Revisiting the thermochemistry of chlorine fluorides

Abstract

In this work, accurate calculations of standard enthalpies of formation of chlorine fluorides (ClF_n, n = 1–7; Cl₂F and Cl₃F₂) were performed through the isodesmic reactions scheme. It is argued that, for many chlorine fluorides, the gold standard method of quantum chemistry (CCSD(T)) is not capable to predict enthalpy values nearing chemical accuracy if atomization scheme is used. This is underpinned by a thorough analysis of total atomization energy results and the inspection of multireference features of these compounds. Other thermodynamic quantities were also calculated at different temperatures. In order to complement the energetic description, elimination curves were studied through density functional theory as a computationally affordable alternative to highly correlated wave function-based methods.