Synthesis and supramolecular association of immobilized NCN-pincer platinum(II) complexes on hyperbranched polyglycerol supports

Pertosylation of hyperbranched polyglycerol (M(n)=2000; M(w)/M(n)=1.3) followed by partial displacement of the tosyl groups with carboxylic acid functionalized NCN-pincer platinum(II) complexes [PtI-2,6-(NMe(2)CH(2))(2)C(6)H(2)-4-COOH], resulted in covalent attachment of the NCN-pincer complexes to the polyglycerol. These functionalized hyperbranched macromolecules have been characterized by (1)H, (13)C, and (195)Pt NMR, UV-visible, and IR spectroscopy. The presence of Pt and I atoms renders them directly visible by transmission electron microscopy (TEM) without staining procedures, which offers images of associated hyperbranched macromolecules. TEM micrographs show disk-shaped structures with a small size-distribution (15-20 nm), and characteristic core-shell ring structures. The thickness of the corona observed in TEM could be correlated with the substitution degree with pincer platinum moieties.