Hydrocarbons radical hydrogenations

Hydrogen atoms can also be formed on catalytic surfaces, during electrolysis and upon decomposition of hydrocarbon radicals. 

The formation of the hydrocarbon radical with the release of a hydrogen atom is a common feamre in these chain reactions. 

The f-butoxy radicals thus formed then abstract hydrogen from hydrocarbons to generate hydrocarbon radicals and f-butyl alcohol. The hydrocarbon radicals in turn generate more r-butoxy radicals by attacking the t-butyl-hypochlorite ... 

Continued addition of 02 beyond one-half the stoichiometric value with the hydrocarbons present encourages a net destruction of the hydrocarbon radicals. For the temperature range 1200-1300 K, production of the hydrocarbon radicals via hydrogen abstraction by 02 is rapid, even assuming an activation energy of 520kJ/mol, and more than adequate to provide sufficient radicals for NO reduction in the stay time range of 125 ms. 

Triplet carbenes have a singly occupied p orbital, as is the case for radicals, and hence react like those radicals. Hydrogen atom transfer reactions are fundamental reaction pathways of triplet carbenes. The reaction of a triplet carbene with a hydrocarbon is quite analogous to the free radical hydrogen atom transfer process (Scheme 9.6). 

The procedure consists essentially in allowing an acetylenecarbinol, R1.R1.C(OH)r C CH or glycol R. aOHJ.C i GfOHj.R,.-R, in which R, R, are various hydrocarbon radicals, to react at low temp with hydrogen peroxide in the presence of sulfuric acid of suitable strength... 

Rate of Initiation. Rate and mode of formation of the first few radicals. Rate of initial attack of the hydrocarbon molecule by free radicals (hydrogen abstraction). 

Rate of Initial Attack of Hydrocarbon Molecule by Free Radicals (Hydrogen Abstraction). 

In contrast to hydrocarbon radicals where hydrogen atom migration is common, fluorine atom migration is rare.105 Pcrfluoroalkyl radical disproportionation is as yet unknown and cannot... 

Bivalent radicals derived from univalent polycyclic hydrocarbon radicals whose names end in -yl by removal of one hydrogen atom from the carbon atom with the free valence are named by adding -idene to the name of the corresponding univalent radical. 

Chlorine derivatives of organic compounds are obtained by substitution, addition, or displacement. Substitution reactinns of Cl on hydrocarbons involve radical attack to remove a hydrogen, forming the hydrocarbon radical as an intermediate R-H + Cl ---------->R -I- HCI. Since a tertiary... 

SALT. A compound formed by replacement of part or all of the hydrogen of an acid by one (or more) element(s) or radrcal(s) that are essentially inorganic. Alkaloids, amines, pyridines, and other basic organic substances may be regarded as substituted ammonias in this connection. The characteristic properties of salts are the ionic lattice in the solid state and the ability to dissociate completely in solution. The halogen derivatives of hydrocarbon radicals and esters are not regarded as salts in the strict definition of the term,... 

Stepwise decarboxylation also occurs, particularly in reactions in which the carboxylate radical (RC02 ) is formed. This radical usually decomposes to a hydrocarbon radical (R-) and C02- The overall decarboxylation product is determined by what R- reacts with If a good hydrogen donor is present, RH is formed if a halogen donor such as Br2 is present, RBr is formed ... 

Substitution of the acetylenic hydrogen atom in 1-ethynylsilatrane by a phenyl group slightly increases the toxicity. The presence of bi- or tricyclic hydrocarbon radicals at the silicon atom leads to a greater increase in toxicity (the LDS0 value for compounds (30) and (41) is 850 and 80 mg/kg, respectively). 

The photo-oxidation of n-butane has been modelled by ab initio and DFT computational methods, in which the key role of 1- and 2-butoxyl radicals was confirmed.52 These radicals, formed from the reaction of the corresponding butyl radicals with molecular oxygen, account for the formation of the major oxidation products including hydrocarbons, peroxides, aldehydes, and peroxyaldehydes. The differing behaviour of n-pentane and cyclopentane towards autoignition at 873 K has been found to depend on the relative concentrations of resonance-stabilized radicals in the reaction medium.53 The manganese-mediated oxidation of dihydroanthracene to anthracene has been reported via hydrogen atom abstraction.54 The oxidation reactions of hydrocarbon radicals and their OH adducts are reported.55... 

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