• Title/Summary/Keyword: cross-reactions

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Kinetics and Mechanism of the Anilinolysis of Aryl N,N-Dimethyl Phosphoroamidochloridates in Acetonitrile

  • Barai, Hasi Rani;Lee, Hai Whang
    • Bulletin of the Korean Chemical Society
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    • v.35 no.3
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    • pp.753-757
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    • 2014
  • The nucleophilic substitution reactions of Y-aryl N,N-dimethyl phosphoroamidochloridates with substituted anilines and deuterated anilines are kinetically investigated in acetonitrile at $65.0^{\circ}C$. A stepwise mechanism with a rate-limiting leaving group departure from the intermediate is proposed based on the positive ${\rho}_{XY}$ value. The deuterium kinetic isotope effects involving deuterated anilines show secondary inverse with all the nucleophiles, rationalized by a dominant backside nucleophilic attack.

Palladium-Catalyzed Coupling between Quinolone Moieties and Heteroaryl Stannes - Synthesis of C-7 heteroaryl Quinolone Derivatives - (팔라듐 촉매를 이용한 퀴놀론핵과 Heteroaryl Stannes의 결합 - C-7 heteroaryl 쿼놀론 유도체의 합성 -)

  • 남상훈;함원훈;김기수;임태균;양재권
    • YAKHAK HOEJI
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    • v.37 no.6
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    • pp.615-620
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    • 1993
  • The cross-coupling reaction of organo tin reagents with a variety of organic halides, catalyzed by palladium, provides a novel method for generating a carbon-carbon bond. We used this method for the antibacterial agents, and synthesis of new quinolone derivatives which have carbon-carbon bond at C-7 position of general quinolone moieties. Aryl tin, quinolone moieties, and palladium catalyst were refluxed in DMF to afford new quinolone derivatives. This palladium catalyzed coupling reactions have capacity for further synthetic elaboration.

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A Study on Penning Effect in Plasma Discharge (플라즈마 방전에서 패닝 효과에 관한 연구)

  • Lee, Jong-chan;Lee, Cheong-hak;Park, Dae-hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.11a
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    • pp.515-517
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    • 1997
  • In this paper, the penning effect was studded to control accelerating of the ionization that means Increasing of cross-sectional collision through penning reactions in the plasma cells of Hg-Ar-Ne (x: 10-x, 60Torr) gas discharge under various concentrations of Ar.

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New Synthesis of Perhydrotriazolotriazoles Catalyzed by TiCl4 under Ambient Conditions

  • Safari, J.;Gandomi-Ravandi, S.;Ghotbinejad, M.
    • Journal of the Korean Chemical Society
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    • v.56 no.1
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    • pp.78-81
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    • 2012
  • Aromatic 2,3-diazabuta-1,3-dienes in glacial acetic acid with isothiocyanate in the presence of catalyst $TiCl_4$ at room temperature produced via criss-cross cycloaddition reactions the corresponding perhydro[1,2,4]triazolo[1,2-a][1,2,4] triazole-1,5-dithiones in relatively high yields and short reaction time.

Development of PCR Assay for Identification of Buffalo Meat

  • Rajapaksha, W.R.A.K.J.S.;Thilakaratne, I.D.S.I.P.;Chandrasiri, A.D.N.;Niroshan, T.D.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.7
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    • pp.1046-1048
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    • 2003
  • A polymerase chain reaction (PCR) assay was developed to differentiate buffalo meat from the meat of Ceylon spotted deer (Axis axis ceylonensis), Ceylon sambhur (Cervus unicolor unicolor), cattle (Bovine), goat (Caprine), pig (Porcine), and sheep (Ovine). A set of primers were designed according to the sequence of the mitochondrial cytochrome b gene of bubalus bubalis and by PCR amplification a band of approximately 242 bp band was observed with buffalo DNA. These primers did not cross-react with DNA of other animal species tested in the study under the specified reaction conditions. A band of 649 bp was observed for all animal species tested when DNA was amplified with the universal primers indicating the presence of mitochondrial DNA in the samples. The technique was sensitive enough to identify rotten (10 days post slaughter), dried and cooked buffalo meat. The absence of a cross reaction with human DNA using the buffalo specific primers eliminates possible false positive reactions.

