Intervalence Charge Transfer in an Osmium(IV) Tetra(ferrocenylaryl) Complex

Area of Science:

• Organometallic Chemistry
• Materials Science
• Electrochemistry

Background:

• Tetraaryl compounds M(aryl)4 exhibit properties influenced by both tetrahedral geometry and the central atom (M).
• Systematic evaluation of how different central atoms modulate reactivity, electrochemistry, and optical behavior is lacking.
• These compounds can serve as building blocks for molecular species or extended materials.

Purpose of the Study:

• To investigate the influence of Os(IV), carbon (C), and silicon (Si) central atoms on the spectroelectrochemical properties of tetra(ferrocenylaryl) complexes.
• To compare the electronic and electrochemical behavior of M(aryl)4 complexes with varying central atoms.
• To explore the potential of these complexes as modular building blocks.

Main Methods:

• Synthesis of tetra(ferrocenylaryl) complexes via Negishi cross-coupling.
• Structural characterization using single-crystal X-ray diffraction.
• Electrochemical analysis using solution voltammetry and spectroelectrochemistry.

Main Results:

• Compounds with Os(IV), C, and Si central atoms exhibited comparable molecular structures.
• Os(IV) species uniquely accessed mixed-valence states.
• Os(IV) complexes displayed a characteristic near-IR absorption band indicative of intervalence charge transfer.
• High electrochemical stability was observed for the Os(aryl)4 unit.

Conclusions:

• The central atom identity significantly impacts the electronic and electrochemical properties of M(aryl)4 complexes.
• Os(IV) tetraaryl complexes demonstrate unique redox activity and potential for intervalence charge transfer.
• These M(aryl)4 compounds are promising modular building blocks for advanced materials and devices.