Ab initio MO study of the cleavage of dioxin by hydroiodic acid

Abstract

Dioxins have very strong toxicity to human health and so they are considered to be one of the most important environmental problems. Many scientists are trying to find the way of degrading dioxins, but the specific way other than the thermal decomposition at high temperature have not been found. We call polychlorodibenzo-p-dioxin (PCDD) "dioxins". Both polychlorodibenzofuran (PCDF) and Co-PCB are analogues of dioxins. PCDD have 75 congeners and they have different toxicity by the numbers and the positions of chlorines. These structures include that two benzene rings are bridged by oxygen. And these bonds are similar to the C-O-C bond of ether. The major process to break the bond of ethers is cleavage by acids. So we examine the cleavage of dioxin by hydroiodic acid compared with that of ether. And we also examine compared with the difference between the gas phase reaction and the liquid phase reaction by the use of the B3LYP hybrid density functional theory.