Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

Initiation of oligomerisations of methyloxirane (1,2-epoxypropane) by Ph₃C⁺SbCl^-₆ and Ph₃C⁺AsF^-₆ (Ph = C₆H₅) has been studied by spectral methods and by chemical analysis of the reaction mixtures and reaction products. The results obtained indicate that the triphenylmethyl salts react with methyloxirane simultaneously in two ways: a) by mechanism of the proton and electron pair transfer from methyloxirane to the Ph₃C⁺ cation to form triphenylmethane and active centers with the end groups -CHO; b) mechanism of the direct addition of the PhC⁺ ion to the methyloxirane oxygen, resulting in formation of active centers with the end groups -O-CPh₃. The relative importance of both mechanisms in the overall initiation process is affected by temperature and by concentration conditions in the reaction mixture.