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We report a series of structurally relevant copper phenanthroline complexes as pre-catalysts for highly selective electrocatalytic reduction of CO2 to C2 products using inexpensive carbon paper electrodes. The Cu complexes with non-substituted phenanthroline promote the production of ethylene with a high faradaic efficiency of 71.2%, while the one with pyridinium-functionalized ligands is more selective for ethanol. The C2 selectivity can be effectively tuned by increasing the number of coordinated phenanthrolines and remains high at a wide range of potentials. [ABSTRACT FROM AUTHOR]

The combination of electron-deficient viologen ligands with electron-rich POMs is a typical acceptor–donor system that has recently received much attention. Under solvothermal and hydrothermal conditions, by introducing three symmetric viologen ligands into POM-based hybrid materials, we successfully constructed four POMs–viologen inorganic–organic hybrid compounds, namely (1,3-bcbpy)2·(δ-Mo8O26) (1) (1,3-bcbpy·2Cl = 1,1′-bis(3-carboxybenzyl)-4,4′-bipyridine dichloride), {CoII(1,4-bcbpy)2(H2O)2[H2(β-Mo8O26)]}·2H2O·2CH2O (2), (1,4-bcbpy)2·(δ-Mo8O26)·2H2O (3) (1,4-bcbpy·2Cl = 1,1′-bis(4-carboxybenzyl)-4,4′-bipyridine dichloride, CH2O = formaldehyde), and {CuII(1,1-pmbby)2(H2O)[H2(β-Mo8O26)2]}·5H2O·C2H7N (4) (1,1-pmbby·2Cl = 1,1′-[1,4-phenylbis(methylene)]bis-(4,4′-bipyridine)dichloride, C2H7N = dimethylamine). These four compounds exhibit different fascinating structures, especially compound 4 is a typical metal–organic framework. Compounds 1–4 exhibit good discoloration behaviors under various external stimuli. For example, compounds 1–4 showed a positive response to the irradiation from a 300 W Xe lamp. When a positive voltage was applied to the ECD based on compounds 1–4, 1/2/3/4-ECD underwent a significant color conversion. What's more, compound 4 also showed obvious discoloration results after heating. In a word, 1–4 are multifunctional discoloration materials under different external stimuli. In addition, the coated filter paper prepared based on compound 3 can be used as a new printing material medium and can be successfully applied in erasable inkless printing and dual anti-counterfeiting. [ABSTRACT FROM AUTHOR]

A scalable, and cost-effective method was employed to prepare self-supported CuSn bimetallic catalyst on carbon paper. The obtained CuSn catalyst demonstrates high faradaic efficiency of CO around or above 90% at a broad potential range from −0.7 to −1.8 V vs. reversible hydrogen electrode, greatly surpassing Cu or Sn counterparts. [ABSTRACT FROM AUTHOR]

The New Journal of Chemistry is a publication that focuses on the chemical sciences and aims to connect researchers worldwide. The document provided is a contents list for the journal's 2024 edition. It includes papers on various topics such as membrane modification, nanoparticle synthesis, targeted therapy, catalysis, and material properties. Two specific papers are highlighted: one discusses the use of cationic lipids in non-viral gene delivery, while the other explores the confinement of metal-organic framework (MOF) etching-induced hollow structures for enhanced activation of peroxymonosulfate. The journal is published by The Royal Society of Chemistry and the Centre National de la Recherche Scientifique. [Extracted from the article]

This document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry." It provides a list of papers published in the latest issue of the journal, covering a wide range of topics in chemistry. The papers explore subjects such as stimuli-responsive luminescence, the synthesis and reactivity of different compounds, and the development of new sensors, luminescent materials, catalysts, and coordination compounds. The journal aims to foster connections within the global chemistry community and reinvest its profits into the field. Additionally, the document includes a correction for a previous paper. [Extracted from the article]

