Phthaloyl peroxide, decomposition

Cyclic peroxides may serve as a source of singlet oxygen. Wasserman et reacted 9,10-diphenylanthracene peroxide (238, conveniently prepared as in Nilsson and Kearns ) with 138 to give 140 rubrene peroxide proved to be considerably less efficient. Decomposition of anthracene peroxide alone takes another course. 32.396 jg treated with phthaloyl peroxide... 

The decomposition of 84 in dimethylaniline was studied by Horner and Briiggemann.74 Greene has published a number of papers on the chemical behavior of the cyclic phthaloyl peroxide (84).72,75-79... 

State they have more than sufficient energy. The excited singlet state of pyrene sensitises the decomposition of [122] and phthaloyl peroxide (Horn and Schuster, 1979). By means of the technique of flash photolysis it was possible to show that these sensitisation reactions produced the pyrene radical cation and heme that the CIEEL mechanisms was operating. 

Phthaloyl peroxide (2.93) on photolytic decomposition generates benzyne via lactone intermediate. 

The effect of variation in the alkyl group of diacyl peroxides upon the rate of decomposition has been extensively investigated. For convenience the data are divided into decompositions of alkyl and aryl alkyl diacyl peroxides including benzoyl and phthaloyl peroxide for reference (Table 78), halogen containing diacyl peroxides (Table 79), unsaturated diacyl peroxides (Table 80), cycloalkyl diacyl peroxides (Table 81) and unsymmetrical diacyl peroxides (Table 82). The data pertain to first-order decompositions and the rate coefficients are represented as... 

IR spectra of IA and N-methyl IA (24) during thermal decomposition show bands of 1810-1830 cm-1, which are in accordance with the proposed /J-lactam 48.121 Analogous decomposition of 30 (R = phenyl) shows bands at 1830 cm-1 106,108 The concentration of 47 in this thermolysis reaction was too small for detection in IR, but UV shows absorption at 575 nm, indicating the presence of 47.106 Photochemical decomposition of phthaloyl peroxide yields 47 and 48 (X = O), showing IR frequencies at 1904 cm-1 (48) and 2139 cm-1 (47),109 which could also be observed in the thermal decomposition of salicylic acid chloride (49) with 1930 cm-1 and 2070 cm-1.121... 

In an attempt to generate benzyne in its triplet state, the benzophenone-sensitized decomposition of phthaloyl peroxide (174) was studied.108 Reaction of the benzyne with / -cyclo-octene gave isomeric cycloadducts in a ratio indicative of reaction of singlet benzyne. These results suggest that the rate of triplet-singlet... 

A common technique of preparing block copolymers is the introduction of peroxide groups into the polymer backbone or as stable end groups. The polymers are then mixed with fresh monomer, and the peroxide groups are decomposed under appropriate conditions to yield block copolymers. For example, polymeric phthaloyl peroxide was polymerized to a limited extent with styrene. The resulting polymer was mixed with methyl methacrylate. On decomposition, the internal and terminal peroxide groups formed radicals that initiated the polymerization of methyl methacrylate, as shown below in Equation 5.11. 

In the search for highly exergonic reactions, which might be chemiluminescent, the decomposition of cis-1,2-dihydro phthaloyl peroxide (24) was considered. 

Both reactions are strongly catalysed by the fluorescer, but in the case of phthaloyl peroxide this is most likely to be the result of the well known induced decomposition of peroxides. This view is supported by the extensive oxidation of the fluorescer, in contrast to their truly catalytic behaviour in the CIEEL mechanism. 

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