Low dimensional structure formation in self-assembled monolayers on Au(111)

We have studied the phase-separation of self-assembled monolayers (SAMs) of dialkyl disulfides on Au surface. Initially, the heat-induced phase-separation of SAMs consisting of unsymmetric disulfide molecules (CF 3 (CF 2 ) 5 (CH 2 ) 2 SS(CH 2 ) 7 CH 3 ) of hydrocarbon and fluorocarbon chains was investigated. We proved that the dimer structure cleaved on the Au surface. Subsequently, we formed one-dimensional nanostructures utilizing an anisotropic phase-separation of SAMs consisting of a mixture of the above unsymmetric disulfide and a symmetric disulfide of hydrocarbon (CH 3 (CH 2 ) 7 SS(CH 2 ) 7 CH 3 ). The wire-like structure with a width of 5 nm and a length ≈100 nm was observed by scanning tunneling microscopy.