Functional modules: Metal ion assembly in novel topological poly(phenylazomethine)s

Poly(phenylazomethine) derivatives are interesting compounds as “functional modules” in organic-metallic hybrid nano-materials. We synthesized oligo(phenylazomethine)s (OPAs), the aniline-capped OPAs (OPA's), and dendritic poly(phenylazomethine)s (DPAs) via dehydration of aromatic amines with aromatic ketones in the presence of TiCl4. DPA derivatives having tris(thienylphenyl)amine and tetraphenylporphyrin as the core (TPA-DPAs and Por-DPAs) and aniline-capped DPAs were obtained during the dehydration of the DPA dendrons with tris(4-aminothienylphenyl)amine, tetra(4-aminophenyl)porphyrin, and aniline, respectively. Stepwise radial complexation with SnCl2 in DPAs, TPA-DPAs, Por-DPAs, and aniline-capped DPAs, was found as stepwise shifts of the isosbestic point during the UV–vis spectroscopic observation. The coordination constants of four kinds of imines in the aniline-capped DPA G4 with trifluoroacetic acid were determined.