• Title/Summary/Keyword: HSAB 이론

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Local Hard-Soft Acid-Base 이론을 이용한 유기 반응의 분석

  • Jeong, In-Chun;Son, Mun-Gi;Sin, Seok-Min
    • Proceeding of EDISON Challenge
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    • 2014.03a
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    • pp.127-139
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    • 2014
  • Hard-Soft Acid-Base (HSAB) 이론은 일반적인 유기, 무기반응의 반응성을 설명하는데 사용되어 왔다. 밀도범함수이론(DFT)을 기반으로 한 계산을 통하여 반응을 기술하기 위해 필요한 화학 퍼텐셜, global/local hardness/softness와 Fukui 함수 등을 얻을 수 있다. B3LYP 수준 하에서 DFT 양자계산을 이용하여 유기 반응을 분석했을 때 local HSAB 이론의 적용여부와 장단점을 알아보고자 하였다. 1-subtituted 다이엔과 비대칭 친다이엔체를 이용한 딜스-알더 반응의 경우 local HSAB 이론을 적용시켜, 오쏘 이성질체가 주 화합물인 이유를 설명할 수 있었다. 작용기를 변화시켰을 때 나타나는 차이점에서 규칙적인 경향성을 볼 수 없다는 사실을 통해서 전자, 입체 효과로 딜스-알더 반응을 분석할 수 없었던 이유를 이해할 수 있었다. Thiocyanate 음이온의 알킬화 반응의 경우 local HSAB 이론을 적용시켰을 때, 얻은 값을 통해서 반응 지점의 선호도를 예측할 수 없었는데 이는 thiocyanate를 생성하는 반응이 속도론적 지배 하에서 우세하는 반응이기 때문이다.

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Kinetic Studies on Halogen Exchanges of 2-Naphthylmethyl Chloride

  • Lee, Ikchoon;Yie, Jae-Eui;Kim, Wang-Ki;Lee, Kae-Soo
    • Nuclear Engineering and Technology
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    • v.8 no.2
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    • pp.77-80
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    • 1976
  • The halogen exchange reactions of 2-naphylmethyl chloride have been investigated in actone and acetonitrile. The results were in good accord with PMO theory and HSAB principle.

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Nucleophilic Substitution at a Carbonyl Carbon Atom(VI)

  • Lee, Hai-Whang;Lee, Ikchoon
    • Nuclear Engineering and Technology
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    • v.7 no.4
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    • pp.311-316
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    • 1975
  • Kinetic studies on the halide exchange reactions of substituted benzoyl chlorides have been carried out. The experimental result has been explained reasonably in terms of HSAB principle and EH-Theory, and addition elimination mechanism has been proposed for this type of reaction.

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Halogen Exchange Reactions of Benzyl Halides Part Ⅱ-Kinetics of Reactions of Iodide Ion with Benzyl Chloride and Bromide in 90% Ethanol-water (벤질 할라이드의 할로겐 교환반응 (제Ⅱ보) 90% 에탄올 용액에서의 염화 및 브롬화 벤질과 요오드화 이온 간의 교환반응 속도)

  • Lee Bon-su;Whangbo Myung Hwan;Lee Ik Choon
    • Journal of the Korean Chemical Society
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    • v.13 no.2
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    • pp.103-108
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    • 1969
  • 전보에 이어 90% 에탄올 용액에서의 염화 벤질 및 브롬화 벤질과 요오드화 이온 간의 교환반응을 연구하였다. HSAB이론을 도입하여 할로겐화 이온의 pb혼합 궤도가 서로 겹치는 전이 상태로서 실험 결과를 설명하였다.

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The Solvent Extraction of Univalent Cation Picrates by New Podands (새로운 포단드에 의한 피크린산 일가 양이온 염의 용매추출)

  • Jung, Jong Hwa;Cho, Sung Bae;Kim, Jineun;Kim, Jae Sang;Lee, Shim Sung
    • Analytical Science and Technology
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    • v.6 no.1
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    • pp.29-37
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    • 1993
  • Some new podands containing phenyl(B), benzyl(Bz), pyridine(Py), quinoline(Q) and naphthalene(Np) as end-groups, and oxygen(O) and sulfur(S) in ether chains as donor atoms have been synthesized. The univalent cation binding characteristics of these podands have been studied by NMR titration and solvent extraction. By NMR titration we have found that the most of podands form 1:1 complexes with $Ag^+$ ion. Especially, the substituted sulfur atoms in ether chains show the effects to enhance the stabilities. We also carried out the extractions of univalent cation picrates including alkaline metal, $Ag^+$, $Tl^+$ and $NH_4{^-}$ ions from aqueous to chloroform layer by using these podands. We found that the extractabilities of $Ag^+$ ion with the quinoline-containing podands such as, $Q_2O_4$, $Q_2O_5$ and $BQO_5$ were 86.8, 86.6 and 48.0% respectively, but the naphthalene-containing podands such as, $Np_2O_4$ and $Np_2O_5$ extracted quite small amount. Otherwise, in cases of $Bz_2O_3S_2$(89.4%), $B_2O_2S_2$(96.8%), $B_2O_3S_2$(58.9%), $Py_2O_2S_2$(58.8%), $Py_2O_3S_2$(42.1%), and $B_2O_4S$(15.0%), interestingly, $Bz_2O_3S_2$ which have sulfur atoms and benzyl groups showed the highest extraction selectivity for $Ag^+$ ion. This result seems due to not only the strong interaction of $Ag^+$ ion with sulfur donors according to the HSAB theory, but also the effective ${\pi}-{\pi}$ stacking interaction between two aromatic end-groups which is enhanced by the flexible methylene spacing group in benzyl groups instead of phenyl groups. The extraction coefficients gave the similar tendency as the extractabilities and the stabilities. From these results, it could be concluded that the predominant factor affected to extraction coefficients is the stabilities, which are strongly influenced by the structures of podands.

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