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 (√ x 2√ )R30° structure and a disordered phase. Interestingly, after annealing the precovered 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 (√ x 2√)R7° structure. These results will be very useful in understanding the formation and thermal behavior of TTA SAMs on gold surfaces.
- Annealing effect
- Ordered domains
- Scanning tunneling microscopy
- Self-assembled monolayers