Efficient room temperature phosphorescence is observed in natural compounds and polymers such as starch, cellulose, bovine serum albumin (BSA), and some other carbohydrates. Whereas being practically nonluminescent in solutions and TLC plates, they emit bright phosphorescence in the crystalline states with lifetime up to microseconds, exhibiting crystallization-induced phosphorescence (CIP) characteristics. The CIP of these natural products without any conventional chromophores offers a new platform for the exploration of conceptually novel luminogens.
GONG YongYangTAN YeQiangMEI JuZHANG YiRenYUAN WangZhangZHANG YongMingSUN JingZhiTANG Ben Zhong
Efficient room temperature phosphorescence (RTP) is rarely observed in pure organic luminogens. However, we have newly observed that benzil and its derivatives are nonluminescent in solvents and thin layer chromatography (TLC) plates, but become highly phosphorescent in crystal state at room temperature, exhibiting typical crystallization-induced phosphorescence (CIP) characteristics. The CIP phenomenon is ascribed to the restriction of intramolecular rotations in crystals owing to effective intermolecular interactions. Such intermolecular interactions greatly rigidify the molecular conformation and significantly decrease the nonradiative deactivation channels of the triplet excitons, thus giving boosted phosphorescent emission at room temperature.
GONG YongYangTAN YeQiangLI HongZHANG YiRenYUAN WangZhangZHANG YongMingSUN JingZhiTANG Ben Zhong
The luminescent liquid crystals (LLCs) are expected to solve the conflicts between the aggregation caused quenching and the requirement of aggregation or self-organization for LCs. Herein, we developed a new strategy of applying aggregation-induced emission (AIE) phenomenon to the molecular design of LCs towards LLCs. In this report, a calamitic liquid crystal based on tolane with AIE characteristics was successfully synthesized and the chemical structure was characterized by 1H, 13C NMR, and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) high-resolution mass spectra. The fluorescence behavior was studied by fluorescence spectroscopy and the liquid crystal phase behaviors were investigated by differential scanning calorimetry (DSC), polarized optical microscopy (POM). The crystal structure was obtained by X-ray diffraction crystallography with P1 space group. Results demonstrated that the sample was AIE active and the LC phases sequence during cooling was nematic, smectic C and smectic B phase.
CHEN YaFeiLIN JieShengYUAN WangZhangYU ZhenQiangLAM Jacky WingYipTANG Ben Zhong
A novel luminogen, CZ2TPAN, with typical D-A architecture was obtained. It shows intramolecular charge transfer and aggregation-induced emission characteristics with high solid-state efficiency of 65.3%. Moreover, it exhibits reversible mechanochromic behavior between crystalline and amorphous states with remarkable emission color change from green (504 nm) to yellow (545nm).
LU YaWeiTAN YeQiangGONG YongYangLI HongYUAN WangZhangZHANG YongMingTANG Ben Zhong
Efficient room temperature phosphorescence(RTP)is rarely observed in pure organic luminogens.However,we have newly observed that benzil and its derivatives are nonluminescent in solvents and thin layer chromatography(TLC)plates,but become highly phosphorescent in crystal state at room temperature,exhibiting typical crystallization-induced phosphorescence(CIP)characteristics.The CIP phenomenon is ascribed to the restriction of intramolecular rotations in crystals owing to effective intermolecular interactions.Such intermolecular interactions greatly rigidify the molecular conformation and significantly decrease the nonradiative deactivation channels of the triplet excitons,thus giving boosted phosphorescent emission at room temperature.
GONG YongYangTAN YeQiangLI HongZHANG YiRenYUAN WangZhangZHANG YongMingSUN JingZhiTANG Ben Zhong
The luminescent liquid crystals(LLCs)are expected to solve the conflicts between the aggregation caused quenching and the requirement of aggregation or self-organization for LCs.Herein,we developed a new strategy of applying aggregation-induced emission(AIE)phenomenon to the molecular design of LCs towards LLCs.In this report,a calamitic liquid crystal based on tolane with AIE characteristics was successfully synthesized and the chemical structure was characterized by1H,13C NMR,and matrix-assisted laser desorption/ionization time-of-flight(MALDI-TOF)high-resolution mass spectra.The fluorescence behavior was studied by fluorescence spectroscopy and the liquid crystal phase behaviors were investigated by differential scanning calorimetry(DSC),polarized optical microscopy(POM).The crystal structure was obtained by X-ray diffraction crystallography with P1 space group.Results demonstrated that the sample was AIE active and the LC phases sequence during cooling was nematic,smectic C and smectic B phase.
