• 폴리머
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• 제34권4호
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• pp.376-380
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• 2010

분자내 전하이동(intramolecular charge transfer, ICT)이 가능한 도너-$\pi$-억셉터(D-$\pi$-A)타입의 발색단 을 근간으로 한 폴리머를 신규 합성하였다. 이 폴리머는 UV-visible spectra 측정결과 용액 상태에서 뿐만 아니라 고체박막 상태에서도 카르보닐기(carbonyl group)에서 기인하는 흡수와 함께 ICT에 의한 장파장 영역에서의 흡수가 관 찰되었다. $Eu^{3+}$ 이온의 첨가에 의해 장파장영역에서 일어나는 흡수의 적색이동(red shift)을 유도하였으며, 더불어 용 액과 박막의 색상도 황색에서 적색으로 변화하는 것이 관찰되었다. 합성된 고분자의 형태 및 유기 용매에 대한 용해도 는 가교제의 함량에 따라 다양한 특성을 나타내었다. 또한, 첨가된 가교제의 함량과 $Eu^{3+}$ 이온의 첨가는 성막 특성의 향상을 유도하였다.

• Macromolecular Research
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• 제12권5호
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• pp.484-489
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• 2004

We have prepared a phenothiazine-based nonlinear optical (NLO) chromophore that displays a fairly high microscopic nonlinearity through intramolecular charge transfer. The phenothiazine unit plays important roles of contributing its high electron donating ability and connecting the resonance pathway through a conjugative effect in the cyclized ring adjacent to the aromatic ring. Theoretical calculations and an absorption spectroscopic study provided useful information concerning the microscopic nonlinearity of the chromophores. We investigated the electro-optic (EO) properties of the guest-host systems in amorphous polycarbonate containing the synthesized chromophores at different concentrations under different poling temperatures. A real-time pole and probe method provided a much greater amount of information regarding how the EO properties can arise and how they can be optimized.

• Bulletin of the Korean Chemical Society
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• 제16권10호
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• pp.972-976
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• 1995

A trace amount of 4-biphenylcarboxylate having a pre-twisted biphenyl moiety was attached to a poly(methyl methacrylate) side chain and the fluorescence properties of the chromophore were investigated in various solvents such as ethyl acetate and butyl chloride. At room temperature, the polymer exhibited a distinct red shift of the short wavelength emission (325 nm) and an enhanced emission intensity around 430 nm upon excitation at the absorption red edge. The temperature dependence of the intensity ratio (R) of the 325 nm emission to the 430 nm emission was observed when exciting at the red edge over the temperature range between -20 and 60 ℃. However, the temperature dependence was not observed when exciting at the shorter wavelength. The Arrhenius plot of the R value shows the activation energy of 6.0 kJ/mol which is in good agreement with the energy required for the twist of the biphenyl moiety. Together with the results of red edge excitation effects it was concluded that the pre-twisted geometry of the biphenyl moiety is preserved by the restriction of the polymer chain to facilitate the formation of the twisted intramolecular charge transfer (TICT) state upon excitation.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2011년도 제44차 학술발표회
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• pp.62-62
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• 2011

Intramolecular charge transfer (ICT) system has received great attentions due to their promising optoelectronic properties For the efficient ICT of the chromophore, their organic compound mainly consists of strong electron donors (e.g. $NR_2$ or OR groups) and acceptors (e.g. CN or $NO_2$ groups). According to the molecular design and synthesis, the ICT compounds can be extended in many application fields. In this study, we have synthesized ICT compounds having a strong electron acceptor and donor. These novel ICT compounds were easily synthesized by a previously described method with some modifications. Their single crystals were grown and their structures were solved and described in this presentation.

• Fibers and Polymers
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• 제1권2호
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• pp.71-75
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• 2000

Intermolecular cyclization of 2-alkylamino-3-chloro-5,6-dicyanopyrazine 2 in the presence of tributylamine in N,N-dimethylformamide (DMF) gave 5,10-disubstituted-2,3,7,8-tetracyano -5,10-dihydrodipyrazino〔2,3-b:2',3'-e]pyrazines 3, which showed strong mesomorphic property and were anticipated as new chromophoric system for functional dye materials. Absorption spectra, fluorescent properties and other physical properties were correlated with their chemical structures. Vanadyl oligomeric porphyrazine with long alkyl groups synthesized from 3 had satisfactory solubility in tetrahydrofuran (THF), diethyl ether and dimethylsulfoxide (DMSO). The syntheses and characterization of vanadyl polymeric porphyrazines derived from 3 with long alkyl groups are reported.

