Synthesis and Photophysical Properties of Novel Fluorescent Quinoline-Based Aryl Substituted Styryl Systems

Investigations into the flexibility of the 3D structure and rigid backbone of quinoline by fluorine addition to enhance its blue emission

Addition of fluorine to the quinoline structure was found to decrease its intermolecular interactions and influence its 3D structure.

Synthesis and Photophysical Properties of Novel 4-Aryl Substituted Thiophen Derivatives with a Vinyl-Quinoline Unit

( E)-2-[2-(4-bromothiophen-2-yl)vinyl]quinoline was prepared through an acid catalysed condensation of 2-meth-ylquinoline and 4-bromothiophene-2-carbaldehyde. Subsequent palladium-catalysed cross-coupling with various arylboronic acids gave a series of novel fluorescent thiophene and quinoline derivatives. The structures of the products were characterised using IR, 1H NMR, 13C NMR, and elemental analysis. The UV-Vis absorption and photo-luminescence spectra of these derivatives were investigated.

Synthesis, Characterisation and Photoluminescent Properties of Quinoline Derivatives Containing both a Biphenyl Group and an α, β-Diarylacrylonitrile Unit

The synthesis of ( E)-2-(4-bromostyryl)quinoline involves an acid catalysed condensation of 2-methylquinoline and 4-bromobenzaldehyde. ( E)-4′-[(2-(Quinolin-2-yl)vinyl)]-(1,1′-biphenyl)-4-carbaldehyde has been synthesised from ( E)-2-(4-bromostyryl)quinoline and 4-formylphenylboronic acid via a Suzuki coupling reaction. A series of novel quinoline derivatives containing both a biphenyl group and an α, β-diarylacrylonitrile unit have been prepared by the base-catalysed condensation between ( E)-4′-[(2-(quinolin-2-yl)vinyl)]-(1,1′-biphenyl)-4-carbaldehyde and various arylacetonitriles. By contrast, the acid-catalysed condensation of the latter aldehyde with several aniline derivatives has been used to synthesise quinolines containing an imine group. These compounds, which have implications for the manufacture of organic light-emitting diodes, emit blue to green fluorescence with maximum emission peaks of 419–531 nm in solution and in the solid state under UV irradiation. Thermogravimetric analysis reveals their good thermal stability with a decomposition temperature range from 313 to 387°C.