Kinetics of the hydrolysis of orthoesters: A general acid-catalyzed reaction. An undergraduate physical organic chemistry experiment using NMR to determine both rate constants of a two-route mechanism

1993 ◽  
Vol 70 (5) ◽  
pp. 421 ◽  
Author(s):  
Richard A. Potts ◽  
Ruth A. Schaller
Keyword(s):  
Organic Chemistry ◽  
Rate Constants ◽  
Physical Organic Chemistry ◽  
Physical Organic ◽  
General Acid ◽  
Acid Catalyzed ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Chemistry Experiment

Dediazoniations in Water: An Integrated Physical Organic Chemistry Experiment

2000 ◽  
Vol 77 (3) ◽  
pp. 384 ◽  
Author(s):  
Carlos Bravo-Díaz ◽  
Ugo Costas-Costas ◽  
Román Pazo-LLorente ◽  
Elisa González-Romero
Keyword(s):  
Organic Chemistry ◽  
Physical Organic Chemistry ◽  
Physical Organic ◽  
Chemistry Experiment

Solvolysis of 1-haloadamantanes. A physical organic chemistry experiment

1977 ◽  
Vol 54 (12) ◽  
pp. 773
Author(s):  
J. Hodge Markgraf ◽  
Mary Anton
Keyword(s):  
Organic Chemistry ◽  
Physical Organic Chemistry ◽  
Physical Organic ◽  
Chemistry Experiment

Kinetics of acid-catalyzed hydrolysis of fluorinated propanoates

1983 ◽  
Vol 48 (10) ◽  
pp. 2805-2811 ◽  
Author(s):  
Oldřich Paleta ◽  
Jaroslav Kvíčala ◽  
Václav Dědek
Keyword(s):  
Rate Constants ◽  
Relative Rate ◽  
Chloride Concentration ◽  
Activation Entropy ◽  
High Activation ◽  
Isokinetic Relationship ◽  
Relative Rate Constants ◽  
Acid Catalyzed ◽  
Kinetics Of ◽  
Hydrolysis Of

Rates of hydrolysis, kH+, of methyl 2-chloro-2,3,3,3-tetrafluoro-(III), 2,3-dichloro-2,3,3-trifluoro-(IV), 2,2,3-trichloro-3,3-difluoro-(V), 2,3,3,3-tetrafluoro-(VI) and 3-chloro-2,3,3-trifluoropropanoate (VII) were measured in 0.5M-HCl in aqueous methanol (80% vol; 76% wt) at 40, 50 and 60 °C. The relative rate constants, krel (50 °C), (for the propanoate III, kH+ = 4.3 . 10-5 l mol-1 s-1; krel = 100) are 311, 100, 38, 9.4, 44 and 15 for the esters II, III, IV, V, VI and VII, respectively (experimental error ±9%). It was found that krel = αβ where α and β are the following factors for groups in the position 2 and 3: CClF 10, CHF 4.2, CCl2 2.8, CF3 10 and CClF2 3.6. The rate constants obey the isokinetic relationship. For the ester III the dependence of log kobs on logarithm of hydrogen chloride concentration is linear at concentrations 0.08-2.4 mol l-1 which, together with high activation entropy ΔS≠ for the esters III-VII (-167 to -217 J mol-1 K-1), shows that the hydrolysis proceeds by an AAC2 mechanism.

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