• Journal of the Korean Chemical Society
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• v.30 no.3
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• pp.296-300
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• 1986

The pseudo-first order rate constants have been obtained for the solvolysis of pseudo-saccharinechloride in MeOH-$H_2O$, EtOH-$H_2O$, MeOH-MeCN and MeOH-$(Me)_2$CO solvents mixtures at various temperatures. Values of n and m in the Kivinen and Grunwald-Winstein plots, respectively, have been determined and the Taft's solvatochromic parameters were obtained; based on these solvent effect parameters as well as on the activation parameters it was concluded that reaction proceeds via an $S_N2$ mechanism.

• Bulletin of the Korean Chemical Society
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• v.29 no.10
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• pp.1927-1931
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• 2008

Rate of solvolysis of diphenylthiophosphinyl chloride in ethanol, methanol, and aqueous binary mixtures incorporating ethanol, methanol, acetone, 2,2,2-trifluoroethanol (TFE) or 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) are reported. Solvolyses were also carried out in TFE-ethanol mixtures. For five representative solvents, studies were made at several temperatures and activation parameters determined. The 29 solvents gave a reasonably precise extended Grunwald-Winstein equation plot, correlation coefficient (R) of 0.933, which improved to 0.983 when the four TFE-ethanol points were excluded. The sensitivities (l = 1.00 and m = 0.64) were similar to those obtained for dimethyl phosphorochloridate and phosphorochloridothionate and diphenylphosphinyl chloride (1). As with the four previously studied solvolyses, an $SN_2$ pathway is proposed for the solvolyses of diphenylthiophosphinyl chloride. The activation parameters, ${\Delta}H^{\neq}$ and ${\Delta}S^{\neq}$, were determined and they are also in line with values expected for an $S_N2$ reaction.

• Journal of the Korean Chemical Society
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• v.21 no.4
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• pp.262-269
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• 1977

The solvolysis of 1-naphthalene-and 2-naphthalenesulfonyl chlorides in acetone-water mixtures have been studied by means of conductometry. The solvent effect and mechanism have been discussed in terms of variation in solvent composition and activation parameters. The reaction was predominantly $S_N2$ type, but bond breaking increased with the increase of water content. The rate constant for 1-naphthyl compound was smaller than that of 2-naphthyl compound due to the ground state stabilization effect and peri-hydrogen effect, and the latter effect was similar to that in ethanol-water mixtures.

• Bulletin of the Korean Chemical Society
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• v.25 no.5
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• pp.699-703
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• 2004

Solvolyses of isopropylsulfonyl chloride (IPSC) in water, D_2O,\;CH_3OD$, and in aqueous binary mixtures of acetone, ethanol and methanol are investigated at 25, 35 and 45$^{\circ}C$. The Grunwald-Winstein plot of first-order rate constants for the solvolytic reaction of IPSC with $Y_{Cl}$ (based on 2-adamantyl chloride) shows marked dispersions into three separate lines for three aqueous mixtures with a small slope (m < 0.30). The extended Grunwald-Winstein plots for the solvolysis of IPSC show better correlation. The kinetic solvent isotope effects determined in water and methanol are in consistent with the proposed mechanism of the general base catalyzed and/or $S_AN/S_N2$ reaction mechanism for IPSC solvolyses based on mass law and stoichiometric solvation effect studies.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2408-2412
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• 2009

The specific rates of solvolysis of methyl fluoroformate have been measured at $40.0\;{^{\circ}C}$ in several hydroxylic solvents. Analysis with the extended Grunwald-Winstein equation leads to sensitivities toward changes in solvent nucleophilicity (l) of $1.33\;{\pm}\;0.10$ and toward changes in solvent ionizing power (m) $0.73\;{\pm}\;0.06$. For methanolysis, a solvent deuterium isotope effect of 3.98 is compatible with the incorporation of general-base catalysis into the substitution process. For four representative solvents, studies were made at several temperatures and activation parameters determined. These observations are also compared with those previously reported for alkyl halogenoformate esters and mechanistic conclusions are drawn.

