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

Abstract

S N Ar has been used to synthesize various functionalized derivatives of pentafluorobenzenes which are highly specific at the para position; and consequently are ideal for building calamitic (rod-like) liquid crystalline molecular systems. Here, we display the effectiveness of S N 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 carboncarbon (or carbon-oxygen [sulfur]) cross-coupling from the analogous aromatic iodide and fluorobenzoate potassium salt. The molecular structures of the prepared perfluorinated terphenyls were demonstrated 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 and high-resolution polarized optical microscope. Both UV-visible absorbance and emission spectra demonstrated solvatochromism. Supramolecular self-assembly of the generated perfluorinated para-terphenyls was monitored by van der Waals and π-π stacking interaction forces. The creation of nanofibrous architectures was monitored by scanning electron microscopy.

Synthesis, molecular docking, and antioxidant activity of new fluorescent tetrafluoroterphenyl analogues

“…Excellent yields (91-96%) for 4-alkoxy-4 0 -iodobiphenyls were obtained by treating the 4-hydroxy-4 0 -halobiphenyls with 1-haloalkane and potassium carbonate in dimethyl formamide (DMF) at room temperature. [16,17] Using diglyme as a solvent, with aryl iodide and potassium perfluorobenzoate, we were able to manufacture fluoroterphenyl at a high yield through Cu(I)-assisted decarboxylation. To facilitate a more efficient complexation between copper iodide and perfluorobenzoate anions, diglyme was used to create a coordination bond with potassium ions, as described previously by Liu et al [15] This reaction is very efficient, producing highquality yields.…”

“…Because of its sensitivity, it could be used instead of more expensive organometallic reagents in cross‐coupling procedures for the production of perfluorinated adducts. [ 16 ] The use of transition metals as catalysts in cross‐coupling processes for the preparation of perfluorinated chemicals has been the subject of more recent studies. However, these still have some issues such as limited selectivity, low yield, and side effects.…”

Synthesis and molecular docking of novel fluorescent alkoxy‐substituted iodobiphenyl analogues

“…It was shown that all iodobiphenyl ethers have an absorption activity in the ultraviolet range. Those absorption peaks could be credited to the π–π * transitions [18, 19]. The absorbance band intensity increased with spreading the alkyl extent.…”

Synthesis and Self-assembly of Novel Nanofeather-like Fluorescent Alkyloxy-Containing Diphenyl Ether Organogelators

“…The organogelators were synthesized according to previous procedures. 38 Under ultraviolet light, aluminum plates coated with a thin layer of silica gel (60) were used to monitor the reaction progress by thin layer chromatography (TLC) (UV 254 ). Flash column chromatography was used to purify the produced chemicals using silica gel 60.…”

“…All solvents were of spectroscopic grade and obtained from Fluka and Sigma-Aldrich (Egypt). The organogelators were synthesized according to previous procedures . Under ultraviolet light, aluminum plates coated with a thin layer of silica gel (60) were used to monitor the reaction progress by thin layer chromatography (TLC) (UV 254 ).…”