A Large Starphene Comprising Pentacene Branches.

Area of Science:

• Organic Chemistry
• Materials Science
• Physical Chemistry

Background:

• Starphenes possess unique physicochemical properties inherited from acenes.
• Larger starphene homologs exhibit instability and low solubility, hindering synthesis.
• Applications in organic electronics and optics are limited by synthetic challenges.

Purpose of the Study:

• To develop a scalable synthesis for pristine [16]starphene.
• To overcome the synthetic difficulties associated with larger starphene derivatives.
• To characterize the structure and electronic properties of [16]starphene.

Main Methods:

• Synthesis of a carbonyl-protected starphene precursor.
• Solid-state thermal conversion to neat [16]starphene.
• Characterization using 13C CP-MAS NMR, TGA, MS MALDI, UV/Vis, FTIR, and high-resolution STM.

Main Results:

• Successful synthesis of pristine [16]starphene on a preparative scale.
• Structural confirmation via high-resolution scanning tunneling microscopy (STM).
• Observation of moderate electronic delocalization between pentacene arms.
• Aromatic character assessed using nucleus-independent chemical shifts (NICS(1)).

Conclusions:

• A novel synthetic strategy enables the production of [16]starphene.
• The synthesized [16]starphene exhibits structural integrity and electronic delocalization.
• This work facilitates further research into starphenes for advanced material applications.