• Journal of Photoscience
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• v.4 no.1
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• pp.1-5
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• 1997

A hitherto unknown diphenylbutadiene analog viz. 1-(p-N,N-dimethylaminophenyl)-4-phenyl-2-methyl-1E,3E-butadiene (10) has been prepared and its absorption, excitation, and fluorescent emission properties in different media including various organic solvents and aqueous bovine serum albumin (BSA) have been studied. For comparision, these properties have also been investigated for the parent diphenylbutadiene (2). Diene 10 exhibits solvent polarity/polarizability-sensitive fluorescence properties ($\lambda$$_{max}$, $\Phi$$_f$, $\tau$$_f$, K$_f$, f). It also binds to the hydrophobic domains of aqueous bovine serum albumin (BSA) with a binding constant of 3.89 x 10$^4$ M$^{-1}$. The relative fluorescence quantum yield of 10 increases, while, the fluorescence lifetime decreases with increasing concentration of-BSA. The results highlight the polar character of the singlet excited state of diphenylpolyenes and the utility of 10 as fluorescence probe for studying microenvironments of organized assemblies and biological supramolecular structures.

• The Korean Journal of Food And Nutrition
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• v.5 no.1
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• pp.23-32
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• 1992

Kinetic studies of nucleophilic substitution reactions of dansyl, bansyl, dabsyl chlorides with pyridines have been investigated at $0^{\circ}C$ in a range of methanol-acetonitrile binary solvent mixtures. The order of magnitude for reactivity of substrates with pyridines in the same reaction condition is dabsyl chloride>dansyl chloride> bansyl chloride. The value of $\rho$n(-2.29~ -4.66) and $\beta$(0.537~0.901) associated with a change substituent in the nucleophile are large and indicate a relatively advanced bond formation in the transition state. Solvatochromic correlations were predicted the increase of bond formation transition state according to the increasing MeCN contents, showing the greater contribution of polarity polarizability ($\pi$*) than hydro-gen bond donar acidity($\alpha$). We conclude that the reactions of dansyl, bansyl, dabsyl chlorides with pyridines proceed via associative Sn2 type reaction mechanism.

• Journal of Photoscience
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• v.1 no.2
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• pp.113-117
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• 1994

The quantum yields of fluorescence ($\Phi$$_f$) and trans $\to$ cis photoisomerization ($\Phi$$_{t$\to$ c}$), trans-4-(2-(9-anthryl)vinyl)pyridine, an aza analogue of 1-(9-anthryl)-2-phenylethylene, were measured in several solvents at room temperature. $\Phi$$_f$ and $\Phi$$_{t$\to$ c}$ are 0.38 and < 0.01 in hexane and 0.02 and 0.38 in acetonitrile, respectively. As solvent polarity decreases, $\Phi$$_{t$\to$ c}$ strongly reduced, whereas $\Phi$$_f$ strongly increased. A singlet mechanism of trans $\to$ cis photoisomerization is suggested since $\Phi$$_{t$\to$ c}$ and $\Phi$$_f$ change in opposite direction.

• Textile Coloration and Finishing
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• v.9 no.5
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• pp.10-18
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• 1997

In order to study the properties of safflower yellow colors, thermodynamic parameters and dyeing properties on the silk in several dyeing conditions were investigated. The uv-visible spectra of safflower yellow colors in several solvents show hypsochromic shift with the polarity of solvent but bathochromic shift with increasing acidity of solution. The apparent diffusion coefficients and standard affinities of dyeing increased with the increase of dyeing temperature. The standard heat of dyeing(${\Delta}H^0$), entropy change(${\Delta}S^0$) and activation energy($E_{act}$) were calculated to be - 1.144kcal/mol, -7.498(5$0^{\circ}C$)~-3.804(9$0^{\circ}C$)cal/molㆍdeg and 0.123kcal/mol, respectively. The concentration of safflower yellow colors in the silk fiber increased with dyeing temperature, time, concentration of colors and acidity of initial dyebath. Silk fabrics were dyed bright yellow by pre-mordanting with tin chloride. Lightfastness of silk fabrics pre-mordanted by tin chloride was not excellent.

