Copper Compounds

Zhang, Jun; Richardson, H. Wayne

doi:10.1002/14356007.a07_567.pub2

Cited by 9 publications

(6 citation statements)

References 60 publications

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“…After air calcination of the polycrystalline Cu specimen, the as‐prepared Cu oxide precursor exhibits a dark and rough appearance (Figure S1a), which is the typical color of cupric oxide (CuO). [14] The electrically insulating characteristics of a thick CuO layer resulted in extensive charge build‐up making XPS studies unfeasible. After the H 2 reduction treatment, the OD‐Cu exhibits a shining orange/pink color (see Figure S1b), indicating the oxide has been reduced across the entire sample surface.…”

Section: Resultsmentioning

confidence: 99%

Direct Evidence of Subsurface Oxygen Formation in Oxide‐Derived Cu by X‐ray Photoelectron Spectroscopy

et al. 2021

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Subsurface oxygen has been proposed to be crucial in oxide-derived copper (OD-Cu) electrocatalysts for enhancing the binding of CO intermediates during CO 2 reduction reaction (CO 2 RR). However,t he presence of such oxygen species under reductive conditions still remains debated. In this work, the existence of subsurface oxygen is validated by grazing incident hard X-rayphotoelectron spectroscopy, where OD-Cu was prepared by reduction of Cu oxide with H 2 without exposing to air.T he results suggest two types of subsurface oxygen embedded between the fully reduced metallic surface and the Cu 2 Ob uried beneath:( i) oxygen staying at lattice defects and/or vacancies in the surface-most region and (ii)interstitial oxygen intercalated in metal structure.T his study adds convincing support to the presence of subsurface oxygen in OD-Cu, whichpreviously has been suggested to play an important role to mitigate the s-repulsion of Cu for CO intermediates in CO 2 RR.

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Section: Resultsmentioning

confidence: 99%

Direct Evidence of Subsurface Oxygen Formation in Oxide‐Derived Cu by X‐ray Photoelectron Spectroscopy

et al. 2021

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“…With regard to the frequently troublesome (and often academic) question of stoichiometry, the early studies used superstoichiometric (1–2 equiv) Cu(OAc) 2 , − with Evans specifically demonstrating that stoichiometric amounts of Cu(OAc) 2 and aerobic conditions were required for the C–O bond forming process to proceed in good yield . Mechanistically, the process is believed to require Cu(II) at the outset; however, in situ Cu(I) disproportionation or oxidation of Cu(I) , likely explains why Cu(I) sources can be used.…”

Section: Discussionmentioning

confidence: 99%

“…Although the number of examples is lower, the use of Cu(II) halides (CuCl 2 , CuBr 2 ) has been reported. Despite halogenation of arylboronic acids and derivatives being known to proceed via ipso -substitution using X 2 generated in situ by the well-known Cu(II)/X – → Cu(I)/X 2 redox process (Scheme ), ,, coupling to counteranions derived from the Cu source has not been reported. However, this is somewhat achievable under certain circumstances; for example, acetate esters are not reported when using Cu(OAc) 2 , although it is possible to prepare phenolate esters by Chan–Lam of AcOH (and other carboxylic acids) using Cu(OTf) 2 …”

Section: Discussionmentioning

confidence: 99%

Mechanistic Development and Recent Applications of the Chan–Lam Amination

et al. 2019

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1. INTRODUCTION 1.1 Generalities and Context 1.2 C-N Bond Formation via Cross-Coupling Reactions 1.3 C-N Bond Formation via Nucleophile-Electrophile Cross-Coupling 1.4 C-N Bond Formation via Nucleophile-Nucleophile Cross-Coupling 2. DISCUSSION 2.1 Discovery 2.2 Development of Reaction Conditions 2.3 A General Mechanistic Description of the Chan-Lam Reaction 2.4 Reactions Variables and Selection of Reaction Conditions 3. SCOPE OF THE CHAN-LAM AMINATION 3.1 Organoboron Variation 3.2 Aryl Amines (Anilines) 3.3 Heteroaryl Amines (Heterocyclic Anilines) 3.4 Alkyl Amines 3.5 Amides 3.6 NH-Heterocycles 3.7 C-N Bond Formation to non-NH-Nucleophiles 3.8 Sulfonamides and Sulfoximes 3.9 Sequential Processes 3.10 C-N Bond Formation on Nucleobases and Peptides 4. MECHANISM 4.1 Historical Context 4.2 Mechanistic Investigations in the Etherification Reaction 4.3 Mechanistic Investigations in the Amination Reaction 4.4 Mechanistic Investigations in the Amination Reaction: Ligand-based Systems 4.5 Mechanism Summary

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“…Secondly, the chemistry of copper is complicated. At typical biological (near-neutral) pHs, particles may form when 'soluble' salts are added to a solution phase, due to oxo-hydroxide formation, polymerisation, cross-linking and precipitation (Paulson and Kester, 1980;Zhang and Richardson, 2016). Finally, particles, whether inadvertently formed or specifically added to a fluid phase, may agglomerate and/or aggregate.…”

Section: Introductionmentioning

confidence: 99%

Copper nanoparticles have negligible direct antibacterial impact

et al. 2020

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Introduction: Soluble copper that can be acquired by bacteria is toxic and therefore antimicrobial. Whether nanostructured copper materials, in either disperse or agglomerated form, have antimicrobial impact, aside from that of their dissolution products, is not clear and was herein addressed. Methods: We took five nanostructured copper materials, two metallic, and three oxo-hydroxides with one of these being silicate-substituted. Four agglomerated in the bacterial growth media whilst the silicate-substituted material remained disperse and small (6.5 nm diameter). Antibacterial activity against E. coli was assessed with copper phase distribution measured over time. Using the dose of soluble copper, and benchmark dose non-linear regression modelling, we determined how well this phase predicted antimicrobial activity. Finally, we used Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) analysis to investigate whether membrane adhesion effects by copper were plausible or if intracellular uptake most likely explained the bacterial impact of copper. Results: Comparison over time of antimicrobial activity against particulate or soluble phases of the aquated materials clearly demonstrated that soluble copper but not particulate forms were associated with inhibition of bacterial growth. Indeed, the benchmark dose modelling showed the soluble dose required to cause a 50% reduction in E. coli growth was strongly clustered -for all particle formulations -at 14.5 mg/L (10-19 mg/L 90% confidence interval). By comparison, total copper levels associated with the same reduction in viability varied widely (45-549 mg/L). Finally, in favour of this soluble product dominance in terms of antimicrobial activity, copper had low association with bacterial membrane (something both soluble and particulate materials could do) but showed high intra-bacterial levels (something only soluble copper could do). Conclusion: Taken together our data show that it is the uptake of soluble but not particulate copper, and the intracellular loading not just contact and membrane association, that drives copper toxicity to bacteria. Therapeutic strategies for novel antimicrobial copper compounds should consider these findings.

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Copper Compounds

Cited by 9 publications

References 60 publications

Direct Evidence of Subsurface Oxygen Formation in Oxide‐Derived Cu by X‐ray Photoelectron Spectroscopy

Direct Evidence of Subsurface Oxygen Formation in Oxide‐Derived Cu by X‐ray Photoelectron Spectroscopy

Mechanistic Development and Recent Applications of the Chan–Lam Amination

Copper nanoparticles have negligible direct antibacterial impact

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