Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Reaction Mechanism for CO Reduction by Mo-Nitrogenase Studied by QM/MM

Jiang, Hao LU orcid and Ryde, Ulf LU orcid (2024) In Inorganic Chemistry 63(34). p.15951-15963
Abstract
We have studied the conversion of two molecules of carbon monoxide to ethylene catalyzed by nitrogenase. We start from a recent crystal structure showing the binding of two carbon monoxide molecules to nitrogenase and employ the combined quantum mechanics and molecular mechanics approach. Our results indicate that the reaction is possible only if S2B dissociates as H2S (i.e., the charge of the FeMo cluster remains the same as in the E0 state, indicating that the Fe ions are formally reduced two steps when CO binds). Eight electrons and protons are needed for the reaction, and our mechanism suggests that the first four bind alternatively to the two carbon atoms. The C–C bond formation takes place already after the... (More)
We have studied the conversion of two molecules of carbon monoxide to ethylene catalyzed by nitrogenase. We start from a recent crystal structure showing the binding of two carbon monoxide molecules to nitrogenase and employ the combined quantum mechanics and molecular mechanics approach. Our results indicate that the reaction is possible only if S2B dissociates as H2S (i.e., the charge of the FeMo cluster remains the same as in the E0 state, indicating that the Fe ions are formally reduced two steps when CO binds). Eight electrons and protons are needed for the reaction, and our mechanism suggests that the first four bind alternatively to the two carbon atoms. The C–C bond formation takes place already after the first protonation (in the E3 state). The next two protons bind to the same O atom, which then dissociates as water. In the same state (E8), the second C–O bond is cleaved, forming the ethylene product. The last two electrons and protons are used to form a water molecule that can be exchanged by S2B or by two CO molecules to start a new reaction cycle. (Less)
Please use this url to cite or link to this publication:
author
and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Inorganic Chemistry
volume
63
issue
34
pages
13 pages
publisher
The American Chemical Society (ACS)
external identifiers
  • pmid:39141025
  • scopus:85201418843
ISSN
1520-510X
DOI
10.1021/acs.inorgchem.4c02323
language
English
LU publication?
yes
id
011db6d7-b4ae-459a-8c79-da8863a67fe6
date added to LUP
2024-08-14 18:28:15
date last changed
2025-04-04 14:30:38
@article{011db6d7-b4ae-459a-8c79-da8863a67fe6,
  abstract     = {{We have studied the conversion of two molecules of carbon monoxide to ethylene catalyzed by nitrogenase. We start from a recent crystal structure showing the binding of two carbon monoxide molecules to nitrogenase and employ the combined quantum mechanics and molecular mechanics approach. Our results indicate that the reaction is possible only if S2B dissociates as H<sub>2</sub>S (i.e., the charge of the FeMo cluster remains the same as in the E<sub>0</sub> state, indicating that the Fe ions are formally reduced two steps when CO binds). Eight electrons and protons are needed for the reaction, and our mechanism suggests that the first four bind alternatively to the two carbon atoms. The C–C bond formation takes place already after the first protonation (in the E<sub>3</sub> state). The next two protons bind to the same O atom, which then dissociates as water. In the same state (E<sub>8</sub>), the second C–O bond is cleaved, forming the ethylene product. The last two electrons and protons are used to form a water molecule that can be exchanged by S2B or by two CO molecules to start a new reaction cycle.}},
  author       = {{Jiang, Hao and Ryde, Ulf}},
  issn         = {{1520-510X}},
  language     = {{eng}},
  month        = {{08}},
  number       = {{34}},
  pages        = {{15951--15963}},
  publisher    = {{The American Chemical Society (ACS)}},
  series       = {{Inorganic Chemistry}},
  title        = {{Reaction Mechanism for CO Reduction by Mo-Nitrogenase Studied by QM/MM}},
  url          = {{http://dx.doi.org/10.1021/acs.inorgchem.4c02323}},
  doi          = {{10.1021/acs.inorgchem.4c02323}},
  volume       = {{63}},
  year         = {{2024}},
}