The document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry." It includes various articles and papers on topics such as copper complexes, lanthanide-based POMs, and coordination polymers. The journal is published by The Royal Society of Chemistry, a leading chemistry community. The document also mentions approved training courses offered by the society. The given document is a list of papers published in the journal Dalton Transactions. The papers cover a range of topics in chemistry, including catalysis, phosphors, materials synthesis, and more. Each paper is identified by its title, authors, and page number. The document also includes a correction and a retraction for two previously published papers. [Extracted from the article]

The document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry." It includes various articles and papers on topics such as combatting bacterial infections, rare-earth metal-organic frameworks, and electrochemical capacitor applications. The journal is published by The Royal Society of Chemistry, a leading chemistry community. The document provides a brief overview of the articles included in the journal issue. The papers cover a range of topics in chemistry, including the synthesis of stable cyclopropenylvinyl ligands, the properties of metal-organic frameworks, the photocatalytic performance of titanium-oxide clusters, and the adsorption mechanisms of heavy metals on silica. Other topics include the synthesis of coordination polymers, the synthesis of salophen complexes, and the behavior of cyanido-bridged complexes. The papers provide valuable insights into various areas of chemical research. [Extracted from the article]

The document is a contents list for the journal CrystEngComm. It provides information about the articles and papers included in the issue, as well as the authors and their research topics. The journal focuses on the design and understanding of solid-state and crystalline materials. The document also mentions the Royal Society of Chemistry, which is a leading chemistry community that connects the world with the chemical sciences. [Extracted from the article]

Chiral surfaces are an object of interest due to their application in catalysis, separation and sensors. Such surfaces can exhibit chirality on the molecular or supramolecular level. Previously, we have studied the thermodynamic features of adsorption on non-porous surfaces with supramolecular chirality. However, for their application in enantiomer separation, enantioselectivity and capacity should be greater. Porous adsorbents are promising for this purpose. In this work, the enantioselectivity of copper borophosphate LiCu2[BP2O8(OH)2] was studied. This zeotype material was obtained by hydrothermal synthesis without any source of chirality. Supramolecular chirality was achieved by spontaneous symmetry breaking via Viedma ripening. XRD and SEM were used to prove the synthesis accuracy. Enantioselectivity during adsorption was studied using the adsorption isotherms of α-pinene and limonene enantiomer analysis. The experimental isotherms were approximated by Langmuir, Dubinin–Radushkevich, Freundlich and Fowler–Guggenheim equations. The t-test was used to prove the reliability of the differences in enantiomer adsorption. The isosteric heats of adsorption were calculated from the adsorption isotherms. The data obtained have shown the ability of the LiCu2[BP2O8(OH)2] surface to recognize both α-pinene and limonene enantiomers. The molecules of α-pinenes adsorbed without pores, with the maximum enantioselectivity coefficient of 1.23 at 80 °C. Limonene molecules adsorbed in pore volume as single molecules or 1D chains. This phenomenon was proved by analysis of isosteric heats. The enantioselectivity of copper borophosphate to limonenes and α-pinenes was similar. The ability of pores with supramolecular chirality (and without molecular chirality) to recognize enantiomers was discovered in this paper for the first time. [ABSTRACT FROM AUTHOR]

The document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry," published by The Royal Society of Chemistry. It includes various articles covering topics such as proton conduction, catalytic dinitrogen reduction, and structural insight into pharmacokinetic parameters. One article titled "Room temperature spin crossover properties in a series of mixed-anion Fe(NH2trz)3(BF4)2−x(SiF6)x/2 complexes" by Xinyu Yang et al. explores the spin crossover properties of these complexes at room temperature. The study investigates how the complexes behave under changes in temperature and pressure, providing insights into their potential applications in molecular electronics and data storage. [Extracted from the article]

