abstraction reaction

abstraction reaction

[ab′strak·shən rē‚ak·shən]
(chemistry)
A bimolecular chemical reaction in which an atom that is either neutral or charged is removed from a molecular entity.
References in periodicals archive ?
The H abstraction reaction from i-[C.sub.8][H.sub.18] by the OH radical ((R15)-(R16)) and the decomposition reaction of [C.sub.8][H.sub.17] radicals formed via this H abstraction reaction from i-[C.sub.8][H.sub.18] ((R17)-(R18)) have a negative influence on ignition.
H abstraction reactions from DMF, to form the dmf252j radical, and the [H.sub.2][O.sub.2] decomposition reaction, to form OH radicals, are also important for DMF ignition.
So, it is concluded that although the aromatic tertiary amine has reactivity and supply hydrogen atoms to hydrogen abstraction reaction of carbonyl, the aliphatic tertiary amine is more reactive and makes an important role in hydrogen abstraction reaction.
The reasons maybe as follows: First, the local amino concentration of PMKPR is higher, which makes the hydrogen abstraction reaction easily happen and produce more radicals to initiate polymerization, thus increases the polymerization rate.
The sensitivity analysis of acetone, Fig.6(a), shows that the thermal decomposition of acetone has the second largest normalized negative sensitivity factor and the hydrogen abstraction reaction exhibits the greatest positive sensitivity.
Most of the decomposition reactions and hydrogen atom abstraction reactions of acetone, but not all of them, are included in this mechanism as well.
Moreover, it was assumed that reactions most likely proceed via saddle point transition state structures than via other thermodynamically less favorable reaction paths; consequently, for example, the hydrogen abstraction reaction rate magnitude is anticipated to proceed in the following order: allylic > tertiary > secondary > primary > vinylic (3).
[51.] Ranzi E., Dente M., Faravelli T., Pennati G., Prediction of kinetic parameters for hydrogen abstraction reactions, Combustion science and technology 95 (1993) 1-50.
Alkyl, hydride, carbonyl, phosphine, and pi ligands are discussed in some detail, followed by oxidative addition, reductive elimination, insertion and elimination, and addition and abstraction reactions. Homogeneous catalysis, characterization methods, and M-L multiple bonds are covered, finishing off with several chapters on applications and novel research in organic synthesis, energy chemistry, clusters and nanoparticles, paramagnetic and high oxidation-state complexes, and bioorganometallic chemistry.
Hydrogen abstraction reactions were found to be relatively slow at lower temperatures in poor hydrogen donating solvents.
Upon demonstrating that it is possible to grow phase-pure nanocrystalline diamond without the mediation of atomic hydrogen abstraction reactions, it was confirmed that many of the undesirable properties of diamond films grown by chemical vapor deposition are by-products of atomic hydrogen and do not represent intrinsic properties of thin diamond films.