Mercury Methylation by Cobalt Corrinoids: Relativistic Effects Dictate the Reaction Mechanism |
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| Authors: | Dr. Taye B. Demissie Brady D. Garabato Prof. Dr. Kenneth Ruud Prof. Dr. Pawel M. Kozlowski |
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| Affiliation: | 1. Centre for Theoretical and Computational Chemistry, Department of Chemistry, UiT The Arctic University of Norway, Troms?, Norway;2. Department of Chemistry, University of Louisville, Louisville, KY, USA;3. Department of Food Sciences, Medical University of Gdansk, Gdansk, Poland |
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| Abstract: | The methylation of HgII(SCH3)2 by corrinoid‐based methyl donors proceeds in a concerted manner through a single transition state by transfer of a methyl radical, in contrast to previously proposed reaction mechanisms. This reaction mechanism is a consequence of relativistic effects that lower the energies of the mercury 6p1/2 and 6p3/2 orbitals, making them energetically accessible for chemical bonding. In the absence of spin–orbit coupling, the predicted reaction mechanism is qualitatively different. This is the first example of relativity being decisive for the nature of an observed enzymatic reaction mechanism. |
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| Keywords: | computational chemistry density functional calculations enzyme catalysis reaction mechanisms transition states |
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