Two novel, discrete lanthanide–macrocycle binary complexes for the detection of hydrogen sulfide are reported. The hydrogen sulfide sensing mechanism utilises the copper sequestration at a secondary binding site, with resulting bimetallic lanthanide(III)/copper(II) complexes (Ln = Eu3+ and Tb3+) exhibiting high selectivity, good sensitivity and excellent reversibility for aqueous hydrogen sulfide. The inclusion of the DO2A macrocycle and 4-(2-pyridyl)-1,2,3-triazole dipicolinic acid ligand, results in a complex with good solubility and stability. The europium(III) complex also displayed a low limit of detection (665 ppb) with a response time of 30 seconds with gaseous hydrogen sulfide. The improved water solubility and stability over a previous complex results in these sensors having the potential for use in environmental monitoring and biological studies for various functional settings. [ABSTRACT FROM AUTHOR]

Lactic acid is an important organic acid with wide applications, and preparation of lactic acid from biomass-derived 1,2-propanediol was considered a green reaction route. In this paper, a Cu modified Au/γ-Al2O3 catalyst was designed for the oxidative esterification of 1,2-propanediol to methyl lactate in an alkali-free methanol system. The structural properties of the Au–Cu/γ-Al2O3 catalyst were characterized by various characterization methods, and interaction between Au nanoparticles and Cu species was discovered. Moreover, the catalytic tests showed that the Cu modified Au/γ-Al2O3 catalysts exhibited higher methyl lactate selectivity than the monometallic Au/γ-Al2O3 catalyst. It was revealed that the synergistic effect between the Au nanoparticles and Cu species could promote the oxidation of primary hydroxyl groups of 1,2-propanediol to produce methyl lactate and reduce the generation of by-products. In addition, a reasonable reaction pathway for the oxidative esterification of 1,2-propanediol was proposed based on the comparative experiments. These findings may provide favorable guidance for design of Au based nanocatalysts for the oxidative esterification of alcohols to esters and carboxylic acids. [ABSTRACT FROM AUTHOR]

CuO/CeO2 catalysts were widely studied as an alternative to precious metal catalysts, and the Cu–Ce synergy was essential to improve the catalytic performance. In this paper, the effects of CuO loading on Cu–Ce synergy in CuO/CeO2 nanorod catalysts and their performance in toluene combustion were systematically investigated. It was found that non-equilibrium plasma facilitated the dispersion of CuO active species on the CeO2 surface. With the increase of the CuO loading from 1 wt% to 4 wt%, the Cu–Ce synergistic effect was gradually improved, which generated Cu+/Cu2+ and Ce3+/Ce4+ redox electron pairs. The highest oxygen vacancy concentration and Cu+ content of CuCe-4 (4 wt%) resulting from strong Cu–Ce synergy accelerated the activation of chemisorbed oxygen and consequently improved the efficiency of toluene catalytic combustion. [ABSTRACT FROM AUTHOR]

The construction of a new electrochemical sensing platform based on a copper metal–organic framework (Cu-MOF) heterostructure is described in this paper. Drop-casting Cu-MOF suspension onto the electrode surface primed the sensor for glutathione detection. The composition and morphology of the Cu-MOF heterostructure were investigated using scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FT-IR), and UV-visible spectroscopy. The Cu-MOF heterostructure can identify glutathione (GSH) with an enhanced sensitivity of 0.0437 μA μM−1 at the detection limit (LOD; 0.1 ± 0.005 μM) and a large dynamic range of 0.1–20 μM. Boosting the conductivity and surface area enhances electron transport and promotes redox processes. The constructed sensors were also adequately selective against interference from other contaminants in a similar potential window. Furthermore, the Cu-MOF heterostructure has outstanding selectivity, long-term stability, and repeatability, and the given sensors have demonstrated their capacity to detect GSH with high accuracy (recovery range = 98.2–100.8%) in pharmaceutical samples. [ABSTRACT FROM AUTHOR]

