Synthesis and characterization of low molecular mass luminescent liquid crystalline materials with 1,3,4‐oxadiazole units

Abstract

The synthesis, and liquid crystalline and photophysical properties of luminescent liquid crystalline compounds based on 1,3‐bis[5‐(4‐alkoxyphenyl)‐1,3,4‐oxadiazole‐2‐yl]benzene (two‐fold symmetry) I and 1,3,5‐tris[5‐(4‐alkoxyphenyl)‐1,3,4‐oxadiazole‐2‐yl]benzene II (three‐fold symmetry) are described. The mesophases were characterized using polarizing optical microscopy and differential scanning calorimetry. In addition, all compounds showed blue fluorescence with emission maxima between 366 and 382 nm, and good quantum yields of photoluminescence (Φ_PL = 45%).

Notes

^aTransitions detected by DSC and optical microscopy (10°C min⁻¹).

^bThermogravimetric measurements, onset of decomposition under nitrogen (10°C min⁻¹).

^aMeasured in CHCl₃.

^bExcited at absorption maxima.

^cStandard quinine sulphate (Φ_f = 0.546) in 1M H₂SO₄.