“Bottom-Up” Meets “Top-Down” Assembly in Nanoscale Polyoxometalate Clusters: Self-Assembly of [P4W52O178]24−and Disassembly to [P3W39O134]19−

Abstract

The pH-controlled assembly/disassembly of a nanoscale {P₄W₅₂O₁₇₈}²⁴⁻ cluster at pH 2 to a {P₄W₄₄O₁₅₂}²⁰⁻ cluster at pH 3−5 via a {P₃W₃₉O₁₃₄}¹⁹⁻ cluster species at pH 2−3 to finally give {P₂W₁₉O₆₉(OH₂)}¹⁴⁻ at pH 6 is reported. This process can be traced in the solid state crystallographically and in solution using dynamic light scattering studies.