Calculation of a Complete Enzymic Reaction Surface:  Reaction and Activation Free Energies for Hydride-Ion Transfer in Dihydrofolate Reductase

2007 ◽  
Vol 3 (3) ◽  
pp. 1203-1211 ◽  
Author(s):  
Peter L. Cummins ◽  
Ivan V. Rostov ◽  
Jill E. Gready
Keyword(s):  
Dihydrofolate Reductase ◽  
Surface Reaction ◽  
Ion Transfer ◽  
Free Energies ◽  
Reaction Surface ◽  
Hydride Ion ◽  
Enzymic Reaction ◽  
Hydride Ion Transfer

scholarly journals An approach to quantum chemical consideration of "hydride" transfer reaction

2004 ◽  
Vol 69 (6) ◽  
pp. 431-439 ◽  
Author(s):  
Alexei Pankratov ◽  
Boris Drevko
Keyword(s):  
Hydrogen Atom ◽  
Quantum Chemical ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Hydrogen Atom Transfer ◽  
Ionization Potentials ◽  
Ion Transfer ◽  
Free Energies ◽  
Hydride Ion ◽  
Hydride Ion Transfer

An approach to the quantum chemical study of "hydride ion" transfer has been proposed, according to which the sequences of changes in ionization potentials, enthalpies and free energies of the affinities to the hydride ion, to the hydrogen atom and to the proton of substrates molecules and their derivatives (cations, radicals, anions), are compared with the experimentally substantiated series of "hydride" mobility. It has been established that the experimental series of "hydride" mobility for six chalcogenopyrans based on "semicyclic" 1,5-diketones is in conformity with the computed ionization potentials of themolecules, and with the affinity of the corresponding radicals to the hydrogen atom involved in the transfer. The direct splitting-out of the hydride ion and the primary deprotonation of the substrates followed by the withdrawal of two electrons was elucidated to be unlikely. Feasible are the mechanisms of "hydride" mobility, the first step of which consists of electron or hydrogen atom transfer from the chalcogenopyrans molecules.

scholarly journals Kinetics and Mechanism of the Oxidation of Substituted Benzaldehydes by Oxo(salen)manganese(v) Complexes

1999 ◽  
Vol 23 (8) ◽  
pp. 480-481
Author(s):  
Varsha Bansal ◽  
Pradeep K. Sharma ◽  
Kalyan K. Banerji
Keyword(s):  
Hydrogen Atom ◽  
Hydrogen Atom Transfer ◽  
Kinetics And Mechanism ◽  
Atom Transfer ◽  
Ion Transfer ◽  
Hydride Ion ◽  
Substituted Benzaldehydes ◽  
Hydride Ion Transfer

The oxidation of benzaldehyde by oxo(salen)manganese(v) complexes proceeds via either a hydride-ion transfer or a hydrogen-atom transfer from the aldehyde to the manganese(v) complex.

The dehydrogenation of 1,4-dihydronaphthalene by tetrachloro-p-benzoquinone

1976 ◽  
Vol 54 (14) ◽  
pp. 2261-2265 ◽  
Author(s):  
Z. M. Hashish ◽  
I. M. Hoodless
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Reaction Rate ◽  
Second Order ◽  
Charge Transfer Complexes ◽  
Ion Transfer ◽  
Hydride Ion ◽  
Rate Determining Step ◽  
Hydride Ion Transfer

The dehydrogenation of 1,4-dihydronaphthalene by tetrachloro-p-benzoquinone in phenetole solution has been investigated. The present work does not fully confirm earlier studies which report that the reaction follows second-order kinetics and that the hydride ion transfer is rate determining. In the investigations described in this paper second-order kinetics are only observed in the later stages of the reaction and a 1:1 stoichiometry of the reactants in the process is not obtained. Substitution of tritium in the 1,4-positions of the hydrocarbon appears to not significantly affect the reaction rate. The present results indicate that charge-transfer complexes are formed in the reaction and it is suggested that electron transfer within these complexes could be the rate-determining step in the dehydrogenation.

Kinetics and mechanism of the oxidation of Substituted Benzylamines by Oxo(Salen)Manganese (V) Complexes

2003 ◽  
Vol 2003 (2) ◽  
pp. 56-57 ◽  
Author(s):  
Rashmi Dubey ◽  
László Kótai ◽  
Kalyan K. Banerji
Keyword(s):  
Kinetics And Mechanism ◽  
Ion Transfer ◽  
Hydride Ion ◽  
Hydride Ion Transfer

The oxidation of substituted benzylamines by oxo(salen) Mn(V) complexes, to the corresponding aldimine, proceeds through a hydride ion transfer from the amine to the oxidant.

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