Liquid-crystalline Janus-type fullerodendrimers displaying tunable smectic-columnar mesomorphism

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Liquid Crystals

Background:

• Dendrimers and fullerenes are advanced molecular architectures with unique properties.
• Liquid crystals exhibit ordered phases between solid and isotropic states.
• Combining these structures offers potential for novel materials with tunable properties.

Purpose of the Study:

• To synthesize Janus-type liquid-crystalline fullerodendrimers.
• To investigate the influence of dendron structure and size on liquid crystalline behavior.
• To understand the role of the fullerene core in self-assembly.

Main Methods:

• 1,3-dipolar cycloaddition reaction for synthesis.
• Polarized optical microscopy, differential scanning calorimetry, and X-ray diffraction for characterization.
• Solution property measurements (dipole moment, dielectric polarization, Kerr constant).

Main Results:

• Successful synthesis of Janus-type fullerodendrimers.
• Achieved either smectic (SmC, SmA) or columnar (Colr-c2mm, Colr-p2gg) mesomorphism based on dendrimer generation.
• Supramolecular organization influenced by dendron size, microsegregation, core deformation, and dipolar interactions.
• C60 core does not alter the type of mesophase formed.
• Microsegregation observed in solution.

Conclusions:

• Liquid-crystalline properties of fullerodendrimers can be precisely controlled by design through dendron selection and size.
• The fullerene moiety does not dictate the mesophase type but contributes to the overall structure.
• The findings provide insights into the structure-property relationships of complex supramolecular assemblies.