Theoretical study on the photodegradation reaction of deca-BDE in THF in the presence of furan

Abstract

Polybrominated diphenyl ethers (PBDEs) have received significant environmental concern because of their potential toxicity to humans and wildlife worldwide. The photodegradation debromination of deca-BDE (BDE209) in the tetrahydrofuran (THF) solvent in the presence of furan is explored using the time-dependent density functional theory combined with the polarizable continuum model. Our calculations reveal that the lone pair–π interaction between BDE209, and THF has a significant effect on the low-lying excitation and reduces the binding energies of C–Br bonds to some extent, which accounts for the photodegradation via the πBDE209σ* excited state and explains experiment successfully. We find that the addition of a small quantity of furan can promote the photodegradation of BDE209 in THF effectively and this is attributed to the π-stacking interaction between BDE209 and furan, which plays an important role in the low-lying π → σ* transitions in the sunlight region.