Chemistry:Silver trifluoromethanesulfonate

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Silver trifluoromethanesulfonate
Silver triflate.png
Silver-triflate-3D-vdW.png
Names
IUPAC name
silver trifluoromethanesulfonate
Other names
Silver triflate
Identifiers
3D model (JSmol)
Abbreviations AgOTf
ChemSpider
EC Number
  • 220-882-2
UNII
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
GHS pictograms GHS05: CorrosiveGHS07: Harmful
GHS Signal word Danger
H315, H319, H335
P260, P261, P264, P271, P280, P301+330+331, P302+352, P303+361+353, P304+340, P305+351+338, P310, P312, P321, P332+313, P337+313, P362, P363, P403+233, P405, P501
NFPA 704 (fire diamond)
Flammability code 0: Will not burn. E.g. waterHealth code 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineReactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no codeNFPA 704 four-colored diamond
0
1
0
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 including, benzene. It is a reagent used in the synthesis of organic and inorganic triflates.

Synthesis

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).[2][3]

[math]\ce{ Ba^2+[{^-}OSO2CF3]2 ->[\ce{H2SO4}][-\ce{BaSO4}] CF3SO2OH ->[\ce{Ag2CO3}] CF3SO2O^- Ag+ }[/math]

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.[4]

Reactions

It is used to prepare alkyl triflates from alkyl halides:[5]

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:[6]

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

References

  1. "Silver trifluoromethanesulfonate" (in en). https://pubchem.ncbi.nlm.nih.gov/compound/76223#section=Safety-and-Hazards. 
  2. R.N. Haszeldine, J.M. Kidd (1954), "Perfluoroalkyl derivatives of sulphur. Part I. Trifluoromethanesulphonic acid" (in German), J. Chem. Soc.: 4228–4232, doi:10.1039/JR9540004228 
  3. T. Gramstadt, R.N. Haszeldine (1956), "33. Perfluoroalkyl derivatives of sulphur. Part IV. Perfluoroalkanesulphonic acids" (in German), J. Chem. Soc.: 173–180, doi:10.1039/JR9560000173 
  4. G.M. Whitesides, F.D. Gutowski (1976), "Reaction of α, ω-di-Grignard reagents with silver(I) salts form carbocyclic rings", J. Org. Chem. 41 (17): 2882–2885, doi:10.1021/jo00879a019 
  5. Stang, Peter J.; Hanack, Michael; Subramanian, L. R. (1982). "Perfluoroalkanesulfonic Esters: Methods of Preparation and Applications in Organic Chemistry". Synthesis 1982 (2): 85–126. doi:10.1055/s-1982-29711. ISSN 0039-7881. 
  6. Steven P. Schmidt; Jay Nitschke; William C. Trogler (1989). "Manganese(I) and Rhenium(I) Pentacarbonyl(Trifluoromethanesulfonato) Complexes". Inorganic Syntheses. 26. pp. 113–117. doi:10.1002/9780470132579.ch20. ISBN 978-0-470-13257-9.