Precision host–guest chemistry of polyphenylene dendrimers

The synthesis of polyphenylene dendrimers with backbone-pendant internal carboxylic acids and nonpolar tetraphenylbenzene chain ends is reported. The host–guest and transport properties of these dendrimers with proflavine, an acridine dye, were investigated. These properties were found not to depend strongly on the number of carboxylic acids, but rather on the structural properties of the stiff dendrimers, binding only 3–4 dyes each for the first- and second-generation dendrimers. The presence of solution accessible polar cavities in the dendrimer provided enhanced solubilization and transport of the polar dyes through a nonpolar phase.