• Journal of the Korean Chemical Society
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• v.27 no.2
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• pp.95-101
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• 1983

The pseudo-first order rate constants have been obtained for the solvolysis of benzoyl cyanide in various aqueous solvent mixtures and ethanol-trifluoroethanol mixtures at 1, 5, 10, 15 and $20^{\circ}C$. Values of n in the Kivinen polt, m values of Grunwald-Winstein polt, $\beta$ values of Leffler relationship and values of m and l in the extended Grunwald-Winstein polt have been calculated and studied the transition state variation caused by solvent changes using the More O'Ferrall polt and quantum mechanical approach. It has been shown that the reaction proceed via the associative $S_N2$ mechanism, using the transition state parameters and quantum mechanical model approach.

• Journal of the Korean Chemical Society
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• v.34 no.3
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• pp.221-226
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• 1990

The solvolysis of substitued phenacyl tosylates was studied in binary solvent mixtures of methanol-acetonitrile and methanol-acetone at 55$^{\circ}C$. Except for m-nitrophenacyl tosylate, the rate constants were increased with both of electron-donating substituents and electron-withdrawing ones and its rate constants were the largest in the binary solvent mixtures of 90% MeOH-10% MeCN. The results show that the reactions were changed with dissociative $S_N2$ mechanism judging from the magnitude of 1/m values going from the electron-withdrawing group to the electron-donating one of the substrate. And above results were consisted with the account for the PES model and QM approach.

• Bulletin of the Korean Chemical Society
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• v.28 no.4
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• pp.657-661
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• 2007

The specific rates of solvolysis of isopropyl fluoroformate are well correlated using the extended Grunwald-Winstein equation, with a sensitivity (l ) to changes in solvent nucleophilicity (NT) and a sensitivity (m) to changes in solvent ionizing power (YCl). The sensitivities (l = 1.59 ± 0.16 and m = 0.80 ± 0.06) toward changes in solvent nucleophilicity and solvent ionizing power, and the kF/kCl values are very similar to those for solvolyses of n-octyl fluoroformate, suggesting that the addition step of an addition-elimination mechanism is rate-determining. For methanolysis, a solvent deuterium isotope effect of 2.53 is compatible with the incorporation of general-base catalysis into the substitution process. The large negative values for the entropies of activation are consistent with the bimolecular nature of the proposed rate-determining step. These observations are also compared with those previously reported for the corresponding chloroformate and fluoroformate esters.

• Journal of the Korean Chemical Society
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• v.31 no.1
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• pp.25-30
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• 1987

Solvolysis of tert-butyl halides and 1-adamantyl tosylate in methanol-acetone mixtures and solvolysis of tert-butyl bromide in methanol-chloroform mixtures have been studied. Solvent ionizing power of methanol-acetone mixtures were calculated by the Grunwald-Winstein equation and discussed the Y value variation caused by substrate changes. Y values based on 1-adamantyl tosylate is superion to others since it varies in wide range for methanol-acetone mixtures. It was found that the order of electrophilic assistance to leaving group is OTs > Cl > Br > I.

• Bulletin of the Korean Chemical Society
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• v.23 no.10
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• pp.1445-1450
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• 2002

Solvolytic rate constants at 25 $^{\circ}C$ are reported for solvolysis of chlorodithioformate (1) in binary mixtures of water with acetone, ethanol, methanol, methanol-d, 50%methanol-d/50%D2O, and 2,2,2-trifluroethanol (TFE), and also in TFE-ethanol mixtures. The Grunwald-Winstein plot shows that the three aqueous mixtures exhibit dispersions into separate line. The correlation is improved only slightly by additional parameters NT for solvent nucleophilicity and/or I for aromatic ring parameter. Rate ratios in solvents of the same $Y_cl$ value, having different nucleophilicity provide measures of the minimum extent of nucleophilic solvent assistance, and the value of 3.35 for $[$k_{40EW}$/$k_97TFE$]_Y$ (EW = ethanol-water), is consistent with an essentially SN1 reaction mechanism. This study has shown that the magnitude of l, m and h values associated with a change of solvent composition is able to predict the SN1 reaction mechanism. log(k/$k_o$) = mY + lN + hI