Homologous series peroxides

HomoaUyhc peroxy-radicals, alkenyl hydroperoxide cychzation, 213-14 Homodesmic reactions, dioxetanes, 164 Homologous series acyl peroxides, 162... 

They further noted (2) that the over-all rate constant for disappearance of acetyl peroxide decreases monotonically with increasing solvent viscosity. The attractive hypothesis (19, 22, 23) that the observed rate decrease with increased viscosity in this homologous series of hydrocarbon solvents reflects the increased importance of cage recombination of acetoxy radicals in the more viscous solvents is subject to further test from the data of this paper. 

The three saturated long-chain rm-butyl peresters are members of a homologous series, and as such, the weighted least-squares regression analysis of the enthalpies of formation r.v. number of carbons yields a methylene increment of —26.7 kJmol-1, a typical value for liquids. The methylene increment for the tert-butyl esters of the Cr, Cio, C12 and C14 acids is —28.0 kJmol-1. The closeness of these two values ensures that the enthalpies of formal reaction 16 will be nearly constant. For the three pairs from Table 3, the value is —70.3 8.1 kJmol-1. The standard deviation from the mean is quite large because the arithmetic difference for the C12 ester and perester, —79.5 kJmol-1, is quite a bit more negative than the differences for the Cio and C14 pairs, —64.4 and —66.9 kJ mol-1, respectively. Unfortunately, the acids and esters are in different phases and so we are reluctant to attempt any comparison between them, such as a formal hydrolysis reaction or disproportionation with hydrogen peroxide. 

The reaction of dodecamethylcyclohexasilane with potassium permanganate, chromic oxide, and potassium dichromate in acetic acid gives a series of homologous cyclic siloxanes (20). Nitrobenzene and hydrogen peroxide (30%) in either formic acid or tcrt-butyl alcohol were found to be less effective oxidizing agents. 

Scheme 3.90, allowing for H NMR spectroscop-ical estimation of the internal cavity dimensions with the use of a series of homologous molecular rulers (e.g., the corresponding aromatic amides). The available space within 429 is estimated to be 5.7 X 14.7 A, and it readily encapsulates dibenzoyl peroxide in [D12] mesitylene solution, which does not decompose for a long time at 70° C. Moreover, the cavity of 429... 

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