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Updated: Sep 19, 2025
12:19
Photogeneration of N-Heterocyclic Carbenes: Application in Photoinduced Ring-Opening Metathesis Polymerization
Published on: November 29, 2018
8.6K
Iron N-Heterocyclic Carbene Photoactive Complexes with Rigid Phenylethynyl Substituents as Ligand π-System
Samuel Persson1, Raj Kumar Koninti2, Mariam Barakat3
1Centre for Analysis and Synthesis, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden.
Inorganic Chemistry
|June 9, 2025
Summary
Researchers enhanced iron complexes using extended π-systems in N-heterocyclic carbene ligands, leading to longer-lived charge transfer states for photosensitizer applications. These modified iron(II) complexes exhibit improved photophysical properties and extended excited-state lifetimes.
Area of Science:
- Coordination Chemistry
- Photochemistry
- Materials Science
Background:
- Designing iron complexes with long-lived charge transfer states for photosensitizers is challenging.
- Iron(II) complexes with N-heterocyclic carbene (NHC) ligands are promising candidates.
Purpose of the Study:
- Investigate the effect of extended ligand π-systems on iron(II) complex properties.
- Develop novel iron complexes for photosensitizer applications.
Main Methods:
- Synthesis of three iron(II) complexes with modified NHC ligands (pbmi).
- Incorporation of phenylethynyl moieties onto the pyridine part of the ligand.
- Spectroscopic (absorption, transient absorption) and electrochemical characterization.
Main Results:
- Phenylethynyl modification red-shifted absorption bands and increased extinction coefficients.
- Lowered MLCT energies and easier ligand reduction observed.
- Stabilization of 3MLCT states by ~0.3 eV, with lifetimes extended to ~17 ps.
Conclusions:
- Extended π-systems in NHC ligands effectively enhance photophysical properties of iron complexes.
- The modified complexes show potential for improved photosensitizer applications.
- The results provide insights into designing iron-based photosensitizers with tunable excited-state dynamics.
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