Abstract: Agent for the fluoridation of organic compounds having the general formula (I), wherein Q+ represents either: (i) a cation having the formula (II), wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 which may be the same or different, represent an alkyl radical having from 1 to 20 atoms of carbon, an aryl radical or an aralkyl radical, the number of atoms of carbon in R.sub.1 +R.sub.2 +R.sub.3 +R.sub.4 being at least equal to 13 and preferably between 15 and 22, or: (ii) a polymer matrix carrying functions of formula (III), wherein: R.sub.5, R.sub.6 and R.sub.7, which may be the same or different, represent a lower alkyl radical having from 1 to 6 atoms of carbon and n is a mean value comprised between 1.5 and 2.5, preferably between 1.8 and 2.1. Utilization for the fluoridation of acetylenic compounds mono or biactivated by addition of HF and for the preparation of organofluorinated compounds by nucleophilic substitution.