Quantitative structure-property relationships (QSPRs) on direct photolysisof PCDDs

By the use of partial least squares (PLS) method and 27 quantum chemical de scriptors computed by PM3 Hamiltonian, a statistically significant QSPR wer e obtained for direct photolysis quantum yields (Y) of selected Polychlorin ated dibenzo-p-dioxins (PCDDs). The QSPR can be used for prediction. The di rect photolysis quantum yields of the PCDDs are dependent on the number of chlorine atoms bonded with the parent structures, the character of the carb on-oxygen bonds, and molecular polarity. Increasing bulkness and polarity o f PCDDs lead to decrease of log Y values. Increasing the frontier molecular orbital energies (E-lumo and E-homo) and heat of formation (HOF) values le ads to increase of log Y values. (C) 2001 Elsevier Science Ltd. All rights reserved.