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.

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.

Zur Theorie der Elektronenübergangsreaktionen in molekularen Komplexen / Theory of Electron Transfer Reactions in Molecular Complexes

1974 ◽  
Vol 29 (6) ◽  
pp. 880-887 ◽  
Author(s):  
P. P. Schmidt
Keyword(s):  
Activation Energy ◽  
Electron Transfer ◽  
Charge Transfer ◽  
Rate Constant ◽  
Reaction Rate ◽  
Charge Transfer Complex ◽  
Rate Theory ◽  
Transfer Step ◽  
Donor And Acceptor ◽  
Inner Sphere

This paper reports a theory of the inner sphere-type electron transfer reaction. Inner sphere reactions, as opposed to the outer sphere variety, require that the solvate or ligand shells surrounding the electron donor and acceptor species undergo considerable change in the course of the electron transfer. In this paper we assume that the electron transfer step takes place in a molecular complex which exists in equilibrium with the reactants. The electron transfer step occurs as a non-radiative charge transfer-type transition. In this manner we treat the charge transfer kinetics, in particular, the evaluation of the reaction rate constant, in the same manner as is usual for non-radiative problems. The analysis leading to the rate constant expression is based on Yamamoto’s general chemical reaction rate theory. The rate constant expressions obtained are quite general, they hold for any degree of strength of coupling between subsystems comprising the entire system. The activation energy, in the Arrhenius form for the rate constant, shows a dependence on the energy (work) of formation of the intermediate charge transfer complex, on vibrational shift energies associated with the molecular motions of the ligands, and on solvent repolarization energies. The activation energy also shows an important dependence on coupling terms which link the vibrations of the molecular inner shell with the polarization states of the (assumed) dielectric continuum which surrounds the charge transfer participants. The approach we take in developing this theory we believe points the way towards the development of a more complete theory capable of accounting for the dynamics of the molecular reorganization leading to the intermediate charge transfer complex as well as accounting for the electron transfer step itself.

scholarly journals Kinetics and Correlation Analysis of Reactivity in the Oxidation of Some α-Hydroxy Acids by Benzimidazolium Dichromate

2018 ◽  
Vol 43 (3-4) ◽  
pp. 300-314
Author(s):  
Dinesh Panday ◽  
Teena Kachawa ◽  
Seema Kothari
Keyword(s):  
Solvent Effect ◽  
Mandelic Acid ◽  
Bond Cleavage ◽  
Hydroxy Acids ◽  
Cyclic Transition ◽  
Hydride Ion ◽  
Rate Determining Step ◽  
Reaction Constant ◽  
Cyclic Transition State ◽  
Hydride Ion Transfer

Kinetic and mechanistic studies of the oxidation of mandelic acid and nine monosubstituted mandelic acids by benzimidazolium dichromate (BIDC) in dimethyl sulfoxide are discussed with an emphasis on correlation of structure and reactivity. The reactions were of first order with respect to BIDC. However, Michaelis-Menten type kinetics were observed with respect to hydroxy acids. The reactions are catalysed by protons. The deuterium isotope effect for the oxidation of mandelic acid ( kH/ kD = 5.91 at 298 K) indicated an α-C-H bond cleavage in the rate-determining step. An analysis of the solvent effect showed that the role of cationsolvation is major. The reaction showed an excellent correlation with the Hammett σ values, the reaction constant being negative. Based on the kinetic data, analysis of the solvent effect and results of structure-reactivity correlation along with some non-kinetic parameters, a mechanism involving rate-determining oxidative decomposition of the complex through hydride-ion transfer via a cyclic transition state to give the corresponding oxoacid is suggested.

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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