[Mn(III)Mn(IV)2Mo14O56](17-): A Mixed-Valence Meso-Polyoxometalate Anion Encapsulated by a 64-Nuclearity Silver Cluster. 
A 64-nuclearity silver cluster encapsulating a unique POM anion [Mn(III)Mn(IV)2Mo14O56](17-) has been synthesized.  The formation of the templating core performs a reassembly process for increasing nuclearities from {MnMo9} to {Mn3Mo14}.  It represents a rare inorganic meso anion containing mixed-valent Mn that is built up by d-{Mn(IV)Mo7} and l-{Mn(IV)Mo7} units connecting together through a {Mn(III)} fragment.