constants were calculated at μ = 0.100 M NaClO4. Activation parameters for the formation reactions were found, ΔH*ast; and ΔS*, 28 ± 6 kJ/mol and 135±20 J/mol, respectively. The results are interpreted as being consistent with dissociative, SN1 mechanism. The kinetics of formation and dissociation were studied by stopped-flow technique at several temperatures. An investigation of the kinetics of exchange of coordinated heterocycles for 1,3,5-triazine, yielded rate saturation that is typical of a limiting SN1 mechanism. Activation parameters of the limiting first-order specific rate of dissociations were found with ΔH* and ΔS* 53±2 kJ/mol and 105±5 J/mol, respectively. From the specific rates of formation and dissociation reactions the equilibrium constants were calculated. © 1998 John Wiley & Sons, Inc. Int J Chem Kinet: 30: 415-418, 1998
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
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