• 제목/요약/키워드: basicity

검색결과 196건 처리시간 0.02초

친핵성 치환반응에 대한 분자궤도론적 연구 (MO Studies on Nucleophilic Substitution Reaction)

  • 이본수;이익춘;양기열
    • 대한화학회지
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    • 제25권3호
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    • pp.145-151
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    • 1981
  • 기체상에서의 이분자 친핵성치환반응에 대한, 고유한 반응성에 대하여 CNDO/2 방법의 분자궤도론적으로 논의 하였다. 친핵체 및 이탈기별로 반응물, 천이상태, 그리고 생성물에 대해 geometry optimization을 하고 구조와 형태를 고찰하였다. CNDO/2수준에서도 정성적인 논의가 가능하였으며 반응성은 친핵체의 염기도와 이로부터 유발된 분극력에 의해 지배되었다

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有機 Halides 와 Amines 間의 光反應에 關한 硏究 (A Study on the Photoreaction between Organic Halides and Amines)

  • 김유선;박용자
    • 대한화학회지
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    • 제6권2호
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    • pp.148-154
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    • 1962
  • The reactions between organic halides$(CCl_4,\;C_6H_5Br,\;C_6H_5Cl,\;C_6H_5I)$ and amines $(C_6H_5NH_2,\;R_2NH,\;R_3N,\;(CH_2)_5NH,\;pyridine)$ were studied under mixed u.v. irradiation. The modes of reactions were examined by means of gas chromatography and product-reactant ratio determination. The reaction of $CCl_4$ with amines give chloroform and hexachloroethanes, and the reaction of aromatic halides with amines gave biphenyl and benzene. In each series of reaction there obtained mainly corresponding amine hydrohalides, but no amination products. The reactivity was in the order of the basicity of amines and of the reactivity of organic hahides, except in the case of cyclic tertiary amine. The result was interpreted as a non-chain photodecomposition process. A competitive proton abstraction reaction path via the formation of a change transfer complex was proposed as the reaction mechanism.

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7-Nitroso-8-Hydroxyquinoline-5-Sulfonic Acid의 금속킬레이트 안정도 상수 (Stability of Metal Chelates of 7-Nitroso-8-Hydroxyquinoline-5-Sulfonate)

  • 최규원;이동형;오준석;이광우
    • 대한화학회지
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    • 제12권3호
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    • pp.81-84
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    • 1968
  • Stabilities of chelates of 7-nitroso-8-hydroxyquinoline-5-sulfonate have been determined for divalent transition metal ions, Mn(Ⅱ), Fe(Ⅱ), Co(Ⅱ), Ni(Ⅱ), Cu(Ⅱ), and Zn(Ⅱ) by means of the Calvin-Bjerrum technique. Comparison of these stability constants with those obtained for 8-hydroxyquinoline, and 8-hydroxyquinoline-5-sulfonate shows that the observed differences are essentially the results of the lower basicity of the sulfonated group and different metal-ligand bond. The divalent metal chelate stability sequence is not in agreement with the reported metal orders for other chelating agents. The stabilities were found to follow the order Mn(Ⅱ) < Fe(Ⅱ) ${\approx}$ Co(Ⅱ) > Ni(Ⅱ) < Cu(Ⅱ) > Zn(Ⅱ).

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환경오염을 줄이면서 고에너지원으로 이용되는 물질에 관한 연구 (A Study on the Matter of Using High Energetic Source with Environmental Pollution Reduce)

  • 노기환;김준태
    • 환경위생공학
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    • 제13권1호
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    • pp.69-81
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    • 1998
  • The reactivity increase of unsunstituted energetic compound in cyclic ethers was found in order of three-membered cyclic form < five-membered cyclic form< four-membered cyclic form. The nucleophilicity and basicity of cyclic ethers can be explained by the negative charge on oxygen atom of cyclic ethers. The reactivity of propagation in the polymerization of cyclic ethers can be represented by positive charge on carbon atom and the LUMO energy of active species of cyclic ethers. The cationic polymerization of substituted cyclic ethers which have pendant energetic groups such as methoxy($-CH_{2}OCH_{3}$), azido($-CH_{2}N_{3}$), and nitrato($-CH_{2}ONO_{2}$) are investigated theoretically using the MNDO methods.

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Mercury Adsorption Behaviors of Copper/Activated Carbons by Electroless Plating

  • 배경민;김병주;박수진
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2009년도 추계학술대회 논문집
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    • pp.304-304
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    • 2009
  • In this study, the adsorption behaviors of mercury ions on the electroless Cu-plated activated carbons have been investigated. The amount of copper on activated carbons have been confirmed by atomic absorption spectrophotometer (AAS). The surface properties of the ACs studied have been characterized by using Boehm's titration method and scanning electron microscopy (SEM).Experimental results showed the adsorption capacity of mercury ions was increased as the electroless Cu plating. This was probably due to the introduction of copper on ACs leaded to an increase in the surface basicity.

