It has been shown that the oxidation of organomercuric salts by inorganic mercuric salts is inhibited by oxygen, accelerated to sonle extent by acids, and will form esters as products even in the presence of much water. Moreover, the system will polymerize acrylonitrile. These evidences of free radical participation are substantiated by the formation of the same products when pernitrous acid replaces inorganic mercuric salt in the system. Kinetic studies show that radicals are involved in a self-regenerating chain in which active monomeric mercurous salt seems to be the carrier.I t has been shown previously (1) that the oxidation of organomercuric salts in which the anion is nitrato is much more facile than maiiltains for systems in which the salts are acetates. Because of this difference in reactivity we have found it convenie~lt to discuss the nitrato and acetato systems separately.
T H E OXIDATION O F ORGANOMERCURIC NITRATESIn the earlier publication (1) it was shown that the reaction of benzylmercuric nitrate with mercuric nitrate in methanol led to benzyl methyl ether and benzyl nitrate. Additional examples have now been sought. Although n-butylmercuric nitrate will not react, cyclohexylmercuric nitrate in methailol contai~ling mercuric nitrate gives an Syo yield of methoxycyclohexane and a 31% yield of cyclohexyl nitrate.Of greater interest is the observation that benzylmercuric nitrate with n~ercuric nitrate in water yields not only benzyl alcohol, benzaldehyde, and benzoic acid but also benzyl nitrate. Similarly cyclohexylmercuric nitrate with mercuric nitrate in water gives not only a 40% yield of cyclohexanol and a trace of forn~ylcyclopentane (to be explained in a forthcomiilg publication) but also a 21% yield of cyclohexyl nitrate. The formation of these nitrate esters in aqueous solution is unusual even though these reaction systems are not entirely homogeneous. T o be sure benzylmercuric chloride has been found (2) to yield benzyl nitrite and nitrate in nitric acid but little water was present in that sq-stem. Certainly cyclohexanol with mercuric nitrate in dilute nitric acid does not form cyc1ohes)il nitrate according to infrared spectral examination. Indeed the formation of appreciable amounts of nitrate esters under conditions where they should be absent or minimal if they were constituents of heteropolar or ionic equilibria indicates strongly that these nitrate esters are formed by a homopolar or free-radical mechanism.