Copper Carboxylate Research Articles

Copper(ii) and triphenylphosphine copper(i) ethylene glycol carboxylates: synthesis, characterisation and copper nanoparticle generation

Ethylene glycol-functionalised copper(II) carboxylates Cu[O2CCR2(OC2H4)nOCH3]2 (n = 0-3; R = H, Me) (2a-e) have been prepared by the reaction of [Cu2(OAc)4·2H2O] with CH3O(C2H4O)nCR2CO2H (1a-e). Upon reduction of 2a-e with triphenylphosphine, the corresponding tris(triphenylphosphine)copper(I) complexes 3a-e were obtained, which could be converted to the bis(triphenylphosphine)copper(I) complexes 4a-e by removal of one phosphine ligand. Based on IR spectroscopy and single crystal X-ray structure analysis the binding motif of the carboxylato group on the copper ion is discussed. DSC, TG and TG-MS experiments were performed to analyse the thermal decomposition mechanism of 2-4. Complex 4c was used as a precursor for the generation of copper nanoparticles by thermal decomposition in hexadecylamine without the need of any further reactants. Depending on the precursor concentration, spherical copper nanoparticles with a mean diameter ranging from 10 to 85 nm as well as nanorods with a length of up to 1.3 μm (aspect ratios ranging between 2 and 32) were obtained. Electron diffraction analysis of the rods suggested that they consist of five domains which are arranged around a fivefold rotational axis.

Structural Observations of Heterometallic Uranyl Copper(II) Carboxylates and Their Solid‐State Topotactic Transformation upon Dehydration

The hydrothermal reactions of uranyl nitrate and metallic copper with aromatic polycarboxylic acids gave rise to the formation of five heterometallic UO(2)(2+)-Cu(2+) coordination polymers: (UO(2))Cu(H(2)O)(2)(1,2-bdc)(2) (1; 1,2-bdc = phthalate), (UO(2))Cu(H(2)O)(2)(btec)⋅4 H(2)O (2) and (UO(2))Cu(btec) (2'; btec = pyromellitate), (UO(2))(2)Cu(H(2)O)(4)(mel) (3; mel = mellitate), and (UO(2))(2)O(OH)(2)Cu(H(2)O)(2)(1,3-bdc)⋅H(2)O (4; 1,3-bdc = isophthlalate). Single-crystal X-ray diffraction (XRD) analysis of compound 1 revealed 2D layers of chains of UO(8) and CuO(4)(H(2)O)(2) units that were connected through the phthalate ligands. In compound 2, these sheets were connected to each other through the two additional carboxylate arms of the pyromellitate, thus resulting in a 3D open-framework with 1D channels that trapped water molecules. Upon heating, free and bonded water species (from Cu-OH(2)) were evacuated from the structure. This thermal transition was followed by in situ XRD and IR spectroscopy. Heating induced a solid-state topotactic transformation with the formation of a new set of Cu-O interactions in the crystalline anhydrous structure (2'), in order to keep the square-planar environment around the copper centers. The structure of compound 3 was built up from trinuclear motifs, in which one copper center, CuO(4)(OH(2))(2), was linked to two uranium units, UO(5)(H(2)O)(2). The assembly of this trimer, "U(2)Cu", with the mellitate generated a 3D network. Complex 4 contained a tetranuclear uranyl core of UO(5)(OH)(2) and UO(6)(OH) units that were linked to two copper centers, CuO(OH)(2)(H(2)O)(2), which were then connected to each other through isophthalate ligands and U=O-Cu interactions to create a 3D structure. The common structural feature of these different compounds is a bridging oxo group of U=O-Cu type, which is reflected by apical Cu-O distances in the range 2.350(3)-2.745(5) Å. In the case of a shorter Cu-O distance, a slight lengthening of the uranyl bond (U=O) is observed (e.g., 1.805(3) Å in complex 4).

