Accurate Prediction of Adiabatic Ionization Energies for PAHs and Substituted Analogues
Abstract
Accurate calculation of AIEs for PAHs and their substituted analogues is important for understanding their electronic properties, reactivity, stability, and environmental/health implications. This work demonstrates that the M06-2X density functional theory (DFT) method performs well in predicting the adiabatic ionization energies (AIEs) of polycyclic aromatic hydrocarbons (PAHs) and related molecules, outperforming common DFT methods and competing in accuracy to the highly accurate CCSD(T)-F12 method. The accuracy of M06-2X is attributed to its large quantity of Hartree-Fock (HF) exchange and its ability to describe diffuse wave functions, which may make it suitable for predicting electronic properties associated with Rydberg-like electronic states. This suggests that M06-2X, with an appropriate basis set, is a reliable and efficient method for studying the PAHs and related molecules in conjunction with experimental techniques. The set of molecules used in this work includes also PAHs with hetero-atoms that can be found in biofuels or nucleic acid bases, making it of great interest for photoionization experiments and mass spectrometry. Down the road, this method will help understanding the relationship of various PAHs to graphene, guiding material research or electronic applications, and validating theoretical calculation methods.
Domains
Chemical SciencesOrigin | Files produced by the author(s) |
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