• Bulletin of the Korean Chemical Society
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• v.6 no.3
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• pp.145-148
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• 1985

The effect of anionic polyelectrolytes, poly(styrenesulfonate) (PSS) and poly(vinylsulfonate) (PVS), on the charge transfer complexing between indole derivatives and methyl viologen($MV^{++}$) cation was investigated. The results were compared with effect of NaCl and an anionic surfactant, sodium dodecylsulfate (SDS). Both PSS and PVS enhanced the complex formation of neutral species (indole and indole acetate at low pH), zwitter ionic tryptophan, and positively charged tryptamine and tryptophan at low pH with $MV^{++}$. This result was attributed to the contribution of hydrophobic interaction, in addition to electrostatic interaction. The enhancing effect of PSS was much higher than that of PVS reflecting the higher hydrophobicity of PSS. The interaction between indole acetate anion and $MV^{++}$ was greatly reduced by addition of PVS and PSS. The higher charge density of PVS was appeared as greater reducing effect indicating the importance of electrostatic force in this case. In all cases, the effect of polyelectrolytes showed maxima, and further addition of PVS and PSS decreased the effect. This behavior was explained in terms of distribution of indole derivatives and $MV^{++}$ in domain of polyanions. The complex formation constants and molar absorptivities of complexes were determined, and the values were compared with those in water and SDS solutions.

• Bulletin of the Korean Chemical Society
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• v.18 no.6
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• pp.567-573
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• 1997

Photoinduced electron transfer from the charge-transfer excited states of Ru(tpy)(bpy(COOH)₂)$CN^+$, Ru(tpy)(bpy(COOH)₂)$Cl^+$, Ru(tpy)(bpy(COOH)₂)H₂+O², and Ru(tpy)(bqu(COOH)₂)$Cl^+$ to the conduction band of TiO₂ has been studied through photoelectrochemical methods. Ru(tpy)(bpy(COOH)₂)$CN^+$ produced the highest current density and open-circuit photovoltage, whereas Ru(tpy)(bqy(COOH)₂)$Cl^+$ produced the lowest values. A potential barrier was employed to explain the experimental result that the rate of the electron transfer increases with increasing the energy difference between the donor and acceptor. A sensitizer with a high current density yielded a high photovoltage and a high conversion efficiency. The reduction rate of the oxidized sensitizer decreased with the increases in the reduction potential of the sensitizer, resulting in a poor stability of a photoelectrochemical cell.

• Journal of the Korean Chemical Society
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• v.34 no.6
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• pp.593-599
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• 1990

A series of new, square planar, and mixed-ligand complexes of Ni(Ⅱ), Pd(Ⅱ), and Pt(Ⅱ) have been prepared. From the observation of electronic spectrum for the variation of the ligand substituents, the very intense absorption band in the visible range is by the electronic transition of dithiolene to diimine ligand, HOMO to LUMO. In the various solvent systems the IT band shows the similar behavior to IT transition of mixed-valence dinuclear complexes followed with Hush theory, happens rto dominently by the inner sphere charge transfer transition. The negative solvatochromism represents that the excited-state electric dipole is reduced or reversed by the electronic transition.

• Bulletin of the Korean Chemical Society
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• v.30 no.12
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• pp.3109-3112
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• 2009

• Bulletin of the Korean Chemical Society
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• v.1 no.2
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• pp.71-73
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• 1980

The electronic structure of photo-skinsensitizing psoralens has been investigated by the FMO method. On the basis of theoretical calculations, optimum value of indices (Ft=0.33) has been proposed which corresponds to the sum of frontier electron density. The results indicate that this index is closely correlated with photo-skinsensitizing carcinogenic activity. The formations of molecular complexes between DNA and photo-skinsensitizing carcinogens is discussed in terms of charge transfer interactions.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.346-349
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• 2009

We investigated the doping effects of $ReO_3$ in different p-type organic semiconductors on the formation of charge transfer complexes and the electrical conductivity by comparing the absorption in ultraviolet-visible-nearinfrared (UV-Vis-NIR) and the current density-voltage characteristics of the hole only devices, respectively. The large energy difference between the HOMO level of host and Fermi energy level of dopant (${\Delta}E$=$E_{HOHO,host}$ - $E_{F,dopant}$) gives higher concentration of CT complexes and enhanced conductivity.

