• Bulletin of the Korean Chemical Society
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• 제24권5호
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• pp.569-572
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• 2003

The majority of dyes belong to the chromophoric class known as donor-acceptor systems. The essential structural feature of such systems is the presence of one or more electron donating groups conjugated to one or more electron withdrawing groups via an unsaturated bridge. The pyrazolin-5-one system is an effective electron acceptor residue, and can also act as a weak electron donor. In our experiments, the various symmetrical and unsymmetrical H-chromophores were synthesized in the indoxyl, imidazo[1,2-a]pyridin-2-one, pyrazolin-5-one, and pyridin-2,6-dione residues, resulting in cross-conjugated donor-acceptor systems. And the visible light absorption was then associated with the migration of electron density from the donor region of the molecule to the acceptor region. Also, it was useful to prepare related non-cross-conjugated donor acceptor chromophores by combining these residues with other electron donor or acceptor moieties. For convenience such chromophores are referred to as merocyanines.

• 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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.1013-1015
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• 2002

1-(9,9-Di-octyl-fluorenyl)-2-substituted-2-cyanvinylene was synthesized and emission feature in solution are presented. Photoluminescence characteristics of 1-(9,9-Di-octyl-fluorenyJ)-2-substituted-2-cyanvinylene are measured by solvents such as carbon tetrachloride, normal hexane, chloroform, ethylaccetate, acetonitrile, methanol. It is shown that depending in the strength of the donor-acceptor internal charge transfer, and emission spectra are more or less red-shifted.

• 대한화학회지
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• 제49권2호
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• pp.155-160
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• 2005

• 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.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2010년도 제3회 국제학회
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• pp.49-50
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• 2010

The near-infrared absorbing donor-acceptor chromophores have been investigated by varying the electron donating and accepting molecular moiety. A series of near-infrared absorbing chromophores were offered narrow and intense absorption band in a various organic solvents. The dyes synthesised were, however, strongly bathochromic shift which extended well into the near-infrared region. The functional uses of dyes are vast in number, and it is convenient to classify them in some way. In all cases, it is the $\Pi$-chromophore that plays a major role in the functional application. "Light absorption" is of course the most commonly used property of a dye chromophore, and it can be employed directly, e.g. in light filters and optical data recording, or it can be used to drive further functional processes, e.g. fluorescence, photochromism, photosensitization.

• 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.

• 한국재료학회지
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• 제6권12호
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• pp.1242-1247
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• 1996

Spatially fixed bichromophoric systems with nonidentical chromophores have been extensively employed for studies of electron transfer and excitation transfer. Excitation hopping behavior between two naphthy1 moieties on 7,14-dihydro-7,14-ethanodibenz[a,h] anthracene(DEA)has been explored by the time-resolved fluorescence anisotropy measurements. The experimentally obtained value of the hopping rate in DEA agrees at least qualitatively with that calculated on the basis of the Dexter's theory, but disagrees with that calculated on the basis of the Forster's theory, indicates that for a pair of donor and acceptor with inter-chromophore separation as short as 4.5 $\AA$, excitation transfer via electron exchange is a predominant process.

• 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.

• 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.