Copper Complexes Research Articles

Novel binuclear copper(II) complexes with sulfanylpyrazole ligands: Synthesis, crystal structure, fungicidal, cytostatic and cytotoxic activity.

New binuclear Cu(II) tetraligand complexes (six examples) with sulfanylpyrazole ligands were synthesized. EPR Studies have shown that in solution the complexes are transformed to the mononuclear one. Fungicidal properties against Candida albicans were found for the Cu complexes with benzyl and phenyl substituents. An in vitro evaluation of the cytotoxic properties of copper chelates against Hek293, Jurkat, MCF-7, and THP-1 cells identified the copper complex with the cyclohexylsulfanyl substituent in the pyrazole core as the lead compound, whereas the copper complex without a sulfur atom in the pyrazole ligand had virtually no cytotoxic or fungicidal activity. The lead Cu(II) complex was more active than cisplatin. Effect of S-containing Cu complex on apoptosis and cell cycle distribution has been investigated as well.

Photoinduced Copper-Catalyzed Asymmetric Three-Component Radical 1,2-Azidooxygenation of 1,3-Dienes.

Radical-involved multicomponent difunctionalization of 1,3-dienes has recently emerged as a promising strategy for rapid synthesis of valuable allylic compounds in one-pot operation. However, the expansion of radical scope and enantiocontrol remain two major challenges. Herein, we describe an unprecedented photoinduced copper-catalyzed highly enantioselective three-component radical 1,2-azidooxygenation of 1,3-dienes with readily available azidobenziodazolone reagent and carboxylic acids. This mildprotocol exhibits a broad substrate scope, high functional group tolerance, and exceptional control over chemo-, regio- and enantioselectivity, providing practical access to diverse valuable azidated chiral allylic esters. Mechanistic studies imply that the chiral copper complex is implicated as a bifunctional catalyst in both the photoredox catalyzed azidyl radical generation and enantioselective radical C-O cross-coupling.

Photoinduced Copper‐Catalyzed Asymmetric Three‐Component Radical 1,2‐Azidooxygenation of 1,3‐Dienes

Radical‐involved multicomponent difunctionalization of 1,3‐dienes has recently emerged as a promising strategy for rapid synthesis of valuable allylic compounds in one‐pot operation. However, the expansion of radical scope and enantiocontrol remain two major challenges. Herein, we describe an unprecedented photoinduced copper‐catalyzed highly enantioselective three‐component radical 1,2‐azidooxygenation of 1,3‐dienes with readily available azidobenziodazolone reagent and carboxylic acids. This mild protocol exhibits a broad substrate scope, high functional group tolerance, and exceptional control over chemo‐, regio‐ and enantioselectivity, providing practical access to diverse valuable azidated chiral allylic esters. Mechanistic studies imply that the chiral copper complex is implicated as a bifunctional catalyst in both the photoredox catalyzed azidyl radical generation and enantioselective radical C‐O cross‐coupling.

Synthesis, structural characterization, in vitro biological activity, and DFT calculations of Cu(II) complex

Using a diazonium combination of aniline and 1,3‐diphenylpropane‐1,3‐dione, the Japp‐Klingemann reaction yielded the 1,3‐diphenyl‐2‐(2‐phenylhydrazono)propane‐1,3‐dione ligand (HL). The copper (II) complex has been made using copper (II) acetate salt. The geometry of HL and its Cu (II) chelate were described through CHN analyses, FTIR, UV–Visible, XRD, TGA, and magnetic susceptibility tests. According to the spectral data, the ligand exhibits monobasic bidentate behavior by connecting through the N atom of hydrazone moiety (=N − NH−) by deprotonating beside the oxygen atom of the carbonyl (C=O) group forming octahedral geometry. Density functional theory (DFT) calculations were done by molecular studio software to examine the optimal geometry of HL and its complexity. MCF‐7 and HepG‐2 cell lines demonstrated anticancer action in response to the HL and its copper (II) complex. Additionally, inhibition zone diameter was used to assess the in vitro antibacterial action of HL and particular complex toward Gram +ve bacteria Staphylococcus aureus and Gram‐ve bacteria Escherichia coli (E. coli). Both viscosity and absorption spectra of Calf‐thymus DNA binding experimentations were used to examine the compounds.

