Polycyclic aromatic hydrocarbons: a QSPR study

This work deals with 48 substances composed exclusively of unsubstituted six-membered fused aromatic rings. In the first step, physicochemical properties which are relevant in environmental studies such as the boiling temperature (Tb), the retention index (RI), n-octanol/water partition coefficient (KOW) and solubility (S) are related with a series of electronic, geometric and topological descriptors. Among them are: electron affinity, the difference between electron affinity and ionization potential (GAP), Wiener, and connectivity indexes, volume, surface area, length-to-breadth ratio and enthalpy of formation. In a second step, these properties were incorporated into the descriptor matrix to build several quantitative structure–property relationships and to obtain prediction rules for the log KOC, log KOA, bioconcentration factor (BCF) and Henry’s law constant (H). Finally, the photo-induced toxicity of freshwater organism Daphinia-Magna is modeled using the following transformed electronic descriptors: electron affinity, ionization potential and Gap.