A novel large heteropolytungstate constructed from two types of lacunary Keggin anions: K7Na13[(PW11O39)2(PW9O34)2(W2O3)2] · 25H2O

A novel crown-shaped heteropolytungstate is formed by covalently linking two [PW11O39]7− and two [PW9O34]9− fragments with four WO6 octahedra, which represents not only the largest tungstophosphate constructed from two types of building blocks without considering the 4f lanthanide or other 3d transition metal ion linkers but also the highest degree of aggregation known in the large clusters incorporating monovacant lacunary anions.