• Bulletin of the Korean Chemical Society
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• v.16 no.3
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• pp.205-210
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• 1995

Catalytic effects of various Schiff base metal(II) complexes on the reduction of thionyl chloride at glassy carbon electrode are evaluated by determining the kinetic parameters from cyclic voltammetry technique. The charge transfer process is affected strongly by the concentration of catalysts during the reduction of thionyl chloride. The catalytic effects are shown by both a shift of the reduction potential for thionyl chloride toward more positive direction and an increase in peak current. The diffusion coefficient value, Do, of the 8.17 ${\times}$ 10-9 $cm^2/s$ was observed at the bare glassy carbon electrode, whereas larger values (0.9-1.09 ${\times}$ 10-8 $cm^2/s$) were observed at the catalyst supported glassy carbon electrode. Significant improvements in the cell performance have been noted in terms of both exchange rate constants and current densities at glassy carbon electrode.

• Journal of the Korean Chemical Society
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• v.29 no.3
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• pp.257-264
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• 1985

Dioxobis(3-methoxysalicyaldehydato)molybdeum(VI) complex has been synthesized by reactions of 3-methoxysalicylaldehyde and ammonium paramolybdate in methanol solution. With appropriate primary amine, the resulting complex gave schiff-base complexes, MoO$_2$(CH$_3$O-sal-N-R)$_2$ in which C=O oxide ligands had been replaced by nitrogen. The properties and possible molecular structure of these complexes were discussed by elemental analysis, spectroscopic studies and electric conductivities measurements. It was found that the Mo(VI) complexes contain a cis-MoO$_2$ group since their infrared spectra two Mo=O band at about 900cm$^{-1}$ and the combining ratios for MoO$_2$-ligand are 1 : 2. Also, electronic spectra of molybdenyl complexes assigned to ligand-to-metal charge transfer transition. All of these complexes are yellow or orange, depolar compound and slightly soluble in alcohol, dichloromethane, chloroform and N,N-dimethylformamide.

• Journal of the Korean Graphic Arts Communication Society
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• v.22 no.1
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• pp.75-82
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• 2004

The photoluminescence and electroluminescence of poly(9-vinylcarbazole) (PVCz) containing different ratio 1.3,5-dimethly-3,5-di-tert-butyl-4,4-diphenoquinone (MBDQ), 1.3,5-diemthyl-3.5-di-tert-butyl-4,4-stylbenquinone (MBSQ) were characterized. As the contents of DQ and SQ increased, the intensity of peaks at 516 and 540nm increased in PL spectra. The results of TOF measurement were shown that the hole mobility of PVCz decreased as the ratio of DQ or SQ increased. On the other hand, the electron mobility of PVCz increased. Therefore Electron transport is more favorable than hole transport in these charge transfer complexes, due to the stronger localization of the holes. Evidence for better electron transport is the higher mobility of electrons in pure DQ or SQ compared to hole mobility in pure PVCz, and lower DQ or SQ concentration required for equivalent mobilities in the charge-transfer complexes.

• Journal of the Korean Chemical Society
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• v.36 no.1
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• pp.3-15
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• 1992

Electronic structures and reactivities of the chromium, molybdenum, and tungsten carbene complexes, $(CO)_5Cr=CCHCH_2(XCH_3)\;,\;(CO)_5Mo=CCHCH_2(XCH_3)\;, and\;(CO)_5W=CCHCH_2(XCH_3)$, are studied by means of Extended Huckel calculations. The origin of the M=Ccarbene double bond is clarified from the diagram of the orbital correlation with the fragment orbitals. The ${\sigma}$ bond of the M=Ccarbene double bond is formed by the electron transfer interaction from the HOMO of the carbene to the LUMO of the $(CO)_5M$. The ${\pi}$ bond is formed through the back-transfer of electrons from one of the degenerated d${\pi}$ orbitals to the LUMO of the carbene. The polarization of charge of the M=Ccarbene bond is calculated to be M=Ccarbene for Mo, and W carbenes. The chemical and physical properties of these complexes are resulted from an appreciable positive charge on the carbene carbon. The electrophilic reactivity of the carbene carbon is not charge controlled, but is controlled by the frontier orbital, LUMO.