1,3-二氧戊烷光敏氧化机理的研究

AN INVESTIGATION OF THE MECHANISM OF THE PHOTOSENSITIZED OXIDATION OF 1, 3-DIOXOLANE

1,3-二氧戊环和它的2位,4位取代物能被空气中的氧气所氧化。在加入增感剂并用紫外光照射时,此氧化反应可以加速10倍左右。为了研究取代基的种类和位置对氧化反应速度的影响,我们比较了1,3-二氧戊环及其几种取代物的氧化速度,同时观察了紫外光和增感剂所起的加速作用。得出的实验结果列于表1。

The photosensitized oxidation of 1, 3-dioxolane was investigated both by experimental method and quantum chemical calculations. From the measured rate of absorption of oxygen, it was found that the oxidation reactivities of the substituted 1, 3-dioxolanes depend on the kind of the substituents. We have also performed CNDO/2 MO calculations on some 1, 3-dioxolanes. According to the postulate that in presence of a photosensitizer, some singlet oxygen will be formed and the reaction will proceed via an activated complex such as: We further calculated the second order perturbation energies ΔE for the oxidation reaction. The calculated ΔE values of the substituted 1, 3-dioxolanes are in proper order which agree fairly well with the experimental results.