Quantitative structure-property relationships for direct photolysis quantum yields of selected polycyclic aromatic hydrocarbons

By the use of partial least squares (PLS) method and 11 quantum chemical descriptors computed by PM3 Hamiltonian, Quantitative Structure-Property Relationships (QSPRs) for direct photolysis quantum yields of selected polycyclic aromatic hydrocarbons (PAHs) were obtained. Direct photolysis quantum yields were predicted for PAHs for which experimental quantum yield values were lacking. Based on the QSPR models, significant PAH molecular characters governing their direct photolysis quantum yields were identified. It can generally be concluded that PAHs with large average molecular polarizability, molecular weight, and heat of formation values tend to have small photolysis quantum yields. PAHs with large values of the energy of the lowest unoccupied molecular orbital (E-lumo), small values of the energy of the highest occupied molecular orbital (E-homo), and large E-lumo-E-homo values, tend to have great photolysis quantum yields. (C) 2000 Elsevier Science B.V. All rights reserved.