三氟甲磺酸

三氟甲磺酸
	IUPAC名; Trifluoromethanesulfonic acid
别名	三氟甲基磺酸、三氟甲烷磺酸、; TfOH、TFSA、TFMS
识别
CAS号	1493-13-6（无水） ; 49789-04-0（一水）
PubChem	62406
SMILES	FC(F)(F)S(=O)(O)=O;
性质
化学式	CF3SO3H
摩尔质量	150.08 g·mol⁻¹
外观	无色液体
密度	1.696 g/mL
熔点	-40 °C
沸点	162 °C
溶解性（水）	混溶
危险性
主要危害	强腐蚀性
	若非注明，所有数据均出自标准状态（25 ℃，100 kPa）下。

三氟甲磺酸是一种很强的有机酸，化学式为CF₃SO₃H。它在酯化反应中可用作催化剂。^[2]^[3]

合成

三氟甲磺酸首次于1954年由Haszeldine和Kidd以如下途径制得:^[4]

三氟甲磺酸的工业制备可通过甲磺酸的电化学氟化（ECF）得到：

CH₃SO₃H + 4 HF → CF₃SO₂F + H₂O + 1.5 H₂

反应产物CF₃SO₂F通过水解，得到三氟甲磺酸。另外，制备三氟甲磺酸也可使用三氟甲基氯化硫为原料，和氯气反应、水解得到：^[5]

CF₃SCl + 2 Cl₂ + 2 H₂O → CF₃SO₂OH + 4 HCl

以上途径制得的粗产物可加入三氟甲磺酸酐蒸馏而纯化。^[3]

性质

三氟甲磺酸滴在纸上，让纸脱水。

三氟甲磺酸常温下是一种有吸水性和脱水性的无色液体，可溶于极性溶剂，如二甲基甲酰胺、二甲基亚砜、乙腈和二甲基砜。但由于接触时反应会剧烈放热，将它加入极性溶剂中可能产生危险。三氟甲磺酸是一种超强酸，K_a = 1 ×10¹²（pKa ~ −12）^[6] 。由于它的热稳定性和化学稳定性很强，它和它的共轭碱（CF₃SO−
3）都有较多的用途。共轭碱三氟甲磺酸根能够抵抗氧化还原反应的发生，这和很多同时具有强氧化性的强酸形成了鲜明的对比，如高氯酸、硫酸、硝酸等。它也不容易让其他物质磺化，因此无需和在使用硫酸、氟代硫酸和氯磺酸时一样担心这个反应的发生。

三氟甲磺酸在湿润的空气中发烟，这源自于形成的一水合物固体，CF₃SO₃H·H₂O，熔点为34~35 °C。^[7]

酸性

三氟甲磺酸是一种超强酸，具有酸的通性，如和金属、氧化物、弱酸盐、碱反应，得到相应的三氟甲磺酸盐：^[8]^[9]

Cu₂(OH)₂CO₃ + 4 CF₃SO₃H → 2 Cu(CF₃SO₃)₂ + CO₂↑ + 3 H₂O

(CH₃)₂NCl + CF₃SO₃H → [(CH₃)₂NClH]CF₃SO₃

它可以直接将W(CH)L₄Cl（L=P(CH₃)₃）质子化，得到[W(CH₂)L₄Cl]CF₃SO₃。^[10]

W(CH)L₄Cl + CF₃SO₃H → [W(CH₂)L₄Cl]CF₃SO₃

它和双(三苯基磷)(乙烯)铂(0)反应，会同时生成乙烷、配盐（(PPh₃)₂Pt(OSO₂CF₃)₂）和酯（CF₃SO₃C₂H₅）。^[11]

形成磺酸衍生物

三氟甲磺酸和醇等有机物发生酯化反应，可以形成酯，但反应中会同时会生成醚和烯烃。如它和乙醇反应，其主产物是乙酸乙酯（45%），同时产物副产物乙醚（19%）和乙烯（13%）。它也可以可逆地和乙烯或乙醚反应，得到三氟甲磺酸乙酯。^[12]

它和五氯化磷加热反应，可以得到三氟甲磺酰氯（53%）和三氟甲磺酸酐（20%）。^[12]

其它反应

三氟甲磺酸和Se(NSO)₂反应，可以得到[Se₂N₂S]₂(CF₃SO₃)₂。^[13]

它和Tl₅[Nb₂S₄Br₈]Br在湿乙腈中反应，得到含S₂桥的水合铌配合物[Nb₂(μ₂-S₂)₂(H₂O)₈](CF₃SO₃)₄·2H₂O。^[14]

