Directing the supramolecular polymerization towards ap referred type of organization is extremely important in the design of functional soft materials.Proposed herein is asimple methodology to tune the length and optical chirality of supramolecular polymers formed from ac hiral bichromophoric binaphthalene by the control of enantiomeric excess (ee). The enantiopure compound gave thin fibers longer than afew microns,while the racemic mixture favored the formation of nanoparticles.T he thermodynamic study unveils that the heterochiral assembly gets preference over the homochiral assembly.T he stronger heterochiral binding over homochiral one terminated the elongation of fibrous assembly,thus leading to ac ontrol over the length of fibers in the nonracemic mixtures.T he supramolecular polymerization driven by p-p interactions highlights the effect of the geometry of atwisted pcore on this self-sorting assembly.The past two decades have witnessed increased attention in the field of the self-assembly of small molecules into complex architectures. [1] This interest in supramolecular polymers formed by noncovalent interactions arises mainly because of a) the desire to mimic life systems so as to understand the process of self-assembly in biological macromolecules [2a] and b) the ability to build nanostructures for practical applications by utilizing ab ottom-up approach. [2b-d] Theb ottom-up approach drives the formation of supramolecular aggregates through acombined effect of different noncovalent intermolecular forces,thus leading to complex superstructures,often possessing af ibrous nature. [3] Molecules possessing chiral centers act as building blocks for the fabrication of helical nanostructures,wherein the supramolecular chirality is determined by the chirality at the molecular level. [4,5] The fascinating structural features of different chiral nanostructures,s uch as helices,n anotapes,a nd nanotubes have attracted great interest because of their resemblance to biological structures [6a] and possible applications in chiral sensing and catalysis. [6b-d] Thep erformance of functional organic materials in optoelectronic devices is largely dependent on the organization of molecular components. [6] Hence,d irecting the selfassembly towards ap referred type of organization is an extremely important step in the design of such materials. Recently,w er eported the self-assembly of chiral binaphthalenes,b earing two perylene bis(imide) (PBI) units (1; Scheme 1), [7] into dissimilar morphologies depending on the solvent system. [8] They formed helical fibers through p-p stacking interactions in methylcyclohexane (MCH), but formed spherical aggregates in chloroform at high concentration. [8] Thef ibrous assemblies gave superior chiroptical properties,including circularly polarized luminescence (CPL) relative to the spherical aggregates.I nt he present work, we introduce an ew methodology to control the length of the fibers through the mixing of enantiomers possessing the opposite chirality.I nt his regard, earlier i...