Computation of gas-phase enthalpies of formation with chemical accuracy: The curious case of 3-nitroaniline

Using a variety of density functional, post-Hartree-Fock and composite methods, in conjunction with extended basis sets, and a homodesmotic reaction, we conservatively propose a gas-phase enthalpy of formation for 3-nitroaniline of 17 ± 1 kcal mol−1, a value that significantly differs from experimental values suggested in compendia of thermochemical data. Assuming that the reported experimental solid-state enthalpy of formation by Nishiyama et al. is reliable at 8.2 ± 0.3 kcal mol−1, an enthalpy of sublimation for 3-nitroaniline of 25 ± 1 kcal mol−1 is estimated.