SINGLET OXYGEN REACTIONS WITH 2,7-DIMETHYL-2,6-OCTADIENE |
| |
Authors: | Charles Tanielian Jacques Chaineaux |
| |
Institution: | Laboratoire de Chimie Organique Appliquée, Associe au CNRS n°81, Institut de Chimie, UniversitéLouis Pasteur 1, rue Blaise Pascal, 67008-Strasbourg, France |
| |
Abstract: | Abstract— Results concerning Rose Bengal sensitized photoxidation of 2,7-dimethyl-2,6-octadiene (A) are discussed. This diolefin may be considered as a model molecule of polyisoprene of polymerization number two with 1,4-4,1 addition mode. All the mono- and dihydroperoxides apt to occur are actually obtained. One of the occurring hydroperoxides, 2,7-dimethyl-dihydroperoxy-3,5-octadiene, which has the structure of a conjugated diene, does not lead to an endoperoxide. This is contrary to Kaplan and Kelleher's hypothesis. On the other hand, no trihydroperoxide forms as a result of further addition of singlet oxygen (1O2). A complete kinetic study has allowed us to determine the rate constants of all the reactions which take place. The reactivity of (A) is twice that of 2-methyl-2-pentene and the addition of 1O2 to one of the double bonds of (A) induces deactivation of the remaining double bond. |
| |
Keywords: | |
|
|