A Molecular Modeling Study of the Catalytic Mechanism of Haloalkane Dehalogenase:  1. Quantum Chemical Study of the First Reaction Step

1997 ◽  
Vol 37 (3) ◽  
pp. 562-568 ◽  
Author(s):  
Jiří Damborský ◽  
Michal Kutý ◽  
Miroslav Němec ◽  
Jaroslav Koča
Keyword(s):  
Molecular Modeling ◽  
Quantum Chemical ◽  
Catalytic Mechanism ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Haloalkane Dehalogenase ◽  
Reaction Step ◽  
Molecular Modeling Study ◽  
Modeling Study

Study of the Electrochemically Initiated Cyanomethylation of Azomethines by Means of the MNDO and AM1 Semiempirical Methods

1995 ◽  
Vol 60 (12) ◽  
pp. 2028-2038
Author(s):  
Jaromír Toušek ◽  
Jaro Komenda ◽  
Ulrich Hess
Keyword(s):  
Quantum Chemical ◽  
Radical Anion ◽  
Main Product ◽  
Reaction Path ◽  
Activation Enthalpy ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Stationary Points ◽  
Semiempirical Methods ◽  
Reaction Step

The semiempirical methods (MNDO and AM1) have been used in the quantum chemical study of electrochemically initiated cyanomethylation of azomethines. Reaction steps leading to the main product of the studied reaction, β-aminonitrile, have been described. The stationary points on the reaction path have been found and the activation enthalpies of reaction steps have been determined. Three possible mechanisms for the abstraction of a proton from acetonitrile have been described (by azomethine radical anion, by β-aminonitrile anion, and by hydrogenated azomethine anion). At the MNDO level, the abstraction of a proton by azomethine radical anion has the highest activation enthalpy (∆H = 197 kJ mol-1) and the abstraction of a proton by hydrogenated azomethine anion has the lowest activation enthalpy (∆H = 146 kJ mol-1). The activation enthalpy of the next reaction step (the reaction of acetonitrile anion with azomethine) is low compared to the activation enthalpies of the previous reation steps (∆H= 12 kJ mol-1).

A quantum chemical study of the acidity of acetylene and 1,2-dihydrobuckminsterfullerene de-rivatives

2018 ◽  
Vol 59 (1) ◽  
pp. 51-53
Author(s):  
M. V. Makarova ◽  
◽  
S. G. Semenov ◽  
R. R. Kostikov ◽  
◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Quantum Chemical Study ◽  
Chemical Study
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