Studies on the pre-edge region of the X-ray absorption spectra of copper(<scp>I</scp>) oxide and the diamminecopper(<scp>I</scp>) ion

Moen, Arild; Nicholson, D.; Rønning, Magnus

doi:10.1039/ft9959103189

Cited by 41 publications

(50 citation statements)

References 28 publications

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“…For this reason, the peak for the 1s → 4p x,y transition would appear at a lower energy with higher intensity than the 1s → 4p z transition. 29,30 The spectra of i-Cu 2 O particles show a higher intensity for peak A and lower intensity for peak B, indicating that i-Cu 2 31−34 This suggestion can be supported on the basis of IR spectroscopy data. In our previous study on IR spectroscopy, 35 the IR spectrum of c-Cu 2 O differentiated from that of pure PVP, indicating that the CO stretch at 1647 cm −1 in the spectra of the crystal is red-shifted compared with that of pure PVP (1655 cm −1 ) because of the weakening of the CO bond in the carbonyl group of PVP.…”

Section: ■ Results and Discussionmentioning

confidence: 66%

Ferromagnetism of Single-Crystalline Cu₂O Induced through Poly(N-vinyl-2-pyrrolidone) Interaction Triggering d-Orbital Alteration

Kim¹,

Kim²,

Sohn³

et al. 2015

J. Phys. Chem. C

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Ferromagnetic-like properties of cuprous oxide (Cu 2 O) are induced through its interaction with chemisorbed surfactant poly(N-vinyl-2-pyrrolidone) (PVP), which alters the intrinsic d 10 configuration of Cu ions. Structural and magnetism-related properties of intact Cu 2 O crystals (i-Cu 2 O) and those capped with PVP (c-Cu 2 O) were examined using various analytical instruments. SEM, TEM (corresponding selected area electron diffraction (SAED)), and XRD of i-Cu 2 O and c-Cu 2 O showed cubic and hexagonal shapes of single crystallinity with facets of {200} and {111}, respectively, resulting from the differential growth rates of the original identical crystals along the facets over time. Bulk magnetic susceptibility (χ) of i-Cu 2 O and c-Cu 2 O at room temperature in field-dependent magnetization and the difference in their magnetic moment in temperature-dependent magnetization showed diamagnetic and ferromagnetic properties, respectively. The difference in the fluorescence mode of X-ray absorption near edge structure (XANES) spectra between i-Cu 2 O and c-Cu 2 O, showing no quadruple pre-edge peak for the transition 1s → 3d in Cu(II) ions with d 9 electronic configuration, indicates an orbital alteration on the surface of cCu 2 O caused by an interaction with PVP. Two peaks for c-Cu 2 O at higher binding energies in O 1s X-ray photoelectron spectroscopy may be indicative of the ligand-to-metal charge transfer (LMCT) from O atoms of PVP to Cu ions of Cu 2 O, generating a chemical interaction through coordination bonding. Large hyperfine splitting constants in electron paramagnetic resonance (EPR) spectra of c-Cu 2 O support this interpretation, with septet hyperfine splitting suggestive of Cu−Cu interactions on the surface of c-Cu 2 O via the interaction with O atoms of PVP. These results demonstrate that PVP capping of Cu 2 O crystal (c-Cu 2 O) induces ferromagnetism of Cu(I) ions through coordination with O atoms of chemically adsorbed PVP. This may induce LMCT and Cu−Cu interactions that lead to changes in electronic configurations, deriving the ferromagnetic moments of c-Cu 2 O.

