$Hg^{2+}$이온 水溶液 內에서의 Chloropentaamminecobalt(III)의 置換反應速度와 메카니즘 (제 1 보)

박병각,이재원,임주상,Byung-Kak Park,Jae-Weon Lee,Joo-Sang Lim 대한화학회 1986 대한화학회지 Vol.30 No.3

Chloropentaamminecobalt(III)의 $Cl^-$리간드와 물 分子의 置換反應에서 H$g^{2+}$ 이온 觸媒의 역할을 알기 위하여 UV分光法으로 速度論的 硏究를 하였다. 觸媒촉매가 一次일차 反應반응形式형식으로 反應반응에 관여함을 알았으며, 觸媒촉매를 考慮 했을때의 速度常數 $k_{obs}$는 3.366$l{\cdot}mol^{-1}sec^{-1}$의 값을 얻었다. 아울러 總括反應은 二次反應 임을 알았으며, $S_N2$ 反應機構로 進行되는 反應 메카니즘을 提案하였다. Kinetic studies were carried out for the substitution of $H-2$O for $Cl^-$ ligand of chloropentaamminecobalt(III) in the presence of $Hg^{2+}$ catalyst by UV spectrophotometer. It has been found that $Hg^{2+}$ ion appears first order dependence and the overall reaction is second order. The reaction system can be believed to occur via $S_N2$ reaction, because the calculated rate equation for our presumed $S_N2$ mechanism is in agreement with the observed one.

Hetero-Atom Model의 超共節理論

박병각,Park, Byung-Kak 대한화학회 1970 대한화학회지 Vol.14 No.1

The methyl group does not possess an unshared pair of electrons. But F.A. Matsen has introduced the concept of the methyl group as a Pseudo-heteroatom which contributes a pair of electrons to ${\pi}$ system. In this heteroatom model, A. Streitwieser et al have assumed that the electrons in a methyl group behave to their approximation as a single electron pair on a single atom. But the theoretical basis on the heteroatom model hyper-conjugation has not studied yet. In this paper, Linear combination of Bond orbital and group theory is used to investigate the theoretical basis for it.

산성용액내에서 trans-[Co(en)$_2$(NO$_2$)Cl]$^+$ 와 [Fe(H$_2$O)$_6$]$^{2+}$ 와의 산화환원반응에 대한 속도론적 연구

박병각,우태하,임주상,송영대,Park Byung-Kak,Woo Tae-Ha,Lim Joo-Sang,Song Yeung-Dae 대한화학회 1990 대한화학회지 Vol.34 No.5

산성용액내에서 trans-[$Co(en)_2(NO_2)Cl]^+$ 착물과 [$Fe(H_20)_6]^{2+}$ 착물과의 산화환원반응 속도를 UV/vis-분광광도계로 측정하여 $H^+$가 관여한 반응속도상수 k$_H^+$, 반응차수 및 열역학적 활성화파라메타를 구하였다. Co(III), Fe(II)에 대해 각각 1차, H$^+$에 대해서 1차로 진행되는 총괄반응이 3차 반응이고 이 때, $H^+$가 작용한 속도상수 $k_H^+$는 6.7 ${\times}\;10^{-1}$ $L^2$/mol$^2$·min이였고 $E_a$, ${\{Delta}H^{\neq}$는 14.5 Kcal/mol, 13.8 Kcal/mol ${\{Delta}S^{\neq}$는 -18.3 e.u였다. 이러한 실험자료로부터 내부권 반응임을 알았으며 그 메카니즘을 제안하였다. Proton behavior was investgated for the redox reaction of trans-[$Co(en)_2(NO_2)Cl]^+$ with aqueous Fe(II) in acidic solution by UV/vis-spectrophotometric method. The reaction order of proton is first one and the rate constant(k$_H^+$) is 6.7 ${\times}\;10^{-1}L^2/mol^2{\cdot}min$. The values of $E_a$, ${\{Delta}H^{\neq}$, ${\{Delta}S^{\neq}$ are 14.5 Kcal/mol, 13.8 Kcal/mol and -18.3e.u., respectively. As the result of analysis of kinetic data, it has been found that this reaction proceeds through inner-sphere mechanism.

