• Rapid Communication in Photoscience
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• v.3 no.1
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• pp.1-15
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• 2014

We summarize recent studies on photoinduced electron- and energy-transfer processes of various supramolecules including imide group(s) as a component. Recently, imides have been employed in various functional molecular systems, because of their excellent photophysical and electron accepting properties. Our research group also employed imides in various supramolecular systems such as donor-acceptor dyads, quantum dots, DNA, and so on. First, we summarize fundamental properties of imides such as photophysical and electrochemical properties. Then, photoinduced processes of imides in the supramolecular systems are described to show their applicability in the various fields.

• 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.

• Applied Biological Chemistry
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• v.20 no.1
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• pp.10-25
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• 1977

The photobiological receptors of phototactic, phototropic, and photomorphogenic responses of various organisms have been described in terms of spectroscopic, photophysical and photochemical properties which may be relevant in elucidating the energy transduct ion mechanism(s) in photobiology. The photoreceptors discussed include carotenoids, flavins, stentorin and phytochrome. Although the molecular modes of their photobiological action still remain largely unexplained, it is possible to suggest several primary molecul ar processes of the photoreceptors in eliciting responses of various organisms to light.

• Bulletin of the Korean Chemical Society
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• v.28 no.11
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• pp.1967-1972
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• 2007

Photophysical properties of a newly-synthesized porphyrin derivative, trans-bis(ferrocene carboxylato)- (5,10,15,20-tetraphenylporphyrinato)tin(IV) [Sn(TPP)(FcCOO)2] were investigated by means of steady-state and fs-time resolved laser spectroscopic techniques, and compared with those of a standard molecule, trans-dichloro( 5,10,15,20-tetraphenyl-porphrinato)tin(IV) [Sn(TPP)Cl2]. The fluorescence spectrum of Sn(TPP)- (FcCOO)2 was observed to exhibit dual emission bands originating from the S2-state and the S1-state, which was greatly quenched as compared to those of Sn(TPP)Cl2. The fs-time resolved fluorescence and transient absorption spectroscopic measurements revealed that the fluorescence quenching is due to formation of the long-lived charge transfer state by intramolecular electron transfer from ferrocene to the S2-excited SnTPP in addition to the enhanced non-radiative deactivation processes.

• Bulletin of the Korean Chemical Society
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• v.35 no.3
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• pp.758-764
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• 2014

Femtosecond vibrational spectroscopy was used to measure the vibrational population relaxation time ($T_1$) of different anions bound to ferric myoglobin ($Mb^{III}$) and hemoglobin ($Hb_{III}$) in $D_2O$ at 293 K. The $T_1$ values of the anti-symmetric stretching (${\nu}_1$) mode of NCS in the $NCS^-$ bound to $Mb^{III}$ ($Mb^{III}$NCS) and $Hb_{III}$ ($Hb_{III}$NCS) in $D_2O$ are $7.2{\pm}0.2$ and $6.6{\pm}0.2$ ps, respectively, which are smaller than that of free NCS. in $D_2O$ (18.3 ps). The $T_1$ values of the ${\nu}_1$ mode of NCO in the $NCO^-$ bound to $Mb^{III}$ ($Mb^{III}$NCO) and $Hb_{III}$ ($Hb_{III}$NCO) in $D_2O$ are $2.4{\pm}0.2$ and $2.6{\pm}0.2$ ps, respectively, which are larger than that of free $NCO^-$ in $D_2O$ ($1.9{\pm}0.2$ ps). The smaller $T_1$ values of the ${\nu}_1$ mode of the heme-bound NCS suggest that intramolecular vibrational relaxation (VR) is the dominant relaxation pathway for the excess vibrational energy. On the other hand, the longer $T_1$ values of the ${\nu}_1$ mode of the heme-bound NCO suggest that intermolecular VR is the dominant relaxation pathway for the excess vibrational energy in the ${\nu}_1$ mode of $NCO^-$ in $D_2O$, and that intramolecular VR becomes more important in the vibrational energy dissipation of the ${\nu}_1$ mode of NCO in $Mb^{III}$NCO and $Hb_{III}$NCO.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2010.03a
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• pp.40-40
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• 2010

Studies on attractive color changing property of dye chromophore and fluorophore have been greatly enjoyed in the related industrial and research fields such as optoelectronics, chemosensor, biosensor and so on. The optical property based on D-$\Pi$-A intramolecular charge transfer (ICT) system of chromophore molecules can be utilized as suitable sensing probes for checking media polarity and determining colorimetric chemosensing effect, especially heavy metal detection. These finding are obtained by absorption and emission properties. In this work, donor-acceptor D-$\Pi$-A type fluorescent dyes were designed and synthesized with the corresponding donor and acceptor groups. The selected donor moieties might be provided prominent amorphous properties which are very useful in designing and synthesizing functional polymers and in fabricating devices. Another reasons to choose are commercial availabilities in high purity and low price. Donor-bridge-acceptor (D-A) type dyes can produce impressive optical-physical properties, yielding them potentially suitable for applications in the synthesis of small functional organic molecules. Small organic functional molecules have unique advantages, such as better solubility, amorphous character, and represent an area of research which needs to be explored and developed. Currently, their applications in metalorganic compounds is rapidly expanding and becoming widespread in self-assembly processes, photoluminescence applications, chiral organocatalysts, and ingrafts with nanomaterials. Colloidal nanoparticles have received great attentions in recent years. The photophysical properties of nanoparticles, particularly in terms of brightness, photostability, emission color purity and broad adsorption range, are very attractive functions in many applications. To our knowledge background, colloidal nanoparticles have been enjoyed their applications in bio-probe research fields. This research interest can be raised by the advantages of the materials such as high photoluminescence quantum yields, sharp emission band, long-term photostability and broad excitation spectra. In recent, the uses of nanoparticles being embedded in a polymer matrix and binded on polymer surface have been explored and their properties such as photo-activation and strong photoluminescence have been proposed. The prepared chromophores and nanoparticles were investigated with absorption and emission properties, solvatochromic behaviors, pH induced color switching effects, chemosensing effects and HOMO/LUMO energy potentials with computer simulation. In addition, synthesized fluorophore dyes and particles were applied onto PE/Aramid fiber fluorescing colorations. And the related details were then discussed.