Tunable Redox Potential, Optical Properties, and Enhanced Stability of Modified Ferrocene-Based Complexes

Area of Science:

• Organometallic Chemistry
• Electrochemistry
• Materials Science

Background:

• Ferrocene derivatives are versatile organometallic compounds with tunable electronic properties.
• Understanding the impact of substituents on ferrocene redox behavior is crucial for designing new materials.

Purpose of the Study:

• To synthesize and characterize ferrocene-based derivatives with varying electron-donating groups.
• To investigate the effect of these substituents on redox potentials, electronic transitions, and chemical stability.
• To explore the relationship between electronic structure and reactivity using computational methods.

Main Methods:

• Synthesis of ferrocene derivatives with methyl and tert-butyl groups.
• Electrochemical analysis to determine redox potentials (FeIII/FeII).
• UV-Vis spectroscopy to study electronic transitions.
• Density Functional Theory (DFT) calculations for electronic structure and reorganization energy.

Main Results:

• Tunable FeIII/FeII redox potentials ranging from +0.403 V to -0.096 V were achieved.
• Electron-donating groups caused slight blue shifts in d-d transitions and significant shifts to the near-IR for ligand-to-metal transitions.
• Enhanced chemical stability against oxygen was observed due to increased electron density on FeIII d-orbitals.
• DFT calculations indicated a decreasing trend in outer shell reorganization energy with more electron-donating units.

Conclusions:

• Electron-donating groups on ferrocene cyclopentadienyl rings provide significant control over redox properties and stability.
• The electronic and optical properties of ferrocene derivatives and their oxidized forms can be systematically tuned.
• These findings offer valuable insights for the development of functional organometallic materials.