Poly(polyoxometalate)s assembled by {Ni6PW9} units: from ring-shaped Ni24-tetramers to rod-shaped Ni40-octamers

Both structure-directing effect and synergistic-directing effect of PW9O34 fragments result in two poly(polyoxotungstate)s (poly(POT)s) of the Ni-24-based tetramer with largest transition metal atoms among ring-shaped poly(POT) tetramers and the Ni-40-based poly(POT) octamer with the highest number of Ni ions among all known poly(POT)s to date, respectively.