In conclusion, six new aza[n]helicenes ([n]AH) of different lengths (n = 9, 11, 13, 15, 17, 19) were successfully synthesized from acyclic precursors via one-shot oxidative fusion reactions with PIFA. The structures of all synthesized azahelicenes were determined using XRD analysis. [17]AH and [19]AH are the first heterohelicenes with a triple-layered helix. The structural parameters of the helicenes (i.e., interplanar distance, interplanar angle, and torsion angle) were compared experimentally and theoretically. The intramolecular interactions became stronger and the aromatic rings became more densely stacked with the elongation of the helical structure. The NCI plots confirmed the existence of an effective π-π interaction between the layers. Electrochemical potentials were measured using CV, and the first oxidation potential shifted to the negative side in response to helicene elongation. The absorption and fluorescence spectra red-shifted as the helical lengths increased, without any distinct saturation points. The optical resolutions of Nbutylated [9]AH and [11]AH were accomplished, and their CD and CPL spectra were measured. The molecular design of the azahelicenes synthesized in this study solves the stability and solubility problems encountered thus far, and may provide an ideal platform for the synthesis of longer heterohelicenes.