A Molecule Carrier
K. L. Wong,1
G. Pawin,1
K.-Y. Kwon,1
X. Lin,1
T. Jiao,1
U. Solanki,1
R. H. J. Fawcett,1
L. Bartels,1*
S. Stolbov,2
T. S. Rahman2
We found that anthraquinone diffuses along a straight line across a flat, highly symmetric Cu(111) surface. It can also reversibly attach one or two CO2 molecules as "cargo" and act as a "molecule carrier," thereby transforming the diffusive behavior of the CO2 molecules from isotropic to linear. Density functional theory calculations indicated a substrate-mediated attraction of
0.12 electron volt (eV). Scanning tunneling microscopy revealed individual steps of the molecular complex on its diffusion pathway, with increases of
0.03 and
0.02 eV in the diffusion barrier upon attachment of the first and second CO2 molecule, respectively.
1 Pierce Hall, University of California, Riverside, CA 92521, USA.
2 Department of Physics, University of Central Florida, Orlando, FL 32816, USA.
* To whom correspondence should be addressed. E-mail: ludwig.bartels{at}ucr.edu