Synthesis, DFT calculations, and investigation of catalytic and biological activities of back‐bond functionalized re‐NHC‐Cu complexes

Five copper complexes (3a–e) stabilized by ring‐expanded back‐bond functionalized N‐heterocyclic carbene ligands (re‐NHCs) were produced in the glovebox by reacting free re‐NHC with CuI precursor. The potential of these re‐NHC‐Cu complexes as catalysts on the synthesis of mono‐ and di‐(1,4‐disubstituted‐1,2,3‐triazoles) by Cu‐catalyzed azide–alkyne cycloaddition (CuAAC) reactions was investigated. Various spectroscopic approaches were utilized to completely characterize the structures of the re‐Cu‐NHC complexes. Furthermore, density functional theory (DFT) calculations were carried out to get further insights into their molecular geometry and CuAAC reaction mechanism. The re‐NHC‐Cu complexes showed high activity on the CuAAC reaction in an open‐air atmosphere at rt. The Gibbs free energies as well as the optimized geometries of the intermediates and the transition states of the determining step of the reactions catalyzed by 3a, 3e, and 3b complexes were computed. Complex 3e was found to be the most efficient catalyst among these re‐NHC‐Cu complexes. Additionally, re‐Cu‐NHC complexes were investigated for their biological activities, including antiproliferative, antioxidant, AChE and TyrE inhibition, and antiparasitic activity. The results showed that the 3b, 3d, and 3e complexes possessed strong antiproliferative activity against human colon carcinoma (HCT‐116) and moderate cytotoxic activity against hepatocellular carcinoma (HepG‐2) cell lines. In addition, effective selective antileishmanial effects were observed for the 3e compound against both promastigotes and amastigotes stages of L. major with an IC50 value of 0.027 and 0.39 μM mL−1, respectively. These results demonstrate that these compounds are promising candidates for the treatment of colorectal cancer and leishmaniasis.

Synthesis and Aerobic Oxidation of Perfluoroalkyl d10 Metal Complexes Supported by 2,7‐Dimethyl‐1,8‐naphthyridine

The coordination chemistry of 2,7‐dimethyl‐1,8‐naphthyridine has been explored with perfluoroalkyl d10 metals, CuI, ZnII, and AgI. This ligand was shown to form dicoordinate CuI and AgI mono‐perfluoroalkyl complexes where naphthyridine coordinates with only one N‐donor, while bidentate coordination with both N‐atoms was observed in Zn bis(perfluoroalkyl) complexes forming a strained four‐membered chelate ring. Copper complexes undergo facile oxidation in the presence of air or excess O2 to give tetracoordinate CuII complexes coordinated to perfluorocarboxylates formed by oxygenation of the metal‐adjacent α‐CF2 position of the corresponding perfluoroalkyl ligands. Another type of product formed by the oxidation of perfluoroethylcopper(I) complexes in the presence of substoichiometric O2 are binuclear CuI‧‧‧CuI complexes with two perfluorocarboxylate ligands. In the presence of an external substrate, alkene, O‐atom transfer was observed to give oxygenated products, resembling the recently reported O‐transfer reactivity of naphthyridine‐supported Ni long‐chain perfluoroalkyl complexes.

Thiosemicarbazone Mixed-Valence Cu(I/II) Complex against Lung Adenocarcinoma Cells through Multiple Pathways Involving Cuproptosis.

