• Title/Summary/Keyword: single-atom

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Novel Naphthalene Based Lariat-Type Crown Ethers Using Direct Single Electron Transfer Photochemical Strategy

  • Park, Hea Jung;Sung, Nam Kyung;Kim, Su Rhan;Ahn, So Hyun;Yoon, Ung Chan;Cho, Dae Won;Mariano, Patrick S.
    • Bulletin of the Korean Chemical Society
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    • v.34 no.12
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    • pp.3681-3689
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    • 2013
  • This study explored a direct SET-photochemical strategy to construct a new family of thioene conjugated-naphthalamide fluorophore based lariat-crown ethers which show strong binding properties towards heavy metal ions. Irradiations of designed nitrogen branched (trimethylsilyl)methylthio-terminated polyethylenoxy-tethered naphthalimides in acidic methanol solutions have led to highly efficient photocyclization reactions to generate naphthalamide based lariat type thiadiazacrown ethers directly in chemo- and regio-selective manners which undergo very facile secondary dehydration reactions during separation processes to produce their corresponding amidoenethio ether cyclic products tethered with electron donating diethyleneoxy- and diethyenethio-side arm chains. Fluorescence and metal cation binding properties of the lariat type enamidothio products were examined. The photocyclized amidoenethio products, thioene conjugated naphthalamide fluorophore containing lariat-thiadiazacrowns exhibited strong fluorescence emissions in region of 330-450 nm along with intramolecular exciplex emissions in region of 450-560 nm with their maxima at 508 nm. Divalent cation $Hg^{2+}$ and $Pb^{2+}$ showed strong binding to sulfur atom(s) in side arm chain and atoms in enethiadiazacrown ether rings which led to significant enhancement of fluorescence from its chromophore singlet excited state and concomitant quenching of exciplex emission. The dual fluorescence emission responses towards divalent cations might provide a new guide for design and development of fluorescence sensors for detecting those metals.

A Study on the 4D Traffic Condition Board based on a Mash-up Technology (Mash-up 기술을 이용한 4D Wall-Map 구성체계)

  • Kim, Joo-Hwan;Yang, Seung-Mook;Nam, Doo-Hee
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.8 no.3
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    • pp.27-33
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    • 2009
  • Content used in mashups is typically obtained from a third party source through a public interface or API (web services). Other methods of obtaining content for mashups include Web feeds (e.g. RSS or Atom), and screen scraping. A mashup or meshup Web application has two parts: A new service delivered through a Web page, using its own data and data from other sources. The blended data, made available across the Web through an API or other protocols such as HlTP, RSS, REST, etc. There are many types of mashups, such as consumer mashups, data mashups, and Business Mashups. The most common mashup is the consumer mashup, which are aimed at the general public. Examples include Google Maps, iGuide, and RadioClouds. 4D Wall-map display is data mashups combine similar types of media and information from multiple sources into a single representation. This technology focus data into a single presentation and allow for collaborative action among ITS-related information sources.

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Crystal and Molecular Structure of Methyl 12-(3-bromophenyl)-9-[(4-methylbenzene)sulfonyl]-22-oxo-13,21-dioxa-9-azapentacyclo[12.8.0.02,11.03,8.015,20]docosa-1(14),3,5,7,15(20),16,18-heptaene-11-carboxylate

  • Kothandan, Gugan;Ganapathy, Jagadeesan;Damodharan, Kannan;Sanmargam, Aravindhan
    • Journal of Integrative Natural Science
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    • v.7 no.2
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    • pp.92-102
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    • 2014
  • The crystal structure of the title compounds with both coumarin and sulfonamide moieties were examined. These two groups have very special for their pharmaceutical and medicinal properties have been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the monoclinic space group C2/c with unit cell dimension a = 28.633(3) ${\AA}$, b= 9.3215(7) ${\AA}$ and c= 24.590(2) ${\AA}$ [alpha & gamma=$90^{\circ}$ beta= $115.976(3)^{\circ}$]. In the structure The S1 atom shows a distorted tetrahedral geometry, with O1-S1-O2 [119.74 $(2)^{\circ}$] and N1-S1-C5 [$105.57(1)^{\circ}$] angles deviating from ideal tetrahedral values are attributed to the Thrope-Ingold effect. The sum of bond angles around N1 ($316.2(1)^{\circ}$) indicates that N1 is in sp2 hybridization. The Pyridine ring adopts boat conformation and pyran rings adopt a sofa conformation. The carboxylate group of atoms were disordered over two positions with site occupancy factors 0.598 (9):0.402 (9). Crystal structure and packing is stabilized by $C-H{\ldots}O$ intra and inter molecular hydrogen bond interactions.