Preparation of the high value-added chemical 2,5-dimethylfuran (2,5-DMF) from the biomass-derived platform molecule 5-hydroxymethylfurfural (HMF) is of great significance in the preparation of biofuels. Here, a bottom-up strategy was used to prepare a metal–organic framework (MOF) material with a two-dimensional nanosheet morphology, named CPM, in which an additive 2-methylimidazole was introduced into the hydrothermal process of Cu2+ ions and terephthalic acid. Subsequently, CPM-700 prepared by heat treatment under an inert atmosphere showed excellent catalytic performance in the reaction of HMF hydrodeoxygenation to 2,5-DMF. The materials before and after pyrogenation were characterized by PXRD, XPS, TEM, N2 adsorption and desorption and so on. It was confirmed that compared with the catalyst derived from the cubic MOF material self-assembled by Cu2+ and terephthalic acid, the morphology of 2D nanosheets was beneficial for the reaction of HMF to 2,5-DMF. Combined with the experimental data, the possible reaction path of 2,5-DMF preparation from HMF is that 2,5-dihydroxymethylfuran was formed by hydrogenation of the aldehyde group on the furan ring, and then 2,5-DMF was obtained by hydrogenolysis. This paper provides an effective route for 2D MOF-derived catalytic materials in the selective hydrogenation of HMF. [ABSTRACT FROM AUTHOR]

Transmetalation plays a very important role in the study of functional MOFs, but it is rarely used in metal–organic salts (MOSs). In this paper, four kinds of MOSs were synthesized by using the tetradentate ligand N,N′-bis (pyridin-4-ylmethyl) ethane-1,2-diamine and MCl2 (M = Zn, Co, Cu), labelled as [H4L]4+·2[CoCl4]2−·2H2O (1), [H4L]4+·2[ZnCl4]2−·2H2O (2), [H4L]4+·[CuCl4]2−·2Cl− (3), and [H4L]4+·2[CuCl4(H2O)]2− (4). Salt 3 was obtained by the metal-ion exchange of salt 1, and salt 4 was successfully synthesized by liquid-assisted grinding (LAG) of salt 3 and CuCl2·2H2O, which was a stoichiometric ratio-controlled transformation that occurred with the change in the geometry of copper(II) anions from [CuCl4]2− and [CuCl4(H2O)]2−. The reaction process was monitored dynamically by atomic absorption spectroscopy (AAS), fluorescence spectroscopy, and powder X-ray diffraction (PXRD). This suggested that transmetalation combined with LAG was an alternative method to obtain MOSs for different metal ions. [ABSTRACT FROM AUTHOR]

Flexible microcircuits are developing rapidly with the trends of miniaturization and foldability in modern electronic products. The chemical growth welding technique of silver seeds offers several advantages, including compatibility with a wide range of substrates, ease of operation, and room temperature growth, making it a promising method for use in the manufacturing of flexible electronics. In this paper, we demonstrated a feasible solution based on silver seeds and the chemical welding process of copper at near room temperature. The growth of copper microcircuits was directly determined by the size and distribution of silver seeds. Seeding parameters for preparing long copper microcircuits were optimized, and two types of possible defects in the as-prepared copper microcircuits were analyzed. Based on the optimized parameters, patterned fine copper microcircuits and large-area copper wires were prepared, and the conductivity and fatigue resistance were verified. [ABSTRACT FROM AUTHOR]

Sensitive detection of glucose is important for public health, but non-enzymatic glucose biosensors still face significant challenges. In this paper, a novel and sensitive non-enzymatic glucose sensor was developed by in situ preparation of CuO nanorod-supported NiCo LDH nanosheet arrays on copper foam (CuO@NiCo LDH NSAs/CF). Because the hierarchical core–shell nanostructure provides more active sites and increases the exposed surface area of the catalyst, the catalytic activity of the electrode was significantly increased. As a working electrode, the CuO@NiCo LDH NSAs/CF catalyst showed good glucose sensing performance in a linear range of 0.6 μM–3 mM and a detection limit of 0.16 μM (S/N = 3). The sensor also showed repeatable responses over a month with negligible interference, and satisfactory recoveries with real human serum samples. [ABSTRACT FROM AUTHOR]

