Diverse Proton-Conducting Nanotubes via a Tandem Macrocyclization and Assembly Strategy
Journal
Journal of the American Chemical Society
Journal Volume
143
Journal Issue
21
Start Page
8145
End Page
8153
ISSN
0002-7863
1520-5126
Date Issued
2021-05-18
Author(s)
Strauss, Michael J.
Jia, Manping
Evans, Austin M.
Castano, Ioannina
Aguilar-Enriquez, Xavier
Roesner, Emily K.
Swartz, Jeremy L.
Chavez, Anton D.
Enciso, Alan E.
Stoddart, J. Fraser
Rolandi, Marco
Dichtel, William R.
Abstract
Macrocycles that assemble into nanotubes exhibit emergent properties stemming from their low dimensionality, structural regularity, and distinct interior environments. We 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. Atomic force microscopy and in solvo X-ray diffraction demonstrate that protonation of the macrocycles under the mild conditions used for their synthesis drives assembly into high-aspect ratio nanotubes. Each of the pyridine-containing nanotube assemblies exhibited measurable proton conductivity by electrochemical impedance spectroscopy, with values as high as 10-3 S m-1 (90% R.H., 25 °C) that we attribute to differences in their internal pore sizes. This synthetic strategy represents a general method to access robust nanotube assemblies from a universal pyridine-containing monomer, which will enable systematic investigations of their emergent properties.
Publisher
American Chemical Society (ACS)
Type
journal article