Quantitative structure-property relationships for vapor pressures of polybrominated diphenyl ethers

Based on quantum chemical descriptors, by the use of partial least squares regression, quantitative structure-property relationship models for subcooled liquid vapor pressures (P-L) of polybrominated diphenyl ether (PBDE) congeners were developed. The Q(cum)(2) value of the optimal model obtained is as high as 0.993, indicating a good predictive ability and robustness of the model. Although disagreements were observed between the predicted log P-L values and log P-L values of validation set, the model obtained can still be used for estimating P-L of other PBDE congeners, considering the fact that accurate P-L values for compounds with low volatility are extremely difficult to determine experimentally. Intermolecular dispersive interactions play a leading role in governing the values of P-L, followed by electrostatic, dipole-dipole and dipole-induced dipole interactions. Intermolecular dispersive interactions also govern the values of enthalpies of vaporization.