Dimeric “paddle-wheel” carboxylates of copper(II): Synthesis, crystal structure and electrochemical studies

The reaction of the sodium salt of para substituted phenyl acetic acid with CuSO4 in water and subsequent treatment with pyridine gives binuclear centro-symmetric complexes pyCu(R–C6H4CH2COO)4Cupy, where R=4-OMe (1) and 4-Cl− (2). The structures of both complexes were solved by X-ray single crystal analysis. The frame of the complexes is constructed as a dimeric ‘paddle-wheel’ with four carboxylate bridges. The apical position is occupied by a pyridine ligand and there is a Cu–Cu bond as well. The compounds demonstrated one-electron redox behavior and their peak currents were found to increase linearly with the square root of the sweep rate (ν1/2). The overall electrode processes were found to be activation plus diffusion controlled. The values of the formal potential (E ´), diffusion coefficient (D) and heterogeneous rate constant (k°) were evaluated for the electroreduction process for both the compounds.

Gaseous phase studies of new copper(II) carboxylate complexes with tert-butylamine as potential precursors for chemical vapor deposition (CVD)

Copper(II) carboxylate compounds with tert-butylamine of the general formula [Cu2(tBuNH2)2(μ-O2CR)4], where R=CnF2n+1, n=1–6, were synthesized in the reaction of copper(II) perfluorinated carboxylates with tert-butylamine generated in situ from tert-butyl isocyanate. The obtained complexes were characterized in the solid state and in the gaseous phase by electron impact mass spectrometry (EIMS), IR spectroscopy, and thermal analysis with the detection of evolved gases. In addition, during the recrystallization of the [Cu2(tBuNH2)2(μ-O2CC3F7)4] complex the (tBuNH3)+(C3F7CO2)− ion pair was isolated, and its X-ray structure was determined. As a result of a mass spectra analysis, the presence of metallated species in the gaseous phase was revealed. Among the species detected, the pseudomolecular ions [Cu2(tBuNH2)2(μ-O2CR)3]+ were found. The fact confirmed the dimeric structure of the studied complexes with bridging carboxylates and axially N-coordinated amines. TGA studies demonstrated that copper transfer to the gaseous phase occurs at atmospheric pressure, which suggests that the obtained compounds can be promising precursors for chemical vapor deposition. The selected Cu(II) compounds were used in the preliminary CVD experiments, and the conformal copper layers were formed with no additional reducing agents.

A Domino Desulfitative Coupling/Acylation/Hydration Process Cocatalyzed by Copper(I) and Palladium(II): Synthesis of Highly Substituted and Functionalized Pyrimidines

AbstractA domino desulfitative coupling/acylation/hydration process to synthesize C‐2‐(2‐oxo‐2‐phenylethylidene)‐ and N‐3‐carbonyl‐substituted pyrimidines by unprecedented CC and CN cross‐coupling reactions is described. This methodology couples 3,4‐dihydropyrimidine‐2‐thiones and alkynes under modified Liebeskind–Srogl conditions using palladium acetate and copper(I) carboxylate. Remarkably the copper(I) carboxylates simultaneously act as desulfitative and acylation reagents in the reaction.

Adsorption study of CO2, CH4, N2, and H2O on an interwoven copper carboxylate metal–organic framework (MOF-14)

Metal–organic frameworks (MOFs) are attractive microporous materials for adsorption separations due to their extraordinary structures and impressive high surface areas. Catenation, or framework interpenetration, can significantly impact the crystal stability and improve the adsorption interactions. This interesting approach was used to obtain {[Cu3(BTB)2(H2O)3]⋅(DMF)9(H2O)2} (MOF-14) as a microporous material with a high surface area and large pore volume, which are desirable parameters for adsorption applications. Here, we report a detailed study of this catenated material with its gas adsorption properties. The potential for adsorption separations is evaluated by measuring pure-component adsorption isotherms for carbon dioxide, methane, and nitrogen. The Ideal Adsorbed Solution Theory (IAST) was used to evaluate adsorption selectivities of MOF-14 for CO2/CH4 and CO2/N2 equimolar mixtures. In addition, water adsorption and the impact of exposure on structural degradation are reported. Compared to other open-metal site MOFs, MOF-14 adsorbs significantly less water. This interwoven MOF is a promising competitor to other MOF materials in the gas separation field due to low interactions with water and high selectivity for CO2 over N2.