用途

三氟甲磺酸可用作一些有机反应的催化剂，如吲哚和吡咯的傅克氨烷基化反应^[15]、醇的酰基化反应^[16]、氢胺化反应及氢烷氧基化反应^[17]等。

安全警示

三氟甲磺酸是已知的最强酸之一，任何时候都应当谨慎地处理该物质。如不慎接触眼睛，它会造成从烧伤甚至到失明不等的严重伤害。如接触皮肤，三氟甲磺酸会造成皮肤烧伤和长期的组织损伤。如少量CF₃SO₃H·H₂O被吸入肺部，它将造成痉挛、炎症和水肿。^[18]

参考资料

^ Gutowski, Keith E.; Holbrey, John D.; Rogers, Robin D.; Dixon, David A. Prediction of the Formation and Stabilities of Energetic Salts and Ionic Liquids Based on ab Initio Electronic Structure Calculations. The Journal of Physical Chemistry B. 16 November 2005, 109 (49): 23196–23208 [2022-07-20]. ISSN 1520-6106. PMID 16375283. doi:10.1021/jp053985l. eISSN 1520-5207. （原始内容存档于2020-02-03）.
^ Howells, R. D., McCown, J. D. Trifluoromethanesulfonic Acid and Derivatives. Chemical Reviews. 1977, 77: 69–92. doi:10.1021/cr60305a005.
^ ^3.0 ^3.1 Trifluoromethanesulfonic Acid. Encyclopedia of Reagents for Organic Synthesis（英语：Encyclopedia of Reagents for Organic Synthesis）. John Wiley & Sons, Ltd. 2006. doi:10.1002/047084289X.rt246.pub2.
^ Haszeldine, R. N.; Kidd, J. M. Perfluoroalkyl derivatives of sulphur. Part I. Trifluoromethanesulphonic acid. Journal of the Chemical Society. 1954, 1954: 4228–4232. doi:10.1039/JR9540004228.
^ Siegemund, G.; Schwertfeger, W.; Feiring, A.; Smart, B.; Behr, F.; Vogel, H.; McKusick, B. Fluorine Compounds, Organic. Ullmann's Encyclopedia of Industrial Chemistry. John Wiley & Sons. 2000. doi:10.1002/14356007.a11_349.
^ Raamat, E.; Kaupmees, K.; Ovsjannikov, G.; Trummal, A.; Kütt, A.; Saame, J.; Koppel, I.; Kaljurand, I.; Lipping, L.; Rodima, T.; Pihl, V.; Koppel, I. A.; Leito, I. "Acidities of strong neutral Brønsted acids in different media." J. Phys. Org. Chem. 2013, 26, 162-170. doi:10.1002/poc.2946
^ Spencer, J. B.; Lundgren, J. O. Hydrogen bond studies. LXXIII. The crystal structure of trifluoromethanesulphonic acid monohydrate, H3O+CF3SO3−, at 298 and 83 K. Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry. 15 September 1973, 29 (9): 1923–1928 [2022-07-20]. ISSN 0567-7408. doi:10.1107/S0567740873005765. （原始内容存档于2022-07-20）.
^ Takei, Tatsuko. Preparation of cupric trifluoromethanesulphonate and its properties. Surface Technology. August 1984, 22 (4): 343–352 [2022-07-23]. ISSN 0376-4583. doi:10.1016/0376-4583(84)90098-0. （原始内容存档于2022-07-23）.
^ Muench, Volker. Synthesis of dimethyl-N-chloroammonium trifluoromethanesulfonate ((CH₃)₂NClH⁺CF₃SO₃^-). Zeitschrift fuer Anorganische und Allgemeine Chemie. 1981, 477: 217–220. ISSN 0044-2313 （德语）. CODEN ZAACAB
^ Holmes, Steven J.; Schrock, Richard R. A tungsten T-shaped methylene complex and related methylidyne hydride complexes. Journal of the American Chemical Society. July 1981, 103 (15): 4599–4600 [2022-07-23]. ISSN 0002-7863. doi:10.1021/ja00405a060. eISSN 1520-5126. （原始内容存档于2022-07-23）.
^ Foley, Paul; Whitesides, George M. Reactions of tetrakis(triphenylphosphine)platinum(0) and (ethylene)bis(triphenylphosphine)platinum(0) with strong proton acids. Inorganic Chemistry. May 1980, 19 (5): 1402–1404 [2022-07-23]. ISSN 0020-1669. doi:10.1021/ic50207a065. eISSN 1520-510X. （原始内容存档于2022-07-23）.
^ ^12.0 ^12.1 Howells, R. D.; Mc Cown, J. D. Trifluoromethanesulfonic acid and derivatives. Chemical Reviews. 1 February 1977, 77 (1): 69–92 [2022-07-23]. ISSN 0009-2665. doi:10.1021/cr60305a005. eISSN 1520-6890. （原始内容存档于2022-07-23）.
^ Haas, Alois; Kasprowski, Joerg; Pryka, Michael. Synthesis, structures, and properties of Cl2TeSeN2S and [Se2N2S]22+[XSO3-]2 (X = F, CF3). Chemische Berichte. 1992, 125 (4): 789–792. ISSN 0009-2940 （德语）. CODEN CHBEAM
^ Sokolov, M. N.; Rogachev, A. V.; Abramov, P. A. Synthesis and Crystal Structure of NB Aqua Complex [Nb2(µ2-S2)2(H2O)8](CF3SO3)4·2H2O. Journal of Cluster Science. 8 June 2014, 26 (1): 27–32 [2022-07-23]. ISSN 1040-7278. doi:10.1007/s10876-014-0738-9. eISSN 1572-8862. （原始内容存档于2022-07-23）.
^ Abid, Mohammed; Teixeira, Liliana; Török, Béla. Triflic Acid-Catalyzed Highly Stereoselective Friedel−Crafts Aminoalkylation of Indoles and Pyrroles. Organic Letters. 7 February 2008, 10 (5): 933–935. ISSN 1523-7060. PMID 18254637. doi:10.1021/ol703095d. eISSN 1523-7052.
^ Dumeunier, Raphaël; Markó, István E. On the role of triflic acid in the metal triflate-catalysed acylation of alcohols. Tetrahedron Letters. January 2004, 45 (4): 825–829. ISSN 0040-4039. doi:10.1016/j.tetlet.2003.11.034.
^ Devon C. Rosenfeld, Shashank Shekhar, Akihiro Takemiya, Masaru Utsunomiya, and John F. Hartwig. Hydroamination and Hydroalkoxylation Catalyzed by Triflic Acid. Parallels to Reactions Initiated with Metal Triflates. Org. Lett. 2006, 8 (19): 4179–4182. doi:10.1021/ol061174+.
^ Trifluoromethanesulfonic acid MSDS. ChemCAS. [2015-03-26]. （原始内容存档于2015-04-02）.

