title: In situ metalation of free base phthalocyanine covalently bonded to silicon surfaces.
abstract: Free 4-undecenoxyphthalocyanine molecules were covalently bonded to Si(100) and porous silicon through thermic hydrosilylation of the terminal double bonds of the undecenyl chains. The success of the anchoring strategy on both surfaces was demonstrated by the combination of X-ray photoelectron spectroscopy with control experiments performed adopting the commercially available 2,3,9,10,16,17,23,24-octakis(octyloxy)-29H,31H-phthalocyanine, which is not suited for silicon anchoring. Moreover, the study of the shape of the XPS N 1s band gave relevant information on the interactions occurring between the anchored molecules and the substrates. The spectra suggest that the phthalocyanine ring interacts significantly with the flat Si surface, whilst ring-surface interactions are less relevant on porous Si. The surface-bonded molecules were then metalated in situ with Co by using wet chemistry. The efficiency of the metalation process was evaluated by XPS measurements and, in particular, on porous silicon, the complexation of cobalt was confirmed by the disappearance in the FTIR spectra of the band at 3290 cm(-1) due to -NH stretches. Finally, XPS results revealed that the different surface-phthalocyanine interactions observed for flat and porous substrates affect the efficiency of the in situ metalation process.
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Catania and INSTM UdR di Catania, v.le A. Doria 6, 95125 Catania, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Lupo
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Catania and INSTM UdR di Catania, v.le A. Doria 6, 95125 Catania, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Tudisco
authors.affiliation: Dipartimento di Chimica and INSTM UdR di Parma Università of Parma Parco Area delle Scienze 17/A, 43124 Parma, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Bertani
authors.affiliation: Dipartimento di Chimica and INSTM UdR di Parma Università of Parma Parco Area delle Scienze 17/A, 43124 Parma, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Dalcanale
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Catania and INSTM UdR di Catania, v.le A. Doria 6, 95125 Catania, Italy.
authors.forename: Guglielmo G
authors.initials: GG
authors.lastname: Condorelli
keywords: X-ray photoelectron spectroscopy (XPS); metalation; phthalocyanine; silicon surface; surface functionalization