Formation and Annealing Effect of Tolanethioacetate Self-Assembled Monolayers on Au(111)

摘要

Self-assembled monolayers (SAMs) were formed by adsorption of thioacetyl-terminated tolanethioacetate (TTA) on Au(111) in a 0.5-mM ethanol solution after one day immersion at room temperature.Molecular-scale STM imaging revealed that the TTA SAMs were composed of two mixed phases;an ordered phase with small domains describing a (3~(1/2) x 2(3~(1/2)) )R30~(deg) structure and a disordered phase.Interestingly,after annealing the pre-covered TTA SAMs on Au(111) at 90 °C for 1 h,the small ordered domains grew unidirectionally,resulting in the formation of unique rod-like domains,which were assigned a (3~(1/2) x 2_(2~(1/2)) )R7° structure.These results will be very useful in understanding the formation and thermal behavior of TTA SAMs on gold surfaces.