Duncan, D.A., Unterberger, W., Hogan, K.A., Lerotholi, T.J., Lamont, C.L.A. and Woodruff, D.P. (2010) A photoelectron diffraction investigation of vanadyl phthalocyanine on Au(111). Surface Science, 604 (1). pp. 47-53. ISSN 0039-6028

Scanned-energy mode photoelectron diffraction using the O 1s and V 2p emission perpendicular to the surface has been used to investigate the orientation and internal conformation of vanadyl phthalocyanine (VOPc) adsorbed on Au(1 1 1). The results confirm earlier indications from scanning tunnelling microscopy that the VO vanadyl bond points out of, and not into, the surface. The VO bondlength is 1.60 ± 0.04 Å, not significantly different from its value in bulk crystalline VOPc. However, the V atom in the adsorbed molecule is almost coplanar with the surrounding N atoms and is thus pulled down into the approximately planar region defined by the N and C atoms by 0.52 (+0.14/−0.10) Å, relative to its location in crystalline VOPc. This change must be attributed to the bonding interaction between the molecule and the underlying metal surface.