A Composite Topological Descriptor for Modeling Stability and Reactivity in Polycyclic Conjugated Hydrocarbons

Abstract

Polycyclic conjugated hydrocarbons (PCHs) are π-conjugated molecules whose stability and electronic reactivity are closely related to molecular topology. In this study, a composite topological descriptor based on the Wiener, Harary, Randić, Zagreb and metric degree polynomial indices was developed for QSPR modeling of condensed aromatic hydrocarbons. A set of structurally different PCH molecules was analyzed using reported thermodynamic and electronic properties. Thermodynamic stability was represented by the enthalpy of sublimation (ΔHsub), while molecular reactivity was approximated using a scaled reciprocal ionization energy descriptor. Correlation and regression analyses showed that the composite descriptor effectively reflects stability and reactivity trends in fused aromatic hydrocarbons.