The reaction of the [Ru(
5-C
5H
5)(
4-C
5H
4O)]
+ fragment, anchored to self-assembled primerlayers of NC
5H
4(CH
2)
2SiO
x or NC(CH
2)
16SiO
x on native silicon (Si/SiO
2) substrates, with sometertiary phosphines PR
3 has been studied by means of in situ ellipsometry. In this way themetal center is effectively inaccessible, and the phosphine can attack only at the cyclopentadienone ligand site. The rate constants derived from in situ ellipsometry are found to bein surprisingly good agreement with those obtained in homogeneous solution for the reactionof [Ru(
5-C
5H
5)(
4-C
5H
4O)L]
+ (L = pyridine, CH
3CN) with PR
3 to yield the
3-cyclopentenoylcomplexes [Ru(
5-C
5H
5)(
3-C
5H
4O-2-PR
3)L]
+. The nature of the ruthenium complexes at thesurface has been established by IR spectroscopy in combination with XPS measurements.Thus, the present study provides a rare example of a direct comparison of the same intrinsicreaction occurring in homogeneous solution and at the solid-liquid interface.
