Supramolecular polymer chemistry: Design, synthesis, characterization, and kinetics, thermodynamics, and fidelity of formation of self-assembled dendrimers

Dendrimers 1a-d were synthesized in 10 steps from dendrons 4-7, bromobenzene and succinic anhydride. Tetraacids 1e and 1f were prepared in an analogous fashion. The aggregation of 1a-f was studied in solution by size exclusion chromatography (SEC), vapor pressure osmometry (VPO), low angle laser light scattering (LLS), small angle neutron scattering (SANS), and by ¹H NMR. The data are consistent with a stable, discrete hexameric aggregate for 1b-d in methylene chloride, non-discrete polymeric aggregates for 1a, 1e, and 1f, and monomers for all compounds in tetrahydrofuran and dimethyl sulfoxide. Kinetic and thermodynamic studies and mixing experiments confirmed the highly cooperative nature of the self-assembly process.