Induction of cuproptosis and targeting of multiple signaling pathways show promising applications in tumor therapy. In this study, we synthesized two thiosemicarbazone-copper complexes ([CuII(L)Cl] 1 and [CuII2CuI(L)2Cl3] 2, where HL is the (E)-N-methyl-2-(phenyl(pyridin-2-yl)methylene ligand), to assess their antilung cancer activities. Both copper complexes showed better anticancer activity than cisplatin and exhibited hemolysis comparable to that of cisplatin. In vivo experiments showed that complex 2 retarded the A549 cell growth in a mouse xenograft model with low systemic toxicity. Primarily, complex 2 kills lung cancer cells in vitro and in vivo by triggering multiple pathways, including cuproptosis. Complex 2 is the first mixed-valent Cu(I/II) complex to induce cellular events consistent with cuproptosis in cancer cells, which may stimulate the development of mixed-valent copper complexes and provide effective cancer therapy.

Catalytically Relevant Organocopper(III) Complexes Formed through Aryl-Radical-Enabled Oxidative Addition.

Stepwise oxidative addition of copper(I) complexes to form copper(III) species via single electron transfer (SET) events has been widely proposed in copper catalysis. However, direct observation and detailed investigation of these fundamental steps remain elusive owing largely to the typically slow oxidative addition rate of copper(I) complexes and the instability of the copper(III) species. We report herein a novel aryl-radical-enabled stepwise oxidative addition pathway that allows for the formation of well-defined alkyl-CuIII species from CuI complexes. The process is enabled by the SET from a CuI species to an aryl diazonium salt to form a CuII species and an aryl radical. Subsequent iodine abstraction from an alkyl iodide by the aryl radical affords an alkyl radical, which then reacts with the CuII species to form the alkyl-CuIII complex. The structure of resultant [(bpy)CuIII(CF3)2(alkyl)] complexes has been characterized by NMR spectroscopy and X-ray crystallography. Competition experiments have revealed that the rate at which different alkyl iodides undergo oxidative addition is consistent with the rate of iodine abstraction by carbon-centered radicals. The CuII intermediate formed during the SET process has been identified as a four-coordinate complex, [CuII(CH3CN)2(CF3)2], through electronic paramagnetic resonance (EPR) studies. The catalytic relevance of the high-valent organo-CuIII has been demonstrated by the C-C bond-forming reductive elimination reactivity. Finally, localized orbital bonding analysis of these formal CuIII complexes indicates inverted ligand fields in σ(Cu-CH2) bonds. These results demonstrate the stepwise oxidative addition in copper catalysis and provide a general strategy to investigate the elusive formal CuIII complexes.

Copper(II) Complexes with Isomeric Morpholine-Substituted 2-Formylpyridine Thiosemicarbazone Hybrids as Potential Anticancer Drugs Inhibiting Both Ribonucleotide Reductase and Tubulin Polymerization: The Morpholine Position Matters.

The development of copper(II) thiosemicarbazone complexes as potential anticancer agents, possessing dual functionality as inhibitors of R2 ribonucleotide reductase (RNR) and tubulin polymerization by binding at the colchicine site, presents a promising avenue for enhancing therapeutic effectiveness. Herein, we describe the syntheses and physicochemical characterization of four isomeric proligands H2L3-H2L6, with the methylmorpholine substituent at pertinent positions of the pyridine ring, along with their corresponding Cu(II) complexes 3-6. Evidently, the position of the morpholine moiety and the copper(II) complex formation have marked effects on the in vitro antiproliferative activity in human uterine sarcoma MES-SA cells and the multidrug-resistant derivative MES-SA/Dx5 cells. Activity correlated strongly with quenching of the tyrosyl radical (Y•) of mouse R2 RNR protein, inhibition of RNR activity in the cancer cells, and inhibition of tubulin polymerization. Insights into the mechanism of antiproliferative activity, supported by experimental results and molecular modeling calculations, are presented.

