Self-assembly of nanotubes and ordered mesostructures using weak interactions

Two simple organic compounds, 5-nitroisophthalic acid (npa) and 4,4′-bipyridine (bpy), were used as building blocks for supramolecular self-assembly by hydrothermal synthesis. SEM, TEM, and XRD were used to analyse the multi-step assembly process in which npa and bpy assembled into nanotubes (or nanobelts) of about 30–100 nm in diameter and several millimetres in length and microtubes (or microbelts). The tubes then further assembled to form complex ordered structures, such as pom-pom-shaped and flower-like mesostructures.

Hydrothermal-promoted, self-assembly of 5-nitroisophthalic acid and 4,4′-bipyridine generates nanotubes possessing a diameter of ~30–100 nm diameter and length of several millimeters as well as novel pom-pom- and flower-shaped mesostructures.