Atom-selective bond breaking in a chemisorbed homonuclear molecule induced by core excitation: N2/Ru(001)
We observe photochemical selectivity for N 1s to pi(*) excitations of chemisorbed N2. By narrow bandwidth synchrotron radiation we selectively excite one of the two atoms of the molecule. Photon stimulated desorption of neutral N atoms predominates for excitations of the N atom close to the surface, whereas excitation of the outer atom ejects predominantly N02 and small amounts of N+, demonstrating the predominant breaking of the inner or outer bond, respectively, of the N2 adsorbate. Analysis on the basis of previously obtained decay electron spectra after atom-selective excitation can explain the mechanism of localized bond breaking.
Romberg
R
Physikdepartment E 20, Technische Universitat Munchen, 85747 Garching, Germany.
Heckmair
N
Frigo
SP
Ogurtsov
A
Menzel
D
Feulner
P