Selenides and diselenides containing oxadiazoles: a new class of functionalised materials

Abstract

A simple and efficient procedure for the synthesis of a new class of organoselenium liquid crystal compounds was developed. The coupling of aryl bromides with elemental selenium was catalysed using copper oxide nanopowder in the presence of potassium hydroxide employing dimethyl sulfoxide as the solvent. This is the first report of the synthesis and characterisation of liquid crystal-based diselenides. Their mesophases were characterised by polarising optical microscopy and differential scanning calorimetry. Compounds 1, 2 and 4b exhibited the smectic A phase. In addition, these compounds showed weak blue fluorescence in solution (λ_{max. em.} 350–405 nm) and a Stokes shift of around 90 nm.

Keywords:

• Selenium
• copper oxide nanopowder
• 1,2,4-oxadiazole
• 1,3,4-oxadiazole

Acknowledgements

We are grateful to CAPES, CNPq (INCT-Catálise) and FAPESC/PRONEX for financial support.