Propionyl radicals, decomposition

The photooxidation of diethyl ketone at 120 and 175°C. using oxygen labeled with 2.8 at.-% of oxygen-18 has been reported more recently.48 The two experiments performed at room temperature yielded negligible amounts of carbon monoxide all the carbon dioxide came from the carbonyl group. The experiments performed at higher temperatures were in substantial agreement with those of Noyes and Finkelstein.80 90% of the carbon monoxide came from the decomposition of the propionyl radical [reaction (45)], in contrast to the acetyl radical which yields only 10-20% of the carbon monoxide under conditions that are apparently comparable. 75% of the carbon dioxide came from the car-... 

Thne-of-flight (TOF) mass spectrometric analysis of the pyrolysis fragments of di-t-butyl peroxide suggests t-BuCO as the primary product, followed by decomposition of this radical into CHj.253 Elsewhere, the kinetics of the pyrolysis of dimethyl, diethyl, and di-t-butyl peroxides in a modified adiabatic bomb calorimeter have been investigated.254 The lifetime of acyloxy radicals, generated by the photolysis or thermolysis of acetyl propionyl peroxide, have been studied. Chemical nuclear polarization has been used to determine the rate constant for the decarboxylation of these radical intermediates.255... 

Besides the above-mentioned approaches varying the parameters governing the initiator decomposition, it is worth mentioning an interesting biphasic study based on the difference of solubility of monomers and the use an original amphiphilic bifunctional initiator, the palmitoyl (3-carboxy propionyl) sebacoyl diperoxide 3 [24], In such conditions, block copolymers of water soluble (acrylamide) and oil soluble (butylmethacrylate) monomers can be obtained by interfacial radical copolymerization as follows ... 

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