Catalyzed Henry Reaction by Compartmentalized Copper‐Pyrazolyl‐Complex Modified Microgels

AbstractCompartmentalization of homogeneous catalysts enhances their catalytic performance and can even increase the selectivity. Microgels can serve as smart catalyst carrier systems offering the compartmentalization combined with good accessibility of the catalyst enabling the recyclability and re‐usability. Yet, the incorporation of coordination complexes into microgels has not been studied systematically, lacking in detailed insight in their structure and catalytic performance. Herein, microgels are synthesized with controlled number and localization of copper(II)‐pyrazolyl‐complexes. The catalytic activity of microgels in the Henry reactions is examined showing significantly higher yields compared to pure copper(II)‐pyrazolyl‐complexes. Furthermore, the localization of the copper(II)‐pyrazolyl‐complexes in the microgel core resulted in higher product yields than for microgel catalysts with copper(II) complexes in the shell. Microgel catalysts are demonstrated with copper(II) complexes that can be used in numerous reaction cycles, allow re‐loading of copper to recover catalytically active centers, and can be applicable in industrially‐relevant catalytic processes.

High anticancer activity in short response time exhibited by a new azobenzene derivative and its copper complex

o‐Aminoazotoluene (OAT), capable of photoisomerization, and o‐vanillin, a potent comutagen, have been used to synthesize a new ligand, HL, [C6H4(CH3)N=NC6H3(CH3)N=CHC6H3(OH)(OCH3)], which, upon complexation with copper(II), results in a new copper(II) complex‐Cu(L)2, [Cu{C6H4(CH3)N=NC6H3(CH3)N=CHC6H3(OCH3)O}2]. Both HL and Cu(L)2 have been characterized by single‐crystal X‐ray diffraction measurements along with other analytical techniques, for example, IR spectroscopy, NMR spectroscopy, UV–Vis spectroscopy, elemental analysis and mass spectrometry. These compounds were tested with different in vitro anticancer assay as well as with in silico studies. A comparative study has been demonstrated on anticancer activity of HL and Cu(L)2 with the ligand HAZ, {C6H5N=NC6H4N=CHC6H3(OH)(OCH3)} and its Cu‐complex, [Cu(AZ)2, Cu{C6H5N=NC6H4N=CHC6H3(OCH3)O}2]. The sensing properties of HAZ, along with the synthesis and structural properties of both HAZ and Cu(AZ)2, have been reported by our group earlier. Cytotoxicity measurements on MCF7 cell lines show that Cu(L)2 and Cu(AZ)2 have higher anticancer activity than their corresponding ligands. The apoptotic effect of Cu‐complex was studied through nuclear fragmentation assay and AO/EB dual‐staining assay on MCF7 cell line. The IC50 value of Cu(L)2 in 0.01% DMSO/water after 24‐h treatment was found 4.2 μM, which is one of the lowest values with this response time compared to the other analogous anticancer compounds. Finally, we have evaluated the expression of hERα protein with respect to Cu‐complexes, and it was observed that Cu(L)2 caused more down‐regulation of hERα as compared to Cu(AZ)2.

Square‐Planar Copper(II) complexes from a Zwitterionic Schiff‐Base N2/N22‐‐Donor Ligand: DNA Interaction and Cytotoxicity

A new tetradentate ligand, namely 3,3'‐((1E,1'E)‐(ethane‐1,2‐diylbis(azaneylylidene))bis(methaneylylidene))bis(pyridin‐2‐amine) (en2ampy) was prepared and two copper(II) complexes, viz. [Cu(en2ampy)]Cl2 (1) and [Cu(en2ampy)](NO3)2 (2), were obtained through its reaction with copper(II) chloride and copper(II) nitrate, respectively. The single‐crystal X‐ray structure of the compounds showed that the metal centre was coordinated in a square‐planar fashion by a doubly deprotonated en2ampy acting as a tetradentate N2/N22‐‐donor ligand. DNA‐binding studies revealed that 1 and 2 were electrostatically binding to DNA, probably in the grooves and cytotoxicity assays showed that the complexes were clearly more efficient than cisplatin against ovarian carcinoma (A2780) cells and the cisplatin‐resistant (A2780Cis) ones.