[1] Gutowski, Keith E.; Holbrey, John D.; Rogers, Robin D.; Dixon, David A. Prediction of the Formation and Stabilities of Energetic Salts and Ionic Liquids Based on ab Initio Electronic Structure Calculations. The Journal of Physical Chemistry B. 16 November 2005, 109 (49): 23196–23208 [2022-07-20]. ISSN 1520-6106. PMID 16375283. doi:10.1021/jp053985l. eISSN 1520-5207. （原始内容存档于2020-02-03）.

[2] Howells, R. D., McCown, J. D. Trifluoromethanesulfonic Acid and Derivatives. Chemical Reviews. 1977, 77: 69–92. doi:10.1021/cr60305a005.

[eros-3] 3.0 ^3.1 Trifluoromethanesulfonic Acid. Encyclopedia of Reagents for Organic Synthesis（英语：Encyclopedia of Reagents for Organic Synthesis）. John Wiley & Sons, Ltd. 2006. doi:10.1002/047084289X.rt246.pub2.

[Haszeldine-4] Haszeldine, R. N.; Kidd, J. M. Perfluoroalkyl derivatives of sulphur. Part I. Trifluoromethanesulphonic acid. Journal of the Chemical Society. 1954, 1954: 4228–4232. doi:10.1039/JR9540004228.

[Gunt-5] Siegemund, G.; Schwertfeger, W.; Feiring, A.; Smart, B.; Behr, F.; Vogel, H.; McKusick, B. Fluorine Compounds, Organic. Ullmann's Encyclopedia of Industrial Chemistry. John Wiley & Sons. 2000. doi:10.1002/14356007.a11_349.