• Bulletin of the Korean Chemical Society
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• 제33권6호
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• pp.1900-1906
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• 2012

Three carbazole chromophores featuring dicyano, cyano, ethyl acetate and dimethyl acetate groups as an acceptor moiety with a ${\pi}$-conjugated spacer and $N$-methyl dibenzo[$b$]pyrole as donor were synthesized by Knovenagel condensation and characterized by IR, $^1HNMR$, $^{13}CNMR$, UV-vis, fluorescence spectroscopy, electrochemistry and theoretical B3LYP/6-$311G^*$ level whilst NLO properties and spectroscopic quantities were calculated. Calculations showed remarkable trend with HOMO located on the donor moiety and LUMO on the acceptors dicyano methylene, cyano, ethyl acetate methylene and dimethyl acetate methylene. In agreement with the calculations, solvatochromic, behavior intramolecular charge transfer band was observed in the visible region.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2553-2559
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• 2011

Two novel quinacridone (QNC) dyes with thiophene or benzene-conjugated bridge and cyanoacrylic acid acceptor were first designed and synthesized for use in dye-sensitized solar cells (DSSCs). The absorption spectra, electrochemical and photovoltaic properties of these dyes were investigated. Under simulated AM 1.5G irradiation conditions, the solar cell based on the quinacridone dye containing thiophene as a bridge unit had a short-circuit photocurrent density of 8.51 $mA{\cdot}cm^{-2}$, an open-circuit voltage of 643.6 mV, and a fill factor of 0.70, corresponding to an overall conversion efficiency of 3.86%.

• Bulletin of the Korean Chemical Society
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• 제26권1호
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• pp.77-84
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• 2005

We prepared the new nonlinear optical chromophores that show fairly high microscopic nonlinearity through intramolecular charge transfer. Phenothiazine and carbazole units played an important role to contribute high electron donability and connect the resonance pathway via conjugative effect in the cyclized ring beside the aromatic ring. Theoretical calculation, electrochemical analysis, and absorption spectroscopic study gave us useful information about the energy states and microscopic nonlinearities of two serial chromophores. We compared the microscopic nonlinearities of four chromophores with the conjugation length and electron donability in the push-pull type NLO chromophores. The effect of gradient donability and lengthening the conjugation were investigated on the electronic state and microscopic nonlinearity.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2010년도 제3회 국제학회
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• pp.40-40
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• 2010

Studies on attractive color changing property of dye chromophore and fluorophore have been greatly enjoyed in the related industrial and research fields such as optoelectronics, chemosensor, biosensor and so on. The optical property based on D-$\Pi$-A intramolecular charge transfer (ICT) system of chromophore molecules can be utilized as suitable sensing probes for checking media polarity and determining colorimetric chemosensing effect, especially heavy metal detection. These finding are obtained by absorption and emission properties. In this work, donor-acceptor D-$\Pi$-A type fluorescent dyes were designed and synthesized with the corresponding donor and acceptor groups. The selected donor moieties might be provided prominent amorphous properties which are very useful in designing and synthesizing functional polymers and in fabricating devices. Another reasons to choose are commercial availabilities in high purity and low price. Donor-bridge-acceptor (D-A) type dyes can produce impressive optical-physical properties, yielding them potentially suitable for applications in the synthesis of small functional organic molecules. Small organic functional molecules have unique advantages, such as better solubility, amorphous character, and represent an area of research which needs to be explored and developed. Currently, their applications in metalorganic compounds is rapidly expanding and becoming widespread in self-assembly processes, photoluminescence applications, chiral organocatalysts, and ingrafts with nanomaterials. Colloidal nanoparticles have received great attentions in recent years. The photophysical properties of nanoparticles, particularly in terms of brightness, photostability, emission color purity and broad adsorption range, are very attractive functions in many applications. To our knowledge background, colloidal nanoparticles have been enjoyed their applications in bio-probe research fields. This research interest can be raised by the advantages of the materials such as high photoluminescence quantum yields, sharp emission band, long-term photostability and broad excitation spectra. In recent, the uses of nanoparticles being embedded in a polymer matrix and binded on polymer surface have been explored and their properties such as photo-activation and strong photoluminescence have been proposed. The prepared chromophores and nanoparticles were investigated with absorption and emission properties, solvatochromic behaviors, pH induced color switching effects, chemosensing effects and HOMO/LUMO energy potentials with computer simulation. In addition, synthesized fluorophore dyes and particles were applied onto PE/Aramid fiber fluorescing colorations. And the related details were then discussed.