The Mechanism of Substitution Reactions at Octahedral Sites. III. Deuterium Isotope Effects in the Acid and Base Hydrolysis of Anionopentaamminechromium(III) Ions

1964 ◽  
Vol 3 (1) ◽  
pp. 133-139 ◽  
Author(s):  
M. Parris ◽  
W. J. Wallace
Keyword(s):  
Isotope Effects ◽  
Base Hydrolysis ◽  
Substitution Reactions ◽  
Octahedral Sites ◽  
Acid And Base ◽  
Deuterium Isotope Effects ◽  
Hydrolysis Of

Mechanism of Substitution Reactions of Complex Ions. IX. Contribution of Inductive Effects to the Rates of Acid and Base Hydrolysis of Cobalt(III) Complexes1,2

1956 ◽  
Vol 78 (12) ◽  
pp. 2676-2678 ◽  
Author(s):  
Fred Basolo ◽  
John G. Bergmann ◽  
Robert E. Meeker ◽  
Ralph G. Pearson
Keyword(s):  
Base Hydrolysis ◽  
Complex Ions ◽  
Substitution Reactions ◽  
Inductive Effects ◽  
Acid And Base ◽  
Hydrolysis Of

Thiohydantoins. XII. Secondary Deuterium Isotope Effects in the Acid- and Base-catalyzed Hydrolysis of 1-Acetyl-5,5-dimethyl-2-thiohydantoin

1972 ◽  
Vol 50 (23) ◽  
pp. 3921-3923
Author(s):  
Wayne I. Congdon ◽  
John T. Edward
Keyword(s):  
Sulfuric Acid ◽  
Temperature Effect ◽  
Sodium Hydroxide ◽  
Isotope Effects ◽  
Temperature Range ◽  
Dilute Sodium Hydroxide ◽  
Acid And Base ◽  
Deuterium Isotope Effects ◽  
Hydrolysis Of

The rates of hydrolysis of 1-acetyl-5,5-dimethyl-2-thiohydantoin and of 1-acetyl-d3-5,5-dimethyl-2-thio-hydantoin in acid and base over the temperature range 11–58 °C have been measured. For the A-1 hydrolysis in 96.3% sulfuric acid, kH/kD decreased from 1.31 at 10.8° to 1.05 at 58.1°; these results accord with the proposed mechanism. For A-2 hydrolysis in 39.6% sulfuric acid and for base-catalyzed hydrolysis in dilute sodium hydroxide, kH/kD υs. temperature passed through a minimum at about 40 and 25° respectively. Some possible reasons for the temperature effect are discussed.

Substitution reactions at octahedral centers. IV. Acid and base hydrolysis of chloropentakis(alkylamine)chromium(III) ions

1969 ◽  
Vol 47 (12) ◽  
pp. 2257-2262 ◽  
Author(s):  
M. Parris ◽  
W. J. Wallace
Keyword(s):  
Base Hydrolysis ◽  
Kcal Mole ◽  
Substitution Reactions ◽  
Hydroxide Ion ◽  
Rate Determining Step ◽  
Acid And Base ◽  
Ph Dependent ◽  
Pattern Of Variation ◽  
Hydrolysis Of ◽  
Independent Reaction

The compounds [Cr(RNH2)5Cl](ClO4)2, where R = H, CH3, C2H5, n-C3H7, and n-C4H9, have been prepared and the replacement of chloride by either water or hydroxide ion subjected to kinetic examination. Below about pH 7 the reaction was acid independent, and ΔHA* was 22.4 kcal mole−1 when ammonia was the inert ligand compared with about 26.4 kcal mole−1 when the inert ligand was a primary amine. The corresponding ΔSA* values increased continuously with R from H to n-C4H9. At higher pH the rate became inversely dependent upon the acidity of the solution, and ΔHB* decreased from 26.7 kcal mole−1 for ammonia as the inert ligand to 25.4 kcal mole−1 for an amine as the inert ligand. For the pH dependent reaction the values obtained for ΔSB* were much larger than for the pH independent reaction but the pattern of variation as the inert ligands were changed was quite similar in the two cases. The great similarity in the trends of ΔS* values for the acid and base hydrolysis reactions has been interpreted in terms of a rate-determining step that is primarily dissociative in both cases.

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