The perfluorinated alcohols (F5C6)(F3C)2COH and (F5C6)(F10C5)COH: synthesis, theoretical and acidity studies, spectroscopy and structures in the solid state and the gas phase.
The perfluorinated alcohols (F5C6)(F3C)2COH and (F5C6)(F10C5)COH: synthesis, theoretical and acidity studies, spectroscopy and structures in the solid state and the gas phase.
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全氟醇 (F5C6)(F3C)2COH 和 (F5C6)(F10C5)COH：合成、理论和酸度研究、固态和气相的光谱和结构。
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
I. Krossing
中科院分区：
文献类型：
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作者：
Nils Trapp;H. Scherer;Stuart A. Hayes;R. J. Berger;A. Kütt;N. Mitzel;J. Saame;I. Krossing
描述了全氟醇(F(5)C(6))(F(3)C)(2)COH(1)和(F(5)C(6))(C(5)F(10))COH(2)的合成。通过相应的酮与C(6)F(5)MgBr反应，然后进行酸性加工，以合理的产率（1:65 %,2:85 %）制备了这两种化合物。通过核磁共振、振动光谱、单晶x射线衍射、酸度测量和气相电子衍射对醇类进行了表征。结合适当的二维核磁共振实验，可以明确地分配（19）F自旋系统中的所有信号，其中2的自旋系统特别复杂。酸度测量和计算的气相酸度表明醇的高酸度。它也被2的晶体结构所支持，2的晶体结构只有一个弱的分子间氢桥。0距离为下午301点。这表明化合物中氧原子的供体强度较低，这部分是通过与不参与氢桥的质子形成两个长度为220和232 pm的分子内CF…H接触来补偿的。在乙腈中的pK(a)值分别为22.2和22.0；计算得到的气相酸度分别为1367和1343 kJ mol(-1) （MP2/TZVPP水平）。
The syntheses of the perfluorinated alcohols (F(5)C(6))(F(3)C)(2)COH (1) and (F(5)C(6))(C(5)F(10))COH (2) are described. Both compounds were prepared in reasonable yields (1: 65%, 2: 85%) by reacting the corresponding ketone with C(6)F(5)MgBr, followed by acidic work-up. The alcohols were characterized by NMR, vibrational spectroscopy, single-crystal X-ray diffraction, acidity measurements and gas-phase electron diffraction. A combination of appropriate 2D NMR experiments allowed the unambiguous assignment of all signals in the (19)F spin systems, of which that of 2 was especially complex. High acidity of the alcohols is indicated by acidity measurements as well as the calculated gas phase acidities. It is also supported by the crystal structure of 2, which exhibits only a single weak intermolecular hydrogen bridge with an O...O distance of 301 pm. This shows the low donor strength of the oxygen atom in the compound, which is partly compensated through formation of two intramolecular CF...H contacts of 220 and 232 pm length to the proton not involved in the hydrogen bridge. The pK(a) values in acetonitrile are 22.2 for 1 and 22.0 for 2; their calculated gas phase acidities are 1367 and 1343 kJ mol(-1) (MP2/TZVPP level).