Decafluorinated and Perfluorinated Warped Nanographenes: Synthesis, Structural Analysis, and Properties

Area of Science:

• Nanocarbon Chemistry
• Materials Science
• Organic Synthesis

Background:

• Fluorination modifies nanocarbon properties but achieving edge-perfluorination without damaging the π-conjugated system is difficult.
• Traditional fluorination methods often lead to structural degradation of nanographenes.

Purpose of the Study:

• To develop a novel bottom-up strategy for synthesizing precisely edge-perfluorinated nanographenes with intact π-conjugated structures.
• To investigate the structural, electronic, and physical properties of these novel fluorinated nanographenes.

Main Methods:

• A bottom-up approach involving fluorine preinstallation.
• Suzuki-Miyaura coupling followed by a Scholl reaction to synthesize decafluorinated and perfluorinated warped nanographenes (DFWNG and PFWNG).
• X-ray crystallography and dynamic studies to analyze structural and flexibility characteristics.

Main Results:

• Successfully synthesized DFWNG and PFWNG with precisely edge-perfluorinated and intact π-conjugated structures for the first time.
• PFWNG exhibited a more twisted saddle-shaped geometry and reduced flexibility compared to DFWNG and pristine WNG.
• Edge-perfluorination improved solubility, lowered the LUMO, and enhanced thermal stability and hydrophobicity, making PFWNG a promising n-type semiconductor.

Conclusions:

• The developed bottom-up fluorination strategy enables the synthesis of edge-perfluorinated nanographenes with preserved π-conjugation.
• Perfluorinated warped nanographenes (PFWNG) demonstrate excellent properties for thermostable/hydrophobic n-type semiconductor applications.
• This strategy holds potential for synthesizing other perfluorinated nanocarbon materials.