Stoichiometric Self-Assembly of Isomeric, Shape-Persistent, Supramacromolecular Bowtie and Butterfly Structures

 Two novel macromolecular constitutional isomers have been self-assembled from previously unreported terpyridine ligands in a three-component system. The terpyridine ligands were synthesized in high yields via a key Suzuki coupling. Restrictions of the possible outcomes for self-assembly ultimately provided optimum conditions for isolation of either a molecular bowtie or its isomeric butterfly motif. These isomers have been characterized by ESI-MS, TWIM-MS, ¹H NMR, and ¹³C NMR. Notably, these structural isomers have remarkably different drift times in ion mobility separation, corresponding to different sizes and shapes at high charge states.

Nanocomposite “Superhighways” by Solution Assembly of Semiconductor Nanostructures with Ligand-Functionalized Conjugated Polymers

Poly(3-hexyl thiophene) containing chain-end thiols or phosphonic acids is crystallized to yield nanowires with the functional groups at the wire edges. CdSe quantum dots and nanorods associate with these fibrils, leading to ‘superhighways’ that consist of alternating parallel lanes of conjugated polymer and CdSe.

Tuning Multiphase Amphiphilic Rods to Direct Self-Assembly

New methods to direct the self-assembly of particles are highly sought after for multiple applications, including photonics, electronics, and drug delivery. Most techniques, however, are limited to chemical patterning on spherical particles, limiting the range of possible structures. We developed a lithographic technique for fabrication of chemically anisotropic rod-like particles in which we can specify both the size and shape of particles and implement multiple diverse materials to control interfacial interactions. Multiphase rod-like particles, including amphiphilic diblock, triblock, and multiblock were fabricated in the same template mold having a tunable hydrophilic/hydrophobic ratio. Self-assembly of diblock or triblock rods at a water/oil interface led to the formation of bilayer or ribbon-like structures.