Constructing a macromolecular K(3,3) graph through electrostatic self-assembly and covalent fixation with a dendritic polymer precursor.

A triply fused tetracyclic macromolecular K(3,3) graph has been constructed through electrostatic self-assembly of a uniformly sized dendritic polymer precursor having six cyclic ammonium salt end groups carrying two units of a trifunctional carboxylate counteranions, and subsequent covalent conversion by the ring-opening reaction of cyclic ammonium salt groups at an elevated temperature under dilution. The K(3,3) graph product was isolated from the two constitutional isomers by means of a recycling SEC technique, as the hydrodynamic volume of the triply fused tetracyclic K(3,3) product is remarkably contracted in comparison with another isomer having a ladder form in solution.