Si trova su / Altri legami
© 2021 Authors.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.