• Bulletin of the Korean Chemical Society
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• v.31 no.4
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• pp.1061-1063
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• 2010

• YAKHAK HOEJI
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• v.40 no.5
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• pp.582-590
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• 1996

For the research of antifungal active constituents from natural products, 226 plants were extracted with ether and methanol, separately, and screened antifungal activity against Candida albicans and Penicillium avellaneum cells. The results demonstrated that 30 samlpes showed antifungal activity in ether or methanol extracts and 17 samples in ether extracts and 20 samples in methanol extracts against C. albicans. Against P. avellaneum, 19 samlpes showed antifungal activity in ether or methanol extracts and 17 samples in ether extracts and 11 samples in methanol extracts, respectively. The antifungal activity of natural products against C. albicans were showed more sensitive than P. avellaneum, and the polarity of the solvent was not specific in antifungal activity.

• Journal of Photoscience
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• v.11 no.3
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• pp.107-113
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• 2004

Synthesis, absorption and fluorescence properties of 3-methyl indole (1), N-(benzenesulfonyl)-3-(3-oxo-but-1-enyl)-indole (2) and 1H-3-(3-oxo-but-1-enyl)-indole (3) are described. Extended conjugation at C-3 of indole as in 3 causes moderate resolution of $^1L_a$ and $^1L_b$ bands. However, 2 having an electron-withdrawing group at indolic nitrogen shows only the $^1L_a$ band. While the $^1L_b$ band largely remains solvent polarity independent, the $^1L_a$ band undergoes moderate red shift in polar solvents. The fluorescence in 2 and 3 originates from the $L_b$ transition. Additionally, interaction of 2 and 3 with BSA indicates that these compounds bind to the hydrophobic site of BSA with the formation of a highly fluorescent BSA-probe complex.

• Bulletin of the Korean Chemical Society
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• v.19 no.11
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• pp.1239-1244
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• 1998

Derivatives of ethylthio α-D-mannopyranoside as glycosyl donors are compared in coupling efficiency and stercoselectivity with varying thiophilic promoters from methyl triflate (MeOTf), dimethyl(methylthio)sulfonium triflate (DMTST) to iodonium dicollidine perchlorate (IDCP), solvents and glycosyl acceptors. IDCP was the most efficient promoter in coupling of perbenzylated ethylthio-α-D-mannopyranosides (1 and 2), giving α-Dmannosyl disaccharides preferentially, whereas inactive in coupling of 4,6-O-benzylidene derivatives 3 and 4. MeOTf and DMTST promoted coupling of 4,6-O-benzylidene derivatives 3 and 4, but P-D-mannopyranosyl disaccharides were formed preferentially. Coupling reaction was retarded as solvent polarity decreased.

• Bulletin of the Korean Chemical Society
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• v.5 no.6
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• pp.219-223
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• 1984

The 8-methoxypsoralen$<^{4',5'}_{5',6}>$ thymidine monoadducts are isolated from the irradiation mixture of 8-methoxypsoralen and thymidine in a dry film state by a flash column followed by lobar column chromatography. Some physical properties of the adducts were determined. The fluorescence maximum and quantum yield of the monoadduct are dependent on the solvent polarity and the phosphorescence to fluorescence quantum yield ratio was 2.10 which was significantly increased by external heavy atoms. The phosphorescence lifetime was 1.2s which is relatively large compared to other coumarin derivatives. Accurate spectral data of the monoadducts are presented.

• Journal of the Korean Chemical Society
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• v.37 no.11
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• pp.929-936
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• 1993

Charge transfer complexes of some electron donors with one electron acceptor have been studied to investigate the maximum absorption wavelength and absorbance by UV-Vis spectrometer in three kinds of solvents, such as ethylene chloride, methylene chloride, and chloroform, at the temperature ranges of 16∼25$^{\circ}$C. 1,2,3,4-Tetrahydrocarbazole (THC), 2-methyl, 3-methyl, and 3-ethyl THC were selected as electron donors while chloranil was used as an electron acceptor in this study. It is found that these complexes forms 1 : 1 complexes, and their maximum absorbance and formation constants decreases with respect to the function of the polarity of solvent and temperature. The polarity of solvents and the temperature have been influenced on the formation constants, which were described using the thermodynamic properties. Moreover, the electronic and steric effects of electron donors have also been effects.