In this investigation, we used computational chemistry to compare two previous research reports based on the capture of carbon dioxide. Each report used a different theoretical model: Hartree-Fock (HF) theory in one case and density functional theory (DFT) in the other.
In the DFT study, the authors computationally evaluated carbon dioxide reactions and interaction energies with nine different anions. In particular, they compared the effect of fluoro substituents on cyclohexanolate and phenolate rings. While the same molecular parameters were examined in the later HF study, the computational method and orbital basis sets were different than in the DFT study.
One goal of the present study was to bridge the gap between these two previous reports. In order to directly compare the data from the later HF investigation with the original DFT study, we chose a similar basis set to def2-TZVP, the basis set used in the original DFT investigation. We ran calculations using this larger basis set, 6-311G* with DFT and the Becke-Perdew (BP) exchange correlation functional as the computational methodology. This similar basis set lets us more closely compare the two studies, allowing a side by side data comparison.
Overall, the comparison between the HF study with the small 3-21G basis set and the current DFT BP/6-311G* study shows that the latter method is a better approximation. In addition, trends first noticed in the HF study persist in the present study. Together, these two results point to the next lines of inquiry in this chemical system.
Brenda Angulo, ’14
Sponsor: Craig Teague