• Title/Summary/Keyword: viologen

Search Result 139, Processing Time 0.023 seconds

A study of the High Sensitive Nonsilver Halide Imaging Material( I ) - Purification of CuPc pigment by a train sublimation technique and preparation of CuPc pigment thin films and it's application for electrophotoconductor - (고감도 비은염 화상재료 개발연구( I ) - CuPc안료의 승화정제 및 전해석출법에 의한 CuPc 박막의 제작과 전자사진감광체에의 응용)

  • 이상남
    • Journal of the Korean Graphic Arts Communication Society
    • /
    • v.8 no.1
    • /
    • pp.53-70
    • /
    • 1990
  • It is well known that viologens such as 1.1 - disubstituted 4, 4` - bipyridinium salts and those used as redox indicator, herbicide and electrocheromic display device because those possess the lowest redox potential in any organic system. Viologen salts produced reversible high blue color under the influence of radical cation by photoreduction This study is related to the synthesis of viologen derivatives and the photoreduction property in water solution stats and the polar aprotic polyvinylpyrrolidone(PVP) matrix.

  • PDF

Photoinduced Electron Transfer in Molecular Photodiode Consisted of Flavin-Viologen Hetero-LB Films (Flavin-Viologen 복합 LB막으로 구성된 분자광다이오드에서의 광유도 전자전달)

  • 김민진;최정우;정성욱;오세용;이원흥;신동명
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 1995.11a
    • /
    • pp.281-284
    • /
    • 1995
  • A molecular photodiode was fabricated with hetero-Langmuir-Blodgett (LB) film consisting of an electron accepter(A) and sensitizer. N-Allyl-N-[3-propylamido-N\",N\"-야(n-octadecyl)]-4,4-bipyridum Dibromide and 7,8-dimethyl-10-dodecyl isoalloxan-zine were used as A and S units, respectively. By aligning hefter-LB film of A/S units on ITO glass with an aluminium thin film, a molecular photodiode with the structure of Metal/Insulator/Metal(MIM) was constructed. Due to excitation by irradiation with a 460nm monochromatic light source, the photo-induced unidirectional flow of electrons in the MIM device could be achieved and was detected as photocurrents. The direction of energy flow was in accordance with the energy level profile across the LB films. The photo switching function was achieved and the rectifying characteristics was obserbed in the molecular devise.

  • PDF

Synthesis of the photochromic and electrochromic dyes and their sensible properties (I) - Dyeing application with photochromic moiety to the fiber substrate- (광변색성 및 전기변색성 색소의 합성 및 특성(I) -광변색성 특성의 섬유소재에의 응용-)

  • Son Young-A;Park Young-Min;Kim Byung-Soon;Kim Sung-Hoon
    • Textile Coloration and Finishing
    • /
    • v.18 no.2 s.87
    • /
    • pp.24-30
    • /
    • 2006
  • The photosensitive spiroxazine compound and the electrosensitive viologen compound were prepared to examine their practical application feasibilities and behaviors. These dyes represent corresponding chromism effects related to their own characteristics of the dye molecules. Thus, the prepared dyes were characterized and their absorption spectra were also investigated. Besides, an interest on direct spiroxazine exhaustion to the polyamide substrates and its photochromic effects within the fiber molecules were determined. The photochromic reaction on the substrates was clearly observed and its reversible decoloration behaviors responded.

Resistance of SOD2-transgenic petunia line to oxidative stress

  • Lee, Su-Young;Han, Bong-Hee;Kim, Yeong-Tae;Kim, Jin-Seog
    • Journal of Plant Biotechnology
    • /
    • v.37 no.4
    • /
    • pp.562-566
    • /
    • 2010
  • SOD2-transgenic $T_3$ petunia line (A2-36-2-1-1-35) was treated with different levels of methyl viologen (MV) to determine its resistance to oxidative stress. Four (4) levels of MV (0, 100, 200, and $400\;{\mu}M$) were applied. The SOD2-transgenic $T_3$ petunia line exhibited a very significant oxidative stress resistance at the highest MV concentration ($400\;{\mu}M$) treatment compared to non-transgenic plant. RNA and protein expression of SOD2 transgene and higher parenchyma cell density in the transgenic petunias exhibiting resistance to oxidative stress proves its contribution to the expression of its resistance to oxidative stress.

