Laser-ablated Th atoms react with F-2 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)(F-2) and ThF5-. These bands shift to 544.2 and 464 cm(-1) in solid neon. The ThF5 molecule has the (ThF3)(F-2) C-s structure and is essentially the unique [ThF3+] [F-2(-)] ion pair based on charge and spin density calculations. Electron capture by (ThF3)(F-2) 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 F-2 and F-2(-) to a cluster as well as dimerization energies.