• Bulletin of the Korean Chemical Society
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• v.31 no.1
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• pp.104-111
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• 2010

The heterogeneous electron transfer at $SiMo_{12}O_{40}^{4-}$ monolayers on GC, HOPG, and Au electrode surfaces are investigated using cyclic voltammetric and electrochemical impedance spectroscopic (EIS) methods. The electron transfer of negatively charged $Fe(CN)_6^{3-}$ species is retarded at $SiMo_{12}O_{40}^{4-}$-modified electrode surfaces, while that of positively charged $Ru(NH_3)_6^{3+}$species is accelerated at the modified surfaces. This is due to the electrostatic interactions between $SiMo_{12}O_{40}^{4-}$ layers on surfaces and charged redox species. The electron transfer kinetics of a neutral redox species, 1,1‘-ferrocenedimethanol (FDM), is not affected by the modification of electrode surfaces with $SiMo_{12}O_{40}^{4-}$, indicating the $SiMo_{12}O_{40}^{4-}$ monolayers do not impart barriers to electron transfer of neutral redox species. This is different from the case of thiolate SAMs which always add barriers to electron transfer. The effect of $SiMo_{12}O_{40}^{4-}$ layers on the electron transfer of charged redox species is dependent on the kind of electrodes, where HOPG surfaces exhibit marked effects. Possible mechanisms responsible for different electron transfer behaviors at $SiMo_{12}O_{40}^{4-}$ layers are proposed.

• Journal of the Korean Chemical Society
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• v.11 no.4
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• pp.126-131
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• 1967

Various amines (Triethylamine, Diethylamine, Dimethylaniline, Pyridine and Diphenylamine) and electron acceptors (Carbontetrachloride, iodine monochloride and iodine) were reacted in the hexane solvent system to form a charge transfer complex in each case. The tendency of forming a charge transfer complex by these electron acceptors was proportional to the basicity of amines and the different type of complex was formed as the polarity of electron donor had markedly changed, which were identified by ultraviolet spectrophotometry. A correlation between the formation of complex and the basicity of amine and the polarity of electron acceptor was discussed.

• Journal of Photoscience
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• v.10 no.1
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• pp.61-69
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• 2003

Mechanistic as well as synthetic aspects of the photoinduced electron transfer reactions of epoxy ketones, bromomethyl-substituted benzocyclic ketones, and tribromomethyl-substituted cyclohexadienones with amines are described.

• Rapid Communication in Photoscience
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• v.4 no.3
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• pp.59-62
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• 2015

We investigated photo-induced electron transfer (PET) in a dye-labeled peptide, fluorophore-Ala-Gly-Gln-Tyr, employing time-resolved fluorescence. As an effort to develop new functional dyes, we studied an acriflavine derivative for the electron-acceptor in the excited state from tyrosine, an electrondonor in the ground-state. The pH dependence of the fluorescence lifetime of the model peptide indicates that electron transfer between the excited dye and tyrosine occurs when the tyrosine is deprotonated. The proton-coupled electron transfer appears to be sequential rather than concerted. We also report direct time measurements on the end-to-end loop formation processes of the peptide in water.

• Journal of Photoscience
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• v.10 no.1
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• pp.105-119
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• 2003

Fullerenes, $C_{60}$ and $C_{70}$, display interesting physicochemical properties in solutions, especially due to their unique chemical structures and their good electron accepting abilities. Solubility of fullerenes in different organic solvents and their unusual solvatochromic behavior, the ability of the fullerenes to form aggregates in solutions, and their electron transfer and charge transfer interactions with variety of electron donors, are the subjects of extensive research activities for more than one decade. Many research groups including ours have contributed substantially in the understanding of the solvatochromism, aggregation behavior, and the photoinduced electron transfer and charge transfer chemistry of fullerenes, in condensed phase. Present article is aimed to summarize the important results reported on the above aspects of fullerenes, subsequent to the earlier report from our group (D.K. Palit and J.P. Mittal, Full. Sci. & Tech. 3, 1995, 643-659).)., 643-659)..

• Bulletin of the Korean Chemical Society
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• v.13 no.4
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• pp.385-388
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• 1992

The transition probabilities for the thermal intramolecular electron transfer and the optical intervalence transfer band for a symmetric mixed-valence Cu(I)-Cu(II) compound were used to extract the PKS parameters $\varepsilon$ = -1.15, ${\lambda}$ = 2.839, and ${\nu}g$- = 923 $cm^{-1}$. These parameters determine the potential energy surfaces and vibronic energy levels. Three pairs of vibrational levels are below the top of the energy barrier in the lower potential surface. The contribution of each vibrational state to the intramolecular electron transfer was calculated. It is shown that the three pairs of vibrational states below the top of the barrier are responsible for most of the electron transfer at 261-306 K. So the intramolecular electron transfer in this system is a tunneling process. The transition probability exhibits the usual high-temperature Arrhenius behavior, but at lower temperature falls off to a temperature-independent value as tunneling from the lowest levels becomes the limiting process.

• Journal of Photoscience
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• v.3 no.3
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• pp.147-151
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• 1996

Dynamics of contact ion-pair between 1, 2, 4, 5-tetracyanobenzene anion and cation of biphenyl derivatives was investigated on the picosecond time scale. Solvent effect on the electron transfer was observed and electron transfer rates were examined using Marcus equation which contains distance dependence of the electron transfer rate in the frequency factor, along with the consideration of molecular shape. From the discussion based on disk model for molecular shape, contribution of interring torsional motion of biphenyl to the inner-sphere reorganization energy is strongly suggested, which leads to the physical explanation for the observed solvent effect on the rate of electron transfer.

• The Journal of the Acoustical Society of Korea
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• v.1 no.1
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• pp.92-96
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• 1982

In this paper, the interaction of electron and phonon in metals is expressed using Hamiltonian operator as follows. By excahnging phonon energy with in the vicinity of isotropical Fermi surface and using following electron and hole operators. We obtain the interaction of electron and phonon. And new Feynman Graphs are tried with the following conditions on. First, when state transfer state, phonon cannot be created. Second, when state transfer state, phonon cannot be destroyed. Third, when state transfer state, phonon can be created or destroyed. Fourth, when state transfer state, phonon can be created or destroyed.

• Bulletin of the Korean Chemical Society
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• v.25 no.6
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• pp.937-940
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• 2004

• Bulletin of the Korean Chemical Society
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• v.28 no.10
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• pp.1683-1688
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• 2007

This paper presents a novel simple method for introducing gold nanoparticles in a poly(4-vinylpyridine) (PVP) polymer layer over a glassy carbon (GC) electrode with the aim of forming a tunable electrochemical interface against a cationic ruthenium complex. Initially, AuCl4 ? ions were spontaneously incorporated into a polymer layer containing positively charged pyridine rings in an acidic media by ion exchange. A negative potential was then applied to electrochemically reduce the incorporated AuCl4 ? ions to gold nanoparticles, which was confirmed by the FE-SEM images. The PVP layer with an appropriate thickness over the electrode blocked electron transfer between the electrode and the solution phase for the redox reactions of the cationic Ru(NH3)6 2+ ions. However, the introduction of gold nanoparticles into the polymer layer recovered the electron transfer. In addition, the electron transfer rate between the two phases could be tuned by controlling the number density of gold nanoparticles.