Oxidation mechanism of diethyl ether: a complex process for a simple molecule

A large no. of org. compds., such as ethers, spontaneously form unstable peroxides through a self-propagating process of autoxidn. (peroxidn.). Although the hazards of org. peroxides are well known, the oxidn. mechanisms of peroxidizable compds. like ethers reported in the literature are vague and often based on old expts., carried out in very different conditions (e.g. atm., combustion). With the aim to (partially) fill the lack of information, in this paper we present an extensive D. Functional Theory (DFT) study of autoxidn. reaction of di-Et ether (DEE), a chem. that is largely used as solvent in labs., and which is considered to be responsible for various accidents. The aim of the work is to investigate the most probable reaction paths involved in the autoxidn. process and to identify all potential hazardous intermediates, such as peroxides. Beyond the detn. of a complex oxidn. mechanism for such a simple mol., our results suggest that the two main reaction channels open in soln. are the direct decompn. (β-scission) of DEE radical issued of the initiation step and the isomerization of the peroxy radical formed upon oxygen attack (DEEOO√). A simple kinetic evaluation of these two competing reaction channels hints that radical isomerization may play an unexpectedly important role in the global DEE oxidn. process.Finally industrial hazards could be related to the hydroperoxide formation and accumulation during the chain propagation step. The resulting information may contribute to the understanding of the accidental risks assocd. with the use of di-Et ether.