Properties of $CuInS_2$ thin film Solar Cell Fabricated by Electron beam Evaporator (전자빔 증착기로 제작한 태양전지용 $CuInS_2$ 박막특성)

  • Yang, Hyeon-Hun;Kim, Young-Jun;Jeong, Woon-Jo;Park, Joung-Yun;Park, Gye-Choon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.379-380
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    • 2005
  • Single phase $CuInS_2$ thin film with a highest diffraction peak (112) at a diffraction angle ($2\Theta$) of $27.7^{\circ}$ was well made by SEL method at annealing temperature of $250^{\circ}C$ and annealing hour of 60 min in vacuum of $10^{-3}$ Torr or in S ambience for an hour. And the peak of diffraction intensity at miller index (112) of $CuInS_2$ thin film annealed in S ambience was shown a little higher about 11 % than in only vacuum. Single phase $CuInS_2$ thin films were appeared from 0.85 to 1.26 of Cu/In composition ratio and sulfur composition ratios of $CuInS_2$ thin films fabricated in S ambience were all over 50 atom%. Also when $CuInS_2$ composition ratio was 1.03, $CuInS_2$ thin film with chalcopyrite structure had the highest XRD peak (112). The largest lattice constant of a and grain size of $CuInS_2$ thin film in S ambience was 5.63 ${\AA}$ and 1.2 ${\mu}m$ respectively. And the films in S ambience were all p-conduction type with resistivities of around $10^{-1}{\Omega}cm$.

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Synthesis and Reaction Chemistry of Some Ferrocene-Containing Chelate Ligands with Dirhodium Acetate: X-ray Crystal Structure of $(\eta^1-(S,R)-CPFA)_2Rh_2(OAc)_4$

  • Kim, Eun-Jin;Kim, Tae-Jeong
    • Bulletin of the Korean Chemical Society
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    • v.15 no.11
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    • pp.990-996
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    • 1994
  • New ferrocene-based chelate amines, $Fe[C_5H_4CH(Me)NMe_2]_2\;(3), \;Fe[C_5H-3(CH(Me)NMe_2)(PPh_2)-1,2]_2\;(4),\;(C_5H_5)Fe(C_5H_3(CH_2NMe_2)(CH(CN)NMe_2-1,2)\;(6),\;and\;(C_5H_5)Fe(C_5H_3(CH_2NMe_2)(CH(Me)NMe_2-1,2)$ (7) have been prepared. The reaction and the coordination chemistry of 4 and other related compounds (S,R)-(1-N,N-dimethylaminoethyl)-2-dicyclohexylphosphino)ferrocene (CPFA) and 1,1'-bis-(diphenylphosphino)ferrocene (BPPF) with $Rh_2(OAc)_4(MeOH)_2$ were investigated. The reaction of the chiral ligand (S,R)-CPFA forms a complex of the type (${\eta}^1$-(S,R)-CPFA-P)$_2Rh_2(OAc)_4$ (8) in which the ligand is coordinated to both rhodium centers in a monodentate fashion through phosphorus. In contrast, the bisphosphine analogues such as BPPF and 4 afford chelate complexes of the type (${\eta}^2-PP)Rh_2(OAc)_4$ (9 & 10) where both ligands act as a chelate bidentate to a single rhodium atom. All these complexes were characterized by microanalytical and spectroscopic techniques. In one case, the structure of 8 was determined by X-ray crystallography. Crystals are monoclinic, space group C2 (No. 5), with a=26.389 (3), b=12.942 (1), c=11.825 (1) A, ${\beta}$=111.22(1)$^{\circ}$, V=3964.7 (8) $A^3$, Z=4, and $D_{calc}$=1.58 g $cm^{-3}$. Two Rh(II) centers are bridged by four $AcO^-$ groups in the ${\eta}^1$ : ${\eta}^1$ mode across a Rh-Rh single bond, and octahedral coordination at Rh(1) and Rh(1') is completed by axially coordinating (S,R)-CPFA and a briding $AcO^-$, respectively.

