title: Mercury Methylation by Cobalt Corrinoids: Relativistic Effects Dictate the Reaction Mechanism.
abstract: The methylation of Hg(II) (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.
authors: Centre for Theoretical and Computational Chemistry, Department of Chemistry, UiT The Arctic University of Norway, 9037, Tromsø, Norway.
authors: Taye B
authors: 0000-0001-8735-4933
authors: TB
authors: Demissie
authors: Department of Chemistry, University of Louisville, 2320 South Brook Street, Louisville, KY, 40292, USA.
authors: Brady D
authors: BD
authors: Garabato
authors: Centre for Theoretical and Computational Chemistry, Department of Chemistry, UiT The Arctic University of Norway, 9037, Tromsø, Norway.
authors: Kenneth
authors: 0000-0003-1006-8482
authors: K
authors: Ruud
authors: Department of Chemistry, University of Louisville, 2320 South Brook Street, Louisville, KY, 40292, USA. pawel@louisville.edu.|Department of Food Sciences, Medical University of Gdansk, Al. Gen. J. Hallera 107, 80-416, Gdansk, Poland. pawel@louisville.edu.
authors: Pawel M
authors: PM
authors: Kozlowski
keywords: computational chemistry; density functional calculations; enzyme catalysis; reaction mechanisms; transition states