Structural Study of Benzene Adsorbed on Si(001) Surface by Photoelectron Diffraction.

The structure of benzene adsorbed on a Si(001)(2 × 1) surface up to saturation at room temperature (RT) has been studied by C 1s photoelectron diffraction (PED). Experimental C 1s PED patterns were measured for two regimes of photoelectron kinetic energies at ~ 100 eV and ~ 1000 eV. Simulation of PED patterns was made for three possible structural models predicted so far. Comparison of actual PED patterns and R-factor analysis leads to the conclusion that the so-called standard butterfly (SB) configuration of benzene is present and stable at the saturation coverage at RT. The present PED patterns were not very sensitive to geometrical parameters of absorbed benzene except for the bond length between the topmost carbons in the SB configuration. [ABSTRACT FROM AUTHOR]