• Applied Chemistry for Engineering
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• v.32 no.5
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• pp.532-540
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• 2021

Sodium dodecanoyl-4-oxybenzenesulfonate (DOBS) salt is a substance that exhibits effective bleaching and antimicrobial abilities at low temperatures. A mild and efficient synthesis method of DOBS starting from dodecanoyl chloride and sodium 4-hydroxybenzene sulfonate was investigated under alkaline conditions using a water (W)-polar aprotic solvent system. First, the reaction was carried out using only water as a solvent system with the variables of temperature and time. The yield was found to be as low as about 5% in most cases under the reaction conditions of more than 30 ℃ and 1 h. In order to develop an efficient solvent system, the effect on the yield of DOBS was evaluated in various solvent systems which were prepared by changing the type of polar aprotic solvents while mixing them with the water. A solvent system in which acetone (AC) and water were mixed showed the best yield and about 82 % under mild reaction conditions (30 ℃, 1 h and atmospheric pressure) was obtained. The prepared DOBS showed good bleaching and antimicrobial activities indicating that it could be used an excellent bleach activator.

• Journal of the Korean Chemical Society
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• v.13 no.2
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• pp.115-120
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• 1969

Kinetics of reactions of halide ions with 1-naphthyl methyl halide have been investigated in anhydrous acetone. Semi-quantitative analysis of the results shows that if the softness of the substrate increases remarkably, the nucleophilicity order of halide ions is $I^- > Br^- > Cl^-$ even in dipolar aprotic solvent. But for 1-naphthyl methyl bromide, though the reaction center which was made soft by symbiosis of bromine atom raises the reactivity of soft nucleophile, nucleophilicity order indicates that soft-soft interaction is interfered by perihydrogen.

• Journal of the Korean Chemical Society
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• v.18 no.4
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• pp.251-258
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• 1974

The rate constants for the nucleophilic substitution reactions of substituted benzoyl chlorides with p-nitroaniline in such solvents as acetone, acetonitrile, methanol, ethanol, etc. were conductometrically determined, and the activation thermodynamic parameters were also evaluated. In result, the reaction rates were faster in protic solvents than in aprotic solvent; in the solvents of similar property, the reaction rate in the solvent of the large dielectric constant was faster than that in the solvent of the small dielectric constant. Hammett plots in individual solvents showed the straight lines with positive slope; and we concluded that the reaction occurred via the addition-elimination mechanism.

• Clean Technology
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• v.19 no.4
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• pp.487-491
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• 2013

To efficiently desorb gold and copper-cyanide complexes adsorbed onto Dowex21K XLT resin, the mixed solvent with HCl and acetone which is a kind of dipolar aprotic solvent was used as a desorbing agent. The desorption efficiency for gold-cyanide complex was the highest as about 94% when the mixing ratio of HCl and acetone based on volume was the 7:3, however, the value decreased as the ratio of acetone increased. In the case of copper-cyanide complex, most of them was desorbed when the amount of HCl was relatively higher than that of acetone, however, desorption efficiency decreased as the ratio of acetone increased. The desorption efficiency for gold and copper-cyanide complexes was the 94 and 100%, respectively at the 0.6 M of HCl with the 7 (HCl) : 3 (Acetone) of mixing ratio and desorption efficiency for gold-cyanide complex not increased any more even though higher HCl concentration was used. And the desorption efficiency for gold and copper-cyanide complexes was about 100% at the S/L raio ${\leq_-}1.0$ whereas desorption efficiency for gold-cyanide complex was very low as about 20-29% at the S/L ratio > 1.0. Also, most of desorption process for gold and copper-cyanide complexes was completed within 120 min.

• Journal of the Korean Chemical Society
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• v.27 no.3
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• pp.167-177
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• 1983

The kinetics of 2-anthracenesulfonyl chloride in methanol-water, ethanol-water, acetone-water and acetonitrile-water has been studied by electroconductometric method. For media in which water has the same mole fraction, the rate was greater in protic solvent than in dipolar aprotic solvent and it was greater consistently in methanol-water than in ethanol-water over the whole range of solvent composition investigated, while the two rates in acetone-water and acetonitrile-water inverted at about 0.9 of mole fraction of water. Both m value, susceptibility of rate to the ionizing power and n value, solvent participation number in the transition state were much smaller in protic solvent. These values and the activation parameters show that solvolysis of 2-anthracenesulfonyl chloride proceeds by $ S_N2$ mechanism.

