TERRACE INDUCED HOMOCHIRAL SELF-ASSEMBLY OF ZINC PHTHALOCYANINEON COPPER (111) SURFACE

It is still a challenge to find a suitable method to fabricate a well-defined homochiral surface from achiral molecules, and one of the possible methods is to modify surfaces with organic molecular assemblies. Large-area chiral self-assembly nanostructures have been observed at room temperature by depositing ZnPc molecules on a Cu(111) surface. The growth process has been investigated. ZnPc molecules get adsorbed first at the terrace steps, and then extend over the lower terrace until the whole terrace is covered with ZnPc molecules; such growth process would be stopped when the self-assembly nanostructure run into a decorated upper terrace step edge. We found that the terrace steps with specific directions with respect to the close-packed directions of the substrate can induce homochiral self-assembly on the lower terraces. So we can propose a possible way to fabricate a well-defined homochiral surface from achiral organic molecules.