Surface‐Driven Keto–Enol Tautomerization: Atomistic Insights into Enol Formation and Stabilization Mechanisms. (25th November 2018)

• Record Type: Journal Article
• Authors: Attia, Smadar; Schmidt, Marvin‐Christopher; Schröder, Carsten; Pessier, Pascal; Schauermann, Swetlana
• Is Part Of: Angewandte Chemie. Volume 130:Number 51(2018)
• Page Start: 16901
• Page End: 16906
• Publication Date: 2018-11-25
• Subjects: Carbonylverbindungen -- Keto-Enol-Tautomerisierung -- Modelle der heterogenen Katalyse -- Rastertunnelmikroskopie -- Schwingungsspektroskopie; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201808453
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Tautomerisation of simple carbonyl compounds to their enol counterparts on metal surfaces is envisaged to enable an easier route for hydrogenation of the C=O bond in heterogeneously catalyzed reactions. To understand the mechanisms of enol formation and stabilization over catalytically active metal surfaces, we performed a mechanistic study on keto–enol tautomerization of a monocarbonyl compound acetophenon over Pt(111) surface. By employing infrared reflection adsorption spectroscopy in combination with scanning tunneling microscopy, we found that enol can be formed by building a ketone–enol dimer, in which one molecule in the enol form is stabilized through hydrogen bonding to the carbonyl group of the second ketone molecule. Based on the investigations of the co‐adsorption behavior of acetophenone and hydrogen, we conclude that keto–enol tautomerization occurs in the intramolecular process and does not involve hydrogen transfer through the surface hypothesized previously. Abstract : Um die Bildung und Stabilisierung von Enolen auf katalytisch aktive Metalloberflächen zu untersuchen, wurde eine mechanistische Studie zur Keto‐Enol‐Tautomerisierung von Acetophenon über Pt(111) ausgeführt.