• Bulletin of the Korean Chemical Society
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• v.19 no.12
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• pp.1337-1341
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• 1998

The charge transfer (CT) complex dyes between electron donor phenothiazine and electron acceptors namely, 2, 3-dichloro-1,4-naphtoquinone and 2,3-dichloro-5-nitro-1,4-naphtoquinone, were formed in the dichloromethane solution and electrochromic properties were studied using Bu4NC1O4 as supporting electrolyte. A 1 : 1 correspondence between the donor and acceptor molecules in the CT complex was found.

• Bulletin of the Korean Chemical Society
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• v.30 no.9
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• pp.1933-1938
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• 2009

New $\pi$-conjugated polymer with vinylene linkage, poly((10-hexyl-3,7-phenothiazine)-alt-(4-(4-butyl-phenyl)- 3,5-diphenyl-4H-[1,2,4]triazole)-3,5-vinylene) (PTV-TAZ) was synthesized by the Heck coupling reaction. The photoluminescence (PL) maximum wavelength and the band gap energy of PTV-TAZ film were 555 nm and 2.41 eV, respectively. The HOMO energy level of PTV-TAZ was -4.99 eV, which was slightly lower than that of PTV (-4.89 eV). Electron deficient aromatic 1,2,4-triazole (TAZ) in the polymer backbone does not affect the HOMO energy level significantly. The maximum efficiency and brightness of double layer structured electroluminescent (EL) device (ITO/PEDOT (30 nm)/PTV-TAZ (60 nm)/Al) were 0.247 cd/A and 553 cd/$m^2$, respectively, which were significantly higher than those of the device based PTV (1.65 ${\times}\;10^{-4}$ cd/A and 4.3 cd/$m^2$). This is due to that TAZ unit improves electron transporting ability in the emissive layer. The turn-on voltage (defined as the voltage required to give a luminescence of 1 cd/$m^2$) of brightness of the device based on PTV-TAZ was 12.0 V, which was similar to that the based on PTV (11.5 V). This is due to that the ionization potential of PTV-TAZ is very similar to that of PTV.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.585-587
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• 2004

We report the characterization of white light emitting devices fabricated using conjugated polymer blends. Blue emissive poly[9,9-bis(4'-n-octyloxyphenyl) fluorene-2,7-diyl-co-10-(2'-ethylhexyl)phenothiazine-3,7-diyl] [poly(BOPF-co-PTZ)] and red emissive poly(2-(2'-ethylhexyloxy)-5-methoxy-1,4-phenylenevinylene) (MEH-PPV) were employed in the blends. The inefficient energy transfer between these blue and red light emitting polymers (previously deduced from the PL spectra of the blend films) enables the production of white light emission through control of the blend ratio. The PL and EL emission spectra of the blend systems were found to vary with the blend ratio. The EL devices were fabricated in the ITO/PEDOT/blend/LiF/Al configuration and white light emission was obtained for one of the tested blend ratios.

• Journal of the Korean Magnetic Resonance Society
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• v.4 no.2
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• pp.82-90
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• 2000

Photoinduced charge separation of alkylphenothiazines in molecular assemblies such as positively, negatively and neutrally charged micelle interface results in the paramagnetic phenothiazine cation radical. This was studied as a model system for the light energy conversion into chemical energy. The photoproduced phenothaizne cation radical was identified and its amount was quantized with electron spin resonance (ESR). The microenvironment of photoproduced cation radical was studied with pulsed-ESR. Such a charge separation is enhanced by the optimization of various structural factors of the molecular assemblies. The structural factors of molecular assemblies have focused on the interface charge, interface structure with different headgroups and interfacial perturbation by disolving interface active organic additives.

• Journal of Information Display
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• v.2 no.4
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• pp.8-14
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• 2001

Three types of conjugated polymers, poly(PZ-Pi), poly(PZ-BPI) and poly(PZ-NPI) were synthesized by Schiff-base reaction. These new conjugated polymers exhibited improved solubility in common organic solvents due to the presence of alkyl side chains as well as azomethine groups, Double layer LEDs made with the synthesized polymers as emitting layer and $Alq_3$, as electron transporting layer exhibited enhanced EL emission and efficiency compared to those of single layer LEDs. Double layer LEDs exhibited gradual shift in the emission peak th the single layer LED, made of only $Alq_3$ as the emitting layer as the thickness of $Alq_3$ layer increased.

• Journal of Photoscience
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• v.12 no.1
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• pp.25-32
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• 2005

Binding of N-Alkyl phenothiazines (NAP) to bovine serum albumin (BSA) was studied by spectroscopic methods.It was found that the phenothiazine ring common to all drugs makes major contribution to interaction. However, the nature of alkylamino group at position 10 influences the protein binding significantly. Stern-Volmer plots indicated the presence of static component in the quenching mechanism. The high magnitude of rate constant of quenching indicated that the process of energy transfer occurs by intermolecular interaction and thus the drug-binding site is in close proximity to tryptophan residues of BSA. Binding studies in presence of hydrophobic probe, 8-anilino-1-naphthalein-sulphonic acid showed that there is hydrophobic interaction between drug and the probe and they do not share common sites in BSA. Thermodynamic parameters obtained from data at different temperatures showed that the binding of NAP to BSA predominantly involve hydrophobic forces. The effects of some cations and anions common ions were investigated on NAP-BSA interactions. The CD spectrum of BSA in presence of drug showedthat binding of drug leads to change in the helicity of the protein.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.117.2-117.2
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• 2011

