• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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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.

• Textile Coloration and Finishing
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• v.25 no.1
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• pp.13-17
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• 2013

A new assembly derived from 2,3-dibromo-5,6,7,8-tetrafluoroquinizarin and sodium diethyl-carbamodithiolate, was prepared as an efficient $Fe^{3+}$ colorimetric chemosensor with high selectivity over other cations $Fe^{3+}$, $Na^+$, $Mg^{2+}$, $Pb^{2+}$, $Cd^{2+}$, $Ni^{2+}$, $Ca^{2+}$, $Cu^{2+}$, $Hg^{2+}$, $Zn^{2+}$ : from the dark blue to brown color change that is visible by eyes. This assembly produced large bathochromic shift of 228 nm in the presence of $Fe^{3+}$ compared with the corresponding absorption maximum of the parent dye.

• Macromolecular Research
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• v.12 no.5
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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.

• Fibers and Polymers
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• v.1 no.2
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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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• v.33 no.6
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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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• v.18 no.2
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• pp.156-161
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• 1997

Aqueous 6-hydroxyquinoline in the first excited singlet state undergoes protonation to the imine group first in 15 ps, then in the time scale of 40 ps deprotonation from the enol group and finally, however, quickly as in 11 ps electron rearrangement to change into a resonance hybrid structure of quinoid-prevailing forms. Despite the fact that the decay time constant is smaller than the formation time constant, fluorescence from excited protropic zwitterion is observed to assign its maximum at 510 nm. The electron rearrangement is basically an intramolecular charge transfer from the deprotonated oxygen atom to the positively charged iminium ring without any notable change in nuclear geometry, producing a zwitterionic quinoid structure with much a smaller electric dipole moment than the zwitterionic protropic species. This photoproduct formed by consecutive excited state proton and electron transfers shows a smaller dipole moment in S1 than in S0 and a hypsochromic shift although its S1 state has (π, π*) character.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.48-48
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• 2012

화학센서는 분석물질과 감응물질간의 화학적 반응을 통해 분석물질을 선택적으로 인지하고 이를 통하여 특정물질을 실시간으로 분석할 수 있는 기술이다. 최근 화학센서로 색소를 이용하여 음이온을 진단/감응하는 기술이 각광 받고 있으며, 더불어 음이온을 선택적으로 인지함에 있어 검출하고자 하는 특정 음이온에 대한 민감도를 높이기 위한 노력이 계속되고 있다. 감응물질로 이용되는 색소는 주로 분자 내 전하 이동형 색소(intramolecular charge transfer dye)로 주위 환경 변화에 민감하게 반응하며, 자극에 따른 변화를 흡수와 발광, 굴절률의 변화 등으로 나타낸다. 또한 다양한 음이온 중 분석물질로써 연구 가치가 큰 음이온에는 플루오린화물(fluoride)이 있다. 이는 플루오린화물이 치아 보호와 골다공증에 중요한 역할을 하는 순기능을 가지는 반면 고농도 상태에서는 불소증(fluorosis)을 비롯한 악영향을 잠재적으로 가지기 때문에 그 양을 인지하는 것이 중요하게 여겨지기 때문이다. 따라서 본 연구에서는 2-(3,5,5-trimethylcyclohex-2-enylidene)-malononitirle과 indole-3-carboxaldehyde를 통하여 분자 내 전하 이동형 색소를 합성하고, $^1H$ NMR, GC-mas, EA로 합성된 색소의 물성을 분석하였다. 우선 반응물인 2-(3,5,5-trimethylcyclohex-2-enylidene)-malononitirle을 합성하기 위해 dimethylfor mamide(DMF) 용매 하에서 isophorone과 malononitrile을 12시간 반응시키고, 얻어진 결과물을 정제한다. 이후 indole-3-carboxaldehyde와 10시간 환류시켜 색소를 얻는다. 합성된 색소는 F 이온 검출에 이용되며, UV-vis 분광법을 이용하여 분석물질에 따른 흡수 정도와 강도 변화를 살펴본다. 연구의 최종적인 목적은 비단 진단/감응 색소의 합성이 아니라 나노 섬유 소재와 색소의 접합을 통해 진단/감응형 나노 섬유를 개발하는 것으로 이를 위해 전기방사법이 이용된다.

• Bulletin of the Korean Chemical Society
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• v.31 no.9
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• pp.2531-2536
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• 2010

Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations have been employed to investigate the molecular structures and absorption spectra of two dyes containing diphenylaniline and 4-diphenylamino-diphenylaniline as donor moiety (TPA1 and TPA3). The geometries indicate that the strong conjugation is formed in the dyes. The electronic structures suggest that the intramolecular charge transfer from the donor to the acceptor occurs, and the electron-donating capability of 4-diphenylamino-diphenylaniline is stronger than that of diphenylaniline. The computed highest occupied molecular orbital (HOMO) energy levels are -5.31 and -4.90 eV, while the lowest unoccupied molecular orbital (LUMO) energies are -2.29 and -2.26 eV for TPA1 and TPA3, respectively, revealing that the interfacial charge transfer between the dyes and the semiconductor electrode are electron injection processes from the photon-excited dyes to the semiconductor conduction band. Furthermore, all the experimental absorption bands of TPA1 and TPA3 have been assigned according to the TDDFT calculations.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1573-1576
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• 2007

ABCV-Py, a new red fluorescent material, in which two identical electron donor (dimethylamino group) and acceptor (cyano group) moieties are linked to two independent biphenyl groups which share the same core phenyl, has been synthesized for use in OLED application. Performance of red doped electroluminescent devices using ABCV-Py as dopant were measured with various host materials, $Alq_3$, CBP, DPVBi, and p-terphenyl. The performance of device with DPVBi host material was better than those with other host materials and high doping concentration could be applied on device with ABCV-Py as dopant.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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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%.