| With the development of material science,the solar energy utilization ratio improved gradually,from absorption and utilization of ultraviolet(UV)part of sunlight to visible part of sunlight,more energy of sunlight convert to available energy for human.For usual luminescent materials,the UV light or near-infrared(NIR)light can be converted to visible light by down-conversion(DC)or up-conversion(UC),the power of visible part of sunlight can be enhanced by these luminescent materials to some extent.To further improve the power of visible part of sunlight and realize UC of sunlight without dependence of rare earth metals,fluorescent polymer materials will meet a new challenge and opportunity.Thus,in this article the author focuses on the synthesis and application of wavelength-focusing(WF)molecule materials,which can convert UV light and NIR light of sunlight to visible light simultaneously.In Chapter 1,the types of reactions of alkyl diazoacetate were summarized.In addition,the author introduced the synthesis and application of pyrazoline and derivatives.At last,the DC and UC fluorescent materials were induced,and their photoluminescent mechanisms were presented.In Chapter 2,focusing wavelengths refers to shifting unequal wavelengths to equal wavelengths,and WF molecules should be able to shift the portions of shorterand longer wavelengths of incident light to an identical wavelength in between,by which polychromatic light is converted to monochromatic light,and a broad spectrum is narrowed down.EDA was Rayleigh scattering suppressed WF molecule,after cycloaddition or polymerization as a subunit to form a macromolecule,its Rayleigh scattering was greatly reduced and fluorescence property enhanced.The WF behavior of diazoacetate-contained molecules was further confirmed via fluorescence imaging,in addition to its spectroscopic characterization.Diazoactate-and fumarate-contained molecules were WF molecules,for example,regardless of whether 346 or 686 nm light was absorbed by the diazoactate-contained molecules,only 452 nm of fluorescence was emitted.Another example is the fumarate-contained molecules,which was stimulated using wavelength bands of 300-500 nm and 580-900 nm broadband light and emitted light at only 507 nm.In Chapter 3,author reported a high conversion rate(?F=0.4108)for a WF photoluminescent oligomer(OCACP)with densely grafted 2-pyrazoline that was prepared by free-radical polymerization of 3-carbethoxy-5-acrylatecarbethoxy-2-pyrazoline(CACP),a chromophore with good fluorescence(?F=0.0171).The photoluminescence integrated intensity(PLII,368-635 nm)of OCACP was determined to be square dependent on the intensity of the incident dichromatic light(UV light and NIR light).After further investigation the relationship between the intensity of incident dichromatic light and the corresponding PLII(368-635 nm),the PLII(368-635 nm)was measured to be square dependent on the power of the UV part of incident dichromatic light and linearly dependent on the intensity of the NIR part of incident dichromatic light.Thus,author reasonably proposed the mechanism of WF,and the conversion mechanism includes UV quantum cutting and NIR two-photon absorption.In Chapter 4,author reported a high conversion rate(?F=0.5184)for a fluorescent oligomer,1,4-butanediol-bis(5-carbonyl-3-carbethoxy-2-pyrazoline)(OBBP).It was prepared by the novel cyclopolycondensation of 1,4-butanediol-bis(5-carbonyl-3-carbethoxy-2-pyrazoline)(BBP),a chromophore with good fluorescence(?F=0.0573).After polymerization,a green fluorescent protein(GFP)-mimetic structure was formed,in which methylene chain(-CH2-CH2-CH2-CH2-)as a flexible group benefites its folding,and an azo group sites in the rigid pyrazoline ring because of a resonance effect.These factors collectively contribute to the excellent efficiency of the fluorescence performance of the oligomer.In addition,the 370 nm UV light and 710 nm NR light can be converted to 452 nm visible light simultaneously,and good-quality live-cell imaging can be achieved conveniently by multiphoton excitation at UV-vis and near-infrared light.In Chapter 5,Organoaluminum-mediated copolymerization of alkyl diazoacetate with alkyne was confirmed to be a novel reaction by 1H NMR,FT-IR,MALDI-ToF-MS and elemental analysis,and alkyl diazoacetate is incorporated into backbone without nitrogen release as a main process.The obtained copolymers had a great deal of azo groups and exhibited a good fluorescent property.Additionally,the obtained copolymer achieved good-quality live-cell imaging with an enhancement in the fluorescence intensity through two-wavelength excitation of the cell rather than increasing the dye dosage or laser power and had great potential for applications in fluorescence imaging and as probes.In Chapter 6,(5R)-5-cyano-3-carbmenthoxy-2-pyrazoline(5R-CCMP)was synthesized by 1,3-diploar cycloaddition of(-)-menthyl diazoacetate with acrylonitrile,the absolute configurations and crystallographic data of 5R-CCMP was got by X-ray single crystal diffraction.Because the hydrogen bonding interactions between 5R-CCMP,in three-dimensional space 5R-CCMP formed a double-chain,new pyrazoline rings and five-membered rings are constructed by hydrogen bonds,and one pyrazoline ring is alternated with one five-membered ring,which contributes to a continuous three dimensional net structure.In addition,5R-CCMP had WF fluorescent property,cell imaging indiacted that 5R-CCMP can label cytoplasm,and obtained good-quality live-cell imaging by multiphoton excitation at UV-vis and near-infrared light.In Chapter 7,author proposed a simple method for measurement quantum yield of fluorescence molecule.Calculating the relationship between concentration and quantum yield by fluorescence spectrophotometer and standard fluorescence dyes,and then we obtained the concentration confidence interval.The determinand is prepared into a solution of a certain concentration,which belongs to the concentration confidence interval,and then we can get the quantum yield of determinand by fluorescence spectrophotometer and calculation. |
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