We report herein the solution and solid-state studies of conformationally flexible multidecker naphthalenediimides (NDIs) in which the chromophoric NDI units intramolecularly assemble into a series of discrete pi-stacks. The X-ray crystallography reveals the existence of exclusively all-syn NDIs orientations in lower congeners while all-anti in a higher congener, suggesting short- to long-range pi center dot center dot center dot pi interactions throughout the slipped pi(NDI) chromophoric array. The UV/vis and fluorescence spectra evaluate the discrete pi-stacks by remarkable optical changes upon cooling in solution. Furthermore, we carried out a systematic electrochemical investigation to gain an insight into redox properties of the long-range pi-stacked structures. The higher congener (5NDI) shows a ten-electron reversible reduction process in a small working potential window (similar to 0.8 V). To our knowledge, this is an unusual observation in an organic molecular system to undergo up to ten-electron reduction. These results pave the way to design multidecker pi-stacks in which structural control with specific electronic properties would be engineered.