• Rapid Communication in Photoscience
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• v.5 no.2
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• pp.21-26
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• 2016

Many kinds of fluorescent polypyridine compounds including bpy and dppz derivatives are described in understanding the recent current of fluorescent materials having photofuctionality. Those polypyridine compounds have the photofunctionality such as the fluorescence recognition and/or photo-switching. Furthermore, those compounds are applicated for the construction of long ranged photoinduced electron/energy transfer system. Various fluorescent ${\pi}-conjugation$ systems connected by amide or imine bond as well as the simple fluorescent bpy derivatives are introduced in this review paper.

• YAKHAK HOEJI
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• v.35 no.4
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• pp.288-294
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• 1991

A new fluorescent derivatizing reagent was developed to be used in HPLC for the trace determination of primary and secondary amines. This new reagent, 1-(N,N-dimethylamino)pyrene-6-sulfonyl chloride, was synthesized by the chlorination of sodium 1-(N,N-dimethylamino)pyrene-6-sulfonate which was obtained from 1-(N,N-dimethylamino)pyrene after sulfonation. Ephedrine and norephedrine were derivatized quantitatively by this reagent. The optimum conditions for the derivatization such as pH, reagent concentration, reaction time and reaction temperature ware examined. The structures of derivatives were identified by IR, $^{1}$H-NMR and MS methods. The fluorescence properties and the stability of the derivatives were examined. The derivatives were separated on silica column with an isocratic elution using the mixture of n-hexane and ethylacetate and monitored by fluorescene detector. Linear calibration curves were obtained and detection limits in a 10 $\mu$l injection volume were 5 picomole for ephedrine and norephedrine.

• YAKHAK HOEJI
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• v.36 no.5
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• pp.506-511
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• 1992

The Prostaglandins were derivatized rapidly with monodansyl cadaverine as a fluorophore in mild conditions. The carboxylic moiety of prostaglandins was activated with diethyl phosphorocyanidate and successively coupled with fluorophore in dimethylformamide at room temperature. The labeling yield was reached about 95% at 15 min using arachidic acid $(C_{20:0})$ as a test sample. This derivative showed constant fluorescent intensity at $4^{\circ}C$ for 180 days. The derivatives of prostaglandins were shown high solvent selectivity with tetrahydrofuran in reversed-phase column. therefore, these derivatives could be successfully separated on YMC pack A-212(S-5 120A C8) column in tetrahydrofuran-based eluents. The detection limits of these derivatives was ca. 500 fmol and determination limits was ca. 5 pmol as injected amount in fluorescent detection $({\lambda}ex.\;340\;nm,\;{\lambda}em.\;520\;nm)$. In this method, the ranges of recovery and coefficient of variation were $93.6{\sim}102.7%$ and $4.3{\sim}5.8%$, respectively.

• Rapid Communication in Photoscience
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• v.3 no.4
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• pp.76-78
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• 2014

Fluorescent nucleic acids were prepared utilizing the polymerase extension (PEX) reaction to incorporate fluorescent molecules. 2'-Deoxyuridine triphosphate (dUTP) derivatives possessing pyrene molecules as fluorophores were synthesized using the aqueous-phase Sonogashira coupling between 5-Iodo-dUTP and acetylene-linked pyrene molecules. The incorporation of the pyrene (Py)-labeled deoxyuridine triphosphates (PyU) into DNA by polymerase was evaluated by polyacrylamide gel electrophoresis, demonstrating that the PyU can work as a good substrate for the PEX reaction. The fluorescent properties of the functionalized DNA prepared by the PEX reaction were characterized by steady-state fluorescence measurements. The Py-conjugated DNA showed typical emission spectra of the pyrene, and the DNA with two pyrene molecules connected to each other by a diethylene glycol linker exhibited a broadened emission attributed to the electronic interaction between the Py molecules.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1593-1598
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• 2011

Blue fluorescent materials based on 9,9'-diethyl-2-diphenylaminofluorene derivatives were synthesized and characterized. These materials were used as the blue dopant materials for the emitting layer of organic light-emitting diode devices with the following device structure: ITO/DNTPD (40 nm)/NPB (20 nm)/MADN: dopants (2%, 20 nm)/$Alq_3$ (40 nm)/Liq (1.0 nm)/Al. All devices exhibited highly efficient blue emission. One of these devices exhibited a maximum luminance, luminous efficiency, power efficiency and CIE x, y coordinates of 8400 $cd/m^2$, 8.10 cd/A at 20 $mA/cm^2$, 3.36 lm/W at 20 $mA/cm^2$ and (0.151, 0.159), respectively. A deep blue device with CIE coordinates of (0.152, 0.139) showed the maximum luminance, luminous efficiency and power efficiency of 8630 $cd/m^2$, 6.31 cd/A at 20$mA/cm^2$ and 2.62 lm/W at 20 $mA/cm^2$, respectively.

