dimethylamino)ethanol, 108-01-@ 2-mercaptoethyl alcohol, 60-24-2.The spontaneous hydrolysis of 2,4-dinitrophenyl phosphate dianion (I) is catalyzed by cationic micelles of the choline-derived surfactant (11, ~-C~~H~~N + M~Z C H Z C H~O H B~-) , but this surfactant is no more effective than cetyltrimethylammonium bromide, CTABr. Zwitterionic micelles (111, n-ClzHzaN+MezCH&Oz-) are relatively ineffective catalysts, Added primary amines increase reaction rate in the presence of micelles of CTABr or 11, but much of the rate enhancement is due to attack by amine upon the aryl group. The effect of the amine increases with its chain length, but secondary amines have less effect, and no attack on the aryl group was found with tertiary amines. The reaction of ethyl p-nitrophenyl phosphate monoanion in the presence of CTABr or I1 is slightly inhibited by added primary amine. In the absence of micelles, amines increase overall reaction rate by attacking the aryl group without markedly catalyzing hydrolysis.
Diethyl hydroxyl amine is an efficient trap for alkyl, alkoxy, and peroxy radicals. The specific rate constant for the reaction of ethyl radicals (gas phase, 25"C), tert-butoxy radicals (benzene solution, 115"C), and poly (peroxystyryl) peroxy radicals (styrene solution, 50°C) were evaluated as 7.2 X lo5, 7.7 X lo7, and 2.9 X lo5 M-l-sec-', respectively. Several possible secondary reactions of the nitroxide radicals are discussed.
CooperativeProgram supported by the Ford Foundation is gratefully acknowledged. We thank the S.R.C. for a Senior Visiting Fellowship (to J.M.B.) while on leave from the University of Wamicli.
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