Ab initio molecular orbital calculations are reported for ions SiC2F+, SiC2H2F+, SiC2HF2+, SiC2F3+, and SiC2F5+ Structure optimizations were performed for several minima at both HF/6-31G(d,p) and MP2(full)/6-31G(d,p). For the SiC2H2F+ and SiC2HF2+ potential energy surfaces transition structures for interconversion between ions were optimized at HF/6-31G(d,p) and profiles for interconversion between various isomers are given. The SiC2F5+ potential energy surface is remarkably flat and has been examined at both HF/6-31G(d,p) and MP2(full)/6-31G(d,p) levels. The five potential energy surfaces reported here are compared with those of the analogous ions in which the fluorine atoms are replaced by hydrogens.