• Journal of Integrative Natural Science
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• v.2 no.2
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• pp.73-77
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• 2009

Silyl-containing tetraphenylsilole, 1,1-bis(trisilyl)tetraphenylsilole, has been synthesized from the reaction of dichlorotetraphenylsilole and dichlorotrisilane and characterized by using NMR spectroscopy. Bis(trisilyl)tetraphenylsilole exhibits an unusual optical property and its optical property was characterized by UV-vis and fluorescence spectroscopy. Absorption wavelength maxima of bis(trisilyl)tetraphenylsilole was 380 nm. Bis(trisilyl)tetraphenylsilole displayed an emission band at 530 nm with an excitation wavelength of 380 nm.

• Textile Coloration and Finishing
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• v.33 no.4
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• pp.169-181
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• 2021

Five dyes based on phthalocyanine, a dye on azo, and a dye on anhraquinone were prepared from corresponding starting material to investigate the effects of substituent on thermal-stability of dyes which is essentially required to apply to the color filters. Synthesized dyes were confirmed their chemical structure using by 1H-NMR, MASS and Elemental analysis. The thermal-stability was evaluated by the weight reductions measured by TGA analysis comparing to that of conventional C.I. Pigment Blue 15:6. The absorption maxima were measured by UV-VIS spectrophotometer then the effects of substituent on absorption maximum was also investigated.

• Macromolecular Research
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• v.9 no.2
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• pp.116-121
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• 2001

A series of poly(1,4-phenylenevinylene-alt-3-alkyl-2,5-thienylenevinylene)s (alkyl = hexyl [PPV-alt-6-TV] and octyl (PPV-alt-8-TV] group) have been synthesized by the Heck coupling reaction. These polymers were characterized using $^1$H-NMR, FT-IR spectroscopy, and thermogravimetric analysis (TCA). They are solvent processible and have obviously copolymeric structure. The photophysical properties of the polymers were investigated using UV-visible and steady-state photoluminescence(PL) spectroscopy. We studied the change of light-emitting properties by incorporating the thiophene group into the PPV polymer backbone using alternating copolymer system. The properties of two synthesized polymers are very similar, but they exhibited apparent changes of light-emitting properties compared with other PPV backbone based polymers. The broad absorption bands from 350 to 570 nm are due to $\pi$-$\pi$* transitions of the polyconjugated systems. The absorption maxima of the two polymers were found at about 452 and 448 nm for PPV-alt-6-TV and PPV-alt-8-TV, respectively. The copolymers showed broad PL spectra between 550 and 700 nm without vibronic bands and PL emission maxima of PPV-alt-6-TV and PPV-alt-8-TV are about 620 and 605 nm, respectively. The copolymers exhibited the red emission (PPValt-6-TV), but more red shifted emissions are needed to obtain real red color.

• Applied Biological Chemistry
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• v.19 no.4
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• pp.243-247
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• 1976

A potent intracellular-lipid-producing yeast, Rhodotrorular glutinis var. glutinis sw-17 was studied on the production of carotenoids after shaking the cultures for 8 days at $25^{\circ}C$. The pigments were extracted with solvents and chromatographed with columns for its isolation. The carotonoids were identified by their positions on the column, and by their light-absorption curves. Close agreement was obtained between the absorption maxima of the isolated pigments and published literature values. The characteristic wave length maxima and the extinction values used for quantitative determination. The caroteniod pigments produced by the yeast were composed of torularhodin(28.52%), torulene(38.16%), neurosporene(1.49%), ${\gamma}-carotene(9.88%)$, ${\beta}$-zeacarotene(2.0%), ${\beta}-carotene(19.95%)$ and ${\delta}-carotene(trace)$.

• Molecules and Cells
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• v.46 no.8
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• pp.513-525
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• 2023

Orange carotenoid protein (OCP) of photosynthetic cyanobacteria binds to ketocarotenoids noncovalently and absorbs excess light to protect the host organism from light-induced oxidative damage. Herein, we found that mutating valine 40 in the α3 helix of Gloeocapsa sp. PCC 7513 (GlOCP1) resulted in blue- or red-shifts of 6-20 nm in the absorption maxima of the lit forms. We analyzed the origins of absorption maxima shifts by integrating X-ray crystallography, homology modeling, molecular dynamics simulations, and hybrid quantum mechanics/molecular mechanics calculations. Our analysis suggested that the single residue mutations alter the polar environment surrounding the bound canthaxanthin, thereby modulating the degree of charge transfer in the photoexcited state of the chromophore. Our integrated investigations reveal the mechanism of color adaptation specific to OCPs and suggest a design principle for color-specific photoswitches.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1182-1182
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• 2001

In this study, the newly constructed optical measurement system, which was mainly composed of a parametric tunable laser and a near infrared photoelectric multiplier, was introduced to clarify the optical characteristics of wood as discontinuous body with anisotropic cellular structure from the viewpoint of the time-of-flight near infrared spectroscopy (TOF-NIRS). The combined effects of the cellular structure of wood sample, the wavelength of the laser beam λ, and the detection position of transmitted light on the time resolved profiles were investigated in detail. The variation of the attenuance of peak maxima At, the time delay of peak maxima Δt and the variation of full width at half maximum Δw were strongly dependent on the feature of cellular structure of a sample and the wavelength of the laser beam. The substantial optical path length became about 30 to 35 times as long as sample thickness except the absorption band of water. Δt ${\times}$ Δw representing the light scattering condition increased exponentially with the sample thickness or the distance between the irradiation point and the end of sample. Around the λ=900-950 nm, there may be considerable light scattering in the lumen of tracheid, which is multiple specular reflection and easy to propagate along the length of wood fiber. Such tendency was remarkable for soft wood with the aggregate of thin layers of cell walls. When we apply TOF-NIRS to the cellular structural materials like wood, it is very important to give attention to the difference in the light scattering within cell wall and the multiple specular-like reflections between cell walls. We tried to express the characteristics of the time resolved profile on the basis of the optical parameters for light propagation determined by the previous studies, which were absorption coefficient K and scattering coefficient S from Kubelka-Munk theory and n from nth power cosine model of radiant intensity. The wavelength dependency of the product of K/S and n, which expressed the light-absorbing and -scattering condition and the degree of anisotropy, respectively, was similar to that of the time delay of peak maxima Δt. The variation of the time resolved profile is governed by the combination of these parameters. So, we can easily find the set of parameters for light propagation synthetically from Δt.

