Studies on the Decomposition of Tetra-alkylammonium Salts in Solution. IV. The α-Deuterium Secondary Isotope Effect

1971 ◽  
Vol 49 (1) ◽  
pp. 129-132 ◽  
Author(s):  
E. C. F. Ko ◽  
K. T. Leffek
Keyword(s):  
Isotope Effect ◽  
Ion Pair ◽  
Deuterium Isotope Effect ◽  
Solvent Interaction ◽  
Temperature Range ◽  
Carbonium Ion ◽  
Alkylammonium Salts ◽  
Rate Ratios

The secondary deuterium isotope effect is reported for the decomposition of benzyl-α-d2-phenyldimethylammonium bromide in both chloroform and acetone solvent, over a temperature range of 25 to 30°. The magnitudes of the rate ratios are compared to literature values for SN1 reactions, from which it is concluded that the mechanism of the decomposition involves a carbonium ion or ion-pair. The variation of the isotope effect with solvent is rationalized in terms of specific solvent interaction with the benzyl group.

Hydrolysis of α-bromoisobutyrate ion in water

1967 ◽  
Vol 45 (18) ◽  
pp. 2071-2077 ◽  
Author(s):  
B. N. Hendy ◽  
W. A. Redmond ◽  
R. E. Robertson
Keyword(s):  
Temperature Dependence ◽  
Isotope Effect ◽  
Deuterium Isotope Effect ◽  
Detailed Mechanism ◽  
Temperature Range ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of

The temperature dependence of the rate of hydrolysis of α-bromoisobutyrate ion in water was determined over a temperature range 9–37 °C. From these data corresponding values of ΔH≠, ΔS≠, and ΔCP≠ have been derived. The implication of these terms, together with corresponding data for hydrolysis in D2O and for the secondary deuterium isotope effect from the hydrolysis of (CD3)2CBrCOO−, provide a basis for reexamining the detailed mechanism with particular reference to accompanying solvent reorganization.

Studies on the decomposition of tetra-alkylammonium salts in solution. Part I. Phenylbenzylmethylallylammonium iodide

1968 ◽  
Vol 46 (8) ◽  
pp. 1215-1220 ◽  
Author(s):  
K. T. Leffek ◽  
F. H.-C. Tsao
Keyword(s):  
Reaction Kinetics ◽  
Isotope Effect ◽  
Optical Activity ◽  
Chloroform Solution ◽  
Activation Parameters ◽  
Deuterium Isotope Effect ◽  
Alkylammonium Salts ◽  
Triple Ion

The loss of optical activity from phenylbenzylmethylallylammonium iodide in chloroform solution has been found to be entirely due to decomposition; racemization as such does not take place. The products are benzyl iodide and allylmethylaniline. A mechanism involving decomposition via a triple ion is deduced from the reaction kinetics. The activation parameters (ΔH≠ and ΔS≠) and a secondary deuterium isotope effect are reported.

The kinetics and mechanisms of the gas phase pyrolyses of exo-2-norbornyl chloride and cyclopentyl chloride

1979 ◽  
Vol 57 (19) ◽  
pp. 2621-2625 ◽  
Author(s):  
J. L. Holmes ◽  
D. L. McGillivray ◽  
D. Yuan
Keyword(s):  
Gas Phase ◽  
Hydrogen Chloride ◽  
Isotope Effect ◽  
Deuterium Isotope Effect ◽  
Temperature Range ◽  
Elimination Reactions ◽  
Chloride Elimination ◽  
Kinetics Of

The gas phase pyrolyses of exo-2-norbornyl chloride and cyclopentyl chloride were studied in the temperature range 570–670 K. The results obtained show that these compounds behave as typical secondary halides insofar as the kinetics of their hydrogen chloride elimination reactions are concerned. Labelling experiments showed that in the formation of both norbornene and cyclopentene, a cis-1,2 elimination with a deuterium isotope effect of ∼3 was involved. Nortricyclene also was produced from exo-2-norbornyl chloride, via a trans 1,3 elimination; this process is analogous to a fragmentation of the ionized molecule. No gas phase Wagner–Meerwein rearrangement was involved in the formation of either norbornene or nortricyclene.

Sign in / Sign up

Export Citation Format

Share Document