Assessment of a Computational Protocol for Predicting Co-59 NMR Chemical Shift

In the present study, we benchmark computational protocols for predicting Co-59 NMR chemical shift. Quantum mechanical calculations based on density functional theory were used, in conjunction with our NMR-DKH basis sets for all atoms, including Co, which were developed in the present study. The best protocol included the geometry optimization at BLYP/def2-SVP/def2-SVP/IEF-PCM(UFF) and shielding constant calculation at GIAO-LC-& omega;PBE/NMR-DKH/IEF-PCM(UFF). This computational scheme was applied to a set of 34 Co(III) complexes, in which, Co-59 NMR chemical shift ranges from +1162 ppm to +15,100 ppm, and these were obtained in distinct solvents (water and organic solvents). The resulting mean absolute deviation (MAD), mean relative deviation (MRD), and coefficient of determination (R-2) were 158 ppm, 3.0%, and 0.9966, respectively, suggesting an excellent alternative for studying Co-59 NMR.

Automated summary

In this study, computational protocols for predicting Co-59 NMR chemical shift were benchmarked. Quantum mechanical calculations based on density functional theory were used, along with NMR-DKH basis sets developed for all atoms, including Co. The best protocol involved geometry optimization at BLYP/def2-SVP/def2-SVP/IEF-PCM(UFF) and shielding constant calculation at GIAO-LC-ωPBE/NMR-DKH/IEF-PCM(UFF). This computational scheme was applied to a set of 34 Co(III) complexes with Co-59 NMR chemical shift ranging from +1162 ppm to +15,100 ppm, obtained in different solvents (water and organic solvents). The resulting mean absolute deviation (MAD), mean relative deviation (MRD), and coefficient of determination (R-2) were 158 ppm, 3.0%, and 0.9966, respectively, indicating an excellent alternative for studying Co-59 NMR.