Luminescent tetranuclear copper(I) and gold(I) heterobimetallic complexes: A phosphine acetylide amidinateorthogonal ligand framework for selective complexation.

The synthesis of phosphine acetylide amidinate stabilized copper(I) and gold(I) heterobimetallic complexes was achieved by reacting ligand [{Ph2PC≡CC(NDipp)2}Li(thf)3] (Dipp = N,N'-diisopropylphenyl) with CuCl and Au(tht))Cl, yielding the eight membered ring [{Ph2PC≡CC(NDipp)2}2Cu2] and the twelve membered ring [{Ph2PC≡CC(NDipp)2}2Au2]. {Ph2PC≡CC(NDipp)2}2Cu2] features a Cu2 unit, which is bridged by two amidinate ligands, served as a metalloligand to synthesize the heterobimetallic CuI/AuI complexes [{(AuX)Ph2PC≡CC(NDipp)2}2Cu2] (X = Cl, C6F5). In these reactions the central ring structure is retained. In contrast, when the twelve membered ring [{Ph2PC≡CC(NDipp)2}2Au2] was reacted with CuX (X = Cl, Br, I and Mes), the reaction led to rearrangement of the central ring structure to give [{(AuX)Ph2PC≡CC(NDipp)2}2Cu2] (X = Cl, Br, I and Mes), which feature the same the eight membered Cu2 ring as above. These compounds were also synthesized by a one-pot reaction. The luminescent heterobimetallic complexes were further investigated for their photophysical properties.

Structural Diversity and Rare η1 Cu-C Interactions in CuI Complexes of 1,2,3-Triazole-Functionalized Bisphosphines.

This manuscript describes the synthesis of copper complexes of 1,2,3-triazolyl-phosphines: o-Ph2P(C6H4){1,2,3-N3CC6H5)C(PPh2)} (L1), (C6H5){1,2,3-N3C(C6H4(o-PPh2))-C(PPh2)} (L2), 3-Ph2P(C5H3N){1,2,3-N3C(C6H5)C(PPh2)} (L3), o-Ph2P(C6H4){1,2,3-N3C(C5H5N)C(PPh2)} (L4), and {(3,5-Ph2PC6H4-o)21,2,3-N3CCH} (L5). The reactions of L1-L3 with CuI salts afforded dimeric complexes having the general formula [Cu2(μ -X)2L2] (L = L1, X = Cl, Br and I: 1 - 3; L= L2, X = Cl, Br and I: 4- 6; L = L3; X = Cl, Br, and I: 7-9). The reaction of L4 with CuI in a 1:2 molar ratio afforded 1D-coordination polymer [{(CuI)2{o-Ph2P(C6H4){1,2,3-N3C(C5H5N)C(PPh2)}-μ-((k1-N)(k2-P,P))}}]n (10). The reaction of L5 with cuprous halides (CuX) (X = Br, I) yielded mononuclear complexes [CuX{(3,5-Ph2PC6H4-o)21,2,3-N3CCH}-κ2P,P] (X = Br, 12; I, 13). Crystal structures of complexes 12 and 13 showed close interactions between CuI and the triazole C7 carbon. These relatively short Cu···C7 separations may be due to the η1-C interaction (dπ-pπ bond) between the triazolic carbon atom (via pz orbital) and CuI or three-centered two-electron interaction between CuI and the triazolic C-H bond. The existence of the Cu···C interaction was further evinced by the QTAIM analysis in compounds 12 and 13.

