Surface anchoring and dynamics of thiolated azobenzene molecules on Au(111)

Jongweon Cho; Niv Levy; Armen Kirakosian; Matthew J Comstock; Frank Lauterwasser; Jean M J Fréchet; Michael F Crommie

doi:10.1063/1.3168524

Surface anchoring and dynamics of thiolated azobenzene molecules on Au(111)

J Chem Phys. 2009 Jul 21;131(3):034707. doi: 10.1063/1.3168524.

Authors

Jongweon Cho¹, Niv Levy, Armen Kirakosian, Matthew J Comstock, Frank Lauterwasser, Jean M J Fréchet, Michael F Crommie

Affiliation

¹ Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA.

PMID: 19624221
DOI: 10.1063/1.3168524

Abstract

We have investigated the temperature-dependent behavior of thiolated azobenzene molecules on Au(111) using scanning tunneling microscopy. The addition of a thiol functional group to azobenzene molecules leads to increased surface anchoring of single azobenzene molecules to gold. Thiolated azobenzene shows diverse surface morphology and does not form well-ordered structures at low coverage. At elevated temperatures, anchored molecules are observed to spin in place via hindered rotation. By measuring the number of rotating molecules as a function of temperature and using a simple model, we are able to estimate the energy barrier and attempt frequency for thermally induced hindered rotation to be 102+/-3 meV and 110+/-2 GHz, respectively.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Azo Compounds / chemistry*
Gold / chemistry*
Particle Size
Sulfhydryl Compounds / chemistry*
Surface Properties
Thermodynamics*

Substances

Azo Compounds
Sulfhydryl Compounds
Gold
azobenzene