Ingold radical

K. U. Ingold, Free Radical Substitution Reactions, Wiley-Interscience, New York, 1971. 

The reactivity of pyridine relative to that of benzene has been measured using the competitive technique developed by Ingold and his schoool for corresponding studies of electrophilic aromatic substitution. The validity of the method applied to free-radical reactions has been discussed. Three sources of the phenyl radical have been used the results obtained are set out in Table II. 

In the former (Ingold) nomenclature this was called the SRN1 mechanism (see IUPAC, 1989a). This scission may consist of two steps, forming first an aryldiazenyl radical and the phenylthiolate radical (see Sec. 8.6). 

VALGiMiGLi L, BANKS J T, INGOLD K u and LuszTYK J (1995) Kiuetic solveut effects on hydroxylic hydrogen atom abstractions are independent of the nature of the abstrarting radical. Two extreme tests using vitamin E and phenol, J Am Chem Soc, 117, 9966-71. 

Wayner, D., Burton, G., Ingold, K.U. and Locke, S. (1985). Quantitative measurement of total peroxyl radical trapping antioxidant capability of human blood plasma by controlled peroxidation. FEBS Lett. 187, 33-37. 

Wayner, D.D., Burton, G.W., Ingold, K.U., Barclay, L.R.C. and Locke, S.J. (1987). Antioxidants in human blood plasma. The relative contributions of vitamin E, urate, ascorbate and protein to the total radical trapping antioxidant activity. Biochim. Biophys. Acta 925, 408-413. 

The preparation of cyclobutanes via the catalytic conditions can be extremely efficient provided that the radical formed after epoxide opening is sterically shielded and cyclization promoted by the Thorpe-Ingold effect. It... 

In the case of DiPK our experimental findings have not enabled us to decide between these two possibilities. However, according to the work of Rosantsev Q and IngoldS-i reactions between peroxy radicals and nitro-xides derived from tetramethylpiperidine are not very probable, so reaction (15) should not be important. 

The isotope effect was measured in the reaction of peroxyl radical with deuterated cumene (PhMe2CH and PhMe2CD) J. A. Howard, K. U. Ingold, and M. Symonds [78]... 

Howard and Ingold studied this equilibrium reaction in experiments on the oxidation of tetralin and 9,10—dihydroanthracene in the presence of specially added triphenylmethyl hydroperoxide[41]. They estimated the equilibrium constant K to be equal to 60 atm-1 (8 x 103 L mol-1, 303 K). This value is close to T=25atm-1 at 300 K (A/7=38kJ mol-1), which was found in the solid crystal lattice permeable to dioxygen [84], The reversible addition of dioxygen to the diphenylmethyl radical absorbed on MFI zeolite was evidenced and studied recently by the EPR technique [85],... 

KU Ingold, BP Roberts. Free-Radical Substitution Reaction. New York Wiley-Interscience, 1971. 

Howard and Ingold [54] observed the same tendency in reactions of primary and secondary peroxyl radicals with several hydrocarbons. The following table gives the values of rate constants (L mob1 s 1) at 303 K. 

The reactivity of tertiary peroxyl radicals of different structures is very close, as it was evidenced by measuremets of Howard and Ingold [55,56]. The rate constants (L moR1 s-1) of four tertiary peroxyl radicals with a few alkylaromatic hydrocarbons (T = 303 K) are presented below. 

GR Hodges, MJ Young, T Paul, KU Ingold. Free Radic Biol Med 29 434-441, 2000. 

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