Formation of a novel honeycomb structure consisting of 2-mercaptomethylthiophene derivatives on Au(111) Building units to form the unique structure

2-Mercaptomethylthiophene derivatives were prepared and their adsorpion states on a gold single crystal surface were studied by scanning tunneling microscopy under ultrahigh-vacuum conditions. Two ordered phases were observed for the mercaptomethylthiophene derivatives: the first phase is composed of one-dimensional molecular rows and the second has a previously unknown two-dimensional honeycomb structure. A comparative study for various types of thiols leads us to conclude that the mercaptomethylthienyl moiety is a building unit for the formation of the specific structure and that the molecules are arranged with upright configuration in the structure.