A Kinetic Study on Solvolysis of Diphenyl Thiophosphorochloridate

Bulletin of the Korean chemical society

Han Joong Koh¹  Suk Jin Kang¹  Dennis N Kevill¹ 

关键词: Diphenyl thiophosphorochloridate;    Extended Grunwald-Winstein equation;    SN2 mechanism;   

DOI  :  

学科分类：化学（综合）

来源: Korean Chemical Society

【 摘 要 】

Rates of solvolyses of diphenyl thiophosphorochloridate ((PhO)₂PSCl, 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)₂PSCl, 1) were similar to those obtained for diphenyl phosphorochloridate ((PhO)₂POCl, 2), diphenylphosphinyl chloride (Ph₂POCl, 3) and diphenylthiophosphinyl chloride (Ph₂PSCl, 4). As with the previously studied of 3~4 solvolyses, an S_N2 pathway is proposed for the solvolyses of diphenyl thiophosphorochloridate (1). The activation parameters, ツH× (= 11.6~13.9 kcal?mol^-1) and ツS× (= -32.1 ~ -42.7 cal?mol-1?K^-1), were determined, and they were in line with values expected for an SN2 reaction. The large kinetic solvent isotope effects (KSIE, 2.44 in MeOH/MeOD and 3.46 in H₂O/D₂O) are also well explained by the proposed SN2 mechanism.

【 授权许可】

Unknown