• Bulletin of the Korean Chemical Society
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• 제29권10호
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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.

• 대한화학회지
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• 제61권1호
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• pp.25-28
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• 2017

Solvolyses with the reaction center being the sulfur of 4-(chlorosulfonyl)biphenyl ($C_6H_5C_6H_4SO_2Cl$, 1) was studied under solvolytic conditions and the extended Grunwald-Winstein equation was applied. The thirty five kinds of solvents gave a reasonable extended Grunwald-Winstein plot with a correlation coefficient (R) of 0.940. The sensitivity values (l = 0.60 and m = 0.47) of 1 were smaller than those obtained for benzenesulfonyl chloride ($C_6H_5SO_2Cl$, 2; l = 1.10 and m = 0.61) proposed to undergo dissociative $S_N2$ mechanism. These l and m values for the solvolyses of 1 can be considered to support a $S_N2$ pathway with some ionization reaction. The activation parameters, ${\Delta}H^{\neq}$ and ${\Delta}S^{\neq}$, were determined and they are also in line with values expected for a bimolecular reaction. The kinetic solvent isotope effect (KSIE) of 1.26 is also in accord with a bimolecular mechanism, probably assisted by general-base catalysis.

• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2413-2417
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• 2011

The specific rates of solvolysis of 1- naphthyl chloroformate (1-NaphOCOCl, 1) and 2-naphthyl chloroformate (2-NaphOCOCl, 2) have been determined in a wide range of solvents at 2.0 and 10.0$^{\circ}C$. These give a satisfactory correlation over the full range of solvents when the extended (two-term) Grunwald-Winstein equation is applied. The sensitivities (l and m-values) to changes in solvent nucleophilicity ($N_T$) and solvent ionizing power ($Y_{Cl}$) are similar to those reported previously for solvolysis of phenyl chloroformate, which has been suggested to proceed through an addition-elimination mechanism with the addition step being rate determining. For four representative solvents, studies were made at several temperatures and activation parameters determined. These observations were also compared with those previously reported for phenyl chloroformates and naphthoyl chlorides.

• Bulletin of the Korean Chemical Society
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• 제25권2호
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• pp.307-310
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• 2004

• Bulletin of the Korean Chemical Society
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• 제30권10호
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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.

• Bulletin of the Korean Chemical Society
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• 제30권2호
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• pp.383-388
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• 2009

Rates of solvolyses of diphenyl thiophosphorochloridate ($(PhO)_2$PSCl, 1) in ethanol, methanol, and aqueous binary mixtures incorporating ethanol, methanol, acetone and 2,2,2-trifluoroethanol (TFE) are reported. For four representative solvents, studies were made at several temperatures and activation parameters were determined. The 30 solvents gave a reasonably precise extended Grunwald-Winstein plot, correlation coefficient (R) of 0.989. The sensitivity values (l = 1.29 and m = 0.64) of diphenyl thiophosphorochloridate ($(PhO)_2$PSCl, 1) were similar to those obtained for diphenyl phosphorochloridate ($(PhO)_2$POCl, 2), diphenylphosphinyl chloride ($Ph_2$POCl, 3) and diphenylthiophosphinyl chloride ($Ph_2$PSCl, 4). As with the previously studied of 3~4 solvolyses, an $S_N$ pathway is proposed for the solvolyses of diphenyl thiophosphorochloridate (1). The activation parameters, ${\Delta}H^{\neq}\;(=11.6{\sim}13.9\;kcal{\cdot}mol^{-1})\;and\;{\Delta}S^{\neq}\; (=\;-32.1\;{\sim}\;-42.7\;cal{\cdot}mol^{-1}{\cdot}K^{-1})$, were determined, and they were in line with values expected for an $S_N$2 reaction. The large kinetic solvent isotope effects (KSIE, 2.44 in MeOH/MeOD and 3.46 in $H_2O/D_2$O) are also well explained by the proposed $S_N$2 mechanism.

• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2285-2289
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• 2014

The solvolysis rate constants of 5-dimethylamino-naphthalene-1-sulfonyl chloride ($(CH_3)_2NC_{10}H_6SO_2Cl$, 1) in 31 different solvents are well correlated with the extended Grunwald-Winstein equation, using the $N_T$ solvent nucleophilicity scale and $Y_{Cl}$ solvent ionizing scale with sensitivity values of $0.96{\pm}0.09$ and $0.53{\pm}0.03$ for l and m, respectively; the correlation coefficient value was 0.955. These l and m values can be considered to support an $S_N2$ reaction pathway having a transition state (TS) structure similar to that of the benzenesulfonyl chloride reaction. This interpretation is further supported by the activation parameters, i.e., relatively small positive ${\Delta}H^{\neq}$ (12.0 to $15.9kcal{\cdot}mol^{-1}$) and large negative ${\Delta}S^{\neq}$ (-23.1 to $-36.3cal{\cdot}mol^{-1}{\cdot}K^{-1}$) values, and the solvent kinetic isotope effects (SKIEs, 1.34 to 1.88). Also, the selectivity values (S = 1.2 to 2.9) obtained in binary solvents are consistent with the proposed mechanism.

