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Novel luminescent organogelators based on nucleoside functionalized with carbazole (UC8, UC12 and UC16) were designed and synthesized. Their gelation ability was tested and it was found that both UC12 and UC16 could form stable organogels in toluene/petroleum ether. The UV-vis absorption, fluorescence emission and IR spectral changes during the gelation of UC12 proved that the self-assembly was driven by H- bonding. The morphology of the xerogel UC16 obtained from toluene/petroleum ether (v/v = 1/1) displayed tough rod-like microstructures, and 3D networks formed from lots of nanofibers were observed for the xerogel UC16 obtained from toluene/petroleum ether (v/v = 2/1). It was interesting that the obtained organogels emitting blue light could be destroyed by the addition of F-, accompanied with the declining the emission intensity. Therefore, these organogels could be used as sensory materials to recognize F-. [ABSTRACT FROM AUTHOR]

4-(Carbazol-9-yl)benzaldehyde could emit yellow RTP, which could last for 3 s because of efficient intersystem crossing. Moreover, multicolor luminescent switches could be realized by simply applying a mechanical force stimulus. [ABSTRACT FROM AUTHOR]

New indolocarbazole derivatives have been synthesized via Cadogan reaction. It has been found that the reductive cyclization of 3-(2-nitrophenyl)carbazoles prefers to take place on 4-position instead of 2-position in carbazole rings. Because electrophilic substitution was one of the main steps in Cadogan reaction and the Fukui function analysis for 9-methyl-3-(2-nitrophenyl)-9 H -carbazole revealed that more positive part of f − ( r ) function was localized at 4-position than at 2-position in carbazole, the 4-position was the favorite reactive site for the reductive cyclization. Such regioselective Cadogan reaction would be useful for the synthesis of π-extended N -fused heteroacenes with desired functionalities. [ABSTRACT FROM AUTHOR]

New branched benzothiadiazole-cored conjugated oligomers with terminal carbazoles 1 and 2 have been synthesized. It was found that no obvious shifts of the maximal absorption bands for 1 and 2 were detected in the films compared with those in solutions, indicating weak π-π stacking occurred in the solid states on account of site isolation effect of the branched architectures. Hence, the synthesized oligomers could emit strong red light in the films. Notably, the emission of the films based on 1 and 2 could be quenched obviously upon exposed to gaseous TNT and DNT. The fluorescence quenching efficiency of the oligomer 2 -based film reached 91% when exposed to the saturated vapor of DNT for 3 min at 55 °C. The linear Stern–Volmer plot and the decrease of the fluorescence lifetime of 2 induced by DNT suggested the fluorescence sensing mechanism was due to the photo-induced electron transfer. [ABSTRACT FROM AUTHOR]

Highlights: [•] Synthesis of phenanthroimidazole derivatives with terminal carbazole or pyrene. [•] Photophysical properties of phenanthroimidazole derivatives. [•] Electroluminescent properties of phenanthroimidazole derivatives. [ABSTRACT FROM AUTHOR]