Synthesis and Crystal Engineering of Fluorinated Rubrenes.

Area of Science:

• Organic electronics
• Materials science
• Chemical synthesis

Background:

• Rubrene is a high-mobility organic semiconductor.
• Oxidation stability is crucial for organic semiconductor performance.
• Fluorination is a strategy to tune electronic properties and stability.

Purpose of the Study:

• To investigate the effect of partial fluorination on the oxidation stability of rubrene.
• To synthesize novel fluorinated rubrene derivatives.
• To characterize the molecular structure, packing, and electronic properties of these compounds.

Main Methods:

• Synthesis of six fluorinated rubrenes via propargyl alcohol dimerization and Suzuki coupling.
• Single crystal X-ray diffraction (XRD) for molecular structure and packing analysis.
• Hirshfeld surface analysis and fingerprint plots for intermolecular interactions.
• Cyclic voltammetry (CV) to determine HOMO and LUMO energy levels.

Main Results:

• Successful synthesis of six fluorinated rubrene derivatives.
• XRD revealed four distinct molecular packing structures, including herringbone and 2D brick arrangements.
• Hirshfeld analysis provided insights into intermolecular forces.
• CV demonstrated a decrease in HOMO and LUMO energy levels correlated with increased fluorination.

Conclusions:

• Partial fluorination enhances the oxidation stability of rubrene.
• Fluorination systematically tunes the electronic properties (HOMO/LUMO levels) of rubrene.
• The observed molecular packing influences material properties for potential applications in organic electronics.