Two novel telluroniobates with efficient catalytic activity for the imidation/amidation reaction.

We present the synthesis and catalytic properties of two novel telluroniobates {Te 15 Nb 21 } and {Te 10 Nb 14 }. {Te 15 Nb 21 } is the first trimeric telluroniobate with the largest number of tellurium atoms in the Te-Nb system. Besides, both clusters exhibit excellent catalytic activity in the amidation reactions of anhydrides and amines, and cyclic imides and bi-amides can be controllably synthesized, which represents a breakthrough in the catalysis of polyoxoniobates.