Rod-like D-π-A-π-D Schiff base liquid crystal for continuous ion sensing, live cell imaging, fingerprint imaging and...

A series of rod-like D-π-A-π-D Schiff base liquid crystals were synthesized, featuring a BTD central acceptor unit connected to N-trialkoxybenzyl carbazole terminal donor groups through imine linkages at both ends. The series includes hydroxyl-containing derivatives BOH/n (n = 12, 14, 16), hydroxyl-free BH/12, and the corresponding boron complex BOB/12 derived from BOH/12. Among them, BOH/n can self-assemble into the Col_rec/c2mm LC phase, while BH/12 can self-assemble into the Col_rec/p2mm LC phase, and boron complex BOB/12 can self-assemble into the Col_hex/p6mm LC phase. Further compound BOH/n can self-assemble into a luminescent organic gel in organic solvents with wrinkled sheet morphologies. Photophysical studies revealed that all compounds showed J-aggregation form. All compounds except BOB/12 exhibited the AIEE effect. The fluorescence quantum yield in solution and the absolute solid quantum yield of BOB/12, reached as high as 85 % and 41 % respectively which is 14 and 3 times higher than those of the corresponding BOH/12. Based on the ion recognition result of BOH/12, a non-conventional sequential detection method for the identification sequence of Fe³⁺-Cu²⁺-Al³⁺ was constructed and applied successfully as test paper detection. Additionally, BOH/12 was successfully utilized as live cell imaging, potential fingerprint imaging, and white light emitting devices (WLED).