Control and Application of Surface Dynamics at the Single-Molecule Scale
Speaker: Ludwig Bartels, University of California, Riverside
Date & Time: January 19, 2009 - 11:00am
Location: Chem. 260
I will present investigations of the surface interaction and dynamics of individual molecules attached to copper surfaces. In particular, I will show how by a judicious combination of molecular structure and substrate geometry complex adsorbate dynamics and patterns can emerge: (e.g. uniaxial diffusion ‘bipedal locomotion / walking’, 1, 2 a honeycomb several times the molecular size3). I will also address the formation and stability of thiol bonds to surfaces, which are frequently used in prototypical systems for molecular electronics. Here we find facile molecular rearrangements at temperatures as low as 60K, which suggest severe challenges in their application.4 Finally, I will show how the time-scale for resolving molecular motion can be pushed from the millisecond range associated with scanning tunneling microscopy to the picosecond realm by means of femtosecond laser excitation.5
(1). Wong, K. L., et al., SCIENCE 2007, 315, 1391-1393.
(2). Kwon, K. Y., et al., PHYS REV LETT 2005, 95, (16), 166101.
(3). Pawin, G., et al., SCIENCE 2006, 313, (5789), 961-962.
(4). Wong, K., et al., APPL PHYS LETT 2006, 88, 183106.
(5). Bartels, L., et al., SCIENCE 2004, 305, (5684), 648-651.