[6] Raamat, E.; Kaupmees, K.; Ovsjannikov, G.; Trummal, A.; Kütt, A.; Saame, J.; Koppel, I.; Kaljurand, I.; Lipping, L.; Rodima, T.; Pihl, V.; Koppel, I. A.; Leito, I. "Acidities of strong neutral Brønsted acids in different media." J. Phys. Org. Chem. 2013, 26, 162-170. doi:10.1002/poc.2946

[7] Spencer, J. B.; Lundgren, J. O. Hydrogen bond studies. LXXIII. The crystal structure of trifluoromethanesulphonic acid monohydrate, H3O+CF3SO3−, at 298 and 83 K. Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry. 15 September 1973, 29 (9): 1923–1928 [2022-07-20]. ISSN 0567-7408. doi:10.1107/S0567740873005765. （原始内容存档于2022-07-20）.

[8] Takei, Tatsuko. Preparation of cupric trifluoromethanesulphonate and its properties. Surface Technology. August 1984, 22 (4): 343–352 [2022-07-23]. ISSN 0376-4583. doi:10.1016/0376-4583(84)90098-0. （原始内容存档于2022-07-23）.

[9] Muench, Volker. Synthesis of dimethyl-N-chloroammonium trifluoromethanesulfonate ((CH₃)₂NClH⁺CF₃SO₃^-). Zeitschrift fuer Anorganische und Allgemeine Chemie. 1981, 477: 217–220. ISSN 0044-2313 （德语）. CODEN ZAACAB

[10] Holmes, Steven J.; Schrock, Richard R. A tungsten T-shaped methylene complex and related methylidyne hydride complexes. Journal of the American Chemical Society. July 1981, 103 (15): 4599–4600 [2022-07-23]. ISSN 0002-7863. doi:10.1021/ja00405a060. eISSN 1520-5126. （原始内容存档于2022-07-23）.

[11] Foley, Paul; Whitesides, George M. Reactions of tetrakis(triphenylphosphine)platinum(0) and (ethylene)bis(triphenylphosphine)platinum(0) with strong proton acids. Inorganic Chemistry. May 1980, 19 (5): 1402–1404 [2022-07-23]. ISSN 0020-1669. doi:10.1021/ic50207a065. eISSN 1520-510X. （原始内容存档于2022-07-23）.

[Howells-12] 12.0 ^12.1 Howells, R. D.; Mc Cown, J. D. Trifluoromethanesulfonic acid and derivatives. Chemical Reviews. 1 February 1977, 77 (1): 69–92 [2022-07-23]. ISSN 0009-2665. doi:10.1021/cr60305a005. eISSN 1520-6890. （原始内容存档于2022-07-23）.

[13] Haas, Alois; Kasprowski, Joerg; Pryka, Michael. Synthesis, structures, and properties of Cl2TeSeN2S and [Se2N2S]22+[XSO3-]2 (X = F, CF3). Chemische Berichte. 1992, 125 (4): 789–792. ISSN 0009-2940 （德语）. CODEN CHBEAM

[14] Sokolov, M. N.; Rogachev, A. V.; Abramov, P. A. Synthesis and Crystal Structure of NB Aqua Complex [Nb2(µ2-S2)2(H2O)8](CF3SO3)4·2H2O. Journal of Cluster Science. 8 June 2014, 26 (1): 27–32 [2022-07-23]. ISSN 1040-7278. doi:10.1007/s10876-014-0738-9. eISSN 1572-8862. （原始内容存档于2022-07-23）.

[15] Abid, Mohammed; Teixeira, Liliana; Török, Béla. Triflic Acid-Catalyzed Highly Stereoselective Friedel−Crafts Aminoalkylation of Indoles and Pyrroles. Organic Letters. 7 February 2008, 10 (5): 933–935. ISSN 1523-7060. PMID 18254637. doi:10.1021/ol703095d. eISSN 1523-7052.

[16] Dumeunier, Raphaël; Markó, István E. On the role of triflic acid in the metal triflate-catalysed acylation of alcohols. Tetrahedron Letters. January 2004, 45 (4): 825–829. ISSN 0040-4039. doi:10.1016/j.tetlet.2003.11.034.

[17] Devon C. Rosenfeld, Shashank Shekhar, Akihiro Takemiya, Masaru Utsunomiya, and John F. Hartwig. Hydroamination and Hydroalkoxylation Catalyzed by Triflic Acid. Parallels to Reactions Initiated with Metal Triflates. Org. Lett. 2006, 8 (19): 4179–4182. doi:10.1021/ol061174+.

[18] Trifluoromethanesulfonic acid MSDS. ChemCAS. [2015-03-26]. （原始内容存档于2015-04-02）.

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