Oxygen phthaloyl peroxide

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... 

Carboxylate esters readily undergo photodecomposition with loss of carbon dioxide. Not surprisingly, lactones and related oxygen heterocycles undergo related transformations. A wide variety of lactones behave in this fashion" for example, the cyclic dilactone (505) is converted on irradiation to the [2.2]paracyclophane (506). Of particular interest is the use of the jS-lactone (507) as a precursor of matrix-isolated cyclobutadiene (508)." Phthaloyl peroxide (509) has similarly been employed as a precursor of benzyne (510). A careful examination in an argon matrix at 8 K has revealed that the / -lactone (511) and the keto ketene (512) are intermediates... 

OXYGEN, SINGLET Cerium(IV) oxide-Hydrogen peroxide. Phthaloyl peroxide. 

Phthaloyl peroxide as singlet oxygen source Oxidative isobenzofuran ring opening... 

Strong chemiluminescence was observed only in dimethylphthalate as solvent. Small quantities of water enhanced the light yield but oxygen had no distinct influence on the chemiluminescence [24 a]. Phthaloyl peroxide exhibits chemiluminescence with a series of other fluorescent compounds such as BPEA, pyrene, perylene, 1,3-diphenyl isobenzofuran, and fluorescein. 

The reactions of these peroxides are clearly different from those of diphenoyl peroxide. The mechanism is likely to be complex since oxidative transformation of the added fluorescer occurs to a large extent. The main differences are that peroxides related to phthaloyl peroxide show little loss of CO2 (about 17%) whereas the yield in the case of diphenoyl peroxide is about 80%. Quenching by oxygen is observed, but in the CIEEL pathway quenchers such as H2O, oxygen and tetramethyl ethylene have little influence. 

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