• Journal of the Korean Society of Tobacco Science
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• v.2 no.1
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• pp.1-7
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• 1980

Gel filtration column chromatography (Sephadex G-75), dialysis an d Brushite column chromatography were carried out to separate the brown pigmented macromolecule from water extracts of the cured leaf tobaccos. The two distinct macromolecules having different molecular weight were separated by the Sephadex column chromatography. Brushite also separated two different species of macromolecules which might have different electronic structures. According to the enzymatic degradation of protein in Burley and Hicks, chymotrypsin showed the best degradation ratio, ie., 16-30% in Burley and 38-57% in Hicks. Similar effect was observed with pepsin. However, very low effect of degradation was revealed with trypsin. The sample treated with the proteolytic enzymes revealed the disappearance of the first peak and the slight decrease of the 2nd peak height in the separation profile of Sephadex. After dialysis, the brown pigmented macromolecule was pyrolyzed at $300^{\circ}C$ and the strongly fluorescent components not identified before pyrolysis were detected with TLC separation. Absorption spectrum of these fluorescent compounds was monitored in benzene and the absorption maxima at 265nm and 275 nm were obtained. Considering absorption maxima and shape of the spectrum, those fluorescent compounds seem to be PAH derivatives.

• Applied Biological Chemistry
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• v.23 no.2
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• pp.123-130
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• 1980

Thiamine derivatives of thiamine tetrahydrofurfuryl disulfide (TTFD) and thiamine propyl disulfide (TPD) were obtained in a good yield and purity by use of thiothiamine $(SB_1)$ and also described in details for the preparing sodium tetrahydrofurfuryl thiosulphate (Bunte's salt) with and without KI. The optimum reaction conditions for the preparation of TTFD was set in which the Box-Wilson plan was applied. The reaction conditions are as follows; 1. pH value of aqueous solution of thiol type of $B_1{\cdot}HCl;12.09$ 2. Quantity of Bunte's salt (to $B_1{\cdot}HCl\;20G$); 35.01g 3. Reaction temperature; $15.59^{\circ}C$ Studies on ultraviolet absorption were made at various pH and showed that the absorption maxima are shifted with change of pH. The absorption maxima are at $244{\sim}246nm,\;234{\sim}235nm$ in TTFD, and $245{\sim}246nm,\;233{\sim}235nm$ in TPD. The structure was proved by the infrared spectral evidence. Quantitative determination was studied.

• Textile Coloration and Finishing
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• v.9 no.1
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• pp.44-49
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• 1997

Recent investigation and developments of A. Iqbal on diketo-pyrrolo-pyrrole (DPP) pigments has prompted us to synthesize and close observation of a few properties of these molecules. Described are synthesis, via 1-phenyl-2-ethoxycarbonyl-5-pyrrolinone intermediate, of asymmetric derivatives such as 1,4-Diketo-3-(4-chlorophenyl)-6-phenyl-pyrrolo-(3,4c)-pyrrole (4), 1,4-Diketo-3-(4-bromophenyl)-6-phenybpyrrolo-(3,4c)-pyrrole (5), 1,4-Diketo-3-(3-cyanophenyl)-6-phenyl-pyrrolo-(3,4c)-pyrrole (6), 1,4-Diketo-3-(4-cyanophenyl)-6-phenyl-pyrrolo-(3,4c)-pyrrole (7), 1,4-Diketo-3-(4-pyridyl)-6-phenyt-pyrrolo-(3,4c)-pyrrole (8), 1,4-Diketo-3-(3-pyridyl)-6-phenyl-pyrrolo-(3,4c)-pyrrole (9), 1,4-Diketo-3-(2-pyridyl)-6-phenyl-pyrrolo-(3,4c)-pyrrole (10), 1,4-Diketo-3-($\beta$-naphthyl)-6-phenyl-pyrrolo-(3,4c)-pyrrole (11), and UV-Vis absorption spectrum of the above compounds. Results from calculation of their absorption maxima using PISYSTEM are also described.

• Analytical Science and Technology
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• v.8 no.1
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• pp.47-53
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• 1995

The aggregation of Pyronin G($PG^+$) with tetraphenylborate($TPB^-$) anion has been investigated in aqueous solution by absorption and fluorescence spectrophotometries. The addition of 1,4-dioxane in aqueous solution of $PG^+$ and $TPB^-$ dissociates the aggregates of PG-TPB due to the increased hydrophobicity of the mixed solvent as compared to pure water, and yields higher $PG^+$ momomer concentration than aqueous $PG^+$ solution. The aggregation is not observed in any organic solvents except in water. The absorption maxima of $PG^+$ are correlated relatively well with ${\pi}^*$ scale and $(n^2-1)/(2n^2+1)$ funtion. But better linear relationship was obtained with ${\pi}^*$ scale for alcohols.