Conformational change in 4-pyridineethanethiolate self-assembled monolayers on Au(111) driven by protonation/deprotonation in electrolyte solutions.

Self-assembled monolayers (SAMs) of 4-pyridineethanethiol (4-PyEtS) formed on a Au(111) surface were investigated in aqueous electrolyte solutions by cyclic voltammetry and in situ scanning tunneling microscopy (STM). On the basis of reductive desorption of 4-PyEtS on Au(111), the reduction peak potential was found to be -0.86 V vs.