Copper (II)‐TEMPO Interaction

Abstract: Copper (II) complexes with N‐oxyl reactants such as TEMPO can selectively oxidize alcohols to aldehydes or ketones. The proposed copper intermediates of the oxidation reaction were extensively theoretically studied, but they were never experimentally detected. Here, we present an analysis of “frozen” intermediates that contain alcohols without α‐hydrogen atoms, thus preventing oxidation. The copper (II)‐TEMPO complexes with a bipyridine‐type ancillary ligand were isolated by electrospray ionization mass spectrometry and investigated spectroscopically by cryogenic photodissociation spectroscopy. The vibrational characteristics of the complexes suggest that TEMPO retains its unpaired electron even upon coordination with copper (II). In agreement, the electronic photodissociation spectra of the TEMPO‐copper (II) complexes show a characteristic band for gaseous copper (II) complexes. These results contradict interpretations of some previous density functional theory (DFT) analyses of possible reaction intermediates. The experimental data were confronted with theoretical results obtained by pure DFT (OPBE, TPSS) and hybrid DFT (TPSSH, B3LYP) calculations. The methods favor different ground states and capture various aspects of the experimental results demonstrating a multiconfigurational character of the copper (II)‐TEMPO complexes.

Angaben zum Objekt

• Standort: Deutsche Nationalbibliothek Frankfurt am Main
• Umfang: Online-Ressource
• Sprache: Englisch

Verweise und Beziehungen

• Erschienen in: Copper (II)‐TEMPO Interaction ; day:31 ; month:03 ; year:2023 ; extent:11 ; Israel journal of chemistry ; (31.03.2023) (gesamt 11)

Beteiligte, Orts- und Zeitangaben

• Urheber: Mehara, Jaya ; Roithova, Jana

Weitere Informationen

• DOI: 10.1002/ijch.202300011
• URN: urn:nbn:de:101:1-2023033115403862092875
• Rechteinformation: Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Letzte Aktualisierung: 14.08.2025, 10:55 MESZ