EPR and magnetic studies of a novel copper metal organic framework (STAM-I)

The magnetic interaction between dinuclear copper (II) in a new copper carboxylate compound, STAM-1, has been investigated by means of EPR and SQUID measurements. The powder EPR spectra, measured at 9.80 and 34.5GHz and at different temperatures, show the typical lines of the triplet state (S=1), attributed to Cu2+–Cu2+ dimers, in addition of a temperature dependent central lines. The zero field splitting parameters obtained are |Dobs|=0.337cm−1 and E∼0. Magnetic susceptibility data, performed in the range 1.8–300K, shows a strong antiferromagnetic exchange coupling between the Cu2+ centers in the paddle-wheel units with the exchange coupling constant 2J=−334±4cm−1.

Redox-Induced Conformational Change in Mercaptoalkanoic Acid Multilayer Films

We discuss the assembly, structure, and stability of multilayer molecular films formed from multiple mercaptoalkanoic acid monolayers ligated via carboxyl and thiol interactions with divalent copper ions. Using dual-polarization interferometry to study the assembly of multilayer films in real time, we observe a clear linear relationship between the number of layers within a film and the overall average film thickness. Unexpectedly, however, we find a restructuring of the lower monolayer upon association of the Cu(2+) ions to form the Cu carboxylate surface. In particular, the thickness of the lower monolayer was found to decrease significantly, accompanied by an increase in the film density. The conformation of the monolayer subsequently recovered to that observed originally following the reduction of the Cu ion to Cu(+) upon chemisorption of the adlayer. Comparable restructuring was also observed in molecular dynamics simulations of a bilayer film assembled on a gold surface. Our combined experimental and theoretical study suggests that the observed restructuring is a result of charge-charge interactions between adjacent Cu ions that exist in the +2 oxidation state in the copper carboxylate surface and in the +1 oxidation state following chemisorption of the adlayer.

Binuclear complexes with the “Chinese Lantern” geometry as intermediates in the liquid-phase oxidation of dibenzyl ether with atmospheric oxygen in the presence of copper(II) carboxylates

Reactions of copper(II) carboxylates with dibenzyl ether (DBE) gave binuclear complexes of the formula Cu2(μ-OOCR)4(DBE)2 (R = But, Ph, and CF3). The complexes were characterized by X-ray diffraction. The axial positions in the lantern-type dimer are occupied by the coordinated DBE molecules. The complexes seem to be analogs of intermediate catalysts for the oxidation of DBE with atmospheric oxygen in the presence of transition metal complexes. When stored in air, the complex Cu2(μ-OOCPh)4(DBE)2 underwent oxidation into Cu2(μ-OOCPh)4(HOOCPh)2, which was characterized by X-ray diffraction. The geometry of its framework is similar; the structure is stabilized by intramolecular H bonds between the axially oriented benzoic acid molecules and the adjacent bridging benzoate anions.

Extraction of copper(II) carboxylates with chloroform under substoichiometric conditions

The features are considered of binding carboxylic acids (HR) as dimeric solvated copper(II) complexes at the copper(II) extraction with chloroform under substoichiometric conditions, with excess of the metal ion in the aqueous phase. The fundamental difference in the optimization of the quantitative extraction of copper(II) in the form of any carboxylate with a maximum ratio of Cu:R and the total binding with carboxylic acids to form the copper complex of the minimum stoichiometry was noted. It was found that quantitative binding of HR occurred at the extraction of mixed-ligand acetate-carboxylate copper(II) complexes without control over the aqueous phase acidity when acetic acid medium or copper(II) acetate was used, but not copper chloride, nitrate, perchlorate, or sulfate. The possibility of determination by extraction-photometric method by the color of the Cu(II) complex was shown that was suitable only to those carboxylic acids, whose logarithm of the partition coefficient in the water-chloroform mixture was higher than three.

A three-component co-crystal and a mono crystal isolated from the same crystallisation of a copper(II) carboxylate

The vagaries of recrystallisation are highlighted in this contribution which describes the full characterisation of crystals isolated from the recrystallisation of [Cu2L4(EtOH)2] from a 1 : 2 mixture of DMSO and CHCl3 (v/v); L is 4-nitrobenzoate. Slow evaporation over four weeks yielded blue-green crystals of 1 that were shown to be a rare example of a three-component co-crystal comprising [CuL2(OH2)(DMSO)]2, [CuL2(OH2)2(DMSO)] and [CuL2(OH2)(DMSO)2] in the ratio 1 : 2 : 2. After crystals of 1 were removed from the solution, blue crystals of 2 were isolated after another week had elapsed. These proved to be [CuL2(OH2)(DMSO)2] and to be the trans-DMSO isomer of one of the components of 1. The supramolecular aggregation in each crystal structure features ten-membered {…HOH…OCOCuOCO} synthons whereby the hydrogen atoms of a water molecule link two carbonyl-O atoms of another complex molecule. In 1, these synthons lead to an isolated six-copper aggregate, and in 2, these lead to supramolecular chains. IR and thermal analysis (TGA and DSC) data are also presented. Crystal data for (1): triclinic, P-1, a = 13.9035(4), b = 15.5305(4), c = 15.7069(4) Å, α = 80.062(2), β = 83.174(2), γ = 70.109(2)°, V = 3134.75(15)Å3, Z = 2, R = 0.036. Crystal data for (2): monoclinic, C2/c, a = 30.0180(16), b = 5.8440(3), c = 14.2639(8) Å, β = 114.669(7)°, V = 2273.9(2) Å3, Z = 4, R = 0.027.

Evidence for alkene cis-aminocupration, an aminooxygenation case study: kinetics, EPR spectroscopy, and DFT calculations.

Alkene difunctionalization reactions are important in organic synthesis. We have recently shown that copper(II) complexes can promote and catalyze intramolecular alkene aminooxygenation, carboamination, and diamination reactions. In this contribution, we report a combined experimental and theoretical examination of the mechanism of the copper(II)-promoted olefin aminooxygenation reaction. Kinetics experiments revealed a mechanistic pathway involving an equilibrium reaction between a copper(II) carboxylate complex and the γ-alkenyl sulfonamide substrate and a rate-limiting intramolecular cis-addition of N-Cu across the olefin. Kinetic isotope effect studies support that the cis-aminocupration is the rate-determining step. UV/Vis spectra support a role for the base in the break-up of copper(II) carboxylate dimer to monomeric species. Electron paramagnetic resonance (EPR) spectra provide evidence for a kinetically competent N-Cu intermediate with a Cu(II) oxidation state. Due to the highly similar stereochemical and reactivity trends among the Cu(II)-promoted and catalyzed alkene difunctionalization reactions we have developed, the cis-aminocupration mechanism can reasonably be generalized across the reaction class. The methods and findings disclosed in this report should also prove valuable to the mechanism analysis and optimization of other copper(II) carboxylate promoted reactions, especially those that take place in aprotic organic solvents.

