The gas‐phase reactions of D+2, D+3, SiF+, and SiF+3with SiF4and of SiF+and SiF+3with D2have been studied in the center‐of‐mass energy range of 0.2–7 eV using a tandem mass spectrometer. Only one reaction of a silicon‐containing ion with SiF4was observed, namely the highly endothermic transfer of F−from SiF4to SiF+. Hence the SiF4molecule must be almost unique in showing a virtual absence of gas‐phase ionic chemistry in pure SiF4subjected to ionization. Several ion‐molecule reactions were observed in the SiF4–D2system but of these only the dissociative F−transfer from SiF4to D2+is exothermic. The almost total absence of exothermic ion‐molecule reactions means that the ionic distribution pertinent to the plasma chemistry of the SiF4and SiF4–H2systems will be determined solely by the cross sections of the electron impact ionization processes.