Uranium endohedrals are an emerging class of fullerenes that may hold extraordinary properties and exhibit remarkable chemical features.[i] [ii] Our group been on the forefront of research in this area and have made progress in the synthesis of these novel compounds. By optimizing reactive conditions, we have seen a markedly improved selective production of uranium endohedrals using the Kraetschmer – Huffmann arc discharge process. Here we report the successful synthesis of several families of uranium endohedrals characterized by mass spectrometry which include clusters of the type U₂X (X= C, N, O). Mono-metallic uranium endohedrals, with general formula U@C_n, have also been synthesis and characterized by x-ray crystallography (see Fig 1.) Electrochemical studies of some of these new compounds have been conducted and are reported herein. These findings realize a two-decade long effort in the scientific community for physical studies of such endohedral fullerenes. ^{[iii] [iv] [v]}