Columnar mesomorphism from a new luminescent thiazolo[5,4-d]thiazole-based core

Two new mesogenic compounds having a bicyclic aromatic thiazolo[5,4-d]thiazole linked to four 1,3,4-oxadiazol heterocycles were synthesised and their liquid-crystalline properties were investigated. The compounds exhibit enantiotropic hexagonal columnar mesophase with strong homeotropic orientation induced under confinement, and a wide mesophase range. The molecular packing is preserved at room temperature, especially the pi-stacking inside the columns, which is essential for good charge carrier transport. They show high thermal stability, blue photoluminescence in solution, and blue-green in thin film. The morphology of spin-coated films is smooth even after thermal annealing, where large molecular-ordered domains were induced, but preserving the photoluminescence quantum yield. All characteristics suggest that this new class of mesogenic molecules is promising for technological applications.

Automated summary

Two new mesogenic compounds with unique molecular structure show promising liquid-crystalline properties, including good thermal stability, smooth molecular packing, and excellent optoelectronic performance, making them potential candidates for technological applications.