Bennett mechanism

In the bimolecular decay of peroxyl radicals, a short-lived tetroxide is an intermediate. When a hydrogen is present in /3-position to the peroxyl function, a carbonyl compound plus an alcohol and O2 [Russell mechanism, e.g. reaction (42)] or two carbonyl compound plus H2O2 (Bennett mechanism, not shown) may be formed in competition to a decay into two oxyl radicals plus O2 [e.g. reaction (43) for details of peroxyl radical chemistry in aqueous solution, see Refs. 2 and 39]. 

Preemployment tests—examinations administered by potential employers to determine applicants job qualifications and readiness examples include the Bennett Mechanical Comprehension Test (BMCT) by George K. Bennett (S T version) the Richardson, Bellows, Henry Company "Test of Chemical Comprehension" (S T version, 1970) and the California Math Test. Types include reading comprehension, accuracy checking, block counting, and tests developed in-house. 

A variety of preemployment tests are given to Job applicants in the chemical processing industry, including the Bennett Mechanical Comprehension Test and the "Test of Chemical Comprehension." Tests may focus on mechanical aptitude, reading comprehension, and/or basic math skills. 

In originally considering the 5 3 mechanism, involving base catalysis, Bennett, Brand, James, Saunders and Williams were trying to account for the small increase in nitrating power which accompanies the addition of water, up to about 10%, to sulphuric acid. The dilution increases the concentration of the bisulphate ion, which was believed to be the base involved (along with molecular sulphuric acid itself). The correct explanation of the effect has already been given ( 2.3.2). 

A number of authors have developed mechanistic descriptions of the processes causing secondary nucleation in agitated crystallizers (Ottens etal., 1972 Ottens and de Jong, 1973 Bennett etal., 1973 Evans etal., 1974 Garside and Jancic, 1979 Synowiec etal., 1993). The energy and frequency of crystal collisions are determined by the fluid mechanics of the crystallizer and crystal suspension. The numbers of nuclei formed by a given contact and those that proceed to survive can be represented by different functions. 

Bennett, S. B., and Bannister, R. L. (1981). Pulverized Coal Power Plants The Next Logical Seep. Mechanical Engineering 103 i2) 18-24. 

Wang J, Jin Y, Rapp KL, Bennett M, Schinazi RF, Chu CK (2005) Synthesis, antiviral activity, and mechanism of drug resistance of d- and L-2, 3 -didehydro-2, 3 -dideoxy-2 -fluorocarbocycUc nucleosides, J Med Chem 48 3736-3748... 

Bennett JS Mechanisms of platelet adhesion and aggregation an update. Hosp Pract (Off Ed) 1992 27 124. 

Goheen and Bennett showed that regular nitric acid could be used, in about two molar excess, for the oxidation of dimethyl sulphoxide to dimethyl sulphone in 86% yield. The reaction temperature was 120-150°C with a reaction time of about 4 hours. The mechanism for this reaction was postulated to involve initially a protonated sulphoxide species (which has been shown to be present in other strongly acidic systems ) followed by nucleophilic attack by nitrate, and the loss of nitrogen dioxide as shown in equations (4) and (5). 

R. G. Bennett and R. Kellogg, Mechanisms and Rates of Radiationless Energy Transfer, in Progress in Reaction Kinetics, Vol. 4, G. Porter, ed., Pergamon Press, London (1966). 

Lopez JM, Bennett MK, Sanchez HB, Rosenfeld JM, Osborne TE. Sterol regulation of acetyl coenzyme A carboxylase a mechanism for coordinate control of cellular lipid. Proc Natl Acad Sci USA 1996 93 1049-1053. 

Bennett, G. and Kellogg, R. (1967). Mechanisms and rates of radiationless energy transfer. Prog. React. Kinet. 4, 215-38. 

Higgins L, Bennett GA, Shimoji M, et al. Evaluation of cytochrome P450 mechanism and kinetics using kinetic deuterium isotope effects. Biochemistry 1998 37(19) 7039-7046. 

Bennett s re-examination (72) of the bromination of PtBr2(oS)2 has shown (by p.m.r. spectroscopy) that a 5-membered ring system is formed. This observation may be satisfactorily rationahsed in terms of a mechanism analogous to that given above for the bromination of AuBr(vp). 

The same type of mechanism can account for Bennett s observations that, on reaction with methanol, the 5-membered ring-system in PtBra (oSBr) (oS) rearranges to the 6-membered ring in PtBr3(oS-OMe)(oS). The apparent discrepaincies in the rates of this reaction and of the same reaction reported by Erskine (8) may, it is suggested here, by explained in the following terms ... 

In the following sections, only the most useful of the empirical correlations will be reviewed. For fuller compilations of empirical relationships, reference should be made to the reviews of Isbin, Moen and Mosher (II), Bennett (B9), or Gresham et al. (G7). Additional correlations based on operating large-diameter pipe lines have been given by Baker (B2, B3, B4). References to more recent relationships will be found in succeeding sections, and more detailed discussions of the mechanics of various flow patterns are given in Sections IV and V. 

Bennett, P.B., Yazawa, K., Makita, N. and George, A.L. (1995) Molecular mechanism for an inherited cardiac-arrhythmia. Nature, 376, 683-685. 

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