Synthesis, characterization and self-assembly of fluorescent fluorine-containing liquid crystals.

SN Ar has been used to synthesize a variety of functionalized derivatives of pentafluorobenzenes which are highly specific at the para position; and consequently are ideal for the building of calamitic (rod-like) liquid crystalline molecular systems. Herein, we display the effectiveness of SN Ar chemistry as a convenient method toward the synthesis of fluorescent liquid crystalline perfluorinated comprising ethers and thioethers in excellent yields and high purity. In the current work, we describe the synthesis, self-assembly and mesogenic properties of new perfluorinated para terphenyls bearing various para-substituted alkoxy and thioalkoxy chains. The terphenyl core was prepared using Cu(I) (or Cu(I)/Phenanthroline)-catalyzed decarboxylative carbon-carbon (or carbon-oxygen (sulfur)) cross-coupling from the analogous aromatic iodide and fluorobenzoate potassium salt. The molecular structures of the prepared perfluorinated terphenyls were proved with 1 H, 13 C, and 19 F NMR, as well as FT-IR and X-ray crystallography. The liquid crystalline properties and mesogenic phases were characterized with) differential scanning calorimetry (DSC) and high resolution polarized optical microscope (POM). Both of UV-Vis absorbance and emission spectra demonstrated solvatochromism. Supramolecular self-assembly of the generated perfluorinated para terphenyls was monitored via van der Waals and π-π stacking interaction forces. The creation of nanofibrous archetectures was monitored by scanning electron microscopy (SEM). This article is protected by copyright. All rights reserved.