title: Thermal immobilization of ferrocene derivatives on (111) surface of n-type silicon: parallel between vinylferrocene and ferrocenecarboxaldehyde.
abstract: Monolayers attached to a Si(111) surface through Si-C-C or Si-O-C covalent bonds were prepared by the thermally activated reaction (150 degrees C) of vinylferrocene (VFC) or ferrocenecarboxaldehyde (FCA) molecules with hydrogen-terminated Si(111) substrate in order to compare their reactivities. The resulting monolayers gave a couple of redox waves on voltammograms due to ferrocenyl moieties tethered at the surface. The voltammetric quantification revealed that the growth of electrochemically active layers was terminated within 5 h and the final surface coverages of the active ferrocenyl moieties were 58% and 16% for VFC- and FCA-based monolayers, respectively, indicating that the aldehyde molecule is less reactive. X-ray photoelectron spectroscopy and ellipsometry, however, gave an indication that the growth of the VFC layer did not self-terminate and proceeded beyond a monolayer, while this overgrown part of the layer was not electrochemically active.
authors.affiliation: Department of Materials Science and Engineering, Kyoto University, Yoshida-hommachi, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Naomasa
authors.initials: N
authors.lastname: Tajimi
authors.forename: Hikaru
authors.initials: H
authors.lastname: Sano
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Murase
authors.forename: Kyung-Hwang
authors.initials: KH
authors.lastname: Lee
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sugimura