Understanding Copper(I)-Ethylene Bonding Using Cu K-Edge X-ray Absorption Spectroscopy.
Inorg Chem
; 62(47): 19298-19311, 2023 Nov 27.
Article
en En
| MEDLINE
| ID: mdl-37963391
Copper plays many important roles in ethylene chemistry, thus generating significant interest in understanding the structures, bonding, and properties of copper(I)-ethylene complexes. In this work, the ethylene binding characteristics of a series of isolable Cu(I)-ethylene compounds supported by a systematic set of fluorinated and nonfluorinated bis- and tris(pyrazolyl)borate and the related bis(pyrazolyl)methane ligands have been investigated. Through a combination of X-ray absorption spectroscopy and quantum chemical calculations, we characterize their geometric and electronic structures and the role that fluorinated ligands play in lowering the electron density at Cu sites. Such ligands increase the ethylene-to-Cu σ-donor interaction and, correspondingly, decrease the Cu-to-ethylene π back-bonding. This latter interaction leads to a partial vacancy in the Cu 3d level, which manifests experimentally as a low-energy feature in the Cu K pre-edge, allowing for its direct observation and comparison within a series of Cu(I) compounds. The pre-edge feature is reproduced by TD-DFT calculations, and its energy position and total intensity are used to quantitatively probe Cu-ethylene bonding. The variations in the Cu electronic structure influence the stability and overall ethylene bonding strength of these compounds, ultimately showing how substituents on the supporting ligands have a notable effect on their physical and chemical properties.
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1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Inorg Chem
Año:
2023
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos