Sulfoxide bond dissociation enthalpies predicted by DFT paired with Pople, Dunning, and Karlsruhe basis sets

Computational analysis was conducted to determine the bond dissociation enthalpies (BDEs) of S–O bonds in eight molecules, which were subsequently compared to their experimentally derived BDEs. Computational BDEs were determined utilizing various combinations of density functional theory (DFT) functionals with an assortment of basis sets. Specifically, DFT methods including M06-2X, mPW1LYP, ωB97X-D3, PBE0, and B3P86 were paired with basis sets def2-TZVP/J, def2-TZVP, aug-<i>cc</i>-pV(T + d)Z, 6-311 + G(2df,2p), and def2-QZVP. The comparison between computational and experimental BDEs was evaluated through graphical representation, yielding slope, coefficient of determination (R²), and root mean square error (RMSE) metrics. Additionally, comparative analyses were expanded to include complete basis set methods (CBS-QB3 and CBS-4M), which exhibited comparatively lower accuracy in predicting experimentally determined S–O BDEs than the DFT methods. Among all methods tested, the B3P86/aug-<i>cc</i>-pV(T + d)Z and B3P86/def2-QZVP methods are recommended for computational prediction of BDEs for sulfoxides.