Synthesis and Structural Characterization of Main Group 15 Organometallics R3M and R(Ph)2P(=N-Ar)(M = P, Sb, Bi; R = phenanthrenyl; Ar = 2,6-iPr2-C6H3)

  • Lee, Eun-Ji;Hong, Jin-Seok;Kim, Tae-Jeong;Kang, Young-Jin;Han, Eun-Me;Lee, Jae-Jung;Song, Ki-Hyung;Kim, Dong-Uk
    • Bulletin of the Korean Chemical Society
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    • v.26 no.12
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    • pp.1946-1952
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    • 2005
  • New group 15 organometallic compounds, M$(phenanthrenyl)_3$ (M = P (1), Sb (2), Bi (3)) have been prepared from the reactions of 9-phenanthrenyllithium with $MCl_3$. A reaction of 9-(diphenylphosphino)phenanthrene with 2,6-diisopropylphenyl azide led to the formation of (phenanthrenyl)${(Ph)}_2P$=N-(2,6-$^iPr_2C_6H_3$) (4). The crystal structures of 2 and 4 have been determined by single-crystal X-ray diffractions, both of which crystallize with two independent molecules in the asymmetric unit. Compound 2 shows a trigonal pyramidal geometry around the Sb atom with three phenanthrenyl groups being located in a screw-like fashion with an approximately $C_3$ symmetry. A significant amount of CH- -$\pi$ interaction exists between two independent molecules of 4. The phosphorus center possesses a distorted tetrahedral environment with P-N bond lengths of 1.557(3)$\AA$ (P(1) N) and 1.532(3)$\AA$ (P(2)-N), respectively, which are short enough to support a double bond character. One of the most intriguing structural features of 4 is an unusually diminished bond angle of C-N-P, attributable to the hydrogen bonding of N(1)-H(5A) [ca. 2.49$\AA$ between two adjacent molecules in crystal packing. The compounds 1-3 show purple emission both in solution and as films at room temperature with emission maxima ($\lambda_{max}$) at 349, 366, and 386 nm, respectively, attributable to the ligand centered $\pi$ $\rightarrow$ $\pi^\ast$ transition in phenanthrene contributed by the lone pair electrons of the Gp 15 elements. Yet the nature of luminescence observed with 4 differs in that it originates from $\pi$ (diisopropylbenzene)-$\pi^\ast$ (phenanthrene) transitions with the $\rho\pi$contribution from the nitrogen atom. The emission maximum of 4 is red-shifted ranging 350-450 nm due to the internal charge transfer from the phenanthrenyl ring to the N-arylamine group as deduced from the ab initio calculations.

Electrospray ionization tandem mass fragmentation pattern of camostat and its degradation product, 4-(4-guanidinobenzoyloxy)phenylacetic acid (Camostat 및 분해산물 4-(4-guanidinobenzoyloxy)phenylacetic acid의 전자분무 이온화 텐덤 질량 fragmentation 패턴)

  • Kwon, Soon-Ho;Shin, Hye-Jin;Park, Ji-Myeong;Lee, Kyoung-Ryul;Kim, Young-Jin;Lee, Sang-Hoo
    • Analytical Science and Technology
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    • v.24 no.2
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    • pp.78-84
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    • 2011
  • The fragmentation patterns of a serine protease inhibitor, camostat, and its degradation product, 4-(4-guanidinobenzoyloxy)phenylacetic acid (GBPA), were for the first time investigated by a triple quadrupole tandem mass spectrometry equipped with an electrospray source (ESI-MS/MS) in positive and/or negative ion mode under collision-induced dissociation (CID). The positive CID spectrum of camostat showed distinctly that the single bond (C-O) cleavage between carbonyl group and oxygen atom of the ester bonds of the compound favorably occurred and then the loss of N,N-dimethylcarbamoylmethyl group was more susceptible than that of guanidine moiety. In the positive ion CID spectrum of GBPA, the initial cleavage between the carbonyl group and oxygen atom of 4-guanidinobenzoyloxy group also occurred, yielding the most abundant fragment ion at m/z 145. On the other hand, the negative CID spectrum of GBPA characteristically showed the occurrence of the most abundant peak at m/z 226 resulting from the sequential neutral losses of $CO_2$ and HN=C=NH from the parent ion at m/z 312.

Synthesis and Crystal Structure of Yttria-Stabilized Zirconia (이트리아를 첨가한 저코니아의 합성과 결정구조)

  • Kim, Won-Sa;Suh, Il-Hwan;Bak, Ro-Hak;Kim, Moon-Jib;Kim, Huhn-Jun;Lee, Chang-Hee;Kim, Yong-Che;Seong, Baek-Seok;Lee, Jeong-Soo;Shim, Hae-Seop;Kim, Yi-Kyung;Lee, Jin-Ho
    • Journal of the Korean earth science society
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    • v.18 no.6
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    • pp.553-558
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    • 1997
  • Colorless and transparent cubic zirconia($Zr_{0.73}Y_{0.27}O_{1.87}$) crystal has been synthesized by the Bridgman-Stock-bager method(also called Skull melting method). $Y_2O_3$ is used as stabilizer. The crystal shows a vitreous luster with a slight oily appearance. Under a polarizing microscope, it shows isotropic nature with no appreciable anisotropism. Mohs hardness value is measured to be $8{\sim}8\frac{1}{2}$ and specific gravity 5.85. Under ultraviolet light it shows a faint white glow. The crystal structure of yttria stabilized zirconia was determined, using single crystal X-ray diffraction techniques to be a cubic symmetry, space group $Fm\overline{3}m({O^5}_h)$ with $a=5.1552(5){\AA}$, $V=136.99(5){\AA}^3$, Z=4, and R=0.0488 for 29 unique reflections. Each zirconium atom is at the center of eight oxygen atoms situated at the corners of a surrounding cube and each oxygen atom is at the center of a tetrahedron of zirconium atoms. So a coordination of 8:4 holds in the structure.

