Investigating Metal-Metal Bond Polarization in a Heteroleptic Tris-Ylide Diiron System

Area of Science:

• Inorganic Chemistry
• Organometallic Chemistry
• Materials Science

Background:

• Diiron complexes are crucial in various catalytic processes.
• Understanding the electronic structure and reactivity of diiron centers is key to designing new catalysts.
• C3-symmetric ligands offer unique coordination environments for metal centers.

Purpose of the Study:

• To synthesize and characterize a series of C3-symmetric diiron complexes.
• To investigate the electronic structure and bonding in these diiron complexes.
• To explore the S-atom transfer reactivity of the synthesized complexes.

Main Methods:

• Synthesis of C3-symmetric diiron complexes.
• Crystallographic, spectroscopic (NMR, UV-vis, Mössbauer), and computational (DFT, CASSCF) characterization.
• Investigation of S-atom transfer reactions.

Main Results:

• Successful synthesis and characterization of novel C3-symmetric diiron complexes.
• Distinct coordination environments for the two iron centers (FeN and FeC).
• High-spin iron centers with short Fe-Fe distances but weak orbital overlap.
• Redox localization to the FeC center.
• Formation of Fe4S and Fe4S2 clusters upon S-atom transfer.

Conclusions:

• The C3-symmetric diiron complexes possess unique structural and electronic properties.
• The Fe-Fe bond, despite its short distance, exhibits weak orbital overlap.
• Oxidation is localized to the FeC center.
• S-atom transfer provides a route to Fe4S and Fe4S2 cluster formation.