The RS-•HSR hydrogen bond:: Acidities of α,ω-dithiols and electron affinities of their monoradicals
The RS-•HSR hydrogen bond:: Acidities of α,ω-dithiols and electron affinities of their monoradicals
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DOI：
10.1021/ja0039684
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发表时间：
2001-10-10
影响因子：
15
通讯作者：
Brauman, JI
中科院分区：
文献类型：
--
作者：
Karty, JM;Wu, YS;Brauman, JI
使用傅里叶变换离子回旋共振 (Fr-ICR) 质谱仪测量了 1,2-乙二硫醇、1,3-丙二硫醇和 1,4-丁二硫醇的气相酸度 (DeltaG(acid)(o))。这些化合物的硫醇盐单自由基的绝热电子亲和势 (EA) 是根据使用 cw-ICR 获得的相应硫醇盐单阴离子的电子光脱离光谱来确定的。与类似的单硫醇物质相比，二硫醇表现出增强的酸度（在 DeltaG(acid)(o) 中高达 8.7 kcal/mol）和更高的 EA（高达 6.7 kcal/mol）。这些差异归因于分子内 RS-。硫醇阴离子中的 HSR 氢键。 RO-的考虑因素。 α、omega-二醇的单阴离子和 [CH3O- 中的 HOR 氢键。 HOCH3]络合阴离子提示RS-。 HSR 氢键提供高达 9 kcal/mol 的额外稳定性。
Gas-phase acidities (DeltaG(acid)(o)) have been measured for 1,2-ethanedithiol, 1,3-propanedithiol, and 1,4- butanedithiol, using a Fourier transform ion cyclotron resonance (Fr-ICR) mass spectrometer. Adiabatic electron affinities (EAs) of the thiolate monoradicals of these compounds were assigned from electron photodetachment spectra of their corresponding thiolate monoanions, acquired using a cw-ICR. The dithiols exhibit enhanced acidities (up to 8.7 kcal/mol in DeltaG(acid)(o)) and greater EAs (up to 6.7 kcal/mol) than analogous monothiol species. These differences are attributed to an intramolecular RS-. HSR hydrogen bond in the thiolate anion. Considerations of the RO-. HOR hydrogen bond in monoanions of alpha,omega -diols and in the [CH3O-. HOCH3] complex anion suggest that the RS-. HSR hydrogen bond provides up to 9 kcal/mol extra stabilization.