An Ethynylene-Bridged Pentacene Dimer: Two-Step Synthesis and Charge-Transport Properties.

Area of Science:

• Materials Science
• Organic Chemistry
• Solid-State Physics

Background:

• Pentacene derivatives are crucial organic semiconductors.
• Conventional synthesis of ethynylene-bridged systems is often lengthy.
• Achieving high charge carrier mobility in organic materials is a key challenge.

Purpose of the Study:

• To develop a facile and efficient synthesis for ethynylene-bridged pentacene dimers (PenD).
• To investigate the solid-state electronic properties of the synthesized PenD.
• To explore the potential of PenD in organic electronic devices.

Main Methods:

• Two-step synthesis of PenD from pentacenequinone, bypassing traditional stepwise methods.
• Single-crystal X-ray diffraction to analyze molecular packing and electronic interactions.
• Fabrication and characterization of dip-coated films for charge carrier mobility measurements.

Main Results:

• Successful synthesis of a rigid and planar ethynylene-bridged pentacene dimer (PenD).
• Single crystals revealed a brickwork motif, indicating two-dimensionally extended electronic interactions.
• Achieved an average hole mobility of 0.24 cm²/V·s in dip-coated films, comparable to single-crystal devices.

Conclusions:

• The developed two-step synthesis offers a facile route to ethynylene-bridged π-conjugated systems.
• The brickwork packing in PenD promotes significant electronic interactions in the solid state.
• This work enables the development of novel organic semiconducting materials for high-performance electronics.