Synthesis,Characterization And Properties Of Liquid Crystal Compounds Based On Pyrrolo-Annelated Tetrathiafulvalenes

Tetrathiafulvalene (TTF) and its crystalline derivatives have been extensively studied, and proven to be promising molecular building blocks for organic optoelectronic applications due to their excellent electronic and optical properties. TTF derivatives having a LC phase should be more promising semiconductor materials because the ordered molecular structures in the LC phase will generate fewer structural defects on the macroscopic scale.However, the research of TTF-based LCs has been restricted, mainly due to the synthetic limitations.We have designed and successfully synthesized a new series of pyrrolo-annelated tetrathiafulvalene (TTF) derivatives with liquid crystal properties, which have pyrrolo-annelated TTF as a rigid structure, with different lengths of alkoxy groups as side chains.The structure of the compounds were characterized by1H and13C-NMR, mass spectrometry.To study the electrochemical properties of the compounds synthesized using cyclic voltammetry (CV). Studies show that the pyrrolo-annelated TTF derivatives have higher redox potential, and the redox potential is not affected by the number of carbon atoms in the end of alkyl chains.The target compounds and F4-TCNQ can interact each other, forming a F4-TCNQ-/TTF+charge transfer complex.The compoundsl5a-c,24a-c have liquid crystals using a differential scanning calorimeter (DSC), polarizing microscopy (POM), wide angle X-ray diffraction (WARD), the liquid crystal phases change with the growth of the terminal alkoxy chain lengths. The compound15a as hexagonal columnar phase and the compound15b-c as SmA phase; the compound24a-b as Nematic phase,24c are inclined columnar phase.