The stability and activity of metal nanoparticles (MNPs) are strongly influenced by the ligands used as stabilizers. We describe the first example of Pt NPs ligated by imidazolium-amidinate ligands (Pt/ICy.(R-Ph)NCN; Scheme 1), which are formed by the addition of an N-heterocyclic carbene (NHC) to a carbodiimide (NCN). The surface chemistry of these NPs was investigated by FT-IR and solid state NMR on samples containing coordinated CO. Interestingly a Knight shift was observed in the 13C MAS NMR spectra. We present evidence for the coordination of a nitrogen ligand (ICy. (Ph)NC15N) onto a metal nanoparticle (Pt and Ru) by 15N solid-state NMR. This coordination mode was confirmed by DFT calculations (Figure 1) and XPS analysis. The activity of the Pt NPs as hydrogenation catalyst was investigated. Indeed, an interesting ligand effect has been observed in the hydrogenation of carbonyl groups when electron donor/acceptor groups are introduced in the N-substituents.

Pt NPs ligated by zwitterionic imidazolium-amidinates: A notable ligand effect in hydrogenation of carbonyl groups

253rd National Meeting (2017)

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