Design of a Copper(II) Complex with Tetradentate Bis‐Benzotriazole‐Appended Bipyridine Ligand and its Catalytic Application in A3 Coupling Reaction

AbstractIn this report, a Cu(II) complex Cu‐L4 containing a new tetradentate benzotriazole‐appended bipyridine ligand was synthesized and characterized fully via spectroscopic and crystallographic techniques. The crystal structure of the complex revealed that the ligand is bound to copper in a tetradentate fashion in a plane and the axial positions are occupied by an anion and a solvent molecule, resulting in a distorted octahedral geometry of the complex in solid‐state. This air‐stable complex was utilized as homogeneous precatalyst for the synthesis of several propargylamine derivatives by 3‐component A3 coupling reactions of aldehydes, amines, and alkynes under aerial atmosphere.

Theoretical exploration of copper based electrolytes for third generation dye sensitized solar cells

Dye-sensitized solar cells (DSSCs) present a promising avenue for addressing the escalating need for clean energy solutions. These innovative cells offer a sustainable approach to meet the rising demands for environmentally friendly power sources. An assessment was conducted on a copper complex containing a hexadentate ligand, serving as a redox shuttle, alongside triphenylamine-based organic dyes in the construction of DSSC. This study thoroughly investigates the electronic structures, FMO, MEP surfaces, and photophysical properties of copper redox shuttle and triphenylamine dyes employing DFT and TDDFT calculations. The copper system, [Cu(bpyPY4)]2+/+, analyzed in this study, is anchored by the hexadentate polypyridyl ligand bpyPY4 (6,6′-bis(1,1-di(pyridine-2-yl)ethyl)-2,2′-bipyridine), scrutinized as a redox shuttle (RS). The assessed redox potential for [Cu(bpyPY4)]2+/+ is −4.67 eV. This indicates that the dye can effectively undergo regeneration by transferring electrons from the reduced form of the redox shuttle to the oxidized form of the dye. The photovoltaic efficiency has been analyzed with regard to various factors, including the energy gap between the HOMO and LUMO, the excited-state oxidation potential (Edye*), electron injection ability (∆Ginj), electron regeneration (∆Greg), light harvesting efficiency, short-circuit current density (JSC) and the open-circuit voltage (Voc). This study sheds light on present-day developments and forthcoming prospects in utilizing 3d transition metal-based redox shuttles, presenting them as compelling candidates for integration with organic dyes in Dye-Sensitized Solar Cells (DSSCs). This integration holds promise for more efficient solar spectrum absorption and enhanced performance of solar devices.

Verification of the Inverse Scale Effect Hypothesis on Viscosity and Diffusion by Azo-Amino Acid Schiff Base Copper Complexes

Microdroplets generated in microfluidic devices are attracting attention as a new chemical reaction field and are expected to improve reactivity. One of the effects of microscaling is that the ratio of the force that acts on the diffusion and movement of substances to gravity is different from that of ordinary solvents. Recently, we proposed a hypothesis for determining reaction acceleration through micro-miniaturization: If a reaction is inhibited by setting the volume and viscosity of the solution to conditions that are unfavorable to the reaction on a normal scale, that reaction can be promoted in microfluidics. Therefore, for the purpose of this verification, (1) we used an amino acid Schiff base copper(II) complex with an azobenzene group to demonstrate the polarization-induced orientation in a polymer film (the redirection that is mechanically maintained in a soft matter matrix). Numerical data on optical anisotropy parameters were reported. (2) When the reaction is confirmed to be promoted in laminar flow in a microfluidic device and its azo derivative, a copper(II) complex is used to increase the solvent viscosity or diffusion during synthesis on a normally large scale. We will obtain and discuss data on the investigation of changing the solvent volume as a region. The range of experimental conditions for volume and viscosity did not lead to an improvement in synthetic yield, nor did (3) the comparison of solvents and viscosity for single-crystal growth of amino acid Schiff base copper(II) complexes having azobenzene groups. A solvent whose viscosity was measured was used, but microcrystals were obtained using the diffusion method.

Synthesis, Structural Characterisation, and Electrochemical Properties of Copper(II) Complexes with Functionalized Thiosemicarbazones Derived from 5-Acetylbarbituric Acid.