As the production of electric vehicles and lithium-ion batteries continues to rise, concerns over resource scarcity and supply shortages of critical metals, including Cu, Ni, Co, Mn, and Li, have become increasingly urgent. To address these concerns and promote environmental protection, there is a growing demand for the recycling of hazardous waste containing these critical metals as secondary resources. Therefore, this paper proposes a novel synergistic solvent extraction system of D2EHPA-NNPA, which fills a gap in the lack of a suitable extraction system for the hydrometallurgical industry of secondary resources containing Cu, Ni, Co, Mn, and Li. With the specific extraction sequence of D2EHPA-NNPA, a novel process has been designed and proposed for the stepwise extraction of Cu, Ni, Co, Mn, and Li from secondary resources, which significantly simplifies process flows while avoiding cross-contamination of the extractants and the production of industrial wastewater. Furthermore, the proposed "extraction-scrubbing-stripping" process has been investigated from both macroscopic and microscopic perspectives, demonstrating that the novel synergistic solvent extraction system of D2EHPA-NNPA is a viable option for industrial applications to promote a circular economy and achieve sustainability objectives. [ABSTRACT FROM AUTHOR]

We report the solvothermal synthesis of a dansyl anchored hafnium based fluorescent metal–organic framework (MOF) having the formula [Hf6O4(OH)4(L)6]·H2O·6DMF (H2L = 2-((5-(dimethylamino)naphthalene)-1-sulfonamido)terephthalic acid). The synthesized material showed high fluorescence emission properties as well as high thermal (stable up to 330 °C) and chemical stability. It also exhibited a wide range of pH tolerance as well as a high BET surface area of 703 m2 g−1. The activated MOF showed ultra-fast (detection time < 10 s) and ultra-sensitive sensing properties towards Cu(II) and the biologically important biomarker 3-nitrotyrosine (3-NTyr) in a HEPES medium at a physiological pH of 7.4. Along with high selectivity, very low detection limits of 229 nM and 539 nM were obtained for Cu(II) and 3-NTyr respectively. Furthermore, this probe was utilised for the detection and quantification of Cu(II) and 3-NTyr in biosamples (urine and serum) with very low RSD values (2.3–4.8%). Additionally, this probe was employed to detect the presence of Cu(II) as a pollutant in various environmental water samples. Furthermore, for rapid economic detection of Cu(II), a MOF coated fluorescent paper strip was demonstrated. Thorough mechanistic investigations displayed that a complexometric interaction between Cu(II) and the probe is the main reason for the quenching of fluorescence intensity. This proposed mechanism was well supported by experimental evidence. On the other hand, the FRET mechanism is proposed based on the experimental observations for dynamic quenching of the fluorescence intensity of the probe in the presence of 3-NTyr. [ABSTRACT FROM AUTHOR]

In this paper, the water dissociation abilities of transition metals Cr, Co, Ni, Cu, and surface Cr incorporated into Co, Ni, and Cu matrix were estimated using density functional theory. The calculations indicate that the transition metal matrix can markedly affect the ability of surface Cr to promote H2O dissociation. The barriers of the H2O dissociation step on Cr, Co, Ni, and Cu increase in sequence. After introducing Cr into a transition metal matrix, the H2O dissociation ability of Cr reduces. Compared with pure metals, doping the Co surface with Cr is less favorable for H2O dissociation and introducing Cr onto Ni and Cu surfaces can accelerate the H2O dissociation reaction and Cr–Ni has stronger H2O dissociation ability than Cr–Cu. The electron distribution calculations show that the electron deviation levels from Cr to the metal matrix are a key factor in affecting the H2O dissociation ability of surface Cr, and strong electron deviation is advantageous. The adsorption calculations reveal that the OH-binding energy of catalyst cannot relate to its H2O dissociation ability and follows a rough volcano relationship with its alkaline HER performance. [ABSTRACT FROM AUTHOR]

