TY - JOUR
T1 - Quantum Chemical Study of the Redox Potential of the Co(OH2)6 2+/3+ Couple and the Singlet-Quintet Gibbs Energy Difference of the Co(OH2)6 3+ Ion
AU - Rotzinger, François P.
AU - Li, Hui
N1 - Funding Information:
Some of the computations were performed at the Institut des Sciences et Ingeníerie Chimiques, Ecole Polytechnique Fed́ eŕ ale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland. This work was partially supported by a seed grant from the Nebraska Center for Integrated Biomolecular Communication (NIH, National Institutes of General Medical Sciences, No. P20-GM113126). The reviewers’ helpful comments are gratefully acknowledged.
Publisher Copyright:
Copyright © 2018 American Chemical Society.
PY - 2018/8/20
Y1 - 2018/8/20
N2 - The geometry and vibrational frequencies of Co(OH2)6 2+ in the quartet state and Co(OH2)6 3+ in the singlet and quintet states were computed with quantum mechanics/molecular mechanics (QM/MM), whereby the LC-BOP-LRD functional was used for the QM part involving the Co(OH2)6 n+ (n = 2, 3) ions. The surrounding 124 MM water molecules were treated with the MMFF94 force field. The hydration energy differences between low-spin Co(OH2)6 3+ and Co(OH2)6 2+ or Co(OH2)6 3+ in the quintet state were also calculated using this method. The electronic energy of the Co(OH2)6 n+ (n = 2, 3) ions was calculated with wave function theory, multistate extended general multiconfiguration quasi-degenerate second-order perturbation theory and spin-orbit configuration interaction. The redox potential of the Co(OH2)6 2+/3+ couple, and the singlet-quintet (adiabatic) Gibbs energy difference of Co(OH2)6 3+, computed based on these data, agree with the experiment.
AB - The geometry and vibrational frequencies of Co(OH2)6 2+ in the quartet state and Co(OH2)6 3+ in the singlet and quintet states were computed with quantum mechanics/molecular mechanics (QM/MM), whereby the LC-BOP-LRD functional was used for the QM part involving the Co(OH2)6 n+ (n = 2, 3) ions. The surrounding 124 MM water molecules were treated with the MMFF94 force field. The hydration energy differences between low-spin Co(OH2)6 3+ and Co(OH2)6 2+ or Co(OH2)6 3+ in the quintet state were also calculated using this method. The electronic energy of the Co(OH2)6 n+ (n = 2, 3) ions was calculated with wave function theory, multistate extended general multiconfiguration quasi-degenerate second-order perturbation theory and spin-orbit configuration interaction. The redox potential of the Co(OH2)6 2+/3+ couple, and the singlet-quintet (adiabatic) Gibbs energy difference of Co(OH2)6 3+, computed based on these data, agree with the experiment.
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U2 - 10.1021/acs.inorgchem.8b01308
DO - 10.1021/acs.inorgchem.8b01308
M3 - Article
C2 - 30070480
AN - SCOPUS:85051849702
SN - 0020-1669
VL - 57
SP - 10122
EP - 10127
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 16
ER -