In order to investigate the reaction of the halides MX 3 (M = P, As; X = F, Cl, Br, I), PCl 5, POCl 3, POBr 3, RSCl (R = Ph 3C, Ph, Et, Cl, SCl), SOCl 2, and WF 6 with CF 2 we used the complex Cd(CF 3) 2·2 CH 3CN as precursor of CF 2. In accordance with Krause and Morrison [1] we found that this complex can also react as trifluoromethylation agent depending on the nature of the covalent halide and the reaction conditions. Already at room temperature Cd(CF 3) 2·2 CH 3CN reacts with MX 3 (M = As; X = Cl, Br, I; M = P; X = Br, I), PCl 5, and S 2Cl 2 forming difluorohalomethyl compounds, e. g. X 2MCF 2X, by insertion of CF 2. The reaction products are thermically stable substances being rather resistant to hydrolysis in some cases. Only the iodo- derivatives decompose slowly to CI 2F 2 and to diphosphanes or diarsanes, resp.. In the reaction of CF 2 with oxohalides, however, COF 2 and the corresponding reduced halides are formed. On the other hand the cadmium complex reacts with RSCl (R = Cl, SCl, Et) as trifluoromethylation agent under substitution of chlorine by a CF 3-group forming trifluoromethylsulfanes and CClF 3.