Mechanistic Elucidation of Dimer Formation and Strategies for Its Suppression in Electrochemical Reduction of Fac-Mn(bpy)(CO)3Br

Magnus Haugaard Rønne, Monica Rohde Madsen, Troels Skrydstrup, Steen Uttrup Pedersen, Kim Daasbjerg*

*Corresponding author for this work

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaperJournal articleResearchpeer-review

Abstract

Development of new catalytic approaches for reduction of small molecules is an aspiring technology to alleviate increasing energy demands without use of fossil fuels. One of the most promising molecular catalysts for reduction of CO 2 is fac-Mn(bpy)(CO) 3Br (bpy=2,2’-bipyridine). In this work, the mechanism of electrochemical reduction of this complex is elucidated using cyclic voltammetry along with digital simulations. It is revealed that the dimer complex, Mn 2(bpy) 2(CO) 6, is not, as often assumed, formed by dimerization of the singly reduced manganese complex, [Mn(bpy)(CO) 3] ., but instead from its reduction to [Mn(bpy)(CO) 3] , followed by further reaction with Mn(bpy)(CO) 3Br (rate constant=1.75×10 5 M −1 s −1). On the basis of cyclic voltammetry, infrared-spectroelectrochemistry, and 1H NMR spectroscopy, we establish that this parent-child reaction involving Mn(bpy)(CO) 3Br as electrophile can be diverted by adding either acids or iodomethane as substituting electrophiles. This demonstrates that [Mn(bpy)(CO) 3] , which is the central catalyst for CO 2 reduction, can be formed at less extreme potentials than previously believed by suppressing the parent-child reaction.

Original languageEnglish
JournalChemElectroChem
Volume8
Issue11
Pages (from-to)2108-2114
Number of pages7
ISSN2196-0216
DOIs
Publication statusPublished - Jun 2021

Keywords

  • IR spectroscopy
  • cyclic voltammetry
  • manganese
  • molecular electrochemistry
  • reaction mechanism
  • ALKYL
  • CO2 REDUCTION
  • COMPLEXES
  • SUBSTITUENTS
  • DIMERIZATION
  • ELECTROCATALYSTS
  • RHENIUM
  • MANGANESE
  • HOMOGENEOUS REDOX CATALYSIS
  • LIGAND

Fingerprint

Dive into the research topics of 'Mechanistic Elucidation of Dimer Formation and Strategies for Its Suppression in Electrochemical Reduction of Fac-Mn(bpy)(CO)3Br'. Together they form a unique fingerprint.

Cite this