William Dichtel received a B.S. degree in Chemistry from MIT. Dichtel obtained his Ph.D. degree from UC-Berkeley under Prof. Jean M. J. Fréchet. He was a joint postdoctoral researcher with Prof. Fraser Stoddart, UCLA, and Prof. James Heath, Caltech. He began his independent academic career at Cornell University in 2008 and was promoted to Associate Professor in 2014. In 2016, he moved to Northwestern University as the Robert L. Letsinger Professor of Chemistry.

2025 NASA Symp

Mechanically Interlocked Two-Dimensional Polymers

Mechanical bonds confer unique properties to polymers, but polymerizations that form mechanical bonds efficiently are rare. A new type of solid-state polymerization will be presented, in which one monomer infiltrates crystals of another to form a macrocycle and mechanical bond at each repeat unit of a two-dimensional (2D) polymer. The 2D mechanically interlocked polymer is easily prepared on multigram scales and has unique thermal transitions at high temperatures that make it of interest for extreme environments such as in space.

2021 NASA Symp

Synthesis Supramolecular Polymerization of Nanotubes Based on Protonation-Induced Assembly of Macrocycles

Macrocycles that assemble into nanotubes exhibit emergent properties stemming from their low dimensionality, structural regularity, and distinct interior environments. I will present report a versatile strategy to synthesize diverse nanotube structures in a single, efficient reaction by using a conserved building block bearing a pyridine ring. Imine condensation of a 2,4,6 triphenylpyridine-based diamine with various aromatic dialdehydes yields chemically distinct pentagonal [5+5], hexagonal [3+3], and diamond-shaped [2+2] macrocycles depending on the substitution pattern of the aromatic dialdehyde monomer. Modifying these macrocycles to achieve emergent mechanical and transport properties will also be discussed.