Cu–ZrO2 nanocomposite catalyst for selective hydrogenation of levulinic acid and its ester to γ-valerolactone

Several copper based catalysts were prepared, characterized and evaluated for the hydrogenation of levulinic acid and its methyl ester. Among these, nanocomposites of Cu–ZrO2 and Cu–Al2O3 quantitatively catalyzed the hydrogenation of levulinic acid and its methyl ester to give 90–100% selectivity to γ-valerolactone in methanol and water respectively. Both the Cu–ZrO2 and Cu–Al2O3 nanocomposites were prepared by the co-precipitation method using mixed precursors under controlled conditions. XRD results showed that the main active phase of the reduced Cu–ZrO2 catalyst was metallic copper and particle size was found to be of 10–14 nm by HRTEM. The active metal leaching was at a maximum for the Cu–Al2O3 catalyst in a water medium due to the formation of a copper–carboxylate complex that was blue in colour. Surprisingly, copper leaching was completely suppressed in the case of the Cu–ZrO2 catalyst in methanol in spite of the substrate loading was increased from 5 to 20% w/w. The excellent recyclability of the Cu–ZrO2 catalyst with complete LA conversion and >90% GVL selectivity makes it a sustainable process having a commercial potential.

Pair distribution function-derived mechanism of a single-crystal to disordered to single-crystal transformation in a hemilabile metal–organic framework

Flexible metal–organic frameworks (MOFs) are materials of great current interest. A small class of MOFs show flexibility driven by reversible bonding rearrangements that lead directly to unusual properties. Cu-SIP-3 is a MOF based on the 5-sulfoisophthalate ligand, where the strong copper–carboxylate bonds ensure that the three-dimensional integrity of the structure is retained while allowing bonding changes to occur at the more weakly bonding sulfonate group leading to unusual properties such as the ultra-selective adsorption of only certain gases. While the integrity of the framework remains intact during bonding changes, crystalline order is not retained at all times during the transformations. X-Ray diffraction reveals that highly crystalline single crystals lose order during the transformation before regaining crystallinity once it is complete. Here we show how X-ray pair distribution function analysis can be used to reveal the mechanism of the transformations in Cu-SIP-3, identifying the sequence of atomic displacements that occur in the disordered phase. A similar approach reveals the underlying mechanism of Cu-SIP-3's ultra-selective gas adsorption.

Copper(II) Carboxylate Dimers Prepared from Ligands Designed to Form a Robust π···π Stacking Synthon: Supramolecular Structures and Molecular Properties

The reactions of bifunctional carboxylate ligands (1,8-naphthalimido)propanoate, (L(C2)(-)), (1,8-naphthalimido)ethanoate, (L(C1)(-)), and (1,8-naphthalimido)benzoate, (L(C4)(-)) with Cu(2)(O(2)CCH(3))(4)(H(2)O)(2) in methanol or ethanol at room temperature lead to the formation of novel dimeric [Cu(2)(L(C2))(4)(MeOH)(2)] (1), [Cu(2)(L(C1))(4)(MeOH)(2)]·2(CH(2)Cl(2)) (2), [Cu(2)(L(C4))(4)(EtOH)(2)]·2(CH(2)Cl(2)) (3) complexes. When the reaction of L(C1)(-) with Cu(2)(O(2)CCH(3))(4)(H(2)O)(2) was carried out at -20 °C in the presence of pyridine, [Cu(2)(L(C1))(4)(py)(4)]·2(CH(2)Cl(2)) (4) was produced. At the core of complexes 1-3 lies the square Cu(2)(O(2)CR)(4) "paddlewheel" secondary building unit, where the two copper centers have a nearly square pyramidal geometry with methanol or ethanol occupying the axial coordination sites. Complex 4 contains a different type of dimeric core generated by two κ(1)-bridging carboxylate ligands. Additionally, two terminal carboxylates and four trans situated pyridine molecules complete the coordination environment of the five-coordinate copper(II) centers. In all four compounds, robust π···π stacking interactions of the naphthalimide rings organize the dimeric units into two-dimensional sheets. These two-dimensional networks are organized into a three-dimensional architecture by two different noncovalent interactions: strong π···π stacking of the naphthalimide rings (also the pyridine rings for 4) in 1, 3, and 4, and intermolecular hydrogen bonding of the coordinated methanol or ethanol molecules in 1-3. Magnetic measurements show that the copper ions in the paddlewheel complexes 1-3 are strongly antiferromagnetically coupled with -J values ranging from 255 to 325 cm(-1), whereas the copper ions in 4 are only weakly antiferromagnetically coupled. Typical values of the zero-field splitting parameter D were found from EPR studies of 1-3and the related known complexes [Cu(2)(L(C2))(4)(py)(2)]·2(CH(2)Cl(2))·(CH(3)OH), [Cu(2)(L(C3))(4)(py)(2)]·2(CH(2)Cl(2)) and [Cu(2)(L(C3))(4)(bipy)]·(CH(3)OH)(2)·(CH(2)Cl(2))(3.37) (L(C3)(-) = (1,8-naphthalimido)butanoate)), while its abnormal magnitude in [Cu(2)(L(C2))(4)(bipy)] was qualitatively rationalized by structural analysis and DFT calculations.

