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Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
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Identifying Reactivity Differences of Two-Carbon-Atom-Based Legacy Refrigerants at Group 9 Metal Pincer Complexes
Luc A Mauro1, Isabelle A Herlinger1, Shane J Hall1
1Department of Chemistry, Lehigh University, 6 E Packer Ave., Bethlehem, Pennsylvania 18015, United States.
ACS Organic & Inorganic Au
|December 8, 2025
Summary
This study details metal-mediated C-H activation of refrigerants, showing fluorination degree dictates product formation. It presents the first metal-mediated dehydrofluorination of R-143a and stable iridium complexes with legacy refrigerants.
Area of Science:
- Organometallic Chemistry
- Catalysis
- Materials Science
Background:
- Legacy refrigerants possess high global warming potential.
- C-H activation of alkanes by transition metals is challenging.
- Functionalizing fluorinated compounds is crucial for chemical synthesis.
Purpose of the Study:
- To investigate metal-mediated C-H activation of legacy refrigerants.
- To explore the influence of fluorination degree on reaction pathways.
- To develop methods for repurposing high-global-warming-potential refrigerants.
Main Methods:
- Comparative experimental studies of C-H activation reactions.
- Density Functional Theory (DFT) analyses of organometallic intermediates and products.
- Spectroscopic and structural characterization of reaction products.
Main Results:
- Demonstrated that C-H activation can yield stable M-(H)-Rf complexes or M-(fluoroolefin) complexes, depending on refrigerant fluorination.
- Reported the first metal-mediated dehydrofluorination of R-143a via beta-fluoride elimination.
- Observed and characterized direct C-H activation products for R-125 and R-134a, forming stable iridium complexes.
Conclusions:
- The stability of observed [Ir-(H)-(Rf)] complexes is significant, offering new avenues for studying migratory insertion reactions.
- This work provides a foundation for repurposing high-global-warming-potential refrigerants.
- DFT calculations elucidated the electronic and structural effects of fluorination on C-H activation and fluoroolefin binding.
Keywords:
C−H activationfluoroalkanesfluoroolefinshydrofluorocarbonsiridium pincer complexesrefrigerantsMore Related Videos
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