A QSPR Study on Debromination of PBDEs with CPCM Solvation Model

Abstract

The quantitative structure property relationship (QSPR) study was performed in this work to develop models to predict the normalized reaction rate constants for the reductive debromination of polybrominated diphenyl ethers (PBDEs) by zero-valent iron (ZVI). In order to consider the solvent effect, conductor-like polarizable continuum model (CPCM) was applied to optimize the geometries and obtain the molecular descriptors using the pseudopotential basis set. The prediction results with the inclusion of solvent effect are slightly better than that of the corresponding gas-phase calculations. The artificial neural network (ANN) model could be more satisfactory to predict the rate constants than the partial least squares regression (PLSR) and principal component analysis-multiple linear regression analysis (PCA-MLR) models.

Theoretical Studies on Structures, Properties and Dominant Debromination Pathways for Selected Polybrominated Diphenyl Ethers

“…The previous studies showed that EA Ada may act as an indicator of toxicity for halogenated aromatic hydrocarbons [ 38 , 41 ]. PCDDs, PCBs, PCDFs, and PCDEs with the positive EA values act as electron acceptors in the reaction with receptors in living cells [ 38 , 41 ]. Thus, the PBDEs with the positive EA Ada may also participate in electron-transfer reactions [ 42 ].…”

“…Pan et al further adopted the above basis set for bromine to study the photodegradation reaction of BDE-209 in tetrahydrofuran (THF) [ 37 ]. In our previous studies, the pseudo-potential SDD basis set was used for Br atom and 6-31+G(d) basis set for C, H, O atoms to obtain molecular descriptors, which were used to predict the debromination rate constants for PBDEs in both gas-phase and solution [ 23 , 38 ].…”

“…Solvents have a significant influence on the properties for solute, thus the calculational results for PBDEs might show an obvious discrepancy between in gas phase and in solution. Polarizable continuum model (PCM) is based on the reaction field theory characterized by the dielectric constant ε [ 38 ]. The conductor-like polarizable continuum model (CPCM), as the development of the polarizable continuum model (PCM), has a much simpler formalism to deal with the complex systems [ 46 ].…”

“…The conductor-like polarizable continuum model (CPCM), as the development of the polarizable continuum model (PCM), has a much simpler formalism to deal with the complex systems [ 46 ]. The CPCM solves the electrostatic potential using the solvation charges instead of the electron density [ 38 , 46 ].…”