The reactions of Cu(hfac)(2) (where hfac = 1,1,1,5,5,5-hexafluoroacetylacetonate), a precursor for the chemical vapor deposition (CVD) of copper, and hfacH with high-surface-area SiO2 have been investigated by transmission FTIR spectroscopy. The SiO2 surface was prepared in three different ways to produce different combinations of reactive surface functionalities. These were (I) a highly dehydroxylated surface which possessed isolated surface hydroxyl groups and four-membered siloxane rings, (II) a dehydroxylated surface which possessed both isolated and hydrogen-bonded surface hydroxyl groups, and (III) an as-loaded surface, containing a higher concentration of isolated and hydrogen-bonded surface hydroxyl groups. The reagents, Cu(hfac)(2) and hfacH, were each dosed at low temperature (-130 degrees C) and higher temperature (25 degrees C), and their temperature-dependent behavior was investigated. The species hfacH molecularly adsorbed on surfaces I-III at -130 degrees C and molecularly desorbed on heating to -50 degrees C on surfaces II or III. However, hfacH reacted with surface I on heating to -75 degrees C. In contrast, when surfaces II and III were treated with hfacH at 25 degrees C, no interaction was observed while reaction with surface I was observed. Surfaces I-III when treated with Cu(hfac)(2) at -130 degrees C gave rise to IR spectra similar to the gas-phase spectrum for this compound. On heating, Cu(hfac)(2) may aggregate on all three surfaces. On heating to higher temperatures (25 degrees C), Cu(hfac)(2) hydrogen-bonded with the isolated surface hydroxyl groups and reacted with the hydrogen-bonded surface hydroxyl groups and the strained siloxane bridges on all three surfaces, exhibiting similar adsorption/desorption characteristics (such as uptake and temperature-dependent spectra). The changes in FTIR data observed on heating are believed to be due to interaction between the adsorbate, derived from Cu(hfac)(2) and surface oxo groups (from surface hydroxyl groups or siloxane rings). These results are consistent with observed decomposition of Cu(hfac)(2) on SiO2 during CVD of copper. Furthermore, these data suggest that selective CVD onto metals in the presence of SiO2 cannot be obtained simply by changing the relative concentration of the reactive sites on these silica surfaces because Cu(hfac)(2) reacts with both the hydrogen-bonded surface hydroxyl groups and the strained siloxane rings. It is likely that most SiO2 surfaces contain at least one of these reactive surface functional groups.