The invention provides ligand compositions for use in preparing discrete coated nanostructures, as well as the coated nanostructures themselves and devices incorporating same. Methods for post-deposition shell formation on a nanostructure and for reversibly modifying nanostructures are also provided. The ligands and coated nanostructures of the present invention are particularly useful for close packed nanostructure compositions, which can have improved quantum confinement and/or reduced cross-talk between nanostructures.