Both TcO2F3 and ReO2F3 are infinite chain, fluorine-bridged polymers in the solid state. Their solution structures have been studied by F-19 and Tc-99 NMR spectroscopy in SO2ClF solution and shown to exhibit cyclic (MO2F3)(3) (M = Tc, Re) and (ReO2F3)(4) structures that have been confirmed by simulation of the F-19 NMR spectra. The trimers dominate in both the technetium and rhenium systems, with both the tetramer and trimer existing in equilibrium in the rhenium system. A low concentration of a higher, possibly pentameric, cyclic rhenium polymorph is also present in equilibrium with the trimer and tetramer.