Self-Assembling Dendronized Dendrimers

The amine groups from the periphery of poly(propylenimine) dendrimers [DAB-(NH2)(n)] (n = 4 and 8) were reacted with the carboxylic groups of five different first and second generation self-assembling dendrons. The amidation was mediated by the peptide bond forming reagent 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT)/N-methylmorpholine (NMM). All the resulting dendronized dendrimers self-assemble into helical pyramidal columns that self-organize into columnar hexagonal and columnar rectangular 2D lattices and in supramolecular spheres that self-organize into 3D Pm (3) over barn and P4(2)/mnm tetragonal lattices. The structural and retrostructural analysis of the supramolecular dendrimers by X-ray diffraction experiments demonstrated that supramolecular dendritic spheres are assembled from various spherical fragments, including conical and half-sphere in which the DAB dendrimer is confined to their apex. Dendritic-crown is the most frequently encountered conformation of the dendronized dendrimers that is responsible for the assembly of helical pyramidal columns.