Applications of Computational Chemistry for Fluorinated Compounds Across the Periodic Table

In honor of Prof. Joe Francisco’s contributions to chemistry, the first part will focus on predicting the energetic properties of potential new refrigerants and etching materials that go beyond the initial replacements for the chlorofluorocarbons, the hydrofluorocarbons (HFCs). Because of concerns about alkane HFCs as global warming agents due to their atmospheric lifetimes and ability to absorb infrared radiation, there is continued interest in HFCs with lower global warming potentials due to shorter lifetimes. As there is a lack of thermochemical data for many of these new HFCs, the composite correlated molecular orbital G3MP2 method has been used to calculate the heats of formation and ionization energies for all of the C1 to C3 HFCs as well as some C4 compounds. The ionization energy of these compounds was also calculated as well as carbene formation from propenes. The current work provides the most complete, reliable set of thermochemical data for these compounds. The prediction of the properties of actinide compounds is needed for nuclear energy production from molten salt nuclear reactors as well as for environmental remediation from the production of nuclear weapons and energy. Prediction of the properties of actinides requires methods that treat relativistic effects due their high atomic number. A description of the energetics and bonding in diatomic uranium compounds will be given. The geometries and electronic structures of early actinide fluorides, AnFx (An=Ac, Th, Pa, U), with the actinide in a range of oxidation states were predicted using advanced computational electronic structure methods. The fluoride affinities, fluorocation affinities, ionization energies, electron affinities, F2 and F2− binding energies, and bond dissociation energies were calculated. Novel structures were predicted for the fluorides when an additional F above the number needed for the highest oxidation is added or in the cation derived from the highest oxidation state fluoride.