Solvophobically-driven 3-D self-assembly of “exploded”-type polyphenylene dendrimers

Abstract

The three-dimensional self-assembly of a shape-persistent third-generation polyphenylene dendrimer into an extensively interdigitated hexamer was studied with ultra-high-mass MALDI-TOF mass spectrometry and dynamic light scattering. Remarkably, the high-precision assembly occurs in the absence of electrostatic or hydrogen-bonding interactions, and is the product of Lilliputian solvophobic interactions, mediated by the dendrimer arm size and shape. The assembly size can be tuned from monomer to dimer to hexamer simply by varying the solvent composition. Further growth or chain end densification results in fundamentally different aggregation or in disruption of the perfect packaging of the macromolecules. This hexameric structural motif is completely different than what has been previously accessible with conventional self-assembly and marks the beginning of a new direction in 3D nanofabrication.