Silver trifluoromethanesulfonate

Template:Chembox image cellTemplate:Chembox image cellTemplate:Chembox AllOtherNamesTemplate:Chembox headerbarTemplate:Chembox IndexlistTemplate:Chembox JmolTemplate:Chembox ChEMBLTemplate:Chembox ECHATemplate:Chembox E numberTemplate:Chembox IUPHAR ligandTemplate:Chembox UNIITemplate:Chembox CompToxTemplate:Chembox headerbarTemplate:Chembox SolubilityInWaterTemplate:Chembox HazardsTemplate:Chembox Datapage checkTemplate:Yesno

Silver trifluoromethanesulfonate

Template:Longitem	Template:Unbulleted list
Abbreviations	AgOTf
ChEBI	Template:Unbulleted list
ChemSpider	Template:Unbulleted list
DrugBank	Template:Unbulleted list
EC Number	Template:Unbulleted list
KEGG	Template:Unbulleted list
Template:Longitem	Template:Unbulleted list
RTECS number	Template:Unbulleted list
Template:Longitem	CF3SO3Ag
Molar mass	256.937 g/mol
Odor	odorless
Melting point	Template:Chembox CalcTemperatures

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).

$\mathrm{B}\mathrm{a}{\phantom{A}}^{2+}[{}^{\text{-}}\mathrm{O}\mathrm{S}\mathrm{O}{\phantom{A}}_2\mathrm{C}\mathrm{F}{\phantom{A}}_3]{\phantom{A}}_2\underset{-\mathrm{B}\mathrm{a}\mathrm{S}\mathrm{O}{\phantom{A}}_4}{\overset{\mathrm{H}{\phantom{A}}_2\mathrm{S}\mathrm{O}{\phantom{A}}_4}{\to }}\mathrm{C}\mathrm{F}{\phantom{A}}_3\mathrm{S}\mathrm{O}{\phantom{A}}_2\mathrm{O}\mathrm{H}\stackrel{\mathrm{A}\mathrm{g}{\phantom{A}}_2\mathrm{C}\mathrm{O}{\phantom{A}}_3}{\to }\mathrm{C}\mathrm{F}{\phantom{A}}_3\mathrm{S}\mathrm{O}{\phantom{A}}_2\mathrm{O}{\phantom{A}}^{-}\mathrm{A}\mathrm{g}{\phantom{A}}^{+}$

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.

Reactions

It is used to prepare alkyl triflates from alkyl halides:

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:

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