Ferroelectric Liquid Crystalline Dendrimers:  Synthesis, Thermal Behavior, and Electrooptical Characterization

The preparation and characterization of a series of novel ferroelectric liquid crystalline dendrimers are presented. End-capping of 1-, 2-, and 3-generation dendrimers based on 2,2-bis(hydroxymethyl)propionic acid with mesogens gave surface-functionalized liquid crystalline compounds with 6, 12, and 24 mesogen-containing units, respectively. 4‘ ‘-((R)-1-Methylheptyloxy)phenyl 4-{4‘-[10-(hydroxycarbonyl)decyloxy]phenyl}benzoate was synthesized and used as a mesogen-containing unit. The purity and structure of each compound were determined by 1H NMR spectroscopy, size exclusion chromatography, and elemental analysis. Differential scanning calorimetry and optical microscopy were used to investigate the mesomorphic properties of the mesogen-functionalized dendrimers. The materials displayed a variety of mesophases, including the smectic C* phase. All the liquid crystalline dendrimers showed ferroelectricity, and tilt angle and spontaneous polarization measurements were performed. The obtained results show that the ferroelectric properties of the materials are independent of the generation number of the dendritic scaffold.