<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Compounds (III) and (VII) are tris‐(peroxotantalum)‐substituted Dawson‐ and Keggin‐type derivatives, whereas (IV) and (VIII) are tetrameric oligomers containing an unprecedented {Ta<sub>12</sub>} and {Ta<sub>16</sub>} core, respectively.</p> </abstract>