Theoretical studies of bond dissociation energies of S-NO for S-nitrosothiols

The S-NO bond dissociation energies (BDEs) for S-nitrosothiols (RSNO) compounds are computed using the DFT (B3LYP, B3PW91 and B3P86) with the 6-31g∗∗ and 6-311g∗∗ basis set. By comparing the computed energies and experimental results, we find that the B3PW91/6-31g∗∗ and B3P86/6-311g∗∗ method can give good results of BDE, which have the mean absolute deviations of 7.39 and 7.57 kJ/mol, respectively. Considering the smaller maximum difference, we recommend the B3PW91 method combined with 6-31g∗∗ basis set, as a satisfactory method of computing the BDEs for removal of the NO group in RSNO compounds. In addition, we find that the mean absolute deviation reduces from 9.07 to 7.39 kJ/mol when the 6-311g∗∗ basis set in the B3PW91 model is replaced by 6-31g∗∗ basis set, which proves that B3PW91 DFT method is sensitive to the basis sets.