Physisorption of an organometallic platinum complex on silica: An ab initio study

The interaction of trimethyl methylcyclopentadienyl platinum (MeCpPtMe ₃) with a fully hydroxylated SiO ₂ surface has been explored by means of ab initio calculations. A large slab model (3 × 3 × 4 supercell) cut out from the hydroxylated β-cristobalite SiO ₂ (111) surface was chosen to simulate a silica surface. Density functional theory calculations were performed to evaluate the energies of MeCpPtMe ₃ adsorption to the SiO ₂ surface. Our results show that the physisorption of the molecule is dependent on both (i) the orientation of the adsorbate and (ii) the adsorption site on the substrate. The most stable configuration was found with the MeCp and Me ₃ groups of the molecule oriented toward the surface. Finally, we observe that van derWaals corrections are crucial for the stabilization of the molecule on the surface. We discuss the relevance of our results for the growth of Pt-based nanostructured materials via deposition processes such as electron beam-induced deposition.