Sorting the Assemblies of Unsymmetrically Covalently Functionalized Mn-Anderson Polyoxometalate Clusters with Mass Spectrometry

The unsymmetrical Mn-Anderson polyoxometalate cluster, [N(C4H9)4]3[MnMo6O18(C4H6O3NO2)(C4H6O3NH2)] (1; N(C4H9)4+ = TBA+), has been prepared and characterized by X-ray crystallography and electrospray ionization mass spectrometry (ESI-MS). Covalent functionalization of compound 1 leads to the controlled assemblies of unsymmetrical alkoxopolyoxometalate clusters of compounds 2−5, which can be directly observed in solution as revealed by ESI-MS studies.