Organic Acids
REACH
Trifluoromethanesulfonic acid
CAS Number
1493-13-6
EC Number
216-087-5
Abbreviation
TfOH
What is Trifluoromethanesulfonic acid?
Trifluoromethanesulfonic acid (CAS 1493-13-6), known as triflic acid or TfOH, is one of the strongest known Brønsted acids and a highly reactive proton donor.
Where is Trifluoromethanesulfonic acid used?
- Pharmaceutical synthesis: drives acid-catalyzed cyclizations, glycosylations and Friedel-Crafts-type reactions where milder acids fail
- Polymer manufacturing: initiates cationic polymerization for specialty polymers, including polybenzimidazoles and polyarylenes for membranes
- Textile and paper processing: catalyst for surface treatment and finishing chemistries requiring precise pH control
- Triflate salts serve as precursors to ionic liquid systems and metal triflate Lewis acid catalysts.
Other Names (Synonyms)
Triflic acid|TfOH
What are the physical properties of Trifluoromethanesulfonic acid?
Melting Point <25 °C
Boiling Point 162 °C
Density 1.69 g/cm³ (liquid)
Flash Point None
Appearance Clear very light yellow liquid
Color slightly brown
Form Fuming Liquid
Water Solubility SOLUBLE
Vapor Pressure 8 mm Hg ( 25 °C)
Refractive Index n 20/D 1.327(lit.)
pH <1 (H2O)
Log P 0.3 at 25℃
How is Trifluoromethanesulfonic acid classified and handled safely? Learn More
Danger
GHS05· Corrosive GHS07· Irritant
Hazard Statements
H290 May be corrosive to metals
H302 Harmful if swallowed
H314 Causes severe skin burns and eye damage
H319 Causes serious eye irritation
H335 May cause respiratory irritation
Precautionary Statements
P234 Keep only in original packaging.
P260 Do not breathe dust/fume/gas/mist/vapours/spray.
P261 Avoid breathing dust/fume/gas/mist/vapours/spray.
P264 Wash … thoroughly after handling.
Which trade and regulatory codes apply to Trifluoromethanesulfonic acid?
HS Code 29049020
UN Number 3265
ADR Class 8
Packing Group II
Storage Class 8A - Combustible corrosive hazardous materials
WGK (Germany) 2