• YAKHAK HOEJI
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• v.36 no.4
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• pp.370-378
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• 1992

A simple and sensitive high performance liquid chromatographic method to quantitate ${\alpha}-keto$ acids in serum and urine was investigated. ${\alpha}-Keto$ acids react with 1,2-diamino-4,5-methylenedioxybenzene (DMB) in the presence of 2-mercapto-ethanol and sodium hydrogen sulfite to form highly fluorescent derivatives, substituted 6,7-methylenedioxyquinoxalinol. The derivatization procedure was performed in water bath at $100^{\circ}C$, and completed within 50 min. By the use of a reversed-phase column and multi-step gradient with two solvents, a mixture containing twelve of these derivatives were efficiently resolved within 35 minutes. The optimal wavelengh of the fluorescence detector are ${\lambda}_{ex}=364\;nm$ and ${\lambda}_{em}=445\;nm$. The quantitation of the individual ${\alpha}-Keto$ acids was reproducible with relative standard deviation of $3.0{\sim}7.9%$ and had a detection limits of $10{\sim}60$ fmol, except for p-hydroxyphenylpyruvic acid (960 fmol).

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.178-180
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• 2003

We performed semiempirical (AMl and ZINDO) and ab initio (HF and DFT) calculations, to investigate molecular structures and optical properties of DCM and its derivatives. DCM and its derivatives are used as a red fluorescent dopant of the organic electroluminescent host materials, $Alq_3$. We have studied the relationship between the molecular structure and the optical properties of these molecules for the improvement of EL efficiencies. Wavelength at the absorption maximum was found to be red-shifted when the molecule is substituted with both strong electron donating and withdrawing functional groups. A new red fluorescent dye was predicted by QSPR study based on calculations and experimental data.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2884-2888
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• 2010

Two red fluorescent DCJTB derivatives (Red 1 and 2) based on modified pyrans were synthesized and their electroluminescent properties were investigated. Multilayered OLEDs were fabricated with the device structure of ITO/NPB (40 nm)/Red 1, 2 or DCJTB (0.5 or 1%): $Alq_3$ (20 nm)/$Alq_3$ (40 nm)/Liq (2 nm)/Al. All devices exhibited efficient red emissions. In particular, a device containing emitter Red 2 as a dopant in the emitting layer, the maximum luminance was $8737\;cd/m^2$ at 12.0 V, the luminous and power efficiencies were 2.31 cd/A and 1.25 lm/W at $20\;mA/cm^2$, respectively. The peak wavelength of the electroluminescence was 638 nm with the CIE (x,y) coordinates of (0.63, 0.36) at 7.0 V.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.9
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• pp.577-582
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• 2017

The white light of a hybrid LED is obtained by using red and green organic fluorescent layers made of polymethylmethacrylate (PMMA) films, which function as color down-conversion layers of blue light-emitting diodes. In this research, we studied the fluorescence properties of a red organic fluorophore, employing perylene bisimide derivatives applicable to hybrid LEDs. The solubility, thermal stability, and luminous efficiency are important characteristics of organic fluorophores for use in hybrid LEDs. The perylene fluorescent compounds (1A and 1B) were prepared by the reaction of 4-bromophenol and 4-iodophenol with N,N'-bis(4-bromo-2,6-diisopropylphenyl)-1, 6,7,12-tetrachloroperylene-3,4,9,10-tetracarboxyl diimide (1) in the presence of dimethyl formaldehyde (DMF) at $70^{\circ}C$. The synthesized derivatives were characterized by using $^1H-NMR$, FT-IR, UV/Vis absorption and PL spectra, and TGA analysis. Compounds 1A and 1B showed absorption and emission at 570 nm and 604 nm in the UV/Vis spectrum. We also documented favorable solubility and thermal stability characteristics of the perylene fluorophores in our work. Perylene fluorophore 1, with the 4-bromophenol substituent 1A, exhibited particularly good thermal stability and solubility in organic solvents.

• Journal of Photoscience
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• v.9 no.3
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• pp.71-74
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• 2002

The fluorescent conjugated aromatic imine derivatives are systematically designed and synthesized as the high yield through the simple one-pot condensation reaction. The emission of the synthesized conjugated aromatic imine derivatives can be tuned efficiently in the range of about 100 nm by the change of electron donating groups constituting parent molecule, which shows the considerable quantum yields from 0.38 to 0.56.