Building on this success, we synthesized longer and more intricate ladders (e.g., L2-PF6, L3-PF6, and L4-PF6) from dianilines or dialdehydes as starting materials, with yields ranging from 56 to 80%. The structures were extensively characterized by infrared spectroscopy (Supplementary Figs. ), NMR spectroscopy ( 1 H and heteronuclear, Supplementary Figs. 5-59), high-resolution electrospray ionization mass spectrometry, and single crystal X-ray diffraction analysis (Supplementary Tables ). In addition to the facile installation of terminal anchor moieties for STM-BJ (Fig. ), this method provided a diverse array of ladders with adjustable backbones, pendent substituents, and counter anions.