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Section: ■ Results and Discussionmentioning

confidence: 66%

Ferromagnetism of Single-Crystalline Cu₂O Induced through Poly(N-vinyl-2-pyrrolidone) Interaction Triggering d-Orbital Alteration

Kim¹,

Kim²,

Sohn³

et al. 2015

J. Phys. Chem. C

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“…This, together with the energies, indicates that 2p 6s(Hg) and 2p ligand orbitals are possible assignments 10,11 . In the case of copper(I) compounds at the K-edge, the intensity of the pre-edge peak is connected to the 1s 4p transitions often observed for transition metal compounds 19,20 .…”

Section: X-ray Absorption Spectroscopymentioning

confidence: 99%

An X-ray absorption spectroscopic study at the mercury LIII edge on phenylmercury(II) oxygen species

Jackson

Moen

Nicholson

et al. 2000

J. Chem. Soc., Dalton Trans.

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“…Among transition-metal catalyzed processes, reactions involving copper remain particularly difficult for rigorous mechanistic investigation due to the low reduction potential of copper (+0.159 V from Cu 2+ to Cu + , and +0.520 V from Cu + to Cu 0 (1)), the propensity for Cu + species to disproportionate in solution (2), the generally poor ability of copper to back-bond to ligands (3), and the well-documented tendency of copper complexes to aggregate (4). Despite these complications, copper catalysis has been employed successfully for decades in a variety of methods including carbon–heteroatom bond formation (5), carbon–carbon bond formation (6), oxidative processes (7, 8), and, most recently, dipolar cycloadditions (Fig.…”

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confidence: 99%

Direct Evidence of a Dinuclear Copper Intermediate in Cu(I)-Catalyzed Azide-Alkyne Cycloadditions

Worrell

Malik

Fokin

2013

Science

745

564

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The copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC) has become a commonly employed method for the synthesis of complex molecular architectures under challenging conditions. Despite the widespread use of copper-catalyzed cycloaddition reactions, the mechanism of these processes has remained difficult to establish due to the involvement of multiple equilibria between several reactive intermediates. Real-time monitoring of a representative cycloaddition process via heat flow reaction calorimetry revealed that monomeric copper acetylide complexes are not reactive toward organic azides unless an exogenous copper catalyst is added. Furthermore, crossover experiments with an isotopically enriched exogenous copper source illustrated the stepwise nature of the C–N bond-forming events and the equivalence of the two copper atoms within the cycloaddition steps.

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Studies on the pre-edge region of the X-ray absorption spectra of copper(I) oxide and the diamminecopper(I) ion

Cited by 41 publications

References 28 publications

Ferromagnetism of Single-Crystalline Cu₂O Induced through Poly(N-vinyl-2-pyrrolidone) Interaction Triggering d-Orbital Alteration

Ferromagnetism of Single-Crystalline Cu₂O Induced through Poly(N-vinyl-2-pyrrolidone) Interaction Triggering d-Orbital Alteration

An X-ray absorption spectroscopic study at the mercury LIII edge on phenylmercury(II) oxygen species

Direct Evidence of a Dinuclear Copper Intermediate in Cu(I)-Catalyzed Azide-Alkyne Cycloadditions

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Studies on the pre-edge region of the X-ray absorption spectra of copper(I) oxide and the diamminecopper(I) ion

Cited by 41 publications

References 28 publications

Ferromagnetism of Single-Crystalline Cu2O Induced through Poly(N-vinyl-2-pyrrolidone) Interaction Triggering d-Orbital Alteration

Ferromagnetism of Single-Crystalline Cu2O Induced through Poly(N-vinyl-2-pyrrolidone) Interaction Triggering d-Orbital Alteration

An X-ray absorption spectroscopic study at the mercury LIII edge on phenylmercury(II) oxygen species

Direct Evidence of a Dinuclear Copper Intermediate in Cu(I)-Catalyzed Azide-Alkyne Cycloadditions

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Ferromagnetism of Single-Crystalline Cu₂O Induced through Poly(N-vinyl-2-pyrrolidone) Interaction Triggering d-Orbital Alteration

Ferromagnetism of Single-Crystalline Cu₂O Induced through Poly(N-vinyl-2-pyrrolidone) Interaction Triggering d-Orbital Alteration