Synthesis, crystal structures, and characterization of copper(II) carboxylate complexes incorporating 1,10-phenanthroline and bipyridine

A series of Cu(II) carboxylate complexes (carboxylate = 2-fluorobenzoic acid (2-HFBA) or 4-fluorobenzoic acid (4-HFBA)) containing either one chelating 1,10-phenanthroline (phen) or 2,2′-bipyridine (bipy) have been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, and thermal analyses. In [Cu(bipy)(H2O)(2-FBA)2] (1), [Cu(bipy)(H2O)(4-FBA)2] (3), and [Cu(phen)(H2O)(2-FBA)2] (4), Cu is five-coordinate in a square pyramidal geometry and four-coordinate in [Cu(phen)(2-FBA)2] (2). The four complexes are extended into 1-D chains through hydrogen-bonding and π ··· π interactions in 1 and 4, only hydrogen-bonding in 2, and π ··· π interactions in 3. These contacts lead to aggregation and supramolecular self-assembly.

ChemInform Abstract: Copper(I) Oxide and Benzoic Acid “On Water”: A Highly Practical and Efficient Catalytic System for Copper(I)‐Catalyzed Azide—Alkyne Cycloaddition.

AbstractPre‐prepared copper(I) carboxylates are not necessary for the process, since they can be replaced by a combination of cheap, stable Cu2O and carboxylic acid.

Syntheses and Characterization of Copper(II) Carboxylate Dimers Formed from Enantiopure Ligands Containing a Strong π···π Stacking Synthon: Enantioselective Single-Crystal to Single-Crystal Gas/Solid-Mediated Transformations

