Laser-ablated Th atoms react with F2 in condensing noble gases to give ThF4 as the major product. Weaker higher frequency infrared absorptions at 567.2, 564.8 (576.1, 573.8) cm–1, 575.1 (582.7) cm–1 and 531.0, (537.4) cm–1 in solid argon (neon) are assigned to the ThF, ThF2 and ThF3 molecules based on annealing and photolysis behavior and agreement with CCSD(T)/aug-cc-pVTZ vibrational frequency calculations. Bands at 528.4 cm–1 and 460 cm–1 with higher fluorine concentrations are assigned to the penta-coordinated species (ThF3)(F2) and ThF5–. These bands shift to 544.2 and 464 cm–1 in solid neon. The ThF5 molecule has the (ThF3)(F2) Cs structure and is essentially the unique [ThF3+][F2–] ion pair based on charge and spin density calculations. Electron capture by (ThF3)(F2) forms the trigonal bipyramidal ThF5– anion in a highly exothermic process. Extensive structure and frequency calculations were also done for thorium oxyfluorides and Th2F4,6,8 dimer species. The calculations provide the ionization potentials, electron affinities, fluoride affinities, Th–F bond dissociation energies, and the energies to bind F2 and F2– to a cluster as well as dimerization energies.