The electrochemical reduction of CO2 to CO is a powerful approach to achieving carbon neutrality. Herein, we report a five-nuclear copper cluster-based metal–azolate framework CuTz-1 as an electrocatalyst for the electrochemical CO2 reduction reaction. It achieved a faradaic efficiency (FE) of 62.7% for yielding CO with a partial current density of −35.1 mA cm−2 in flow cell device, which can be preserved for more than ten hours with negligible changes of the current density and FE(CO). Studies of electrocatalytic mechanism studies revealed that the distance of Cu–N was increased, and the coordination number of the Cu ion was reduced, while the oxidation state of Cu was decreased after the electrocatalysis. These findings offer valuable insights into structural changes that influence the performance of the catalyst during the process of the electrochemical reduction of CO2 process. [ABSTRACT FROM AUTHOR]

This document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry." It provides a list of articles published in the journal, covering various topics in inorganic chemistry. The journal is published by The Royal Society of Chemistry, a reputable chemistry community. The document includes research papers on topics such as catalysis, spin state switching, targeted therapy for breast cancer, and photocatalysis. It also includes an expression of concern and a correction for previous papers. [Extracted from the article]

This paper investigates the reactivity and optical properties of transition metal-incorporated organoantimony(V) clusters prepared by a solvothermal route. The detailed structural characterization of novel heterometallic M2Sb4 oxo clusters is reported herein. Single crystal X-ray diffraction revealed the formation of hexanuclear organoantimony(V) based oxo clusters [(p-ClC6H4Sb)4V2(O)2(μ3-O)2(μ2-O)2(t-BuPO3)4(μ2-OCH3)4] (1), [M2(p-iPr-C6H4Sb)4(μ3-O)2(μ2-O)2(μ2-OCH3)4(t-BuPO3)4(py)2]·xCH3OH, where M = Mn, x = 2 (2), Co, x = 1 (3), Ni, x = 2 (4) and Cu, x = 2 (5). The magnetic behaviour of the clusters was probed by magnetic susceptibility measurements. Optical absorption studies showed that bandgap reduction can be achieved by incorporating an appropriate transition metal into the homometallic Sb6 oxo cluster. [ABSTRACT FROM AUTHOR]

In this paper, a cyclic (CuIpz)3·CH3CN (1) precursor and a mixed-valence pentanuclear complex Cu I3 Cu II2 (OH)pz6·CH3CN (2) have been synthesized and structurally characterized by single-crystal X-ray diffraction, where pzH = 4-chloro-3,5-diphenylpyrazole. The excellent catalytic activity of 2 has been demonstrated in the chemical fixation of CO2 into value-added cyclic carbonates, which can be carried out at ambient pressure and room temperature along with ultra-high yield and perfect steric hindrance tolerance. Based on density functional theory (DFT) calculations and comparison with the catalytic performance of 1, it is proposed that the coordinatively unsaturated CuII atoms of 2 are probably the active sites for this catalytic reaction. [ABSTRACT FROM AUTHOR]

A non-enzymatic electrochemical biosensor was developed for highly sensitive detection of creatinine using copper nanoparticles supported over polymelamine formaldehyde. The synergy between the electrodeposited copper nanoparticles over the highly porous polymer (eCu-PMF) provided a greener platform to boost up the electron transport at the electrode electrolyte interface by eliminating the role of redox species as well as interference of major interferents like glucose, dopamine, and ascorbic acid in physiological media 0.1 M PBS (pH 7.4). The proposed sensor exhibited a wide detection range of 100 fM-60 mM with high sensitivities of 0.320 mA nM -1 cm -2 and 3.8 mA nM -1 cm -2 . Moreover, the sensor was applied to real samples of serum creatinine and recoveries of 97 to 114% were found. Additionally, a paper-based flexible screen-printed electrode was fabricated which displayed an excellent activity with the same detection range of 100 fM-60 mM and long-term storage stability of 15 days.

