The role of the transition state bond order and reaction energy in methyl nucleophilic substitutions

Tetrahedron ◽  
1987 ◽  
Vol 43 (6) ◽  
pp. 1109-1116 ◽  
Author(s):  
Sebastião J. Formosinho
Keyword(s):  
Transition State ◽  
Bond Order ◽  
Reaction Energy ◽  
Nucleophilic Substitutions

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.

scholarly journals Kinetic Analysis of the Effect of Poliovirus Receptor on Viral Uncoating: the Receptor as a Catalyst

2001 ◽  
Vol 75 (11) ◽  
pp. 4984-4989 ◽  
Author(s):  
Simon K. Tsang ◽  
Brian M. McDermott ◽  
Vincent R. Racaniello ◽  
James M. Hogle
Keyword(s):  
Activation Energy ◽  
Transition State ◽  
Kinetic Analysis ◽  
Transition State Theory ◽  
State Theory ◽  
Viral Receptor ◽  
Poliovirus Receptor ◽  
Entropic Stabilization ◽  
Entropic Effects

ABSTRACT We examined the role of soluble poliovirus receptor on the transition of native poliovirus (160S or N particle) to an infectious intermediate (135S or A particle). The viral receptor behaves as a classic transition state theory catalyst, facilitating the N-to-A conversion by lowering the activation energy for the process by 50 kcal/mol. In contrast to earlier studies which demonstrated that capsid-binding drugs inhibit thermally mediated N-to-A conversion through entropic stabilization alone, capsid-binding drugs are shown to inhibit receptor-mediated N-to-A conversion through a combination of enthalpic and entropic effects.

ChemInform Abstract: Key Role of Water for Nucleophilic Substitutions in Phase Transfer Catalyzed Processes.

ChemInform ◽  
2010 ◽  
Vol 32 (37) ◽  
pp. no-no
Author(s):  
Domenico Albanese ◽  
Dario Landini ◽  
Angelamaria Maia ◽  
Michele Penso
Keyword(s):  
Phase Transfer ◽  
Nucleophilic Substitutions

Elucidating the role of solvents in acid catalyzed dehydration of biorenewable hydroxy-lactones

2020 ◽  
Vol 5 (4) ◽  
pp. 651-662 ◽  
Author(s):  
Gourav Shrivastav ◽  
Tuhin S. Khan ◽  
Manish Agarwal ◽  
M. Ali Haider
Keyword(s):  
Free Energy ◽  
Transition State ◽  
Energy Barrier ◽  
Free Energy Barrier ◽  
Activation Free Energy ◽  
Acid Catalyzed

Utilizing the differential stabilization of reactant and transition state in the polar and apolar solvents to lower the activation free energy barrier for acid-catalyzed dehydration of hydroxy lactones.

On the role of the surface oxygen species during A–H (A = C, N, O) bond activation: a density functional theory study

2015 ◽  
Vol 51 (13) ◽  
pp. 2621-2624 ◽  
Author(s):  
Jong Suk Yoo ◽  
Tuhin S. Khan ◽  
Frank Abild-Pedersen ◽  
Jens K. Nørskov ◽  
Felix Studt
Keyword(s):  
Density Functional ◽  
Bond Activation ◽  
Bond Cleavage ◽  
Oxygen Species ◽  
Final States ◽  
Surface Oxygen ◽  
Density Functional Theory Study ◽  
Reaction Energy ◽  
Functional Theory

During A–H (A = C, N, O) bond cleavage on O* or OH* pre-covered (111) surfaces, the oxygen species play the role of modifying the reaction energy by changing the species involved in the initial and final states of the reaction.

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