The reaction between 5-acetylbarbituric acid and 4-dimethylthiosemicarbazide or 4-hexamethyleneiminyl thiosemicarbazide produces 5-acetylbarbituric-4-dimethylthiosemicarbazone (H2AcbDM) and 5-acetylbarbituric-4N-hexamethyleneiminyl thiosemicarbazone (H2Acbhexim). Eight new complexes with different copper(II) salts have been prepared and characterized using elemental analysis, molar conductance, UV-Vis, ESI-HRMS, FT-IR, magnetic moment, EPR, and cyclic voltammetry. In addition, three-dimensional molecular structures of [Cu(HAcbDM)(H2O)2](NO3)·H2O (3a), [Cu(HAcbDM)(H2O)2]ClO4 (4), and [Cu(HAcbHexim)Cl] (6) were determined by single crystal X-ray crystallography, and an analysis of their supramolecular structure was carried out. The H-bonded assemblies were further studied energetically using DFT calculations and MEP surface and QTAIM analyses. In these complexes, the thiosemicarbazone coordinates to the metal ion in an ONS-tridentate manner, in the O-enolate/S-thione form. The electrochemical behavior of the thiosemicarbazones and their copper(II) complexes has been investigated at room temperature using the cyclic voltammetry technique in DMFA. The Cu(II)/Cu(I) redox system was found to be consistent with the quasi-reversible diffusion-controlled process.

Synthesis, Spectral Characteristics, Sensing Properties and Microbiological Activity of New Water-Soluble 4-Sulfo-1,8-naphthalimides

A new water-soluble polyamidoamine (PAMAM) dendrimer modified with 4-sulfo-1,8-naphthalimide (DSNI) and its monomeric structural analogue (MSDI) were synthesized. Their photophysical properties were investigated in organic solvents of different polarities and aqueous solutions. The effect of pH on fluorescence intensity was determined. It was found that the dendrimer emits blue fluorescence in an acidic medium, which is quenched in an alkaline environment. This phenomenon is due to the possibility of suppression of nonradiative photoinduced electron transfer in acidic media. The influence of different metal ions (Cu2+, Pb2+, Sn2+, Sr2+, Mg2+, Ba2+, Co2+, Hg2+, Zn2+, Ni2+, Fe3+, Al3+) and anions (CN−, S2−, S2O52−, HPO42−, H2PO4−, F−, CH3COO−, NO2−, CO32−, SO42−) on the intensity of the emitted fluorescence was studied. Quenching was only found in the presence of Cu2+. This makes the dendrimer suitable for determining copper ions in water solutions in the presence of other metal ions and anions. Additionally, DSNI was used as a ligand to obtain a stable copper complex, the structure of which was investigated by electron paramagnetic resonance (EPR), infrared spectrum, and elemental analysis. Two copper ions were found to form a complex with one dendrimer. The in vitro microbiological activity of the new compounds against bacteria Pseudomonas aeruginosa and two viruses HRSV-2 and HAdV-5 was investigated. With a view to obtaining antibacterial and anti-viral textiles, cotton fabrics were treated with the three compounds, and then their activity against the same microbial strains was investigated. It was found that the microbiological activity was preserved after the application of the new compounds to the cotton fabrics.

Unusual Stability of an end-on Superoxido Copper(II) Complex under Ambient Conditions.

Superoxido copper complexes play an important role as usually short-lived intermediates in biology and chemistry. The unusual stability of anend-onsuperoxido copper complex observed in an oxygen-enhanced atom transfer radical polymerization (ATRP) led to a detailed mechanistic investigation of the formation of [CuII(Me6tren)(O2•-)]+(Me6tren = tris(2-dimethyl-aminoethyl)amine) under ambient conditions. The persistence of the superoxido copper complex could be explained by a reaction cycle including the peroxido complex[(Me6tren)2CuII2(O2)]2+together with [CuI(Me6tren)(DMSO)]+and [CuII(Me6tren)(OH)]+in the overall reaction.