A Spontaneous Growth of a Diaphorase Enzyme Layer over a Gold Electrode for the Catalytic Reduction of $NAD^+$

  • Kim, So Hyeong;Yun, Se Ok;Gang, Chan
    • Bulletin of the Korean Chemical Society
    • /
    • v.22 no.11
    • /
    • pp.1192-1196
    • /
    • 2001
  • A diaphorase enzyme electrode for the catalytic reduction of NAD+ , the oxidized form of nicotinamide adenine dinucleotide, has been prepared. The enzyme layer grew spontaneously over an aminoethanethiol self assembled monolayer on a go ld plate electrode. The growth was accomplished by simply dipping the electrode covered by the aminoethanethiol monolayer into a solution containing both glutaraldehyde and diaphorase. We suggested that the glutaraldehyde as a cross-linking reagent was attached to the amino groups of the aminoethanethiol monolayer and the diaphorase enzyme molecules were bound to free aldehyde groups of the glutaraldehyde. Further attachments of the enzyme molecules over the bound enzyme molecules continued with the bridging of the glutaraldehyde. In frequency measurements with a quartz crystal microbalance, the frequency decrease was much more than it was for that of the enzyme monolayer formation, and an enzyme layer thicker than a monolayer was formed. The modified electrode was employed to reduce NAD+ , using diffusional methyl viologen as an electron transfer mediator. The NAD+ was electrocatalytically reduced, and the catalytic current was almost equivalent to that with the multilayered electrode of ten enzyme layers.

Electrocatalytic Reduction of Dioxygen at Glassy Carbon Electrodes with Irreversible Self-assembly of N-hexadecyl-N'-methyl Viologen

  • Lee, Chi-Woo;Jang, Jai-Man
    • Bulletin of the Korean Chemical Society
    • /
    • v.15 no.7
    • /
    • pp.563-567
    • /
    • 1994
  • The electroreduction of dioxygen at glassy carbon electrodes with irreversible self-assembly of N-hexadecyl-N'-methyl viologen $(C_{16}VC_1)$ proceeds at potentials more positive than those where the reduction occurs at bare electrodes. The electrocatalyzed reduction takes place at potentials well ahead of those where the catalyst is reduced in the absence of dioxygen and the limiting currents observed at rotating disk electrodes did not deviate from the thoretical Levich line up to 6400 rpm, indicating that the electrocatalysis is extremely rapid. The rate constant for the heterogeneous reaction between $C_{16}V^+C_1$ immobilized on the electrode surface and $O_2$ in solution was estimated to be ca. $10^8\;M^{-1}s^{-1}$. The half-wave potential of dioxygen reduction was independent of solution pH.

Association of Methyl Viologen and Its Cationic Radical with Sodium Dodecyl Sulfate

  • Park, Joon-Woo;Nam, Hye-L.
    • Bulletin of the Korean Chemical Society
    • /
    • v.5 no.5
    • /
    • pp.182-187
    • /
    • 1984
  • The polarographic and conductometric studies of methyl viologen $(MV^{++})$ solutions with varying concentration of sodium dodecyl sulfate (SDS) showed strong association of $MV^{++}$ and its cationic radical, $MV^+$., with SDS below the critical micelle concentration. The stoichiometries of these associations were found to be their electric charge ratios. Both electrostatic and hydrophobic interactions were found to contribute to the associations. The formation constant of$MV^+.DS^-$ in 0.1 M NaCl was $7{\times}10^3M$. The $MV^{++}$-SDS association was observed to be cooperative leading to formation of large aggregates. In the presence of $MV^{++}$, the micellization of SDS was formation of SDS homo-micelle without direct involvement of $MV^{++}$.