The formation of two-dimensional self-assemblies of ordered, packed gold natioparticles is described. The nanoparticles were coated by a diamide thiol ligand (DASH) that ensured the connection of the nanoparticles through hydrogen bonds. The stability of the colloidal solutions is discussed with respect to the stability of the normal dodecanethiol-coated particles. (C) 2004 Elsevier Inc. All rights reserved.