Copper is one of the most important transition metals in our body for various physiological functions. An imbalance in the homeostasis of copper in our body can lead to various neurological disorders such as Alzheimer's disease, Parkinson's, and Menkes disease. As a result, there is a need for the detection of excess copper present in the environment and the human system. In this work, we have designed a quinoline-based fluorescent/colorimetric probe (QHS) for rapid and selective detection of copper ions via quenching of fluorescence/color change from yellow to peach which is visible to the naked eye. The probe displayed high selectivity towards copper(II), i.e. , Cu(II) in the presence of different metal analytes in water samples. The sensing mechanism of the probe was confirmed by NMR, HRMS, IR spectroscopy, and SEM. The detection limit of Cu(II) ions was found to be 0.493 μM which is lower than the tolerable limit of copper (20 μM) in drinking water as per the EPA. The probe was also utilized for the visualization of Cu(II) in cell lines. The probe was also demonstrated for its application in real-time detection of aqueous samples using portable paper strips.

Sodium bisulfite is a food additive, and its excessive intake can be harmful to human health. In this work, a new method for detecting bisulfite was developed based on the Etch-Cu-HCF nanozyme with enhanced polyphenol oxidase-like (PPO-like) activity. The Etch-Cu-HCF nanozyme was obtained from the ammonia erosion of the Cu-HCF nanozyme, and its PPO-like activity was enhanced by nearly 100% than that of the Cu-HCF nanozyme. It is possible that the Cu/Fe ratio of Etch-Cu-HCF increased after ammonia etching and more copper active sites were exposed. In addition, based on the PPO-like activity of the Etch-Cu-HCF nanozyme, 2,4-dichlorophenol (2,4-DP) can be oxidized to its corresponding quinone-like product, which can combine with 4-aminoantipyrine (4-AP) to obtain colorful products with UV absorption at 510 nm. However, the quinone-like product can be consumed by bisulfite via an addition reaction, which reduces the binding of the quinone-like product to 4-AP, resulting in a decrease in the UV absorbance of the system at 510 nm. Therefore, a new method for the detection of bisulfite was developed. The detecting range was 0–50 μM, and the detecting limit was 0.47 μM. The method has good selectivity and was successfully applied for the analysis of bisulfite in food. [ABSTRACT FROM AUTHOR]

A series of copper(II) complexes with different anions of composition [CuPhen(Hpz)2X2] (Phen = 1,10-phenanthroline; Hpz = pyrazole; X = CF3COO− (1), Otf− (2), Cl− (3), Otf = CF3SO3) have been synthesized. The structures of all obtained complexes were determined by direct X-ray diffraction analysis. In complexes 1–3 the equatorial planes are occupied by N-donor ligands, while the axial positions belong to the anions of various acids. Crystal structures 1–3 are additionally stabilized by hydrogen bonds, the type of which depends on the nature of the anion. The stability of the complexes upon dissolution in 0.9% NaCl was confirmed by UV-vis spectroscopy. The study of the biological properties of 1–3 showed high antibacterial activity against the non-pathogenic strain of Mycolicibacterium smegmatis (MIC (minimum inhibiting concentration) = 8–10 nmol per disk). The cytotoxic effect of various concentrations of complexes 1–3 on human ovarian adenocarcinoma cells (SKOV3) and human dermal fibroblasts (HDF) was measured in vitro. All complexes exhibit high anticancer activity, exceeding the activity against healthy cells. [ABSTRACT FROM AUTHOR]

A zirconium-MOF with a sulphonic acid functionalized biphenyldicarboxylic acid linker was synthesized by a solvothermal process. The material was characterized by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET) analysis, infrared (IR) spectroscopy, energy-dispersive X-ray spectroscopy (EDX), and FESEM analysis. The fluorescence sensing experiment towards the detection of Cu2+ was carried out. The detection time for Cu2+ was only 15 s with a very low limit of detection, which is 0.22 μM. The Stern–Volmer constant was found to be 5.5 × 105 M−1. For easy handling and real field application purposes, we developed a paper-strip based sensing device. The systematic study of the mechanism by EDX, PXRD, TRPL, and UV-Vis spectroscopy revealed that the quenching of fluorescence intensity by copper(II) was due to the fluorescence resonance energy transfer. [ABSTRACT FROM AUTHOR]