二中心 H${\u}$ckel 法의 應用 脂肪族 아민의 염기도 [Ⅰ]

박병각,이무상,홍영석,Byung Kak Park,Mu Sang Lee,Young Suek Hong 대한화학회 1971 대한화학회지 Vol.15 No.3

On the baisis of the calculations by the two centre Huckel method for sigma electron system, the electronic structure of the various aliphatic amines including ammonia, and the relationship between the observed $pK_b$ and the change in the sigma electronic energy, ${\Delta}E{\sigma}$ in the course of protonation are discussed. A parallelism is observed between the $pK_b$ and the calculated ${\Delta}E{\sigma}$ of the amines. Also, it is observed that the electron densities of hydrogen atom directly bonded to nitrogen of the amines, likewise have a linear relationship with the $pK_b$. Therefore, the basicity of the aliphatic amines may be estimated qualitatively by means of the two center Huckel method.

유사분자 착물의 응용 (제 2 보). 새로운 방향족 치환반응 기구

박병각,Park Byung-Kak 대한화학회 1975 대한화학회지 Vol.19 No.3

방향족 치환반응을 모형과하여 유사분자 착물이 천이상태가 될수있음을 단수 Huckel법으로 증명하고 새로운 방향족 치환반응의 기구를 제안하였다. 아울러 이 유사분자 착물을 양자역학적 선동법을 이용하여 안정화 에너지식을 유도하고 많은 탄소화합물의 안정화 에너지식을 유도하고 많은 탄소화합물의 안정화 에너지를 구하였다. 이 안정화 에너지로 어떤 방향족 화합물이 유사분자 착물을 형성하는 위치와 그 화합물의 치환반응의 결합 시약이 방향족 화합물에 부가반응이 일어나는 반응에까지 널리 설명할 수 있는 이점이 있다. A new mechanism is proposed for aromatic substitution, involving the formation of pseudo molecular complexes at the transition state. It accounts for the addition reactions of aromatic compounds with double bond reagents such as ozone, somium tetraoxide and carbene as well as all of the features of electrophilic substitution reactions. The pseudo molecular complex has been proved to be formed by quantum-chemical considerations using the simple Huckel method.

二中心 Huckel 法의 應用. 포화탄화수소의 C-C 切斷 및 水素의 反應性

박병각,이무상,Park, Byung-Kak,Lee, Mu-Sang 대한화학회 1972 대한화학회지 Vol.16 No.2

In connection with two electron binding energy of each bond of saturated hydrocarbons, C-C bond fission and hydrogen abstraction from C-H bond are discussed by means of two center Huckel method. A beautiful correlation could be noticed between the observed bond dissociation energy and the calculated bond energy except for n-butane. Bond dissociation energies between C-C bond were also related to C-C bond fission. We could also find a very close relation between the relative easiness of hydrogen abstraction and the calculated binding energy of C-H bond. In other words, C-H bonds of tertiary hydrogen have been noticed as most weakely bonded and hence the tertiary hydrogen would most easily from the paraffins. In addition, the C-H binding energy is discussed applying ionic character of C-H bond which is derived from its dipole moment (0.4D)

Gelatin 水溶液에서의 [Ni(H$_2O)_6]^{2+}$ 와 [CN]$^-$로 부터 [Ni(CN)$_4]^{2-}$生成에 관한 速度論的 硏究

박병각,이일봉,임주상,이길준,Park Byung-Kak,Il-Bong Lee,Joo-Sang Lim,Gil-Jun Lee 대한화학회 1987 대한화학회지 Vol.31 No.5

反應系 $[Ni(H_2O)_6]^{2+}+4CN^-{\rightleftharpoons}[Ni(CN)_4]^{2-}$를 Counductivity-meter를 이용해서 0.005% Gelatin 水溶額에서 反應速度論을 硏究하였다. $[Ni(CN)_4]^{2-}$와 [CN]$^-$의 反應으로 부터 $[Ni(CN)_4]^{2-}$ 生成速度는 $[Ni(H_2O)_6]^{2+}$에 대해서 1次, [CN]$^-$에 대해서 4次인 총괄反應이 5次로 進行됨을 알았으며, 또한 活性化 파라메타 ${\Delta}H^{\neq}$ 와 ${\Delta}S^{\neq}$는 각각 5.15kcal/mole , -35.07 e.u가 되었다. 그리고 이들의 資料로 부터 이 反應系의 타당한 生成메카니즘을 제안하였다. Kinetics studies on the reaction system of $[Ni(H_2O)_6]^{2+}+4CN^-{\rightleftharpoons}[Ni(CN)_4]^{2-}$ have been carried out in 0.005% gelatin solution at $25^{\circ}C$ by means of conductometry. The fifth-order kinetics were observed in the formation rate of $[Ni(CN)_4]^{2-}$ from the reaction of [Ni(H$_2O)_6]^{2+}$ and [CN]$^-$. The reaction was found first order in $[Ni(H_2O)_6]^{2+}$ and fourth order in [CN]$^-$. ${\Delta}H^{\neq}$ and ${\Delta}S^{\neq}$ were obtained the values of 5.15kcal/mole and -35.07 e.u., respectively. We have proposed the possible mechanism from the data obtained.

