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New dimesitylborylthiophene derivative with terminal tetraphenylethene TPETB has been synthesized. It was found that TPETB exhibited aggregation-induced emission behavior and reversible mechanofluorochromism. For instance, the emission intensity of TPETB in THF/H 2 O with water fraction of 90% was ca. 21 times higher than that in THF. In addition, grinding the as-prepared crystal of TPETB the emitting color changed from sky blue to yellowish green. Meanwhile, the ground powder could recover to crystalline structure with sky blue emission when it was exposed to CH 2 Cl 2 vapor. It was suggested that the transformation between crystalline and amorphous states led to the changes of solid emitting colors in response to external mechanical forces. It should be noted that TPETB could detect F − selectively, and the detection limit was 1.67 × 10 −8 mol/L in CH 2 Cl 2 . [ABSTRACT FROM AUTHOR]

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]

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]

An L-phenylalanine derivative ( C12PhBPCP) consisting of a strong emission fluorophore with benzoxazole and cyano groups is designed and synthesized to realize dual responses to volatile acid and organic amine vapors. The photophysical properties and self-assembly of the said derivative in the gel phase are also studied. C12PhBPCP can gelate organic solvents and self-assemble into 1 D nanofibers in the gels. UV/Vis absorption spectral results show H-aggregate formation during gelation, which indicates strong exciton coupling between fluorophores. Both wet gel and xerogel emit strong green fluorescence because the cyano group suppresses fluorescence quenching in the self-assemblies. Moreover, the xerogel film with strong green fluorescence can be used as a dual chemosensor for quantitative detection of volatile acid and organic amine vapors with fast response times and low detection limits owing to its large surface area and amplified fluorescence quenching. The detection limits are 796 ppt and 25 ppb for gaseous aniline and trifluoroacetic acid (TFA), respectively. [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 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]

Highlights: [•] 2,1,3-Benzothiadiazole-cored H-shaped conjugated compounds were synthesized. [•] Two-photon absorption (TPA) and two-photon induced emission properties were investigated. [•] These compounds emit red light excited by the femtosecond pulsed laser of 820nm. [•] Strong electron donor, enlarged conjugation and branched structure favored the increasing of TPA. [ABSTRACT FROM AUTHOR]

Abstract: New well-defined monodisperse oligocarbazoles-functionalized anthracenes An-OCZn (n =1, 2, 3) have been synthesized through Suzuki cross-coupling reaction of the brominated oligocarbazoles and 9,10-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)anthracene. They show good solubility in organic solvents, including dichloromethane, chloroform, toluene, ethyl acetate, and tetrahydrofuran. It should be noted that, in the case of An-OCZn, the formation of the excimer based on anthracene unit is suppressed completely due to the introduction of oligocarbazoles in 9,10-position of anthracene so that an intense blue-emitting has been afforded. In addition, the obtained An-OCZn exhibit good electrochemical and thermal stabilities. Thus, the oligocarbazoles-functionalized anthracenes can be a class of promising candidates for novel blue-emitting materials employed in OLEDs or related devices. [Copyright &y& Elsevier]

Abstract: Three new donor-π-acceptor (D-π-A) metal-free organic dyes, in which dendritic triphenylamine acts as donor, and furan, thiophene and benzene as π-linkers, were synthesized, characterized and used for the application of dye sensitized solar cell (DSSC). Among the fabricated DSSCs, the device based on the furan as π-linker exhibited a short circuit current density of 14.56 mA cm−2, an open circuit photo voltage of 0.71 V and a fill factor of 0.59, implying a power conversion efficiency (η) of 6.10%. The devices sensitized by dyes with thiophene and benzene as π-linker possessed relative lower η, 5.92% and 4.97%, respectively. [Copyright &y& Elsevier]