Recent studies on the reaction of [X6O19]8− (X = Nb, Ta) polyanions under acidic conditions

This review focuses on the recent studies on the reaction of [X 6 O 19 ] 8− (X = Nb, Ta) under acidic conditions, highlighting the synthesis and structural chemistry of mixed-addendum niobotungstates/tantalotungstates and hetero-peroxo-PONb/Ta clusters.