• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2009.11a
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• pp.115-116
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• 2009

In this study, near-infrared absorbing dyes, namely, new rigidified heptamethine cyanine dyes were synthesized and investigated their properties. The cyanine dyes have been synthesized by a condensation reaction between a quanternary salt containing as activated methyl group and an unsaturated bisaldehyde or its equivalent. We were investigated the synthesis of new rigidified heptamethine cyanine and related the compounds with near infrared absorption. The full spectroscopic characterization of all cyanine were described. Absorption properties in the near-infrared region may cause these dyes to the potential used in bio-probe, optical recording media materials.

• Bulletin of the Korean Chemical Society
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• v.30 no.8
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• pp.1861-1863
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• 2009

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2382-2388
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• 2007

A series of dimethine cyanine dyes were synthesized in a fast, efficient and high yield by the condensation of quaternary salts with 1H-indole-3-carbaldehyde in the presence of piperidine under solvent-free microwave irradiation. The products were identified by 1H NMR, IR, UV-Vis spectra and elemental analysis. The absorption and fluorescence properties of these dyes were investigated both experimentally and theoretically. Calculations performed at a combination of time-dependent density functional theory (TD-DFT) and the polarizable continuum model (PCM) reproduced the π-π* type absorption bands of the dyes. Regression analysis was used for studying theoretical results of the absorption maxima in different solvents. Compared with experimental counterparts, estimated overall uncertainties in the absorption maxima were about ±2%.

• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.287-290
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• 2013

• Journal of the Korean Graphic Arts Communication Society
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• v.26 no.2
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• pp.31-43
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• 2008

The functional dyes, which has various optical characteristics that can be applicable to field of electronic, photo electronic, such as sensor or electrode, were synthesized. Physical property and optical stability was studied with preparation of conductive type film as a kind of optical filter of plasma display panel, by adapting neon cut off dye, which can selectively absorbing between 580 and 610nm wavelength. The filter was prepared with PSA resin, which has functional group of - COOH and - OH, as binder. And the characters such as spectroscopy, heat-proof / wet-proof, thermal stability and commerciality, which must be held by functional dyes, were examined. Conductive type film is the kind of film includes only neon cut off dyes. For the neon cut off dyes, cyanine dyes can be applied. And it is observed that spectrum of before and after the durability test are not changed due to stability of dyes, as the result of coating on the mesh film with PSA binder.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.489-494
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• 2013

An improved method for the preparation of monomethine cyanine dyes with quinoline nucleus by one-pot three-component using 1-methyl-2-quinolinethione, quaternized 2- or 4-methylheterocyclic compounds and methyl p-toluenesulfonate as starting materials was described. Compared with the traditional methods, the new synthetic method reduced the reaction steps, shortened the reaction time, avoided the separation and purification of the intermediate and reduced cost. The dyes absorbed in the region 478.0-563.0 nm and had molar extinction coefficients of $1.3{\times}10^4-9.4 {\times}10^4L\;mol^{-1}\;cm^{-1}$. Their fluorescence maxima and Stokes shifts were in the range of 525.2-594.4 nm and 16.2-80.6 nm in different solvents, respectively. From the spectral properties of the dyes in different solvents, it could be found that the ${\lambda}_{max}$ of the dyes were shorter in protonic solvents, and showed hypsochromic shifts with the increase of polarity of the solvents.

• Textile Coloration and Finishing
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• v.27 no.4
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• pp.270-274
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• 2015

Molecules always show broad absorption band envelopes, and this results from the vibrational properties of bonds. The width of an absorption band can have an important influence on the color of a dye. A narrow band imparts a bright, spectrally pure color to the dye, whereas a broad band can give the same hue, but with a much duller appearance. Typically, half-band widths of cyanine dyes are about 25nm compared to value of over 50nm for typical merocyanine dyes. Thus, cyanine dyes are exceptionally bright. The factors influencing the width of an absorption band can be understood with reference to the Morse curves. The width of the absorption band depends on how closely the bond order of the molecules in the first excited state resembles that in the ground state. We have quantitatively evaluated the "molecular structure-absorption band shape" relationship of dye molecules by means of Pariser-Parr-Pople Molecular Orbital Method(PPP-MO).

• Bulletin of the Korean Chemical Society
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• v.35 no.8
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• pp.2453-2459
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• 2014

Five novel cyanine dyes containing julolidine and indole moieties were synthesized. Several color compensating films for plasma display panels (PDP) were prepared using these dyes. The spectroscopic and physicochemical properties of the synthesized dyes in both solution and film state were evaluated. For each color compensating film, the optimum ratio of dye to binder was determined on the basis of transmittance, half band width, and photo-stability of the color compensating film. The five synthesized dyes showed sharp absorption peaks near 590 nm (orange light) and had molar extinction coefficients above $1{\times}10^5M^{-1}cm^{-1}$. The melting point of the dyes was above $200^{\circ}C$ and photo-stability of the color compensating films was improved by introducing substituents at the 5th position on the indole derivatives.

• Journal of the Korean Graphic Arts Communication Society
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• v.13 no.1
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• pp.73-91
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• 1995

Spectroscopic and Photoelectric Characteristics in the Cyanine and Merocyanine Dye according to systematically change of their structures were experimentally discussed. As result, in solution, Hetero atoms(X) of Cyanine and Merocyanine dye were participated in resonance X of d obital rather than X of pobital,effected in resonance and contributed in extension of conjugated system. in solid film,new spectra,called eximer-fluorenscence,were appeared in 3-dimensional fluorenscence of high density of Cyanine dye but not of Merocyanine. The activational energy of conductivity in Merocyanine dye was lower than in cyanine, an the contrary,the drift mobility was higher and the former in photoelectric characteristics was more effec-tive than the latter. In this paper,authors invertigated the changes of dye structure by molecular obital method to confirm the results of spectroscopic and photoelectric characteristics in the Cyanine and Merocyanine Dye acco-rding to systematically cally change of their structure, and counted total energy on dihedral angle and dipol miments if dyes in S0 and S1.

• Textile Coloration and Finishing
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• v.6 no.1
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• pp.28-32
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• 1994

The synthesis and absorption spectra of squarvlium(SQ) dyes and croconium(CR) dyes were .studied. Absorption spectra of SQ dye in various solvents exhibited a negative solvatochrornism. Thus, it was suggested that the structure of SQ dye may be a highly polar structure. The λ$_{max}$ of CR dyes undergoes a bathochromic shift of about 100nm compared with the corresponding SQ dyes. This shift can be calculated by the Pariser-Parr-Pople molecular orbital method. From the PPP MO calculation results, we found that SQ dye and CR dye have a almost same Highest Occupied Molecular Orbital(HOMO) level(SQ : -8.0eV, CR : -8.09eV). On the other hand, energy levels of Lowest Unoccupied Molecular Orbital(LUMO) of SQ and CR dyes are -4.09eV and -4.13eV respectively. Thus, replacement of five membered ring by four membered ring in SQ dye causes a large bathochromic shift.t.