A detection method for vibrio vulnificus using monoclonal antibodies

  • Chung, Mi-Sun;Rim, Bung-Moo;Boong, Uhm-Tae;Park, Moon-Kook
    • Journal of Microbiology
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    • v.35 no.2
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    • pp.87-91
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    • 1997
  • Monoclonal antibodies were prepared in order to an assay method for Vibrio vulnificus. Sixteen mouse ybridoma cell lines were established by immunization of whole cell antigen to BALB/c mice, fusion with SP2/O myeloma cells, and cloning. Most of them secreted IgM.lambda. antibodies. A sandwich enzyme-linked immunosorbent assay was developed with rabbit anti-V. vulnificus polyclonal antibodies as capture antibody, an IgM monoclonal antibody as detector antibody, and goat anti-mouse IgM-alkaline phosphatase conjugate as developer antibody. The range of detection was 10$\^$4/ to 10 V. vulnificus cells per microplate well. When four related Vibrio species were tested for cross-reactions, V. parahaemolyticus showed 3.5% reactively and V. carchariae, V. fluvialis, and V. furnisii showed negligibal (<1%) cross-reactivity.

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Pyridinolysis of O-Aryl Phenylphosphonochloridothioates in Acetonitrile

  • Lumbiny, Bilkis Jahan;Adhikary, Keshab Kumar;Lee, Bon-Su;Lee, Hai-Whang
    • Bulletin of the Korean Chemical Society
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    • v.29 no.9
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    • pp.1769-1773
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    • 2008
  • fThe kinetics and mechanism of the reactions of Y-O-aryl phenylphosphonochloridothioates with X-pyridines are investigated in acetonitrile at 35.0 ${^{\circ}C}$. The negative value of the cross-interaction constant, $\rho$XY = −0.46, indicates that the reaction proceeds by concerted $S_N2$ mechanism. The observed $k_H/k_D$ values involving d-5 pyridine ($C_5D_5N$) nucleophiles are greater than unity (1.05-1.11). The net primary deuterium kinetic isotope effects, $(k_H/k_D)_{net}$ = 1.28-1.35, excluding the increased $pK_a$ effect of d-5 pyridine are obtained. The transition state with a hydrogen bond between the leaving group Cl and the hydrogen (deuterium) atom in the C-H(D) is suggested for the studied reaction system.

Curing Reaction of Urea-formaldehyde Resin Using Real Time FT-IR Spectroscopy (실시간 FT-IR 분광분석법을 이용한 우레아-포름알데히드 수지의 경화반응)

  • Lee, Young-Kyu;Kim, Hyun-Joong
    • Journal of Adhesion and Interface
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    • v.13 no.2
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    • pp.85-88
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    • 2012
  • In this paper, the curing reaction of UF resins was investigated by a real time FT-IR method. The curing temperature range of the UF resin was $25{\sim}200^{\circ}C$. It was found that the reactions of UF resin at different temperatures resultedin resins with different cross-linked structures. A real time FT-IR spectroscopy can be considered as a good routine analytical tool for following the progress of UF resin curing.

Analysis of the Surface Degradation in UV-irradiated High-Temperature Vulcanized Silicone Rubber (자외선 조사된 HTV 실리콘 고무의 표면열화 분석)

  • 연복희;이태호;허창수;이종한
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.5
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    • pp.411-419
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    • 2000
  • In this paper we have investigated the surface degradation by ultraviolet-irradiation in high-temperature vulcanized silicone rubber. Through the measurement of surface potential decay by corona-charging and of contact angle it is found that the change of surface electrostatic properties and the decrease of contact angle under UV-radiation. For the changes in micro-morphological and chemical structure of the UV-treated silicone rubber we utilized several analytical techniques such as SEM, ATR-FTIR,XPS. From this study it is shown that the chemical reactions(scissoring of side chain(S-$CH_3$) cross-linking and branching) occur on the surface of silicone rubber during the UV-irradiation. Also we obtained the results of the loss of low molecular weight chain by cross-linking and oxidation reaction.

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Correlation Between Cross Interaction Constant and Bond Length in the S$_N$2 Transition State

  • Lee, Ik-Choon
    • Bulletin of the Korean Chemical Society
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    • v.9 no.3
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    • pp.179-182
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    • 1988
  • A simple correlation between cross interaction constants ${\rho}_{ij}$ and bond lengths in the transition state was obtained ; it has been shown that ${\rho}_{ij}$ corresponds to force constant of activation, which in turn is related to bond length by Badger's rule involving only universal constants. A satisfactory correlation between 4-31G ab initio calculated values of bond length and force constant for C-X streching in the transition state of the methyl transfer reaction, $X^-\;+\;CH_3X\;=\;XCH_3\;+\;X^-$, indicated that Badger's rule can be extended to bonds in the transition state. Independence of ${\rho}_{ij}$ values from the variable charge transmission of reaction centers has been demonstrated with nearly constant, experimentally determined I${\rho}$XYI values, and hence similar degree of bond formation, for various $S_N2$ reactions.