Bent-core dimers with top-to-bottom linkage between central units

Area of Science:

• Materials Science
• Organic Chemistry
• Crystallography

Background:

• Bent-core molecules are a class of liquid crystals with unique structural and phase behaviors.
• Understanding the relationship between molecular structure and mesomorphic properties is crucial for designing new materials.

Purpose of the Study:

• To synthesize and characterize a new class of core-to-core dimers of bent-core molecules.
• To investigate the influence of structural modifications on the mesophase behavior and structural parameters of these dimers.

Main Methods:

• Synthesis of novel bent-core molecules with varied spacer lengths, linkage groups, and terminal chain polarities (polyfluoroalkyl, oligosiloxane).
• Structural modification of the outer phenyl ring to mimic polycatenar systems.
• Mesophase behavior analysis using techniques like polarized optical microscopy and differential scanning calorimetry.
• Structural parameter determination through X-ray diffraction.

Main Results:

• Successful synthesis of a new series of bent-core molecules forming core-to-core dimers with a top-to-bottom linkage.
• Demonstration that modifications in spacer length, linkage type, and terminal chain polarity significantly affect mesophase behavior.
• Observation of unique structural parameters influenced by the introduction of polyfluoroalkyl and oligosiloxane units.
• Mimicking polycatenar systems via outer phenyl ring substitution influenced molecular packing and phase behavior.

Conclusions:

• A novel class of bent-core dimers with distinct top-to-bottom core linkages has been established.
• The study provides valuable insights into structure-property relationships in bent-core liquid crystals.
• These findings contribute to the rational design of advanced liquid crystalline materials with tailored properties.