A Study of the Design and Stability of One Dimensional Hydrogen-Bonded Nanotubes

Abstract

Nanotubes are a novel class of materials that show unique properties due to their one-dimensional backbone. Hydrogen-bonded organic nanotubes (HONTs) are among the most promising supramolecular nanotubes because of their structural resemblance with biologically active tubular channels. Most reported HONTs are prepared from large building blocks such as macrocyclic compounds and peptides, which demands complicated synthetic procedures. In this work, we designed and synthesized a triptycene-based building block, 2,8-bis(2-methoxyphenyl)-1,5,7,11-tetrahydro-5,11-[1,2] benzenoanthra[2,3-d:6,7-d'] diimidazole, abbreviated as TAT-Im, through a bottom-up multi-step process from triptycene with tetraamino triptycene (TAT) as an intermediate. TAT-Im was thereafter used to synthesize a tetragonal hydrogen-bonded nanotube. Chapter 1 of the thesis provides a brief overview of nanotubes, especially with respect to supramolecular nanotubes. We then discuss the significance of weak hydrogen bonds in literature to provide context for additional stability in supramolecular structures. In Chapter 2, we discuss the synthetic route of TAT-Im alongside the design of the computational calculation experiments. Chapter 3 provides insight on the characterization of intermediates, and the various crystal structures of TAT-Im in different solvent systems. We also explore the possibilities laid out from the DFT calculation analysis. Finally, Chapter 4 summarizes the discussions carried out in previous chapters and emphasizes the possible directions for studying one-dimensional supramolecular systems.