Assessment of quantum chemical methods for the calculation of homolytic N–F bond dissociation energies

Abstract

Abstract In this article, the performance of a wide range of conventional and double-hybrid DFT methods (in conjunction with Dunning basis sets of double-, triple- and quadruple-zeta quality), as well as a number of Gaussian-n thermochemical protocols are assessed for their ability to compute accurate homolytic N–F bond dissociation energies (BDEs). Their performance is evaluated against a previously reported set of 31 highly accurate gas-phase N–F BDEs obtained using the benchmark-quality W2w thermochemical protocol (See: R.J. O'Reilly, A. Karton, L. Radom, J. Phys. Chem. A 2011, 115, 5496.). Out of all of the DFT/basis set combinations investigated, ωB97 and M06-2X (in conjunction with the aug'-cc-pVDZ basis set) offer the lowest mean absolute deviations (MADs = 2.4 and 2.7 kJ mol–1, respectively). Of the Gaussian-n procedures, G3X offers the best performance (MAD = 1.4 kJ mol–1), whilst the significantly more economical G3X(MP2)-RAD method also offers excellent performance (MAD = 1.8 kJ mol–1).