Sodium Dodecyl Sulfate의 분해반응에 대한 속도론적 연구

이길준,김종용,박병각 嶺南大學校 環境問題硏究所 1994 環境硏究 Vol.14 No.1

하천수에서 분리해 낸 SDS(Sodium Dodecyl Sulfate) 분해균주에 의하여 분해균주량의 변화와 SDS의 농도변화를 주어 SDS를 분해시킬 때 그 분해반응을 속도론적으로 연구하였다. 실험결과 SDS의 분해를 BOD로 표시하여 분해률을 측정한 속도식은 1차로 나타남을 알 수 있었다. 그리고 분해균주량의 변화와 SDS농도의 변화에 따른 속도상수는 분해규준량에는 영향을 받지 않으나 SDS의 농도에는 영향을 받음을 알 수 있었다. 그리고 활성화에너지는 5.304kcal/mol, 활성화 파라메타인 ???와 ???는 각각 4.69kcal/mol, -56.90 e.u.임을 알았다. Kinetic studies were carried out for change in BOD of SDS degradating microorganism isolated from river water. It is found that the decomposition of SDS is first order. Rate constants for the decomposition of SDS and its degrading microorganism found not to have an influence on variation of SDS-degrading microorganism but have an influence on SDS concentration. And thermodynamic parameters, Ea, ???? and ????, were obtained the value of 5.304kcal/mol, 4.69kcal/mol and -56.90 e.u., respectively.

發癌物質과 非發癌物質의 DNA-Modifying Activity에 대한 量子生物學的 解釋

李佶俊,林周相,宋寧大,徐榮培,朴柄珏 嶺南大學校 基礎科學硏究所 1990 基礎科學硏究 Vol.10 No.-

LCAOMO calculation has been carried out for thirty chemical carcinogens and nine metabolites of them. The LUMO electron density which is a measure of ability electron to be accepted and observed DNA-Modifying activity which is a measure of mutation relationship was considered. It was found that the sum of LUMO electron density of 1, 2, 4-positions of a relevant trans-butadiene type (F??) in the compound was correlative to DNA-Modifying activity. This means that carcinogenesis closely relate to mutagensis, since the LUMO electron density is a measure of carcinogenic activity of carcinogens as shown earlier. It was also found that LUMO electron density of 1, 2, 4-positions in compounds increase with their metabolic activation. This is in agreement with the experimental result that carcinogen is more electrophilic as metabolic activation. In conclusion, it may be possible to give a theoretical interpretation on the mutation of chemical carcinogens and explain theoretically the fact that the compound have a strong elestrophilicity on metabolic activation.

Hammett 치환기 상수에 대한 분자궤도론적 해석 (I)

박병각,이갑룡,Byung-Kak Park,Gab-Yong Lee 대한화학회 1986 대한화학회지 Vol.30 No.2

치환-벤조산, -베젠 및 -나프탈렌의 세 계열에 대해 LCAO MO법으로 Hammett치환기 상수를 해석하였다. Hammett ${\sigma}$값은 이론적으로 유도효과와 공명효과의 독립적인 기여의 합으로 취급됨을 알았다. 즉, 유도효과를 정적유도효과(static inductive effect, Is)와 동적유도효과 (dynamic inductive effect, Id)로 나누어 각각 net charge 및 근사자기편극률 지수로 취하고 공명효과로서 치환 분자와 비치환분자의 HOMO에너지 차$({\Delta}E^{HOMO})$로 취하였으며 계산결과 Hammett ${\sigma}$값은 정적유도효과, 동적유도효과 및 ${\Delta}E^{HOMO}$의 합에 의존됨을 알았다. The Hammett's substituent constants were analyzed for the substituted-benzoic acid, -benzene and -naphthalene by LCAO MO method. Hammett's ${\sigma}$-values have been theoretically proved to treat as the sum of independent contribution of inductive effect and resonance effect. That is, Is (static inductive effect) and Id (dynamic inductive effect) corresponding to inductive effect are chosen as net charge and approximate self atom polarizability indices respectively, and ${\Delta}E^{HOMO}$ which is the difference in HOMO energy level between substituted molecule and unsubstituted molecule as resonance effect. In conclusion, it has been found that the observed ${\sigma}$-values depend on the sum of Id, Is and ${\Delta}E^{HOMO}$.