ELECTROCHEMICAL STM INVESTIGATION OF 1,8-OCTANEDITHIOL MONOLAYERS ON AU(1 1 1).: EXPERIMENTAL AND THEORETICAL STUDY

CAROT, LUCRECIA, COMETTO, FERNANDO, MACAGNO, VICENTE, PATRITO, EDUARDO MARTIN

Elsevier

Lugar: Amsterdam; Año: 2006 vol. 600 p. 155 - 155

h3 class="h3">Abstract The surface structure of Au(1 1 1) electrodes covered by 1,8-octanedithiol self-assembled monolayers (SAMs) was studied with in situ scanning tunnelling microscopy (STM) as a function of the electrode potential in acidic and alkaline electrolytes. We investigated the correlation between the dynamics of the SAM and the underlying gold atoms during the reductive desorption and oxidative readsorption processes. The reductive desorption of 1,8-octanedithiol is characterized by a transition from a compact monolayer with an upright molecular configuration to a striped phase with flat lying dithiol molecules, whereas during the oxidative readsorption process the surface first becomes increasingly covered by the striped phase until the transition to the compact phase occurs. We also considered under equivalent conditions 1-octanethiol/Au(1 1 1) SAMs which were used as a reference to evaluate the influence of the ?SH terminal group on the structure and stability