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Current Appointment
Associate Professor of Chemistry, Department of Chemistry
Education
Postdoctoral Research Associate, 2004-05,
University of North Carolina, Charlotte, NC
Postdoctoral Research Associate, 2002-04, Pennsylvania State University, PA
Ph.D., 2002, Cambridge University, UK
BS/MS, 1998, Oxford University, UK
Research Interests
Physical Chemistry, Surface Science, and Nanoscience. A
main focus of the Sykes group is the development of a nanoscale model system and
its use in exploring the fundamental limits of thermally and electrically driven
molecular rotation. The thioether backbone constitutes an excellent test bed for
studying the details of molecular rotation at the single molecule level. By
using low-temperature scanning tunneling microscopy (LTSTM), they are able to
record the dynamics of individual molecular rotors at the atomic scale. They
have investigated how small, simple thioether molecules function as molecular
rotors and are beginning to devise methods for turning them into molecular
motors. Thioether molecules are just 1 nm across and composed of two
carbon chains connected to either side of a sulfur atom. These molecules rotate
randomly in 3D space, but when anchored to a gold surface through the central
sulfur atom, the molecules rotate like a propeller. At very low temperatures (20
Kelvin), the molecules transition between a locked or “frozen” state to one in
which they spin at over one million times per second. They are currently
learning how to unidirectionally “drive” the molecules electrically by exciting
them with electrons supplied by the STM tip. The system has also led us to
exciting chiral analogues which have asymmetric torsional potentials that will
be utilized to drive highly directional motion. Dr. Sykes work has also allowed
the pursuit of a unique aspect of monitoring and inducing symmetry breaking at
the single-molecule level.
Recent Selected Publications
"Experimental Demonstration of a Single-Molecule Electric Motor",
H. L. Tierney, C. J. Murphy, A. D. Jewell, A. E. Baber, E. V. Iski, H. Y.
Khodaverdian, A. F. McGuire, N. Klebanov and E. C. H. Sykes, Nature
Nanotechnology, 2011, Published On-Line 4 September 2011, doi:
10.1038/nnano.2011.142 Available on-line:
Full Text HTML and
PDF
"The Extraordinary Stability Imparted to Silver Monolayers
by Chloride", E. V. Iski, M. El-Kouedi, D. O. Bellisario, C. Calderon, F. Wang,
T. Ye and E. C. H. Sykes, Electrochim. Acta, 2011, 56,
1652-1661
"Regular Scanning Tunneling Microscope Tips can be Intrinsically Chiral",
H. L. Tierney, C. J. Murphy and E. C. H. Sykes, Phys. Rev. Lett., 2011,
106, 010801
"Gently Lifting Gold's Herringbone Reconstruction:
Trimethylphosphine on Au(111)" A. D. Jewell, H. L. Tierney and E. C. H. Sykes,
Phys. Rev. B, 2010, 82, 205401.
"Adsorption Site Distributions on Cu(111), Cu(221), and Cu(643) as Determined by
Xe Adsorption", L. Baker, B. Holsclaw, A. E. Baber, H. L. Tierney, E. C.
H. Sykes, A. J. Gellman, J. Phys. Chem. C, 2010, 114,
18566-18575.
"Surface-Mediated Two-Dimensional Growth of the Pharmaceutical Carbamazepine",
E. V. Iski, B. F. Johnston, A. J. Florence, A. J. Urquhart, E. C. H. Sykes,
ACS Nano, 2010, 4, 5061-5068.
"Dynamics of Molecular Adsorption and Rotation on Nonequilibrium Sites", H. L.
Tierney, A. D. Jewell, A. E. Baber, E. V. Iski, E. C. H. Sykes, Langmuir,
2010, 26, 15350-15355.
"Adsorption, Assembly, and Dynamics of Dibutyl Sulfide on Au{111}", D. O.
Bellisario, A. D. Jewell, H. L. Tierney, A. E. Baber, E. C. H. Sykes, J.
Phys. Chem. C, 2010, 114, 14583-14589.
"Chirality and Rotation of Asymmetric Surface-Bound Thioethers", H. L. Tierney,
J. W. Han, A. D. Jewell, E. V. Iski, A. E. Baber, D. S. Sholl, E. C. H. Sykes,
J. Phys. Chem. C, 2010, 115, 897-901.
Time-Resolved Studies of Individual Molecular Rotors', A.
D. Jewell, H. L. Tierney, A. E. Baber,
E. V. Iski, M. M. Laha and E. C. H. Sykes, J. Phys, Cond. Mat, 2010,
22, 264006.
"Atomic-Scale Geometry and Electronic Structure of Catalytically Important Pd/Au
Alloys',
A. E. Baber, H. L. Tierney and E. C. H. Sykes, ACS NANO, 2010, 4,
1637-1645.
"Understanding the Rotational Mechanism of a Single Molecule: STM and DFT
Investigations of Dimethyl Sulfide Molecular Rotors on Au(111)', H. L. Tierney,
C. Calderon, A. E. Baber, E. C. H. Sykes and F. Wang, J. Phys. Chem. C,
2010, 114, 3152-3155.
Complete listing of publications can be found
HERE.
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