A new anion receptor bearing phenolic hydroxy group based on 3,5- ditertbutylsalicylaldehyde-p-nitrophenylhydrazone （1） was designed and synthesized. Upon addition of AcO- and F-, the receptor exhibited visible colo...A new anion receptor bearing phenolic hydroxy group based on 3,5- ditertbutylsalicylaldehyde-p-nitrophenylhydrazone （1） was designed and synthesized. Upon addition of AcO- and F-, the receptor exhibited visible color changes from deep yellow to purple. However, no obvious color changes were observed on addition of the other anions tested （H2PO4-, Cl-, Br-, I-）. The binding properties of the receptor with anions such as AcO and F- were investigated by UV-Vis and fluorescent titrations. The result indicated that the receptor 1 had a higher affinity to AcO- and F- and a 1：1 host-guest complex was formed through H-bond interactions between 1 and anions.展开更多
The symmetric and quadrupolar donor-acceptordonor(D-A-D)molecules usually exhibit excitedstate charge redistribution process from delocalized intramolecular charge transfer(ICT)state to localized ICT state.Direct obse...The symmetric and quadrupolar donor-acceptordonor(D-A-D)molecules usually exhibit excitedstate charge redistribution process from delocalized intramolecular charge transfer(ICT)state to localized ICT state.Direct observation of such charge redistribution process in real-time has been intensively studied via various ultrafast time-resolved spectroscopies.Femtosecond stimulated Raman spectroscopy(FSRS)is one of the powerful methods which can be used to determine the excited state dynamics by tracking vibrational mode evolution of the specific chemical bonds within molecules.Herein,a molecule,4,4′-(buta-1,3-diyne-1,4-diyl)bis(N,N-bis(4-methoxyphenyl)aniline),that consists of two central adjacent alkyne(-C≡C-)groups as electron-acceptors and two separated,symmetric N,N-bis(4-methoxyphenyl)aniline at both branches as electron-donors,is chosen to investigate the excited-state photophysical properties.It is shown that the solvation induced excited-state charge redistribution in polar solvents can be probed by using femtosecond stimulated Raman spectroscopy.The results provide a fundamental understanding of photoexcitation induced charge delocalization/localization properties of the symmetric quadrupolar molecules with adjacent vibrational markers located at central position.展开更多
A multi-responsive D-A type compound(CYQ)based on pyrone and triphenylamine was designed and successfully synthesized. The target compound exhibited distinct aggregation-enhanced emission(AEE) effect.Solvatochromic ex...A multi-responsive D-A type compound(CYQ)based on pyrone and triphenylamine was designed and successfully synthesized. The target compound exhibited distinct aggregation-enhanced emission(AEE) effect.Solvatochromic experiment and density functional theory(DFT) indicated CYQ possessed excellent intramolecular charge transfer(ICT) ability. Besides, its mechanofluorochromic property(MFC) was found with a 37 nm redshift. Powder wide-angle X-ray diffraction(PXRD) and differential scanning calorimetry(DSC) measurements were performed to demonstrate the transformation from the crystalline to amorphous states upon grinding. Surprisingly,CYQ displayed a hypersensitive response to trace water in organic solvents with an excellent detection limit as low as 0.0096% in tetrahydrofuran(THF). Furthermore, it was found that the fluorescent intensity of CYQ declined progressively upon humidity rise, and its color change can be witnessed by naked eyes. Therefore, the relative humidity(RH) sensing strategy guarantees the AIEgen to become a colorimetric sensor under various conditions.展开更多
基金This work was supported by the Natural Science Foundation of Universities of Inner Mongolia Autonomous Region （No.NG09168 and NG10239）.
文摘A new anion receptor bearing phenolic hydroxy group based on 3,5- ditertbutylsalicylaldehyde-p-nitrophenylhydrazone （1） was designed and synthesized. Upon addition of AcO- and F-, the receptor exhibited visible color changes from deep yellow to purple. However, no obvious color changes were observed on addition of the other anions tested （H2PO4-, Cl-, Br-, I-）. The binding properties of the receptor with anions such as AcO and F- were investigated by UV-Vis and fluorescent titrations. The result indicated that the receptor 1 had a higher affinity to AcO- and F- and a 1：1 host-guest complex was formed through H-bond interactions between 1 and anions.
基金supported by the National Natural Science Foundation of China(No.22133001,No.11774233,No.21773252,No.21773257,No.21827803)the Project for high-grade,precision and advance in Beijing(BUPT)。
文摘The symmetric and quadrupolar donor-acceptordonor(D-A-D)molecules usually exhibit excitedstate charge redistribution process from delocalized intramolecular charge transfer(ICT)state to localized ICT state.Direct observation of such charge redistribution process in real-time has been intensively studied via various ultrafast time-resolved spectroscopies.Femtosecond stimulated Raman spectroscopy(FSRS)is one of the powerful methods which can be used to determine the excited state dynamics by tracking vibrational mode evolution of the specific chemical bonds within molecules.Herein,a molecule,4,4′-(buta-1,3-diyne-1,4-diyl)bis(N,N-bis(4-methoxyphenyl)aniline),that consists of two central adjacent alkyne(-C≡C-)groups as electron-acceptors and two separated,symmetric N,N-bis(4-methoxyphenyl)aniline at both branches as electron-donors,is chosen to investigate the excited-state photophysical properties.It is shown that the solvation induced excited-state charge redistribution in polar solvents can be probed by using femtosecond stimulated Raman spectroscopy.The results provide a fundamental understanding of photoexcitation induced charge delocalization/localization properties of the symmetric quadrupolar molecules with adjacent vibrational markers located at central position.
基金financial support from the National Natural Science Foundation of China (21576194)
文摘A multi-responsive D-A type compound(CYQ)based on pyrone and triphenylamine was designed and successfully synthesized. The target compound exhibited distinct aggregation-enhanced emission(AEE) effect.Solvatochromic experiment and density functional theory(DFT) indicated CYQ possessed excellent intramolecular charge transfer(ICT) ability. Besides, its mechanofluorochromic property(MFC) was found with a 37 nm redshift. Powder wide-angle X-ray diffraction(PXRD) and differential scanning calorimetry(DSC) measurements were performed to demonstrate the transformation from the crystalline to amorphous states upon grinding. Surprisingly,CYQ displayed a hypersensitive response to trace water in organic solvents with an excellent detection limit as low as 0.0096% in tetrahydrofuran(THF). Furthermore, it was found that the fluorescent intensity of CYQ declined progressively upon humidity rise, and its color change can be witnessed by naked eyes. Therefore, the relative humidity(RH) sensing strategy guarantees the AIEgen to become a colorimetric sensor under various conditions.
