• Journal of the Korean Chemical Society
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• v.32 no.5
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• pp.416-421
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• 1988

Kinetic studies for the nucleophilic substitution reactions of benzyl halides(para-substituted benzyl bromides and benzyliodide) with substituted pyridines in MeOH-MeCN mixtures have been carried out in order to elucidate the reaction mechanism. Cross interaction coefficient, ${\rho}_{XY}$ values suggested that the reactions between benzylhalides and substituted pyridines exhibit an dissocitive $S_N$2 mechanism. Hammett (${\rho}_X$, ${\rho}_Y$), Br${\o}$nsted ${\beta}_N$ and solvatochromic correlation coefficient a, s, a/s values were illustrated. Kinetic results were compared between potential energy surface model and quantum mechanical model. The quantum mechanical approach showed to be consistent with kinetic results.

• Journal of the Korean Chemical Society
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• v.51 no.6
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• pp.526-535
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• 2007

Ru(II)-terpyridine complexes (8, 9, 11) linked with adamantyl or β-cyclodextrin moieties were synthesized and characterized based on their 1H and 13C NMR spectra as well as MS spectra. Ru(II)-terpyridine complexes (8, 11) linked with adamantyl moiety were readily dissolved in aqueous solution via encapsulation by β-cyclodextrin when they were mixed with an equimolar amount of β-cyclodextrin. In the similar way, the adamantane guest of the Ru(II)-terpyridine complexes (8, 11) were encapsulated by β-cyclodextrin moiety of the ruthenium complex 9 to afford supramolecular assemblies in aqueous environment. Formation of assemblies was corroborated by 1H NMR spectroscopy.

• Journal of the Korean Chemical Society
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• v.53 no.3
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• pp.308-324
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• 2009

The present work is devoted to study the interaction of $\beta$-aroylacrylic acid derivative (3) with malononitrile in (DMF) in the presence of piperidine and/or ammonium acetate, then using the formed compounds as starting materials for synthesizing fused and isolated heterocyclic systems. It has been established that the $\beta$-aroylacrylic acid (3) reacts with malononitrile in (DMF) in the presence of piperidine as a catalyst with the formation of 4H-pyran derivative (4). By changing the catalyst into ammonium acetate, pyridine derivative (5) has been obtained. Also the N-maleamic acid derivatives (19) and (27) have been synthesized via the interaction of (4) and (5) with maleic anhydride. The purpose of this step is to study the behavior of the formed maleamic acid derivatives – as analogies of $\beta$-aroylacrylic acids – towards different active methylene compounds under Michael addition reaction.

• Journal of the Korean Chemical Society
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• v.26 no.2
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• pp.73-80
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• 1982

The pyridine and 3,5-lutidine complexes of quinquevalent molybdenum have been prepared. The infrared, electronic and reflectance spectra and magnetic susceptibility data of the complexes are reported. It is found that the binuclear complexes contain the di-${\mu}$-oxo-dimolybdenum(V) group, $MoO_2Mo$, and the possible structures are proposed on the basis of elemental analysis and physical measurements.

• Journal of the Korean Chemical Society
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• v.21 no.1
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• pp.38-43
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• 1977

The rate constant of the reaction of 3-or 4-substituted pyridines with benzyl benzenesulfonate in acetone at $35^{\circ}C$ were determined by an electric conductivity method. According to the Hammett plot, the rates were increased the electron donating ability at the $S_N2$ reaction of benzyl benzenesulfonate with pyridine and 4-$NH_2$ pyridine was correlated with ${\sigma}^+$ than Hammett ${\sigma}$ value. This result was explained that $NH_2$ group and N atom in pyridine are largely contribute by resonance. In Br$\"{o}$nsted plot, 4-amino and electron attracting group were deviated from the increasing part at linearity. It was considered to solvent effects on substituents. A mechanistic possibility was proposed to account for the results. Some activation parameters were also calculated.

• Journal of the Korean Chemical Society
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• v.30 no.2
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• pp.159-165
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• 1986

The effects of substituents, pressure and temperature on the dissociation constants of alkylpyrines(2, 3 and 4-methyl and ethyl) were studied by measuring the dissociation constants of pyridines by conductance method at various temperatures and pressures in aqueous solution. The constants were increased as the temperature increase but decreased as pressure increase. From the constants various thermodynamic properties were calculated and discussed the dissociation reactions. It was estimated that alkylpyridines have exceptional dissociation reactions.

• Journal of the Korean Chemical Society
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• v.32 no.2
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• pp.144-148
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• 1988

A novel synthetic route to 1,4-dihydropyridine mono carboxylic acid derivatives is described. Allyl methyl 2,6-dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3, 5-dicarboxylate (IV) was treated with $Pd(OAc)_2$ in dioxane for 30 min at 110$^{\circ}C$ with reflux to give the mono acid compound(V) in 94% yield. The mono acid intermediate was converted to 2-(N-benzyl-N-methylamino)ethyl methyl 2,6-dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3, 5-dicarboxylate (VII) (Nicardipine) and their derivatives in 70~85% yield.

• Electrical & Electronic Materials
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• v.6 no.5
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• pp.428-434
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• 1993

유기물 중에서 광기능성을 가지는 벤젠, 비닐 피리딘 및 스티렌 단량체를 채택하였다. 내정전결합 유동가스형 중합장치를 사용하여 플라즈마 박막을 제조하였으며 이들의 광학특성을 분석하였다. 중합시간, 압력 및 단량체 유량을 일정하게 유지하고 방전전력을 증가시키면 스티렌 박막의 중합률은 선형적으로 증가하나 벤젠 및 비닐 피리딘 박막의 증합률은 비선형적으로 증가한다. 그리고 파장이 변화에 따른 굴절률은 1.55~1.65 정도를 나타냈다. 박막의 굴절률은 방전전력의 증가에 따라 감소하게 된다. 또한 굴절률의 변화에 대한 소멸계수(K)의 계산이 $10^{-3}$정도의 범위에 있으므로 측정 결과가 타당함을 알 수 있다.

• Journal of the Korean Chemical Society
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• v.34 no.3
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• pp.307-309
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• 1990

• Journal of the Korean Chemical Society
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• v.33 no.4
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• pp.413-418
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• 1989

The rates for the reaction of substituted 2-phenylethyl tosylates with substituted pyridines were measured in acetonitrile and that of 2-PNS with substituted pyridines were investigated in both acetonitrile and methanol. The substitutent effect was accelerated by an electron-donating substituent on both substrate and nucleophile. Results showed that More O'Ferrall and quantum mechanical model of predicting transition state structure suggest the reaction proceeds via an $S_N2$ mechanism, in which bond-breaking is more advanced than bond-formation. Transition state variation predicted with the quantum mechanical model is consistent with the experimental results, whereas the predictions provided by the More O'Ferrall plots is found to be inconsistent in leaving group. In the reaction of 2-PNS, the rate constants in acetonitrile were larger than that in methanol.