Ruthenium Complexes of Polyfluorocarbon Substituted Terpyridine and Mesoionic Carbene Ligands: An Interplay in CO<sub>2</sub> Reduction

In coordination chemistry and materials science, terpyridine ligands are of great interest, due to their ability to form stable complexes with a broad range of transition metal ions. We report three terpyridine ligands containing different perfluorocarbon (PFC) tails on the backbone and the corresponding FeII and CoII complexes. The CoII complexes display spin crossover close to ambient temperature, and the nature of this spin transition is influenced by the length of the PFC tail on the ligand backbone. The electrochemical properties of the metal complexes were investigated with cyclic voltammetry revealing one oxidation and several reduction processes. The fluorine‐specific interactions were investigated by EPR measurements. Analysis of the EPR spectra of the complexes as microcrystalline powders and in solution reveals exchange‐narrowed spectra without resolved hyperfine splittings arising from the 59Co nucleus; this suggests complex aggregation in solution mediated by interactions of the PFC tails. Interestingly, addition of perfluoro‐octanol in different ratios to the acetonitrile solution of the sample resulted in the disruption of the F F interactions of the tails. To the best of our knowledge, this is the first investigation of fluorine‐specific interactions in metal complexes through EPR spectroscopy, as exemplified by exchange narrowing.

show abstract

Spin Crossover and Fluorine‐Specific Interactions in Metal Complexes of Terpyridines with Polyfluorocarbon Tails

Nößler

Neuman

Böser

et al. 2023

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

show abstract

Isolation, Characterization and Reactivity of Key Intermediates Relevant to Reductive (Electro)catalysis with Cp*Rh Complexes Containing Pyridyl‐MIC (MIC=Mesoionic Carbene) Ligands

Bens,

Walter,

Beerhues

et al. 2023

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

In recent years, metal complexes of pyridyl‐mesoionic carbene (MIC) ligands have been reported as excellent homogeneous and molecular electrocatalysts. In combination with group 9 metals, such ligands form highly active catalysts for hydrogenation/transfer hydrogenation/hydrosilylation catalysis and electrocatalysts for dihydrogen production. Despite such progress, very little is known about the structural/electrochemical/spectroscopic properties of crucial intermediates for such catalytic reactions with these ligands: solvato complexes, reduced complexes and hydridic species. We present here a comprehensive study involving the isolation, crystallographic characterization, electrochemical/spectroelectrochemical/theoretical investigations, and in‐situ reactivity studies of all the aforementioned crucial intermediates involving Cp*Rh and pyridyl‐MIC ligands. A detailed mechanistic study of the precatalytic activation of [RhCp*] complexes with pyridyl‐MIC ligands is presented. Intriguingly, amphiphilicity of the [RhCp*]‐hydride complexes was observed, displaying the substrate dependent transfer of H+, H∙ or H−. To the best of our knowledge, this study is the first of its kind targeting intermediates and reactive species involving metal complexes of pyridyl‐MIC ligands and investigating the interconversion amongst them.

show abstract

Redox‐Active Triazole‐Derived Mesoionic Imines with Ferrocenyl Substituents and their Metal Complexes: Directed Hydrogen‐Bonding, Unusual C−H Activation and Ion‐Pair Formation

Rudolf,

Batman,

Mehner

et al. 2024

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

We present herein the synthesis, characterization and complexation of ferrocenyl‐substituted MIIs (mesoionic imines) and their metal complexes. In the free MIIs, strong hydrogen bonding interactions are observed between the imine‐N and the C‐H bonds of the ferrocenyl substituents both in the solid state and in solution. The influence of this hydrogen bonding is so strong that complexation of the MIIs with [IrCp*Cl2]2 yields unique six‐membered iridacycles via C‐H‐activation of the corresponding C‐H‐site at the Fc‐substituent and not the Ph‐substituent. This result is in contrast to previous reports in which always a preferential C‐H activation at the phenyl substituent is observed in competitive reactions in the presence of ferrocenyl substituents. The corresponding Ir complexes formed after in‐situ halide exchange reaction exist in either [Ir‐I] contact or as [Ir]+I‐ solvent separated ion‐pairs depending on the solvent polarity. The iodide coordinated and solvent separated ion‐pairs display drastically different physical properties. The TEP (Tolman‐electronic‐parameter) of these ligands was determined and lines up with previously reported MII‐ligands. The redox properties were investigated by a combination of electrochemical and spectroelectrochemical methods. We show here how non‐covalent interactions can have a drastic influence on the physical and chemical properties of these new class of compounds.

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

hi@scite.ai

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Ruthenium Complexes of Polyfluorocarbon Substituted Terpyridine and Mesoionic Carbene Ligands: An Interplay in CO₂ Reduction

Cited by 3 publications

References 97 publications

Spin Crossover and Fluorine‐Specific Interactions in Metal Complexes of Terpyridines with Polyfluorocarbon Tails

Spin Crossover and Fluorine‐Specific Interactions in Metal Complexes of Terpyridines with Polyfluorocarbon Tails

Isolation, Characterization and Reactivity of Key Intermediates Relevant to Reductive (Electro)catalysis with Cp*Rh Complexes Containing Pyridyl‐MIC (MIC=Mesoionic Carbene) Ligands

Redox‐Active Triazole‐Derived Mesoionic Imines with Ferrocenyl Substituents and their Metal Complexes: Directed Hydrogen‐Bonding, Unusual C−H Activation and Ion‐Pair Formation

Contact Info

Product

Resources

About

Ruthenium Complexes of Polyfluorocarbon Substituted Terpyridine and Mesoionic Carbene Ligands: An Interplay in CO2 Reduction

Cited by 3 publications

References 97 publications

Spin Crossover and Fluorine‐Specific Interactions in Metal Complexes of Terpyridines with Polyfluorocarbon Tails

Spin Crossover and Fluorine‐Specific Interactions in Metal Complexes of Terpyridines with Polyfluorocarbon Tails

Isolation, Characterization and Reactivity of Key Intermediates Relevant to Reductive (Electro)catalysis with Cp*Rh Complexes Containing Pyridyl‐MIC (MIC=Mesoionic Carbene) Ligands

Redox‐Active Triazole‐Derived Mesoionic Imines with Ferrocenyl Substituents and their Metal Complexes: Directed Hydrogen‐Bonding, Unusual C−H Activation and Ion‐Pair Formation

Contact Info

Product

Resources

About

Ruthenium Complexes of Polyfluorocarbon Substituted Terpyridine and Mesoionic Carbene Ligands: An Interplay in CO₂ Reduction