The temperature dependence of individual transfer constants in the telomerization of methyl methacrylate with bromotrichloromethane

✍ Scribed by C.A. Barson; R. Ensor

• Book ID: 103071181
• Publisher: Elsevier Science
• Year: 1977
• Tongue: English
• Weight: 331 KB
• Volume: 13
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(77)90048-9

✦ Synopsis

The photoinitiated reactions between methyl methacrylate and bromotrichloromethane have been studied in the temperature range 30-90°; analysis of the telomer products by gel permeation chromatography was used to determine individual transfer constants for species of varying size. Arrhenius plots have been used to find the difference between the energies of activation of the transfer and propagation steps; these show no significant variation with radical size. However the ratio of the pre-exponential factors for transfer and for propagation increases appreciably over the first three steps of the telomerization and is the important factor in determining the magnitude of the individual transfer constants. These results can be explained in terms of association via cyclic structures of the radical-end with other groups in the growing telomer.