Adsorbate Azimuthal Orientation from Reflectance Anisotropy Spectroscopy

B. G. Frederick; J. R. Power; R. J. Cole; C. C. Perry; Q. Chen; S. Haq; Th. Bertrams; N. V. Richardson; P. Weightman

doi:10.1103/PhysRevLett.80.4490

Adsorbate Azimuthal Orientation from Reflectance Anisotropy Spectroscopy

B. G. Frederick, J. R. Power, R. J. Cole, C. C. Perry, Q. Chen, S. Haq, Th. Bertrams, N. V. Richardson, and P. Weightman

Phys. Rev. Lett. 80, 4490 – Published 18 May 1998

Abstract

We have determined the azimuthal orientation of an adsorbate on a metal surface from an intramolecular-transition-derived feature in reflectance anisotropy spectroscopy (RAS). Adsorption of 9-anthracene carboxylic acid onto $p (2 \times 1) O / Cu (110)$ led to an ordered structure with a strong (2%), derivativelike feature at 4.5 eV. Fresnel theory predicts the measured intensity, functional behavior, and sense of the RAS signal for the molecule aligned along [110]. IR measurements confirm that the molecular plane is perpendicular to the surface and STM measurements support the azimuthal orientation. We reassign the sense of the clean Cu(110) surface RA spectrum.

Received 9 December 1997

DOI:https://doi.org/10.1103/PhysRevLett.80.4490

Authors & Affiliations

B. G. Frederick^*, J. R. Power, R. J. Cole, C. C. Perry, Q. Chen, S. Haq, Th. Bertrams, N. V. Richardson^†, and P. Weightman

IRC in Surface Science, University of Liverpool, Liverpool L69 3BX, United Kingdom

^*Present address: Department of Chemistry and Laboratory for Surface Science and Technology, University of Maine, Orono, ME 04469.
^†Present address: School of Chemistry, University of St. Andrews, St. Andrews KY16 9ST, Scotland, United Kingdom.