Silver trifluoromethanesulfonate

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Silver trifluoromethanesulfonate
Silver triflate.png
Names
IUPAC name
silver trifluoromethanesulfonate
Other names
Silver triflate
Identifiers
3D model (JSmol)
ECHA InfoCard 100.018.985
Properties
CF3SO3Ag
Molar mass 256.937 g/mol
Odor odorless
Melting point 286 °C (547 °F; 559 K)
soluble
Hazards
Safety data sheet Oxford MSDS
Harmful (Xn)
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentine Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Silver trifluoromethanesulfonate, or silver triflate is the triflate (CF3SO3) salt of Ag+. It is a white or colorless solid that is soluble in water and some organic solvents. It is a reagent in the synthesis of organic and inorganic triflates.

Synthesis[edit]

An early preparation method starts from the barium salt of trifluoromethanesulfonic acid (TfOH), from which the free TfOH is formed with dilute sulfuric acid, which is then neutralized with silver carbonate (Ag2CO3).[1][2]

Synthese von Silbertriflat aus Bariumtriflat

The silver triflate is thereby obtained in a yield of 95% and can be recrystallized from benzene/tetrachloromethane or ether/tetrachloromethane for purification.

In an improved version by George Whitesides, dilute TfOH is reacted with silver(I)oxide (Ag2O), which produces AgOTf in 98% yield.[3]

Reactions[edit]

It is used to prepare alkyl triflates from alkyl halides:[4]

CF3SO2OAg + RX → CF3SO2OR + AgX (X = iodide usually)

In coordination chemistry, the salt is also useful to replace halide ligands with the more labile triflate ligand. For example, bromopentacarbonylrhenium can be converted to the more labile derivative using silver triflate:[5]

CF3SO2OAg + BrRe(CO)5 → CF3SO2ORe(CO)5 + AgBr

References[edit]

  1. ^ R.N. Haszeldine, J.M. Kidd (1954), "Perfluoroalkyl derivatives of sulphur. Part I. Trifluoromethanesulphonic acid" (in German), J. Chem. Soc.: pp. 4228–4232, doi:10.1039/JR9540004228 
  2. ^ T. Gramstadt, R.N. Haszeldine (1956), "33. Perfluoroalkyl derivatives of sulphur. Part IV. Perfluoroalkanesulphonic acids" (in German), J. Chem. Soc.: pp. 173–180, doi:10.1039/JR9560000173 
  3. ^ G.M. Whitesides, F.D. Gutowski (1976), "Reaction of α, ω-di-Grignard reagents with silver(I) salts form carbocyclic rings" (in German), J. Org. Chem. 41 (17): pp. 2882–2885, doi:10.1021/ja00879a019 
  4. ^ Stang, Peter J.; Hanack, Michael; Subramanian, L. R. (1982). "Perfluoroalkanesulfonic Esters: Methods of Preparation and Applications in Organic Chemistry". Synthesis. 1982 (02): 85–126. ISSN 0039-7881. doi:10.1055/s-1982-29711. 
  5. ^ Steven P. Schmidt, Jay Nitschke, William C. Trogler (1989). "Manganese(I) and Rhenium(I) Pentacarbonyl(Trifluoromethanesulfonato) Complexes". Inorganic Syntheses. 26: 113–117. doi:10.1002/9780470132579.ch20.