ToF-SIMS Investigation of the Initial Stages of MeCpPt(CH3)(3) Adsorption and Decomposition on Nickel Oxide Surfaces: Exploring the Role and Location of the Ligands

摘要

The chemistry of trimethyl(methylcyclopentadienyl)platinum(IV) MeCpPt(CH3)(3), a platinum organometallic compound often used for the chemical deposition of Pt films, on nickel oxide surfaces was investigated. Particular emphasis was placed on following the coordination of the initial ligands, methylcyclopentadienyl (MeCp) and methyl moieties, by using time-of-flight secondary ion mass spectrometry (ToF-SIMS) in combination with X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) computations. It is shown that the MeCp fragment is stable and, upon reacting with NiO surface, remains attached to the Pt center. The methyl groups, on the other hand, can migrate to the nickel surface or remain bonded to the Pt, but on NiO surfaces they prefer to interact with the nickel centers rather than with the oxygen atoms. In addition to these findings, ToF-SIMS data confirmed that gas-phase electron-impact activation can truly enhance the activity of the MeCpPt(CH3)(3) precursor.