Trifluoromethyl cation

Trifluoromethyl cation

The structure of the cation.
Names
Systematic IUPAC name Trifluoromethylcarbenium
Identifiers
CAS Number	18851-76-8
CompTox Dashboard (EPA)	DTXSID001314852
InChI InChI=1S/CF3/c2-1(3)4/q+1
Properties
Chemical formula	CF3+
Molar mass	69.0054
Solubility in water	reacts
Structure
Molecular shape	Trigonal planar
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Trifluoromethyl cation is a molecular cation with a formula of CF₃⁺.

Stability

It is a somewhat stable molecule (compared to methyl cations). The fluorine atoms have lone pairs overlapping with the ring. The overlap is effective due to the relative sizes of the p orbital in the molecule.

Synthesis

While electron-donating fluorine lone pairs are present, it does not exist as its own. The production of an CF₃⁺ cation has been described as "extremely hard". The first relevant reagent, a diaryl(trifluoromethyl) sulfonium salt (Ar₂S⁺CF₃SbF₆⁻) was developed in 1984 by reaction of an aryltrifluoromethyl sulfoxide 1 with SF₃⁺SbF₆⁻ followed by reaction with an electron-rich arene. Now the reaction usually uses 5-(Trifluoromethyl)dibenzothiophenium tetrafluoroborate as the reagent.

One of the active reagents for making the cation.