Synthesize novel highly-nuclear polytungstoarsenate cluster by careful control of pH value

The self-assembly of [As2W19O67(H2O)]14− precursors in acidic aqueous solution with different pH value led to the isolation of a new highly-nuclear polytungstoarsenate aggregates, [{(W4O9)(H2O)2}{As2W19O67(H2O)}2]22− 1. It can be characterized as two [As2W19O67(H2O)]14− units hinged together by a {(W4O9)(H2O)2} fragment. Polyoxoanion 1 is the second largest polytungstoarsenate cluster composed of new {As2W21} building blocks. Crystal data for 1: triclinic, space group C2, a = 26.274(5) Å, b = 24.321(5) Å, c = 18.764(4) Å, β = 128.58(3)°, V = 9373(3) Å3, Z = 2.