• 대한화학회지
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• 제7권4호
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• pp.264-270
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• 1963

前報에서 誘導한 置換基效果 一般關係式은 溶媒組成에 따르는 常數, Y를 potential energy 項에 代置함으로서 solvolysis 反應에 適用할 수가 있다. 新方程式, $\Delta{\Delta}H^\neq=a'Y+b\Delta{\Delta}S^\neq$, 의 適用性은 文獻에 報告된 35個反應에 對한 直線關係를 調査해 봄으로서 檢討하였다. 結果로 平均 相關係數 0.977을 얻었고, 따라서 이 方程式이 solvolysis反應에 一般的으로 適用됨을 밝혔고, 또 Grunwald-Winstein의 式이 지니는 몇몇 難點을 解決할 수가 있음을 알 수 있었다. enthalypy-entopy 直線效果는 外部 enthalpy와 外部 entropy에 限한 것이며, 嚴格히 말해서 外部 enthalpy entropy 直線效果임을 强調하였다.

• Bulletin of the Korean Chemical Society
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• 제26권11호
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• pp.1761-1766
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• 2005

Solvolysis rates of isopropenyl chloroformate (3) in water, $D_2O$, $CH_3OD$ and in aqueous methanol, ethanol, 2,2,2-trifluoroethanol (TFE), acetone, 1,4-dioxane as well as TFE-ethanol at 10 ${^{\circ}C}$ are reported. Additional kinetic data for pure water, pure ethanol and 80%(w/w) 2,2,2-trifuoroethanol (T)-water (W) at various temperatures are also reported. These rates show the phenomena of maximum rates in specific solvents (30% (v/v) methanol-water and 20% (v/v) ethanol-water) and, variations in relative rates are small in aqueous alcohols. The kinetic data are analyzed in terms of GW correlations, steric effect, kinetic solvent isotope effects (KSIE), and a third order model based on general base catalysis (GBC). Solvolyses based on predominately stoichiometric solvation effect relative to medium solvation are proceeding in 3 and the results are remarkably similar to those for p-nitrobenzoyl chloride (4) in mechanism and reactivity.

• Bulletin of the Korean Chemical Society
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• 제30권10호
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• pp.2413-2418
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• 2009

Rates of solvolyses of 4-nitrophenyl phenyl thiophosphorochloridate (4-N$O_2$PhOP(S)(Cl)OPh, $\underline{1}$) in ethanol, methanol, and aqueous binary mixtures incorporating ethanol, methanol, acetone, and 2,2,2-trifluroethanol (TFE) are reported. Thermodynamic parameters were determined at several temperatures in three representative solvents. The extended Grunwald-Winstein equation was applied to 29 solvents and the correlation coefficient (R) showed 0.959. The sensitivities (l = 1.37 and m = 0.62) are similar to those obtained for diphenyl thiophosphorochloridate (($PhO)_2$PSCl, $\underline{2}$), diphenyl phosphorochloridate (($PhO)_2$POCl, $\underline{3}$), diphenyl phosphinic chloride ($Ph_2$POCl, $\underline{4}$), and diphenyl thiophosphinic chloride ($Ph_2$PSCl, $\underline{5}$). The solvolytic reaction mechanism of 4-nitrophenyl phenyl thiophosphorochloridate ($\underline{1}$) is suggested to be proceeded a $S_N$2 process as previously reported result. The activation enthalpies are shown as slightly low as ${\Delta}H^{\neq}\;=\;9.62\;to\;11.9\;kcal{\cdot}mol^{-1}$ and the activation entropies are shown as slightly high negative value as ${\Delta}S^{\neq}\;=\;-34.1\;to\;-44.9\;cal{\cdot}mol^{-1}{\cdot}K^{-1}$ compared to the expected $S_N$2 reaction mechanism. Kinetic solvent isotope effects are accord with a typical $S_N$2 mechanism as shown in the range of 2.41 in MeOH/ MeOD and 2.57 in $H_2O/D_2O$ solvent mixtures.