COActivation by Small Copper, Cobalt, and Yttrium Oxide Clusters Probed via Infrared Multiple‐Photon Dissociation Spectroscopy
Source: PubMed Central Open Access, NCBI / U.S. National Library of Medicine
The interaction of COwith Cu, Co, and Y oxide clusters of different size, composition, and charge is investigated via infrared multiple‐photon dissociation (IR‐MPD) spectroscopy. The IR‐MPD spectra of MO(CO)(M = Cu, Co, Y) complexes reveal the non‐activated binding of COto all cationic clusters. In contrast, COis activated by all anions via formation of carbonate‐like COunits. Density functional theory(DFT) calculations on MOmodel systems suggest that for COactivation in general, the energy difference between the cluster highest occupied molecular orbital (HOMO) and the COlowest unoccupied molecular orbital (LUMO) is crucial. The binding motif of the activated COmolecule, however, depends on a fine interplay between the nature of the orbitals close to the HOMO and the oxidation state of the metal atoms. COformation is favored when the cluster HOMO or any energetically close lying molecular orbital (MO) is at least partially localized on one of the cluster oxygen atoms. In contrast, if such MOs are energetically less favorable,‐(C,O) and‐(O,O) binding to one of the metal atoms can be favored, provided the already positively charged metal atom can transfer electron density, i.e., adopt an even higher oxidation state. Infrared multiple photon dissociation spectroscopy is used to study the activation of COon Cu‐, Co‐, and Y‐oxide clusters. While COactivation is not possible on cationic clusters, the binding motif on anionic clusters depends on a fine interplay between the nature
Abstract
The interaction of COwith Cu, Co, and Y oxide clusters of different size, composition, and charge is investigated via infrared multiple‐photon dissociation (IR‐MPD) spectroscopy. The IR‐MPD spectra of MO(CO)(M = Cu, Co, Y) complexes reveal the non‐activated binding of COto all cationic clusters. In contrast, COis activated by all anions via formation of carbonate‐like COunits. Density functional theory(DFT) calculations on MOmodel systems suggest that for COactivation in general, the energy difference between the cluster highest occupied molecular orbital (HOMO) and the COlowest unoccupied molecular orbital (LUMO) is crucial. The binding motif of the activated COmolecule, however, depends on a fine interplay between the nature of the orbitals close to the HOMO and the oxidation state of the metal atoms. COformation is favored when the cluster HOMO or any energetically close lying molecular orbital (MO) is at least partially localized on one of the cluster oxygen atoms. In contrast, if such MOs are energetically less favorable,‐(C,O) and‐(O,O) binding to one of the metal atoms can be favored, provided the already positively charged metal atom can transfer electron density, i.e., adopt an even higher oxidation state. Infrared multiple photon dissociation spectroscopy is used to study the activation of COon Cu‐, Co‐, and Y‐oxide clusters. While COactivation is not possible on cationic clusters, the binding motif on anionic clusters depends on a fine interplay between the nature and energetic location of the molecular orbitals and the charge (oxidation state) on the metal atoms. graphical