Mixed-Valent Molecular Triple Deckers.

Area of Science:

• Organic Chemistry
• Materials Science
• Supramolecular Chemistry

Background:

• Phenothiazine (PTZ) derivatives are known for their redox activity and potential in electronic applications.
• Organic mixed-valence compounds are crucial for understanding electron transfer processes.
• Stacked molecular architectures offer unique pathways for electronic communication.

Purpose of the Study:

• To synthesize and characterize novel PTZ-arene-PTZ compounds with rigid naphthalene spacers.
• To investigate the electronic communication and electron transfer properties between PTZ units mediated by central arene spacers.
• To explore the potential of these structures for applications in molecular electronics.

Main Methods:

• Synthesis of PTZ-arene-PTZ compounds with benzene and tetramethoxybenzene central units.
• Electrochemical analysis using cyclic voltammetry.
• Spectroscopic characterization including UV/Vis-NIR absorption and EPR spectroscopy.
• Computational studies to understand electronic structure and electron delocalization.

Main Results:

• The synthesized compounds form rigid, stacked PTZ-arene-PTZ structures.
• One-electron oxidized forms exhibit class II organic mixed-valence behavior.
• The unpaired electron is partially delocalized across both PTZ units.
• Intramolecular electron transfer barriers are influenced by the central arene moiety.

Conclusions:

• These are the first rigid organic mixed-valent triple-decker compounds with direct through-stacked electron transfer pathways.
• Oligo-naphthalene building blocks facilitate long-range electron transfer.
• The findings demonstrate potential for developing advanced molecular electronics.