Trialkylsilylethynyl-substituted triphenylenes and hexabenzocoronenes: highly soluble liquid crystalline materials and their hole transport abilities

Four triphenylene (TP) and four hexa-peri-hexabenzocoronene (HBC) derivatives with trialkylsilylethynyl groups were prepared and characterized by differential scanning calorimetry, polarizing optical microscopy, and X-ray diffraction measurements. All compounds were highly soluble in less-polar organic solvents and exhibited a columnar phase, Colh or Colr for the TPs, and Colh for the HBCs. The hole transport ability in the HBCs' columnar phase, 0.4–1.5×10−3 cm2 V−1 s−1 at 40−180 °C, and its temperature dependence were determined by the time-of-flight method using a solution technique.

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