Tri- and tetrafunctional enantiopure ligands have been prepared from 1,8-naphthalic anhydride and the amino acids L-alanine, D-phenylglycine, and L-asparagine to produce (S)-2-(1,8-naphthalimido)propanoic acid (HL(ala)), (R)-2-(1,8-naphthalimido)-2-phenylacetic acid (HL(phg)), and (S)-4-amino-2-(1,8 naphthalimido)-4-oxobutanoic acid (HL(asn)), respectively. Reactions of L(ala)(-) with copper(II) acetate under a variety of solvent conditions has led to the formation and characterization by X-ray crystallography of three similar copper(II) paddlewheel complexes with different axial ligands, [Cu(2)(L(ala))(4)(THF)(2)] (1), [Cu(2)(L(ala))(4)(HL(ala))] (2), and [Cu(2)(L(ala))(4)(py)(THF)] (3). A similar reaction using THF and L(phg)(-) leads to the formation of [Cu(2)(L(phg))(4)(THF)(2)] (4). With the exception of a disordered component in the structure of 4, the naphthalimide groups in all of these compounds are arranged on the same side of the square, central paddlewheel unit, forming what is known as the chiral crown configuration. A variety of π···π stacking interactions of the 1,8-naphthalimide groups organize all of these complexes into supramolecular structures. The addition of the amide group functionality in the L(asn)(-) ligand leads to the formation of tetrameric [Cu(4)(L(asn))(8)(py)(MeOH)] (5), where reciprocal axial coordination of one of the amide carbonyl oxygen atoms between two dimers leads to the tetramer. Extensive supramolecular interactions in 5, mainly the π···π stacking interactions of the 1,8-naphthalimide supramolecular synthon, support an open three-dimensional structure containing large pores filled with solvent. When crystals of [Cu(4)(L(asn))(8)(py)(MeOH)] are exposed to (S)-ethyl lactate vapor, the coordinated methanol molecule is replaced by (S)-ethyl lactate, bonding to the copper ion through the carbonyl oxygen, yielding [Cu(4)(L(asn))(8)(py)((S)-ethyl lactate)] (6) without a loss of crystallinity. With the exception of the replacement of the one axial ligand, the molecular structures of 5 and 6 are very similar. In a similar experiment of 5 with vapors of (R)-ethyl lactate, again a change occurs without a loss of crystallinity, but in this case the (R)-ethyl lactate displaces only slightly more than half of the axial methanol molecules forming [Cu(4)(L(asn))(8)(py){((R)-ethyl lactate)(0.58)(MeOH)(0.42)}] (7). Importantly, in 7, the (R)-ethyl lactate coordinates through the hydroxyl group. When crystals of [Cu(4)(L(asn))(8)(py)(MeOH)] are exposed to vapors of racemic ethyl lactate, the coordinated methanol molecule is displaced without a loss of crystallinity exclusively by (S)-ethyl lactate, yielding a new form of the tetramer [Cu(4)(L(asn))(8)(py)((S)-ethyl lactate)], in which the ethyl lactate in the pocket bonds to the copper(II) ion through the carbonyl oxygen as with 6. Exposure of [Cu(4)(L(asn))(8)(py){((R)-ethyl lactate)(0.58)(MeOH)(0.42)}] to racemic ethyl lactate yields a third form of [Cu(4)(L(asn))(8)(py)((S)-ethyl lactate)], where the three forms of [Cu(4)(L(asn))(8)(py)((S)-ethyl lactate)] have differences in the number of ordered (S)-ethyl lactate molecules located in the interstitial sites. These results demonstrate enantioselective bonding to a metal center in the chiral pocket of both 5 and 7 during single-crystal to single-crystal gas/solid-mediated exchange reactions.

Identification of Different Copper Green Pigments in Renaissance Paintings by Cluster-TOF-SIMS Imaging Analysis

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) imaging using cluster primary ion beams is used for the identification of a green painting layer on the scene The Angels Concert from the Issenheim Altarpiece (painted in 1516) from a German Renaissance painter, Matthias Grünewald. Copper carboxylate clusters inside a basic copper chloride (atacamite) layer have been identified and located in the copper green layer. The mechanisms of transformation of atacamite into copper carboxylates may be initiated by an aging of the paint layers. The combination of the high mass resolution of the technique together with a micrometer spatial resolution and the possibility to simultaneously identify both minerals and organics, has proven to be the method of choice for the study of the stratigraphy of a paint cross-section.

Correction to Highly Organized Structures and Unusual Magnetic Properties of Paddlewheel Copper(II) Carboxylate Dimers Containing the π–π Stacking, 1,8-Naphthalimide Synthon

ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionORIGINAL ARTICLEThis notice is a correctionCorrection to Highly Organized Structures and Unusual Magnetic Properties of Paddlewheel Copper(II) Carboxylate Dimers Containing the π–π Stacking, 1,8-Naphthalimide SynthonDaniel L. Reger*, Agota Debreczeni, Bryn Reinecke, Vitaly Rassolov, Mark D. Smith, and Radu F. SemeniucCite this: Inorg. Chem. 2011, 50, 10, 4669–4670Publication Date (Web):April 19, 2011Publication History Published online19 April 2011Published inissue 16 May 2011https://doi.org/10.1021/ic200654nCopyright © 2011 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views633Altmetric-Citations7LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (725 KB) Get e-Alerts Get e-Alerts