Methyl Affinities of Vinyl Monomers. Part I. Styrene and Phenylated Ethylenes

Alkylation

“…These results show that a'certain amount of nuclear methylation, which may well give rise to the formation of methane by the removal of hydrogen from the addition complex by a methyl radical, does take place. This is, of course, in conflict with the conclusions reached by Levy, Steinberg and Szwarc (1954) and Levy and Szwarc (1955), and while it is true that the latter workers' experiments were conducted at considerably lower concentrations of acetyl peroxide, and in the presence of considerable quantities of /sooctane, and that the reactions may follow a different course under these conditions, it is nevertheless difficult to accept their results as completely accurate in a quantitative sense until detailed product-analyses of the reactions carried out under these conditions become available. The numerical values of the "methyl affinities" of simple aromatic and heterocyclic molecules measured in this way must, at the moment, therefore, be accepted with some reservation, although, in a qualitative sense, there is little reason to doubt that they present a substantially correct picture.…”

“…The methyl affinities of most of the simple benzene derivatives investigated appear roughly to parallel the relative rates of attack on the same compounds by phenyl radicals (Table 4-3). This correlation has been pointed Methyl affinity 1 11 2-5 2-2 ± 0-2 4-2 ± 0-2 3-6 ± 0-2 0-65 ± 015 12-2 ± 1-5 2-4 5-2 10 5 1-65* 11-7 12- Levy and; 2 Heilman, Rembaum and Szwarc (1957); 3 Buckley, . out by Hey and Williams (1955) and by Heilman, Rembaum and Szwarc (1957).…”

“…On the basis of a postulated potential-energy diagram for the addition of a methyl radical to the aromatic nucleus, Levy and Szwarc (1955) have also demonstrated a correlation between the methyl affinities of some hydrocarbons with the singlettriplet excitation energies of these hydrocarbons. These quantities are obviously related to the atom localisation energies, and such a correlation is therefore not unexpected.…”

“…Within the last few years, however, a technique has been devised and used by Szwarc and his co-workers which has been successful in providing at least some of the desired information. This technique was first applied to the reaction of methyl radicals with aromatic hydrocarbons and some heterocyclic compounds, and in this application was described in detail by Levy and Szwarc (1955). The method has also been discussed, and some of the results obtained summarised, by .…”

Absolute Rate Constants for Hydrocarbon Autoxidation. XXII. The Autoxidation of some Vinyl Compounds

“…It has been proposed (1 1, 12) for radical addition reactions to olefins addition of methyl radicals to olefins (14)(15)(16)(17)(18) correlate quite well with eq. 9 and fit the expression…”