• Journal of the Korean Ceramic Society
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• v.46 no.6
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• pp.615-620
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• 2009

The present research was performed to determine the optimal firing condition and holding time for malayaite crystal, which is responsible for the stable pink-red coloration in glaze at high temperatures, using Cr$Cl_3$ as chromophore for the synthesis of $Cr_2O_3-SnO_2-CaO-SiO_2$ system pigments. The malayaite crystal was influenced by the raw materials used for synthesis, firing temperature, and holding time. Thus there are differences in the crystal phase and in the coloration according to the condition of synthesis. When Cr$Cl_3$ was used as chromophore, the pigment could be synthesized at lower temperatures, because Cr$Cl_3$ melts at $1500{^{\circ}C}$, which is much lower than the temperature at which $Cr_2O_3$ melts (higher than $2435{^{\circ}C}$). And the employed Cr ion showed a change in oxidation state. When a mineralizer was used to improve the employment of malayaite and the Cr ion, and the low temperature was maintained at which the malayaite crystal is produced, the production of malayaite crystal was promoted and the employment of chromophore was also promoted in the oxidation state of Cr (IV). The results of the experiment showed that the optimal firing condition was 18 h of holding time at $800{^{\circ}C}$, using Cr$Cl_3$ as chromophore, followed by 2 h at the raised temperature of $1150{^{\circ}C}$. The change in coloration of the Cr (IV) employed by malayaite showed a very rich color of red. Thus it was possible to effectively synthesize sphene-pink pigments with more red tint at a low temperature.

• Journal of the Korean Chemical Society
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• v.42 no.2
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• pp.143-149
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• 1998

When anesthetics were added to a bacteriorhodopsin (bR) in the purple membranes, the 570 nm absorption band shifts to 480 nm. This anesthetic-induced spectroscopic change is reversible. The apparent pKa (6.3) of this equilibrium depends on the nature of the anesthetics in which bR is dispersed. The electric orientation measurements showed that the native bR is easily achieved by relatively small electric field which is oriented at $60^\circ$, while anesthetic-treated bR is not the case. These results demonstrate that the subtle changes in the chromophore and the protein structure surrounding the chromophore by anesthetics influence the spatial orientation of the charged residues in the protein matrix surrounding chromophore.

• Polymer(Korea)
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• v.30 no.5
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• pp.367-372
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• 2006

Electrochromic materials based on conducting polymers with pendant chromophores as well as their electrochromic properties are described. The conducting polymers described aye polypyrrole, polythiophene, poly(3,4-ethylenedioxythiophene), poly (cyclopentadithiophene), and poly (1,4-bis [2- (3,4-ethylenedioxy) thienyl] benzene). The chromophores described are viologen and perylenetetra-carboxylic diimide. When the wavelength ranges of absorption of the conducting polymer and the chromophore aye not overlapping, multiple electrochromism was achieved. When the wavelength ranges are largely overlapping, higher contrast was achieved. An easy method for prediction of the film thickness for maximum contrast of a given electrochromic material is also described.

• Macromolecular Research
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• v.16 no.5
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• pp.434-440
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• 2008

Three-armed, star-shaped molecules containing 4-(N,N-diphenyl)amino-4'-nitroazobenzene chromophores were synthesized to study the diffraction behavior after inscribing surface relief gratings. The two molecules differed in terms of their mode of chromophore attachment to the core. In compound 5, they were bound to the core laterally through alkylene spacers, whereas the chromophores were tethered perpendicularly to the core in compound 4. Although 60 wt% of the polar azobenzene chromophores was comprised of large molecules, no aggregation behavior was observed in the absorption spectra of the thin films. The surface relief gratings were elaborated on the surface of the molecular films by the two-beam interference method. The dynamics of grating formation were studied in terms of the diffraction efficiency using two different film samples made up of two star-shaped molecules. The maximum diffraction efficiency of D-$(ENAZ)_3$, compound 4, was measured to be about 30%, which was significantly high. The mode of chromophore attachment affected the dynamic properties of the diffraction gratings.

• Proceedings of the Korean Society of Potoscience Conference
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• 2002.06a
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• pp.42-42
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• 2002

• Bulletin of the Korean Chemical Society
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• v.20 no.2
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• pp.253-256
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• 1999

• BMB Reports
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• v.36 no.3
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• pp.305-311
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• 2003

A modified actinomycin D was prepared with a hydroxyl group that replaced the amino group at the chromophore 2-position, a substitution known to strongly reduce affinity for double-stranded DNA. Interactions of the modified drug on single-stranded DNAs of the defined sequence were investigated. Competition assays showed that 2-hydroxyactinomycin D has low affinity for two oligonucleotides that have high affinities ($K_a\;=\;5-10{\times}10^6\;M^{-1}$ oligomer) for 7-aminoactinomycin D and actinomycin D. Primer extension inhibition assays performed on several single-stranded DNA templates totaling around 1000 nt in length detected a single high affinity site for 2-hydroxyactinomycin D, while many high affinity binding sites of unmodified actinomycin D were found on the same templates. The sequence selectivity of 2-hydroxyactinomycin D binding is unusually high and approximates the selectivity of restriction endonucleases. Binding appears to require a complex structure, including residues well removed from the polymerase pause site.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.119.2-119.2
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• 2011

Dye-sensitized solar cells (DSSC) are currently attracting wide spread academic and commercial interest for the conversion of sunlight into electricity because of their easy manufacturing process and high efficiency. The solar energy conversion efficiencies of DSSC are strongly dependent on dye molecules adsorbed on the TiO2 surface which used for photosensitization of sun light, since an excited state of dye could inject an electron into the conduction band of semiconductor. We have developed novel organic dyes which have phenothiazine moieties as an electron donor in their charge-transfer chromophore for application of DSSCs. We had synthesized a series of phenothiazine derivatives which have different wave length absorbing chromophore in the molecule with high molar extinction coefficient. The photovoltaic performance of DSSC composed of organic chromophores with broad wavelength absorption property were measured and evaluated by comparison with that of pristine ruthenium dye.

• Microbiology and Biotechnology Letters
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• v.19 no.6
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• pp.604-609
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• 1991

Antibiotic MT-497 was purified from the culture broth of Streptomyces nigr$^1H-NMR$ and composition of amino acids, MT-497 was identified as one of the actinornycin antibiotics containing actinocin chromophore and the peptide with threonine, proline, methyl valine, sarcosine and aspartic acid.

• Rapid Communication in Photoscience
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• v.5 no.2
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• pp.18-20
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• 2016

Through quantum chemical means, we inspect the energetics of the singlet oxygen formation with fluorescent proteins in their triplet excited states. By placing an oxygen molecule at varying distances, we discover that the energetic driving force for the singlet oxygen formation does not depend strongly on the chromophore $-O_2$ distance. We also observe that the chromophore vibrations contribute much to the energy gap modulation toward the surface crossing. Based on our computational results, we try to draw a series of rationalizations of different photostabilities of different fluorescent proteins. Most prominently, we argue that the chance of encountering a surface crossing point is higher with a protein with a lower photostability.