Date of Award

6-1982

Document Type

Union College Only

Degree Name

Bachelor of Science

Department

Chemistry

Language

English

Abstract

The gas phase reaction between ozone and olefins is thought to proceed via an oxy-peroxy biradical intermediate, which may undergo cleavage or a variety of hydrogen abstractions. The validity of this biradical mechanism is investigated in a study of the products and stoichiometry of the gas phase ozonolysis of tetramethylethylene. Various pathways in the ozonolysis mechanism for this olefin are compared thermochemically to assess the relative favorability of the reaction possibilities of the biradical intermediate. Experimentally, olefin-rich and ozone rich reaction conditions are studied in the concentration range 10-800 ppm, using gas chromatography. The concentration of ozone present is determined by a spectrometric buffered KI method. Acetone is identified as a major product in the ozonolysis of tetramethylethylene. The stoichiometry of the reaction is found to be a function of initial reactant concentrations in both olefin-rich and ozone-rich conditions. Acetone yields exhibit direct concentration dependence in the presence of excess olefin and inverse dependence in the presence of excess ozone. In addition, the yield of acetone is overall much lower in an ozone-rich environment than in the olefin-rich case. The possible existence of additional pathways in the biradical ozonolysis mechanism is suggested in terms of these observations. Results of this study are compared with previous work at higher concentrations, and the modelling of atmospheric ozonolysis reactions is considered.

Share

COinS