Ozone Reactions with Aliphatic Ethers in CCl4. Kinetics and Mechanism

Article abstract of DOI:10.1002/kin.550270206

The kinetics and mechanism of ozone reactions with aliphatic ethers in CCl4 solution have been investigated with a set of six symmetrical ethers: ethyl, chloroethyl, iso-propyl, n-butyl, iso-amyl, and n-amyl.The corresponding kinetic constants at ambient temperature are 3.1, 0.035, 5.4, 6.3, 6.8, and 7.8 1/(mol s).Upon ozonation of n-butyl ether the main products are butylalcohol, butyraldehyde (butyric acid), and butyl butyrate.A common precursor of these products is the α-hydrotrioxybutyl ether.Experimental values of the preexponential factors are compared with those calculated according to the activation complex theory with linear or cyclic form of the activated complex.The cyclic form of the activated complexes is unfavorable because of the kinetic factor.Abstraction of hydrogen atom or the far less probable hydride ion abstraction from α-position in the ether molecules is the rate-determining step of ozonation.The rate-determining factors are the electron density and geometry of the reaction center and the energy of the α-C-H bonds.