ORIENTED CRYSTALLINE THIN-FILMS OF TETRACOSANEDIOIC ACID AND ITS METAL-SALTS AT THE AIR-AQUEOUS SOLUTION INTERFACE

Oriented crystalline thin films of alpha,omega-tetracosanedioic acid m etal salts form in situ at the air-liquid interface, following the sim ple procedure described here. It is shown that the Cd2+ and Pb2+ metal ions have a dramatic influence on the packing of the diacid molecules , which self-assemble as multilayer domains approximately 50 Angstrom thick, with the molecules and bound ions perfectly ordered laterally o ver distances up to 1000 Angstrom. These oriented crystallites preserv e their integrity upon transfer to a mica support and can be used to p repare quantum dots (see following communication).