Kinetic Equations of Free-Radical Nonbranched-
Chain Processes of Addition to Alkenes,
Formaldehyde and Oxygen
Volume 2 - Issue 5
Michael M Silaev*
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- Chemistry Faculty, Lomonosov Moscow State University, Russia
*Corresponding author:
Michael M Silaev, Chemistry Faculty, Lomonosov Moscow State University, Vorobievy Gory, Moscow 119991,
Russia
Received: April 23, 2018; Published: May 17, 2018
DOI: 10.32474/AOICS.2018.02.000150
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Abstract
The aim of this study was the conclusion of simple kinetic equations to describe ab initio initiated Nonbranched-chain processes
of the saturated free-radical addition to the double bonds of unsaturated molecules in the binary reaction systems of saturated
and unsaturated components. In the processes of this kind the formation rate of the molecular addition products (1:1 adducts) as
a function of concentration of the unsaturated component has a maximum. Five reaction schemes are suggested for this addition
processes. The proposed schemes include the reaction competing with chain propagation reactions through a reactive free radical.
The chain evolution stage in these schemes involves three or four types of free radicals. One of them is relatively low-reactive
and inhibits the chain process by shortening of the kinetic chain length. Based on the suggested schemes, nine rate equations
(containing one to three parameters to be determined directly) are deduced using quasi-steady-state treatment. These equations
provide good fits for the no monotonic (peaking) dependences of the formation rates of the molecular products (1:1 adducts) on the
concentration of the unsaturated component in binary systems consisting of a saturated component (hydrocarbon, alcohol, etc.) and
an unsaturated component (alkene, allyl alcohol, formaldehyde, or dioxygen). The unsaturated compound in these systems is both a
reactant and an autoinhibitor generating low-reactive free radicals. A similar kinetic description is applicable to the Nonbranchedchain
process of the free-radical hydrogen oxidation, in which the oxygen with the increase of its concentration begins to act as an
oxidation autoingibitor (or an antioxidant). The energetics of the key radical-molecule reactions is considered.
Keywords: Low-reactive radical; Autoinhibitor; Competing reaction; Non branched-chain Addition; Thermochemical Data
Abstract|
Introduction|
Addition to the С=С Bond of Alkenes and their
Derivatives|
Addition to the C=O Bond of Formal-dehyde|
Addition to Oxygen|
General Scheme of the Addition of Free Radicals to
Molecules of Alkenes, Formaldehyde, and Oxygen|
Conclusions|
References|