Same ligand, three first-row metals: comparing M-amido bifunctional reactivity (Mn, Fe, Co)
Matthew R Elsby1, Scott Y H Kim1, Stephan N Steinmann2
1Department of Chemistry and Biomolecular Sciences and Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario, K1N 6N5 Canada. rbaker@uottawa.ca.
Dalton Transactions (Cambridge, England : 2003)
|October 18, 2021
Summary
This study computationally assessed metal bis(amido) complexes, finding manganese (Mn) bis(amido) donors most nucleophilic and reactive for H2 activation. This highlights Mn
Area of Science:
- Inorganic Chemistry
- Computational Chemistry
- Catalysis
Background:
- Metal bis(amido) complexes are crucial in catalysis.
- Understanding their bifunctional reactivity is key for designing new catalysts.
- The electronic properties of the metal center significantly influence reactivity.
Purpose of the Study:
- To computationally evaluate the bifunctional reactivity of three metal SNS (bis)amido complexes.
- To compare the nucleophilicity of the metal-nitrogen (M-Namido) donor across manganese (Mn), iron (Fe), and cobalt (Co) complexes.
- To determine the reaction barriers for a model bifunctional H2 activation reaction.
Main Methods:
- Density Functional Theory (DFT) calculations were employed.
- Hirshfeld charges were analyzed to quantify nucleophilicity and electrophilicity.
- Reaction energy profiles for H2 activation were computed.
Main Results:
- The Mn-Namido donor was identified as the most nucleophilic.
- The Fe metal center exhibited the most electrophilic character.
- The Mn complex demonstrated the lowest reaction barrier (17 kcal mol-1) for H2 activation, followed by Fe (21 kcal mol-1) and Co (29 kcal mol-1).
Conclusions:
- Manganese bis(amido) complexes show superior nucleophilicity and lower activation barriers for H2 splitting compared to Fe and Co analogs.
- Computational insights guide the development of efficient metal-based catalysts for hydrogenation reactions.
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