Synthesis and characterization of luminescent hockey stick‐shaped liquid crystalline compounds

Abstract

A general synthetic strategy, based on a convergent approach, allowed us to prepare a series of luminescent unsymmetrical bent‐core compounds (2,5‐(disubstituted)‐1,3,4‐oxadiazole derivatives), via the Sonogashira crosscoupling reaction, all possessing a similar hockey stick shape. Their mesophases were characterized using polarizing optical microscopy and differential scanning calorimetry. The observed LC phases possess the classical textures of calamitic liquid crystals. Fluorescence in solution for these compounds exhibits strong blue emission (λ_{max em.} = 390–460 nm) with good quantum yields (50–85%).

Acknowledgments

The authors thank Mrs Marly da Silveira Soldi (DSC measurements), also Prof. Edson Minatti and Fabio da Silva Miranda for free access to photophysical instruments. This work was supported by the agencies CNPq‐Brazil and Funcitec/SC.