Publication costs assisted by the Atomic Energy Commission and the Petroleum Research Fund Direct chemiluminescence measurements during the decarboxylation of the tertbutyl and dimethyl a-peroxylactones (2a and 2b) in benzene and carbon tetrachloride afforded singlet yields (a) of 4.7 X 10~4 for both excited tertbutylcarboxaldehyde and acetone, respectively. The required fluorescence quantum yields ( ) were determined to be 0.91 X 10~3 for tertbutylcarboxaldehyde and 1.2 X 10-3 for acetone.The triplet yields (ß) were estimated to be 1.5 X 10"' for tertbutylcarboxaldehyde and 5.3 X 10""2 for acetone by means of rubrene-enhanced chemiluminescence measurements. From this data the ratio in efficiencies of triplet and singlet excited state production (ß/ ) was calculated as 320 ± 55 for the tert-butyl and 115 ± 25 for the dimethyl systems, indicating a great preference for the formation of triplet excited carbonyl products in the -peroxylactone decarboxylation. On the basis of a kinetic analysis of the chemiluminescence intensities (I) and decay times (r) as a function of a-peroxylactone and rubrene concentra-5

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Communications to the Editor 2587 conic Acid Violet": UV (H20) 534 (e 89 200), 447 (sh, e 13 000), 314 (€ 5900), 281 (sh, e 8200), 254 (e 17 800), 238 (sh, 13 100), 228 (sh, t 10 800) nm. Aqueous solutions of either the salt or the acid 4 absorb at the same region in the visible spectrum. Cyclic voltammetry (water) of 4 gave an irreversible oxidation potential at +0.3 V and an irreversible reduction

Sir:a-Peroxylactones possess inherent interest as high energy content molecules and importance as intermediates in chemiluminescent systems;' yet useful synthetic methods for pre-:t 17, I977 Sir: Since the first report by Murray et al.' on the success of chemically modifying a metal oxide electrode by covalently attaching reagents, other l a b o r a t o r i e~,~?~ have shown interest Journal of the American Chemical Society /

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