The kinetics of formation of electron donor–acceptor complexes. A temperature-jump study

1990 ◽  
Vol 68 (2) ◽  
pp. 278-281 ◽  
Author(s):  
M. A. Zon ◽  
H. Fernandez ◽  
L. Sereno ◽  
J. J. Silber
Keyword(s):  
Electron Donor ◽  
Rate Constants ◽  
Temperature Jump ◽  
Diffusion Control ◽  
Diffusion Controlled ◽  
Kinetics Of Formation ◽  
Donor Acceptor ◽  
Eda Complex ◽  
Kinetics Of

The kinetics of the Electron Donor–Acceptor (EDA) complex between N,N,N′,N′-tetramethyl-p-phenylenediamine and m-dinitrobenzene in acetonitrile has been studied by the temperature-jump technique. The magnitude of the rate constants of association and dissociation, although relatively large, is well below the diffusion control values. The calculated rates closely coincide with those obtained by chronoamperometry. An entropy control is suggested for this reaction. The results obtained in this work are useful to demonstrate that the concept about EDA complexes being formed by diffusion-controlled reactions should not be generalized. Keywords: electron donor–acceptor complexes, m-dinitrobenzene, N,N,N′,N′-tetramethyl-p-phenylenediamine, T-jump, kinetics.

Kinetics of formation of silicides: A review

1986 ◽  
Vol 1 (1) ◽  
pp. 205-221 ◽  
Author(s):  
F. M. d'Heurle ◽  
P. Gas
Keyword(s):  
Phase Formation ◽  
Reaction Rate ◽  
Diffusion Control ◽  
Specific Effects ◽  
Diffusion Controlled ◽  
Kinetics Of Formation ◽  
Amorphous Compounds ◽  
Silicide Growth ◽  
Rate Controlled ◽  
Kinetics Of

The kinetics of silicide growth are classified into three different categories: (a) diffusion controlled, (b) nucleation controlled, (c) others (reaction rate controlled). These are analyzed with the aim of understanding both the phenomenology of growth and the specific atomic mechanisms of phase formation. Diffusion-controlled growth is discussed with respect to the Nernst-Einstein equation. Stress relaxation is considered as a possible cause of reaction-rate control. The relative merits of two different types of marker experiments are compared. A few silicides are discussed in terms of what can be inferred about diffusion mechanisms. The competition between reaction-rate and diffusion control phenomena is shown to have specific effects on the sequence of phase formation; it is also related to the formation of some amorphous compounds. Reactions between silicon and alloyed metal films are used to illustrate the respective influences of mobility and driving force factors on the kinetics of silicide growth; they can also be used to underline the dominance of nucleation over diffusion in some silicide formation processes.

Electron donor-acceptor (EDA)-complex enabled SF5Cl addition on alkenes and alkynes

2021 ◽  
Vol 243 ◽  
pp. 109734
Author(s):  
Audrey Gilbert ◽  
Mélodie Birepinte ◽  
Jean-François Paquin
Keyword(s):  
Electron Donor ◽  
Donor Acceptor ◽  
Eda Complex

Modulation spectroscopy. Kinetics for the self-reactions of some α-aminoalkyl radicals in solution

1982 ◽  
Vol 60 (3) ◽  
pp. 274-278 ◽  
Author(s):  
Paul R. Marriott ◽  
Arlindo L. Castelhano ◽  
David Griller
Keyword(s):  
Absorption Spectrum ◽  
Reaction Kinetics ◽  
Unpaired Electron ◽  
Rate Constants ◽  
Lone Pair ◽  
The Self ◽  
Modulation Spectroscopy ◽  
Alkyl Radicals ◽  
Diffusion Controlled ◽  
Kinetics Of

The optical spectra and reaction kinetics of some a-aminoalkyl radicals, RĊHN(CH2R)2; R≡H, Me, Ph, were measured in solution using the technique of modulation spectroscopy. These radicals undergo diffusion controlled self-reaction with rate constants [Formula: see text]. When R≡Ph, the absorption spectrum has a well defined maximum at 346 nm; ε = 3390 M−1 cm−1, while the spectra when R≡H or Me were less intense [Formula: see text] and tailed into the visible. These spectra are substantially red-shifted when compared with those of simple alkyl radicals, an effect which is thought to be due to the interaction between the unpaired electron and the lone pair of electrons on nitrogen.

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