Two squarylium cyanine dyes (Sqs) were synthesized to explore their applications in photoelectrochemical solar cells. Nanocrystalline TiO2 electrodes modified with Sqs have been prepared to probe the photosensitizatio...Two squarylium cyanine dyes (Sqs) were synthesized to explore their applications in photoelectrochemical solar cells. Nanocrystalline TiO2 electrodes modified with Sqs have been prepared to probe the photosensitization effects. A rather high photoelectric conversion efficiency of up to 2.17% and the top incident monochromatic photon-to-photocurrent conversion efficiency (IPCE) of 6.2% at 650nm were obtained from the Sq2-modified nanocrystalline TiO2 electrode.展开更多
Background:The outbreak and continued spread of coronavirus infection(COVID-19)sets the goal of finding new tools and methods to develop analytical procedures and tests to detect,study infection and prevent morbidity....Background:The outbreak and continued spread of coronavirus infection(COVID-19)sets the goal of finding new tools and methods to develop analytical procedures and tests to detect,study infection and prevent morbidity.Methods:The noncovalent binding of cyanine and squarylium dyes of different classes(60 compounds in total)with the proteases NSP3,NSP5,and NSP12 of SARS-CoV-2 was studied by the method of molecular docking.Results:The interaction energies and spatial configurations of dye molecules in complexes with NSP3,NSP5,and NSP12 have been determined.Conclusion:A number of anionic dyes showing lower values of the total energy Etot could be recommended for practical research in the development of agents for the detection and inactivation of the coronavirus.展开更多
In this paper, the interaction between squarylium cyanine and porphyrin in chloroform is investigated by absorption and fluorescence spectroscopy. Emphasis has been put on the mechanism of intermolecular energy transf...In this paper, the interaction between squarylium cyanine and porphyrin in chloroform is investigated by absorption and fluorescence spectroscopy. Emphasis has been put on the mechanism of intermolecular energy transfer. The overlap integral J between the absorption spectrum of squarylium cyanine and the fluorescence spectrum of porphyrin was calculated, which reveals that the singlet-singlet energy transfer may occur &om porphyrin to squarylium cyanine in solution. In comparison of the observed rate constant [k11q=6.1×1013 (mol/L)?1·s?l] for fluorescence quenching of porphyrin by squarylium cyanine with the diffusion rate constant in chloroform [kdif=1.1×1010 (mol/L)?1·s?1] and the rate of energy transfer [ket≤6.7×104 (mol/L)?1·s?1 in the experimentally dilute solutions] estimated from Forster formula, the possibility of energy transfer by electron exchange or/and coulombic mechanism could be excluded. So it has been definitely convinced that the intermolecular energy transfer between them is performed through long-distance radiative mechanism which is in good agreement with the results in experimentally dilute concentration (<10?4 mol/L). Meanwhile, the fluorescence of squarylium cyanine can also be quenched by porphyrin, which suggests that photoinduced charge transfer with other process may occur. In the contrast, the results can be partly contributed to understand the reason why the energy transfer efficiencies of porphyrin ?11/et are always lower than its fluorescence quenching efficiencies ?Iq.展开更多
Four new crown squarylium cyonine dye(2a～2d)were synthesized by condensation of squaric acid with crown benzothiazolium halide(1a～1d) in the presence of pyridine.Their structures have been confired by IR,UV Vis, 1H ...Four new crown squarylium cyonine dye(2a～2d)were synthesized by condensation of squaric acid with crown benzothiazolium halide(1a～1d) in the presence of pyridine.Their structures have been confired by IR,UV Vis, 1H NMR,MS and elemental analyses.It was found that these crown squarylium cyanine dye (2a～2d) were in reserse photochromie equilibriam.展开更多
A cyanine dye, 2-[7-（1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene）-1,3,5-heptatrienyl]-1,3,3-trimethyl-3H-indolium iodide （NK-125）, is doped in 4-cyano-4＇-pentylbiphenyl （5 CB）, and the mixture is sandwiched ...A cyanine dye, 2-[7-（1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene）-1,3,5-heptatrienyl]-1,3,3-trimethyl-3H-indolium iodide （NK-125）, is doped in 4-cyano-4＇-pentylbiphenyl （5 CB）, and the mixture is sandwiched between two pieces of rubbed glass plates. The third-order nonlinear optical properties of the oriented NK-125-SCB layers are measured by the resonant femtosecond degenerate four-wave mixing （DFWM） technique at 760 nm. The third-order nonlinear optical susceptibility of one of the present samples is 5.5×10^-8 esu. The slow DFWM response of the NK-125-SCB layers due to a population grating is accelerated by the increasing laser power because of amplified spontaneous emission （ASE）. On the other hand, we do not observe a similar phenomenon for NK-125- polyethylene glycol （PEG-400）. Oriented NK-125 molecules in nematic liquid crystals must have very high ASE efficiency. Hence the population grating in a DFWM signal disappears within about 4 ps. It is expected that NK-125-SCB can be used as a material for very fast all-optical switching.展开更多
文摘Two squarylium cyanine dyes (Sqs) were synthesized to explore their applications in photoelectrochemical solar cells. Nanocrystalline TiO2 electrodes modified with Sqs have been prepared to probe the photosensitization effects. A rather high photoelectric conversion efficiency of up to 2.17% and the top incident monochromatic photon-to-photocurrent conversion efficiency (IPCE) of 6.2% at 650nm were obtained from the Sq2-modified nanocrystalline TiO2 electrode.
