\(PM_{2.5}\) , a major air pollutant, often carries toxic components such as polycyclic aromatic hydrocarbons (PAHs), which pose potential health risks. This study investigated the relationships between five physicochemical properties-boiling point, molecular mass, enthalpy of vaporization, molar volume, and surface tension-of 15 PAHs and seven molecular topological indices (including the Wiener, Hyper-Wiener, Distance-degree, and Gutman indices) using regression analysis. Results indicated that the selected topological indices were strongly correlated with the properties of PAHs, with correlation coefficients generally exceeding 0.7. In particular, quadratic regression models based on the Distance-degree and Gutman indices showed a very high correlation with enthalpy of vaporization ($R = 0.998$). This work provides quantitative insights into the structure–property relationships of PAHs and may support further theoretical developments in the risk assessment and source control of \(PM_{2.5}\) -bound PAHs.
