Abstract The reaction of the perfluoromethyl compounds CF 3 PI 2 and CF 3 AsI 2 with secondary amines HNR 2 yield the bis (dialkylamino) perfluoromethylphosphines and- arsines CF 3 P (NR 2) 2 and CF 3 As (NR 2) 2. The IR and NMR spectra are reported and discussed. The cleavage of the P N or As N bond with acid molecules is described.