Helical PolymerIn this study, we present the scanning tunneling microscope (STM) images of rationally designed helical polymers with a pattern of pi-pi stacking and successfully identified the single and double helical superstructures. The STM images of helical structures revealed a smallest helical architecture (diameter ca. 1.3 nm) that can be seen so far. Furthermore, the interconversion of single and double helices has been further underpinned via experimental analyses. Significantly, the formation of double helices induced different supramolecular chirality from the single helices. This work was recently reported by Junqiu Liu’s group in Angewandte Chemie International Edition (Angew. Chem. Int. Ed. 2014, DOI: 10.1002/anie.201410975R1 and 10.1002/ange.201410975R1)