Mesoporous tantalum oxide-sodium fulleride composites were synthesized by solution impregnation and characterized by elemental analysis, X-ray diffraction (XRD), Raman spectroscopy, nitrogen adsorption-desorption, X-ray electron photoelectron spectroscopy (XPS), superconducting quantum interference device (SQUID) magnetometry, variable-temperature electron transport measurements, and solid-state C-13 and Na-23 NMR spectroscopy. The room temperature conductivity pattern as a function of sodium reduction level displayed a minimum at n = 3.0 and a maximum at n = 4.5, where n is the formal charge on the fulleride. The variable-temperature conductivity measurements demonstrated that the n = 0.5 and n = 4.5 materials were semiconductors. Solid-state Na-23 NMR spectroscopy of the n = 0.5 composite exhibited three Na environments in the composites: two associated with the tantalum oxide walls and a third associated with the fulleride. The n = 3.0 and n = 4.5 materials showed a large build-up of Na ions in the wall with no visible Na resonances associated with the fulleride, suggesting a structure in which the fulleride units exist as naked anions in one-dimensional chains surrounded first by a layer of Na ions and then by a layer of mesoporous tantalum oxide. Solid-state C-13 NMR experiments showed more than one fulleride species in both the n = 0.5 and the n = 4.5 composites, as well as pure C-60 in the n = 0.5 material, but almost exclusively C-60 in the n = 3.0 material. The retention of carbon throughout reduction suggests that polymerization may have occurred, however this could not be verified by C-13 NMR spectroscopy, because the region where sp(3) fullerene resonances normally appear was obscured by solvent peaks.