Fundamental understanding of the correlation between the structure and reactivity of chemically addressable N-heterocyclic carbene (NHC) molecules on various surfaces is essential for the design of functional NHC-based self-assembled monolayers. In this work, we identified the ways by which the deposition of chemically addressable OH-NHCs on Au(111) or Pt(111) surfaces modified the anchoring geometry and chemical reactivity of surface-anchored NHCs. The properties of surface-anchored NHCs were probed by conducting X-ray photoelectron spectroscopy and polarized near-edge X-ray absorption fine structure measurements. While no preferred orientation was identified for OH-NHCs on Pt(111), the anchored molecules adopted a preferred flat-lying position on Au(111). Dehydrogenation and aromatization of the imidazoline ring along with partial hydroxyl oxidation were detected in OH-NHCs that were anchored on Au(111). The dehydrogenation and aromatization reactions were facilitated, along with partial decomposition, for OH-NHCs that were anchored on Pt(111). The spectroscopic results reveal that stronger metal-adsorbate interactions increase the reactivity of surface-anchored OH-NHCs while decreasing their molecular orientational order.
Strong Metal-Adsorbate Interactions Increase the Reactivity and Decrease the Orientational Order of OH-Functionalized N-Heterocyclic Carbene Monolayers
Cossaro A.;Verdini A.;
2020-01-01
Abstract
Fundamental understanding of the correlation between the structure and reactivity of chemically addressable N-heterocyclic carbene (NHC) molecules on various surfaces is essential for the design of functional NHC-based self-assembled monolayers. In this work, we identified the ways by which the deposition of chemically addressable OH-NHCs on Au(111) or Pt(111) surfaces modified the anchoring geometry and chemical reactivity of surface-anchored NHCs. The properties of surface-anchored NHCs were probed by conducting X-ray photoelectron spectroscopy and polarized near-edge X-ray absorption fine structure measurements. While no preferred orientation was identified for OH-NHCs on Pt(111), the anchored molecules adopted a preferred flat-lying position on Au(111). Dehydrogenation and aromatization of the imidazoline ring along with partial hydroxyl oxidation were detected in OH-NHCs that were anchored on Au(111). The dehydrogenation and aromatization reactions were facilitated, along with partial decomposition, for OH-NHCs that were anchored on Pt(111). The spectroscopic results reveal that stronger metal-adsorbate interactions increase the reactivity of surface-anchored OH-NHCs while decreasing their molecular orientational order.File | Dimensione | Formato | |
---|---|---|---|
acs.langmuir.9b02401.pdf
Accesso chiuso
Descrizione: Articolo principale
Tipologia:
Documento in Versione Editoriale
Licenza:
Copyright Editore
Dimensione
1.04 MB
Formato
Adobe PDF
|
1.04 MB | Adobe PDF | Visualizza/Apri Richiedi una copia |
la9b02401_si_001.pdf
Accesso chiuso
Descrizione: Supporting information
Tipologia:
Altro materiale allegato
Licenza:
Copyright Editore
Dimensione
405.91 kB
Formato
Adobe PDF
|
405.91 kB | Adobe PDF | Visualizza/Apri Richiedi una copia |
Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.