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플라즈마를 이용한 도시 쓰레기 소각재 용융처리 기술 (Slagging treatment of MSW incineration ash by plasma system)

  • 박현서;지규일;장준섭;전석구;배희주;김형진;이시창;주성준;신범수
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 1999년도 추계학술발표회
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    • pp.65-68
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    • 1999
  • A plasma melting system to vitrify ny ash from MSW(Municipal Solid Waste) incinerator has been operated in SHI(Samsung Heavy Industries) since 1996. Waste feeding rate was 200kg/hr. with maximum working power of 500㎾. Because of high melting temperature of fly ash, bottom ash was used as an additive to decrease melting temperature. Data analysis for discharged slag shows volume reduction up to 30% and no leaching of heavy metals such as Pb, Cd, Cr which were an obstacle for landfill and recycle. Atmospheric pollution gas like nitrogen oxides, carbon monoxide, and PCDD/PCDF were restrained below the regulatory limit.

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C.I. Acid Red 57의 제조공정 개선에 관한 연구 (Modification of C.I. Acid Red 57 Synthesis Process)

  • Chung, Sang Woo;Kim, Jae Pil
    • 한국염색가공학회지
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    • 제9권5호
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    • pp.75-81
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    • 1997
  • o-Aminobenzene sulfone-N-ethylanilide, the diazo component of C.I. Acid Red 57, is currently being diazotised by the use of nitrosylsulphuric acid because of its high molecular weight and weak basicity. However, this method has many problems such as complicated manufacturing process and discharge of large volume of strong acidic effluent. In this study, the possibility of replacing nitrosylsulphuric acid method by direct method, which is simpler and produces less effluent, has been checked and the optimum process condition was studied. The effect of HCl concentration, the amount of sodium nitrite and particle size of diazo component on diazotisation yield was investigated. The optimum pH condition for coupling reaction was also evaluated.

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Phenol과 DMA 간의 수소결합 (Intermolecular Hydrogen Bond between Phenol and DMAs)

  • 김복혜;이익춘
    • 대한화학회지
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    • 제10권1호
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    • pp.15-17
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    • 1966
  • Phenol과 각 종 Dimethylaniline(DMA)간의 수소결합을 Infrared Spectrophotometer로 연구하였다. 일반으로 DMA는 n-donor 및 ${\pi}$-donor의 2중 역활을 하나 주로 n-donor로 작용하며 phenol의 O-H stretching frequency의 shift(${\Delta}{\nu}$)는 DMA의 basicity에 비례하였고 (${\Delta}{\nu}$) 와 Hammett의 σcontant사이에는 linearity가 성립함을 알았다.

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分光光度法에 依한 Iodine 의 Pyridine 및 Quinoline 溶液의 硏究 (Spectrophotometric Studies of the Solution of Iodine in Pyridine and Quinoline)

  • 박종회
    • 대한화학회지
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    • 제6권1호
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    • pp.69-72
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    • 1962
  • Spectrophotometric studies have been made on the solutions of elementary iodine in pyridine and quinoline, in the absence of light. The results shown that triiodide ion is produced in both solutions with different rates, and that triiodide ion behaves differently in both solutions. Iodine reacts slowly with pyridine, giving rise to triiodide ion, which is relatively stable in this solvent, hereas, iodine reacts rapidly with quinoline, forming triiodide ion, which interacts further with the medium at slow rate. It has been thought that the difference of the behavior of triiodide ion in both solutions may be due to the stronger basicity of quinoline than pyridine.

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Anion Recognition by a Simple Colorimetric Benzthiazole-Based Receptor

  • Kang, Sung-Ok;Nguyen, Quynh Pham Bao;Kim, Taek-Hyeon
    • Bulletin of the Korean Chemical Society
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    • 제30권11호
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    • pp.2735-2738
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    • 2009
  • A simple colorimetric anion chemosensor based on 2-amino-6-nitrobenzothiazole was synthesized. The addition of tetrabutylammonium (TBA) salts of $F^-,\;{CH_3COO}^-,\;and\;{H_2PO_4}^-$ to the solution of receptor 3 caused dramatic and clearly observable color changes from light to dark yellow due to the deprotonation process which is totally different from previously reported receptors based on the same motif. According to the basicity of the anions, the sensitivity of receptor 3 towards various anions decreased in the following order: ${CH_3COO}^-\;>\;F^-\;>\;{H_2PO_4}^-$.