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Hydrothermal Gold mineralization of the trabong district, vietnam : Mineralogical and geochemical study (베트남 짜봉(Trabong) 지역의 열수 금 광화작용 : 광물 및 지화학적 연구)

  • 한진경
    • Economic and Environmental Geology
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    • v.32 no.2
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    • pp.129-139
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    • 1999
  • Hydrothermal gold deposits of the Trabong district in Vietnam occur as single-stage quartz $\pm$ calcite veins (0.3-1.2 m thick) which fill fault fractures in graphite-bearing gneiss and schist of the Chulai Complex and Kham Duc Formation of the Proterozoic age. Ore grades are 1.3 to 92.4 g/ton Au. Ore mineralogy is very simple, consisting mainly of pyrite with minor amounts of base-metal sulfides and electrum. Gold grains occur in two assemblages as follows: (1) early, Fe-rich (7.2-10.4 mole % FeS) sphalerite + electrum (50.4-64.3 atom % Au) assemblage occurring as inclusions in pyrite; (2) late, Fe-poor «4.7 mole % FeS) sphalerite + galena + electrum (47.6-81.7 atom % Au) assemblage occurring along fractures of pyrites. Based on fluid inclusion data and thermochemical considerations of ore mineral assemblages, ore minerals were formed at high temperatures (about $230^{\circ}C$ to $420^{\circ}C$) from $H_{2}O-CO_{2}(-CH_{4})$-NaCI fluids with the sulfur fugacity of about $10^{-6}$ to $10^{-10}$ atm. Fluid inclusion data also indicate that ore mineralization occurred mainly as a result of fluid unmixing accompanying $CO_2$ effervescence. Calculated oxygen and measured hydrogen isotope compositions of mineralizing waters (${\delta}^{18}O_{V-SMOW}$ values = 5.3 to 8.6$\textperthousand$, ${\delta}D_{V-SMOW}$ values = - 60 to - 52$\textperthousand$), along with the sulfur isotope compositions of vein sulfides (${\delta}^{34}S_{CDR}$ values = - 1.2 to 2.8$\textperthousand$) and carbon isotope compositions of inclusion $CO_2$ (${\delta}^{13}C_{PDB}$ values = - 4.7 to - 2.0$\textperthousand$) indicate that the high temperature (mesohypothermal) gold mineralization formed from a magmatic fluid.

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Isolation and Identification of Antimicrobial Compounds against Helicobacter pylori from Rosemary (Rosmarinus officinalis L.) Extracts (로즈마리(Rosmarinus officinalis L.) 추출물로부터 Helicobacter pylori에 대한 항균물질 분리 및 동정)

  • Yoon, So-Jung;Kim, Jin-Sung;Jo, Bun-Sung;Kim, Jeung-Hoan;Lee, Sun-Ho;Ahn, Bong-Jeun;Cho, Young-Je
    • Journal of Applied Biological Chemistry
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    • v.54 no.3
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    • pp.159-165
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    • 2011
  • Rosmarinus officinalis extracts had a significant antimicrobial activity against Helicobacter pyori. Total phenolic contents and inhibition zone of rosemary extracts were estimated to be 25.7 mg/g and 14 mm at $200{\mu}g/mL$ of phenolic contents, respectively. The Sephadex LH-20 and MCI-gel CHP-20 column chromatographic separations for the phenolic extracts from R. officinalis leaves led to isolation of five acids, whose structures were determined as protocatechuic acid (A), coumaric acid (B), caffeic acid (C), chlorogenic acid (D), and rosmarinic acid (E), from interpretation of spectroscopic data including nagative fast atom bombardment (FAB)-mass, $^1H$-NMR, $^{13}C$-NMR, and IR. All isolated compounds were tested for antimicrobial activity against H. pyori. The purified single compound showed less antimicrobial activity against H. pylori than the mixed purified compounds, which generate A+B, A+E, C+D, C+E (each $200{\mu}g/disc$) excellent as large clear zone by synergy effect. These results indicate rosemary extracts are preventive agents against H. pyori.