We have investigated the bonding configuration of an isolated cis-2-butene molecule (CH3-CH=CH-CH3) on the Pd(110) surface using a cryogenic STM at the sample temperature of 4.7 K. For the precise determination of the bonding site of the molecule, we utilize a novel method of rotating the molecule by injecting tunneling electrons into the molecule. We have observed the rotation of the molecule around the terminal site of a single Pd atom with hopping between four equivalent bonding sites when tunneling electrons with the energy of 170 meV were dosed. The bonding between the cis-2-molecule and the Pd(110) surface is considerably through π-bonding at the carbon double-bond, which makes bonding on the terminal site favorable. However, the analysis of the images of rotating molecule reveals that the C=C is shifted from the terminal site and located at the off-symmetry position.
- Scanning tunneling microscopy
- Surface electronic phenomena (work function, surface potential, surface states, etc.)
ASJC Scopus subject areas
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry