Kinetic isotope effects for nitroalkanes and their relation to transition-state structure in proton-transfer reactions

1975 ◽  
Vol 97 (12) ◽  
pp. 3447-3452 ◽  
Author(s):  
F. G. Bordwell ◽  
William J. Boyle
Keyword(s):  
Proton Transfer ◽  
Transition State ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Transfer Reactions ◽  
State Structure ◽  
Transition State Structure ◽  
Kinetic Isotope ◽  
Proton Transfer Reactions

A MODEL FOR THE HYDROGEN BOND AND PROTON TRANSFER REACTIONS

1964 ◽  
Vol 42 (8) ◽  
pp. 1822-1834 ◽  
Author(s):  
R. F. W. Bader
Keyword(s):  
Proton Transfer ◽  
Transition State ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Transfer Reactions ◽  
Simple Extension ◽  
Kinetic Isotope ◽  
Proton Transfer Reactions ◽  
Hydrogen Deuterium ◽  
Base Strength

A simple extension of Platt's model for determining the force constants in diatomic hydrides is used to investigate the properties of transition states for proton transfer reactions. The model is first tested by comparing the predicted and observed changes in bond lengths and stretching and bending frequencies for [Formula: see text] systems. The quantities predicted for the transition state are the geometry and the perpendicular bending frequencies. The implications of the results with regard to the interpretation of hydrogen–deuterium kinetic isotope effects are discussed. In particular, the variations in both the isotope effect and the geometry of the transition state with changing acid or base strength are considered in detail.

Secondary Kinetic Isotope Effects in Bimolecular Nucleophilic Substitutions. V. The Role of the Solvent in the Reaction Between Methyl Iodide and Pyridine

1972 ◽  
Vol 50 (7) ◽  
pp. 982-985 ◽  
Author(s):  
K. T. Leffek ◽  
A. F. Matheson
Keyword(s):  
Transition State ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
State Structure ◽  
Transition State Structure ◽  
Initial State ◽  
Nucleophilic Substitutions ◽  
Kinetic Isotope ◽  
Deuterium Isotope Effects

Secondary kinetic deuterium isotope effects are presented for the reaction of methyl-d3 iodide and pyridine in four different solvents. Calculations on mass and moment of inertia change with deuteration in the initial state and an assumed tetrahedral transition state, together with internal rotational effects, are used to rationalize the inverse isotope effects. It is concluded from the variation of the isotopic rate ratio, that the transition state structure varies with solvent.

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