基金Molecular graphicsanalyses performed with UCSF Chimera are developed by the Resource for Biocomputing,VisualizationInformatics at the University of California,San Francisco,with support from NIH P41-GM103311.
文摘Background:The outbreak and continued spread of coronavirus infection(COVID-19)sets the goal of finding new tools and methods to develop analytical procedures and tests to detect,study infection and prevent morbidity.Methods:The noncovalent binding of cyanine and squarylium dyes of different classes(60 compounds in total)with the proteases NSP3,NSP5,and NSP12 of SARS-CoV-2 was studied by the method of molecular docking.Results:The interaction energies and spatial configurations of dye molecules in complexes with NSP3,NSP5,and NSP12 have been determined.Conclusion:A number of anionic dyes showing lower values of the total energy Etot could be recommended for practical research in the development of agents for the detection and inactivation of the coronavirus.
基金Project supported by the National Natural Science Foundation of China.
文摘In this paper, the interaction between squarylium cyanine and porphyrin in chloroform is investigated by absorption and fluorescence spectroscopy. Emphasis has been put on the mechanism of intermolecular energy transfer. The overlap integral J between the absorption spectrum of squarylium cyanine and the fluorescence spectrum of porphyrin was calculated, which reveals that the singlet-singlet energy transfer may occur &om porphyrin to squarylium cyanine in solution. In comparison of the observed rate constant [k11q=6.1×1013 (mol/L)?1·s?l] for fluorescence quenching of porphyrin by squarylium cyanine with the diffusion rate constant in chloroform [kdif=1.1×1010 (mol/L)?1·s?1] and the rate of energy transfer [ket≤6.7×104 (mol/L)?1·s?1 in the experimentally dilute solutions] estimated from Forster formula, the possibility of energy transfer by electron exchange or/and coulombic mechanism could be excluded. So it has been definitely convinced that the intermolecular energy transfer between them is performed through long-distance radiative mechanism which is in good agreement with the results in experimentally dilute concentration (<10?4 mol/L). Meanwhile, the fluorescence of squarylium cyanine can also be quenched by porphyrin, which suggests that photoinduced charge transfer with other process may occur. In the contrast, the results can be partly contributed to understand the reason why the energy transfer efficiencies of porphyrin ?11/et are always lower than its fluorescence quenching efficiencies ?Iq.
文摘Four new crown squarylium cyonine dye(2a～2d)were synthesized by condensation of squaric acid with crown benzothiazolium halide(1a～1d) in the presence of pyridine.Their structures have been confired by IR,UV Vis, 1H NMR,MS and elemental analyses.It was found that these crown squarylium cyanine dye (2a～2d) were in reserse photochromie equilibriam.
文摘A cyanine dye, 2-[7-（1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene）-1,3,5-heptatrienyl]-1,3,3-trimethyl-3H-indolium iodide （NK-125）, is doped in 4-cyano-4＇-pentylbiphenyl （5 CB）, and the mixture is sandwiched between two pieces of rubbed glass plates. The third-order nonlinear optical properties of the oriented NK-125-SCB layers are measured by the resonant femtosecond degenerate four-wave mixing （DFWM） technique at 760 nm. The third-order nonlinear optical susceptibility of one of the present samples is 5.5×10^-8 esu. The slow DFWM response of the NK-125-SCB layers due to a population grating is accelerated by the increasing laser power because of amplified spontaneous emission （ASE）. On the other hand, we do not observe a similar phenomenon for NK-125- polyethylene glycol （PEG-400）. Oriented NK-125 molecules in nematic liquid crystals must have very high ASE efficiency. Hence the population grating in a DFWM signal disappears within about 4 ps. It is expected that NK-125-SCB can be used as a material for very fast all-optical switching.
