Details

Autor(en) / Beteiligte

• Tran, N. L.
• Bishop, S. R.
• Grassman, T. J.
• Poon, G. C.
• Bohrer, F. I.
• Trogler, W. C.
• Kummel, A. C.

Titel

NO chemisorption dynamics on thick FePc and ttbu-FePc films

Ist Teil von

• The Journal of chemical physics, 2009-05, Vol.130 (17), p.174305-174305-7

Ort / Verlag

United States: American Institute of Physics

Erscheinungsjahr

2009

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The NO chemisorption dynamics on ordered multilayer iron phthalocyanine (FePc) and quasiamorphous multilayer tetra- t -butyl FePc (ttbu-FePc) films on a Au(111) substrate was investigated using the King and Wells reflection technique. The NO zero coverage or initial sticking probabilities ( S 0 ) were measured as a function of sample temperature ( T s ) and beam energy ( E i ) . The experimental results for both films show a monotonic decrease in S 0 with increasing T s and E i consistent with NO adsorption occurring via a multiple pathway precursor-mediated mechanism in which the adsorbate initially physisorbs to the FePc organics, diffuses, and chemisorbs to the Fe metal center. The saturation coverage is 3% for the multilayer FePc surface and only 2% for the multilayer ttbu-FePc surface consistent with NO chemisorption occurring only on the Fe metal, where NO chemisorbs to 100% of the surface Fe metal centers. The reduced saturation coverage in the ttbu-FePc film is attributed to fewer Fe metal centers in the less dense ttbu-FePc films. A comparison of NO sticking on a multilayer FePc/Au(111) film with NO sticking on a monolayer FePc/Au(111) film shows that S 0 is greater on the multilayer FePc film for all T s and E i , consistent with an increase in collision inelasticity for NO/multilayer FePc/Au(111).