• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.625-628
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• 2012

We investigated the interaction between polyynes (linear carbon chains) and various metal nanoparticles (Ag, Au, and Cu) to provide insight into the optical properties of metal-polyynes systems prepared by different experimental techniques. Polyynes were produced by laser ablation in deionized water, metal nanoparticles solutions, and copper chloride solution. Metal nanoparticles complexes with polyynes were analyzed by Raman, surface-enhanced Raman scattering, and UV-vis spectroscopy.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2439-2442
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• 2012

In order to explore the effects of the solvent on the formation rate of polyynes, we investigated the absorption spectra of polyynes obtained by laser ablation of a graphite target in different solvents at 1064 nm. Polyynes so produced were confirmed by the Raman band around $2200cm^{-1}$ which corresponds to the carbon triple bonds. The production of polyynes by laser ablation turned out to be significantly affected by the ratio of the hydrogen and carbon atoms in the solvent molecule. No clear correlations were observed in the formation of polyynes for other properties of the solvent such bond dissociation energy, thermal conductivity, and total mass of hydrogen atoms per volume of solvent.

• Bulletin of the Korean Chemical Society
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• v.34 no.4
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• pp.1039-1042
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• 2013

Polyynes were prepared by liquid laser ablation of a graphite target in deionized water at various physical conditions such as laser power (20 and 40 mJ/pulse) and ablation wavelengths (355, 532, and 1064 nm). The effects of physical parameters on the linear carbon chain length were examined by analyzing the densities of polyynes with different carbon numbers ($C_6H_2$, $C_8H_2$, and $C_{10}H_2$) as well as their branching ratios. We concluded the photophysical processes turned out to play a more significant role than thermal ones in the formation of polyynes.

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.597-600
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• 2012

Polyynes were formed by laser ablation of a graphite target in deionized water ($H_2O$ and $D_2O$) and various organic solvents such as acetonitrile, n-hexane, and c-hexane and were identified by analyzing ultraviolet (UV) absorption and Raman spectra. We assigned the major UV absorption peaks that coincided with the electronic transitions corresponding to linear polyyne chains. The UV absorption peak intensities of a polyyne solution decreased as the holding temperature of the solution increased. Also, the absorption spectra of polyynes obtained by laser ablation of a graphite target at different volume fractions of $H_2O$ and $D_2O$ were examined.

• Bulletin of the Korean Chemical Society
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• v.30 no.12
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• pp.3073-3074
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• 2009

• Bulletin of the Korean Chemical Society
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• v.7 no.5
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• pp.357-362
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• 1986

Several aryl substituted 1,3,5-hexatriynes were synthesized by the use of aryl containing trimethylsilylated 1,3-butadiyne intermediates. 1-Phenyl-1,3,5-heptatriyne, one of the naturally occurring phototoxic conjugated polyacetylenes, and 1-(1'-naphthyl)-1,3,5-heptatriyne were prepared by the use of 1-trimethylsilyl-1,3-pentadiyne which is a very stable precursor for the 1,3-pentadiyne at room temperature.

• Bulletin of the Korean Chemical Society
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• v.24 no.6
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• pp.780-784
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• 2003

The collective electronic oscillator (CEO) method was developed by Mukamel and collaborators.[Phys. Rev. Lett. 1992, 69, 65; Science 1997, 277, 781] Recently Ⅰ have extended the CEO method to obtain the frequency dependent optical properties with all the contributing components. The brief introduction of the CEO fomalism and its recent applications to linear absorption and two-photon absorption (TPA) of conjugated organic molecules will be discussed. The size scaling of optical properties of polyenes and polyynes have studied by ab initio calculations, and this result is consistent with the coherence length of the time dependent densities to first ($ρ^(1)$) and second order ($ρ^(2)$) in the electric field obtained from the CEO method.

• Korean Journal of Pharmacognosy
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• v.20 no.2
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• pp.71-75
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• 1989

A new polyyne, panaxyne, was isolated from the Korean red ginseng. The structure was determined as tetradeca-13-ene-1, 3-diyne-6, 7-diol by comparison of spectral data. The $ED_{50}\;value$ of panaxyne as cytotoxicity against L1210 cell was $11.0\;{\mu}g/ml$. The lower cytotoxic activity of the substance relative to other ginseng polyynes is presumably due to lack of the essential structural part of hept-1-en-4, 6-diyne-3-ol.

• Bulletin of the Korean Chemical Society
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• v.6 no.3
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• pp.153-157
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• 1985

A diacetylene compound, 1,4-diphenyl-1,3-butadiyne, was photolyzed with 2,3-dimethyl-2-butene, 1,4-cyclohexadiene, dimethyl fumarate, and methyl crotonate, as a model reaction of the phototoxic conjugated polyynes with DNA or RNA and [2 + 2] photocycloadducts were obtained except for 1,4-cyclohexadiene. In the photoreaction of 1,4-diphenyl-1,3-butadiyne with 2,3-dimethyl-2-butene, a [2 + 2 + 2] photoadduct was additionally obtained. The photolysis of 1,4-di-t-buyl-1,3-butadiyne with 2,3-dimethyl-2-butene also yielded a [2 + 2] photoadduct. Fluorescence was observed from all the photoadducts while the reactants did not show any fluorescence.

• Proceedings of the Ginseng society Conference
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• 1988.08a
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• pp.19-24
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• 1988

We have isolated two new cytotoxic polyynes against $L_{1210}$ cell from the root of Panax ginseng. namely acetylpanaxydol and panaxydolchorhydrin. The epoxy group in C-9 and the heptyl group on C-10 of the panaxydol-analogues potentiate the activity. Panaxydol has cis-configuration in epoxy group. There is no diffrernce in activity between cis-. trans- and cis/trans-configurational isomers. The essential structure for the cytotoxicity of panaxydol and its isomers is hept-l-en-4.6-diyn-3-ol.