Since Gratzel and co-workers developed a new type of solar cell based on the nanocrystalline TiO2 electrode, dye-sensitized solar cells (DSSCs) have attracted considerable attention on account of their high solar energy-to-conversion efficiencies (11%), their easy manufacturing process with low cost production compared to conventional p-n junction solar cells. The mechanism of DSSC is based on the injection of electrons from the photoexcited dye into the conduction band of nanocrystalline TiO2. The oxidized dye is reduced by the hole injection process from either the hole counter or electrolyte. Thus, the electronic structures, such as HOMO, LUMO, and HOMO-LUMO gap, of dye molecule in DSSC are deeply related to the electron transfer by photoexcitation and redox potential. To date, high performance and good stability of DSSC based on Ru-dyes as a photosensitizer had been widely addressed in the literatures. DSSC with Ru-bipyridyl complexes (N3 and N719), and the black ruthenium dye have achieved power conversion efficiencies up to 11.2% and 10.4%, respectively. However, the Ru-dyes are facing the problem of manufacturing costs and environmental issues. In order to obtain even cheaper photosensitizers for DSSC, metal-free organic photosensitizers are strongly desired. Metal-free organic dyes offer superior molar extinction coefficients, low cost, and a diversity of molecular structures, compared to conventional Ru-dyes. Recently, novel photosensitizers such as coumarin, merocyanine, cyanine, indoline, hemicyanine, triphenylamine, dialkylaniline, bis(dimethylfluorenyl)-aminophenyl, phenothiazine, tetrahydroquinoline, and carbazole based dyes have achieved solar-to-electrical power conversion efficiencies up to 5-9%. On the other hand, organic dye molecules have large ${\pi}$-conjugated planner structures which would bring out strong molecular stacking in their solid-state and poor solubility in their media. It was well known that the molecular stacking of organic dyes could reduce the electron transfer pathway in opto-electronic devices, significantly. In this paper, we have studied on synthesis and characterization of dendritic organic dyes with different number of electron acceptor/anchoring moieties in the end of dendrimer. The photovoltaic performances and the incident photon-to-current (IPCE) of these dyes were measured to evaluate the effects of the dendritic strucuture on the open-circuit voltage and the short-circuit current.

• The Korean Journal of Pharmacology
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• v.30 no.3
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• pp.343-349
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• 1994

A number of neurological syndromes(e.g. tardive dyskinesia) are developed as a consequence of chronic treatment with neuroleptics or antipsychotic agents. Despite the long and succesful use of phenothiazine derivatives and related agents in the treatment of certain states of mental disease, the mechanisms of these drugs are still poorly understood. One current hypothesis from extensive reviews is that these compounds might significantly interfere with the cyclic nucleotide system in brain (Levin and Weiss, 1977; Nowicki et al., 1991; Haley et al., 1992). Nitric oxide (NO), one of an interesting messenger molecule and aberrant transmitter, is believed to play a important role in biological functions of cyclic nucleotides in nervous system. It has been reported that calcium-dependent NO synthesis in endothelial cytosol is mediated by calmodulin which is supposed to be tightly related to pharmacological actions of antipsychotic agents. In the present study, the effect of several antipsychotic agents on the activity of NO synthesis and formation of cyclic GMP were investigated. These agents inhibited both the formation of $[^3H]L-citrulline$ and that of $[^3H]cyclic$ GMP by concentration-dependent manner, and their inhibiting patterns are so similar to that of calmodulin antagonist.

• YAKHAK HOEJI
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• v.38 no.6
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• pp.637-645
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• 1994

The effect of various drugs on the stability of the liposomal membrane of phosphatidylcholine and cholesterol was studied, employing the fluorescence self-quenching method. Calcein was entrapped into the phospholipid small unilamellar vesicles and the leakage of the fluorescence probe was monitored on adding the drug to the system. The results of the experiments showed that phenothiazine derivatives, some potent local anesthetics and surface active agents were very effective in inducing the leakage of calcein from the liposome. The leakage-inducing activity of these drug substances has been ascribed to their surface activity and the perturbation of the liposomal membrane by these substances. On the other hand drug substance with low surface activity or without amphiphilic moieties did not show any effect or only small effect on the leakage of calcein from the liposomes. The effect of lipid concentration on the stability of the liposomes was also investigated to show that the higher concentrations of lipid more drug was required to induce the leakage. The effect of surface charges of vesicles was also studied, and the results showed that the charge on the liposomes enhanced the stability of the liposomes against the leakage-inducing activity of these drug substances.

• Journal of Information Display
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• v.7 no.4
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• pp.9-12
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• 2006

This paper reports the synthesis and electroluminescent properties of new aromatic compounds as hole-transporting materials based on phenothiazine, such as 1,4-diphenothiazyl-benzene [DPtzB], 1,4-diphenothiazyl-xylene [DPtzX] and 9,10-diphenothiazyl-anthracene [DPtzA]. DPtzB thin film exhibited photoluminescence (PL) maximum emission peak and emission shoulder at 450 and 475 nm, and a maximum emission at 447 nm without emission shoulder was obtained in DPtzX thin film. When DPtzA was excited by incident light of 359 nm, DPtzA showed strong PL emission at 417 nm and weak emission at 600 nm. Luminance efficiency of DPtzB, DPtzX and DPtzA-based electroluminescence (EL) devices was 3.57, 3.46 and 0.47 cd/A, and power efficiency of DPtzB, DPtzX and DPtzA-based EL devices was 1.48, 1.26 and 0.201 m/W.