• Journal of the Korean Chemical Society
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• v.22 no.3
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• pp.111-116
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• 1978

The kinetics of phenylmethanesulfonyl chloride in methanol-water, ethanol-water, acetone-water and acetonitrile-water has been investigated. The rate was faster in protic solvents than in aprotic solvents while susceptibility of rate to the ionizing power, i. e., m of the Winstein plot and solvation number of the transition state were much smaller in protic solvents. This was considered in the light of initial state stabilization by hydrogen-bonding solvation of the protic solvents. It was concluded that the reaction proceeds by an $S_N2$ mechanism in which bond-formation precedes bond-breaking at the transition state in all solvent systems.

• Bulletin of the Korean Chemical Society
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• v.30 no.1
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• pp.197-200
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• 2009

A simple dye having phenol and indole moieties was synthesized and its chromogenic signaling behaviors for the determination of water content in organic solvents were investigated. The compound revealed a pronounced chromogenic behavior in response to the variation of water content in water miscible aprotic organic solvents of acetone, acetonitrile, THF, and dioxane. Significant red shifts and changes in absorption spectra allowed a ratiometric analysis of the signaling behavior. The chemosensing behaviors were particularly pronounced in water content in less than 10% that is suitable for the application of the compound as a probe for the determination of water content in binary aqueous organic solutions having lower water content.

• Journal of the Korean Chemical Society
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• v.31 no.5
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• pp.419-424
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• 1987

Kinetic studies on the solvolysis of para-methyl benzyl nitrate and benzyl nitrate were carried out in aqueous methanol, ethanol, acetonitrile, acetone, tetrahydrofuran and dioxane mixtures at 60$^{\circ}$C. The rates were faster in protic solvent mixtures than in aprotic solvent mixtures. This was considered in the light of transition state stabilization by hydrogen bonding solvation of protic solvent mixtures. Grunwald-Winstein equation, extended Grunwald-Winstein equation and correlation between E$_T$(30) and rate constant were applied in order to discuss the transition state variations caused by changing benzyl substituents and solvents. The results showed that strong electrophilic assistance of solvent is operative in the the water-rich solvents.

• Journal of the Korean Chemical Society
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• v.24 no.1
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• pp.8-14
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• 1980

Solvolysis rate constants for methylchloroformate, $CH_3O$(CO)Cl, methylthiono-chloroformate, $CH_3O$(CS)Cl, and methylthiolchloroformate, $CH_3S$(CO)Cl, have been determined conductometrically in acetone-water and acetonitrile-water mixtures, and activation parameters, ${\Delta}H^{\neq}$ and ${\Delta}S^{\neq}$, have been derived. Results show that in water-rich regions the order of rate increases as $$CH_3O(CO)Cl while in dipolar aprotic solvent-rich region this order reverses. The plots of log k vs. solvent parameters, Y, $\frac{D-1}{2D+1}$ and log($H_2$) show that the order of rate increase in water-rich region is the results of increase in $S_N1$ character. It is concluded that $CH_3S$(CO)Cl solvolyzes via $S_N1$ mechanism whereas $CH_3O$(CO)Cl reacts via $S_N2$ and $CH_3O$(CS)Cl via intermediate mechanism in water-rich region.

• Journal of the Korean Chemical Society
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• v.31 no.3
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• pp.258-270
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• 1987

A series of new thorium nitrate complexes with crown ethers have been synthesized from the reaction of the hydrated thorium nitrate, with the appropriate crown ethers of different cavity sizes in various solvents such as methanol, ethanol, butanol, methylacetate, acetone, tetrahydrofuran and acetylacetone. CHN elemental analysis, ICPAS, thermal analysis and Karl-Fischer method have been used to characterize their compositions, and the spectroscopic methods of IR, UV, $^1H-NMR$, and X-ray diffraction have been employed to determine the structures and solvolysis phenomena of these complexes. and the electrical conductances were measured in DMSO, and water solvent. The solvolysis have been observed only in the complexes synthesized in acetylacetone solvent. In the solvated complexes of 15-crown-5 and 18-crown-6, the mole ratio of $Th^{4+}$: ligand : acetylacetone is found to be 1:1:1, but in the non-solvated complexes of 12-crown-4 and 15-crown-5, the mole ratios of Th:L are 1:2 and 2:3, respectively, and that in the complexes of both 18-crown-6 and dicyclohexano-18-crown-6 is 1:1. All complexes which were not solvated have shown $n{\to}{\sigma}^{\ast}$ electronic transitions of crown ether whereas complexes solvated have exhibited both $n{\to}{\sigma}^{\ast}$ of crown ether and $n{\to}{\pi}^{\ast}$ transitions of acac. The dissociation mole ratio of $Th^{4+}$ and nitrate ion is found to be 1:1 in aprotic solvent, and 1:4 in protic solvent like water.