Abstract The use of 4-dimethylaminopyridine as a catalyst in the reaction of trifluoromethylsulfenyl chloride with hydrogen sulfide at− 78 C cuts down the time of reaction from 30 d to 1 d and gives up to 70% yield of bis (trifluoromethyl) trisulfide (1). Similarly, bis (trifluoromethylthio) selenide (2) can be prepared from hydrogen selenide and trifluoromethylsulfenyl chloride. The influence of other catalysts on the course of the ...