Heterometal Assembly in Dendritic Polyphenylazomethines

Fine-controlled metal–organic hybridization is strongly desired for advanced nano-materials. Dendrimers are highly branched organic macromolecules with successive layers or “generations” of branch units surrounding a central core. Metal–organic hybrid versions have also been produced by trapping metal ions or metal clusters within the voids of dendrimers. Here, we report a technique to form a dendritic organic structure, which includes various metals, with fine control over the number and location of the metal salts through a radial stepwise complexation. FeCl3, GaCl3, VCl3, and SnCl2 were decorated on a phenylazomethine dendrimer with 4th generations at the first, second, third, and forth layers, respectively. These stepwise complexation and heterometal assembling were also supported by TEM observation, 57Fe Mössbauer spectroscopy, XPS measurement, and NMR spectroscopy.