Swarts reaction[′svärts rē‚ak·shən]
the replacement in organic compounds of, most often, chlorine by fluorine through the action of antimony trifluoride (SbF3). The reaction is usually carried out in the presence of Sb salts in which antimony displays an oxidation state of +5. Examples of the products obtained through this process are seen in the following reactions:
CCl4 → CF2 Cl2 + CFCl3
CHCl3 → CHFCl2 + CHF2Cl
CCl3CCl3 → CFCl2 - CFCl2 + CFCl2 - CF2 Cl
C6H5 CCl3 → C6H5CF3
The Swarts reaction is used in laboratory work. A variant of the reaction—fluorination using anhydrous hydrogen fluoride (HF) in the presence of catalytic quantities of Sb salts in which antimony displays oxidation states of + 3 and + 5—has industrial importance and is used in the production of Freons. The reaction was discovered and refined by the Belgian chemist F. Swarts in the late 19th and early 20th centuries.