Systematic Fluorination Is a Powerful Design Strategy toward Fluid Molecular Ferroelectrics

Area of Science:

• Materials Science
• Condensed Matter Physics
• Organic Chemistry

Background:

• Ferroelectric nematic (N_F) liquid crystals exhibit fluid-like properties with macroscopic electric polarization.
• Understanding molecular origins of N_F phase is crucial for designing new materials.

Purpose of the Study:

• Systematically investigate fluorination patterns in homologous series of N_F materials.
• Elucidate molecular factors governing spontaneous polar ordering in fluid ferroelectric nematics.

Main Methods:

• Synthesis and characterization of twenty-seven homologous ferroelectric nematic materials.
• Analysis of fluorination patterns and their impact on N_F phase stability.
• Computational electronic structure calculations to probe molecular charge distribution.

Main Results:

• Specific fluorination patterns, rather than maximal fluorination, were found to yield the most stable N_F phases.
• A delicate balance between polar and apolar nematic phases is controlled by fluorine atom substitution.
• Molecular charge distribution, particularly oscillatory patterns, correlates with higher propensity for polar nematic phases.

Conclusions:

• Provides new insights into the molecular origins of ferroelectricity in nematic liquid crystals.
• Establishes design principles for synthesizing novel ferroelectric nematogens.
• Highlights the importance of precise fluorination for tuning liquid crystal properties.