Two new spectroscopic methods to detect the optical activity of liquid-liquid interfaces have been developed. The first one is the centrifugal liquid membrane （CLM） method combined with a conventional circular dichr...Two new spectroscopic methods to detect the optical activity of liquid-liquid interfaces have been developed. The first one is the centrifugal liquid membrane （CLM） method combined with a conventional circular dichroism （CD） spectropolarimetry and the second one is a more interfacial specific second harmonic generation CD （SHG-CD） spectrometry. In the CLM-CD method, a cylindrical glass cell containing small amounts of organic and aqueous phases was rotated at about 7000 r/min in a sample chamber of a CD spectropolarimeter to generate an interface with a high specific interfacial area between the two-phase liquid membranes. The CD spectra of the J-aggregate of protonated 5,10,15, 20-tetraphenylporphyrin formed at the toluene-sulfuric acid interface have been measured, As for the SHG-CD, a circularly polarized wavelength-variable fs-laser system was constructed to measure the interfacial SHG spectra of a flat liquid-liquid interface. The ion-associated aggregation of a water-soluble anionic porphyrin promoted with a cationic amphiphile at the heptane-water interface was observed by this technique and the observed SHG-CD spectra proved the generation of a characteristic oPtical activity accompanied by the formation of the interfacial aggregate of inherently achiral porphyrin molecules. These methods will pioneer a new field of interfacial chiral chemistry in the studies of solvent extraction mechanisms.展开更多
The trimeric phenylenevinylene with the symmetrical chiral end-groups （ChTPV） was synthesized. The liquid crystalline and luminescent properties of the ChTPV have been studied by differential scanning calorimetry （...The trimeric phenylenevinylene with the symmetrical chiral end-groups （ChTPV） was synthesized. The liquid crystalline and luminescent properties of the ChTPV have been studied by differential scanning calorimetry （DSC）, polarized optical microscopy （POM）, absorption and photoluminescence spectra. The results indicated that the ChTPV exhibits mesophase over a wide temperature range and a typical optical texture of smectic phase. In contrast with the spectra of the solution, that of the film showed blue-shift in maximal absorption and red-shift in maximal emission due to H-type aggregation with parallel alignment of the TPV transition dipole moment.展开更多
The simpler, the better! A series of simple and highly fluorescent salicylaldehyde hydrazide molecules （41 samples） have been designed and prepared. Even though these soft materials contain a very small π-conjugate...The simpler, the better! A series of simple and highly fluorescent salicylaldehyde hydrazide molecules （41 samples） have been designed and prepared. Even though these soft materials contain a very small π-conjugated system, they can go through multiple intramolecular and intermolecular hydrogen bonds promoted excited-state intramolecular proton-transfer （ESIPT） to display strong blue, green, yellow, and orange aggregation-induced emission （ALE） with large Stokes shifts （up to 184 nm） and high fluorescence quantum yields （φ up to 0.20）. Unusual mechanochromic fluorescence en- hancements are also found in some solid samples. Through coordination, hydrogen and halogen bonds, these flexible molecules can be used as Mg2＋ （φ up to 0.46） probes, universal anion （φ up to 0.14） and unprotected amino acids （φ up to 0.16） probes, and chiral diamine （enantiomeric selectivity and φ up to 0.36 and 0.062, respectively） receptors. Combining their advantages of AlE and biocompatibility, these low cytotoxic dyes have potential application in living cell imaging. Furthermore, the effects of different functional groups on the molecule arrangement, ESIPT, AlE, probe, and chiral recognition properties are also examined, which provide a simple and bright paradigm for the design of multiple-stimuli-responsive smart materials.展开更多
基金Supported by the Grant-in-Aid for Scientific Research (No. 16105002) from the Ministry of Education, Science, Sports, and Culture, Japan
文摘Two new spectroscopic methods to detect the optical activity of liquid-liquid interfaces have been developed. The first one is the centrifugal liquid membrane （CLM） method combined with a conventional circular dichroism （CD） spectropolarimetry and the second one is a more interfacial specific second harmonic generation CD （SHG-CD） spectrometry. In the CLM-CD method, a cylindrical glass cell containing small amounts of organic and aqueous phases was rotated at about 7000 r/min in a sample chamber of a CD spectropolarimeter to generate an interface with a high specific interfacial area between the two-phase liquid membranes. The CD spectra of the J-aggregate of protonated 5,10,15, 20-tetraphenylporphyrin formed at the toluene-sulfuric acid interface have been measured, As for the SHG-CD, a circularly polarized wavelength-variable fs-laser system was constructed to measure the interfacial SHG spectra of a flat liquid-liquid interface. The ion-associated aggregation of a water-soluble anionic porphyrin promoted with a cationic amphiphile at the heptane-water interface was observed by this technique and the observed SHG-CD spectra proved the generation of a characteristic oPtical activity accompanied by the formation of the interfacial aggregate of inherently achiral porphyrin molecules. These methods will pioneer a new field of interfacial chiral chemistry in the studies of solvent extraction mechanisms.
基金supported by the National Science Foundation(No.20674005)the major project of Ministry Education of the People's Republic of China(No.104187).
文摘The trimeric phenylenevinylene with the symmetrical chiral end-groups （ChTPV） was synthesized. The liquid crystalline and luminescent properties of the ChTPV have been studied by differential scanning calorimetry （DSC）, polarized optical microscopy （POM）, absorption and photoluminescence spectra. The results indicated that the ChTPV exhibits mesophase over a wide temperature range and a typical optical texture of smectic phase. In contrast with the spectra of the solution, that of the film showed blue-shift in maximal absorption and red-shift in maximal emission due to H-type aggregation with parallel alignment of the TPV transition dipole moment.
基金This work was supported by the National Natural Science Foundation of China （No. 21372169） and Sichuan Provincial Foundation （2008SG0021）. We acknowledge the comprehensive training platform of the specialized laboratory of the College of Chemistry, Sichuan University, for material analysis. We acknowledge the comprehensive training platform of the specialized laboratory of the College of Chemistry, Sichuan University, for material analysis. We would like to thank the Analytical ＆ Testing Center of Sichuan University for CCD X-ray single crystal diffractometer work and circular dichroism CD spectrometer work. We are grateful to Daibing Luo and Yani Xie for help with the single crystal and circular dichroism measurements.
文摘The simpler, the better! A series of simple and highly fluorescent salicylaldehyde hydrazide molecules （41 samples） have been designed and prepared. Even though these soft materials contain a very small π-conjugated system, they can go through multiple intramolecular and intermolecular hydrogen bonds promoted excited-state intramolecular proton-transfer （ESIPT） to display strong blue, green, yellow, and orange aggregation-induced emission （ALE） with large Stokes shifts （up to 184 nm） and high fluorescence quantum yields （φ up to 0.20）. Unusual mechanochromic fluorescence en- hancements are also found in some solid samples. Through coordination, hydrogen and halogen bonds, these flexible molecules can be used as Mg2＋ （φ up to 0.46） probes, universal anion （φ up to 0.14） and unprotected amino acids （φ up to 0.16） probes, and chiral diamine （enantiomeric selectivity and φ up to 0.36 and 0.062, respectively） receptors. Combining their advantages of AlE and biocompatibility, these low cytotoxic dyes have potential application in living cell imaging. Furthermore, the effects of different functional groups on the molecule arrangement, ESIPT, AlE, probe, and chiral recognition properties are also examined, which provide a simple and bright paradigm for the design of multiple-stimuli-responsive smart materials.