In recent years, as a green renewable energy production technology, electrochemical water splitting has demonstrated high development potential. Many materials have been reported as successful catalysts in the water-splitting field. However, it is still a huge challenge to produce bifunctional electrocatalysts for the efficient and sustainable generation of hydrogen and oxygen simultaneously. Herein, we successfully developed oxygen vacancies abundant CuCo layered double oxide (Ov-CuCo-LDO) hollow nanotube arrays (HNTAs) loaded on nickel foam as advanced electrocatalysts for total water splitting. When the current density was 10 mA cm−2, the Ov-CuCo-LDO HNTAs exhibited outstanding onset overpotentials of 53.9 and 72.5 mV for the hydrogen evolution and oxygen evolution reactions (HER and OER) in alkaline medium, respectively, because of the bimetallic synergistic effect between the cobalt and copper and the unique hollow porous structure. In addition, an as-assembled Ov-CuCo-LDO‖‖Ov-CuCo-LDO electrolytic cell showed a small potential of 1.55 V to deliver a current density of 10 mA cm−2. Moreover, it also showed remarkable durability after long-term overall water splitting for more than 20 h. The research results in this paper are of great interest to practical applications of the water decomposition process, providing clear and in-depth insights into preliminary robust and efficient multifunctional electrocatalysts for overall water splitting. [ABSTRACT FROM AUTHOR]

Phosphines bearing guanidine substituents at the backbone are attractive hybrid ligands that have not yet received adequate attention. This paper describes group 11 metal complexes of a guanidine-substituted triphenylphosphine, viz., N′′-[2-(diphenylphosphino)phenyl]-N,N′-diisopropylguanidine (1). Reactions of 1 with Cu(I) and Ag(I) precursors yielded the P,N-chelate complexes [M(1-κ2P,N)2]X, where M/X = Cu/BF4, Cu/Br, Ag/SbF6 and Ag/Br. Conversely, reacting 1 and the hydrochloride 1·HCl with [AuCl(SMe2)] produced the corresponding phosphine complexes [AuCl(1-κP)] and [AuCl(1H-κP)]Cl, which were further converted into [{μ(P,N)-1}2Au2][SbF6]2 and [AuCl(1H-κP)][SbF6], respectively, by reacting with Ag[SbF6]. These compounds and the bis-phosphine complex [Au(1-κP)2][SbF6] were studied as precatalysts in the Au-mediated cyclisation of N-propargylbenzamide and the addition of benzoic acid across terminal alkynes. Of the Au(I)-1 complexes studied, the complex [{μ(P,N)-1}2Au2][SbF6]2 was particularly attractive as a stable and well-defined, silver-free precatalyst, which can be conveniently activated in situ by the addition of a protic acid (either as an additive or a substrate). [ABSTRACT FROM AUTHOR]

Copper complexes have long been considered as a promising class of anticancer or antibacterial therapeutics. In this paper, two novel copper(II) complexes containing a β-carboline derivative and amino acids, namely [Cu(1-Im-βc)(L-Val)]ClO 4 ·0.5H 2 O (Cu1) and [Cu(1-Im-βc)(L-Phe)]ClO 4 ·0.5H 2 O (Cu2), where 1-Im-βc = 1-(2-imidazolyl)-β-carboline, L-Val = L-valine, and L-Phe = L-phenylalanine, were designed and synthesized. The complexes were characterized by elemental analysis, infrared spectroscopy, molar conductivity measurements, and mass spectrometry to determine their spatial structures and compositions. Both complexes bind to DNA by insertion. The complexes also show a good affinity for human serum albumin (HSA). In addition, the antitumor activity of the two complexes against lung cancer cells (A549), cervical cancer cells (HeLa), and breast cancer cells (MBA-MD-231) is significantly superior to that of the traditional antitumor drug, cisplatin. Finally, the anticancer mechanism results show that the complexes can induce apoptosis in HeLa cells, which is associated with mitochondrial damage, oxidative stress caused by reactive oxygen species (ROS) production, and activation of the caspase protein family. This study demonstrates that the introduction of aromatic heterocyclic alkaloid ligands with a broad spectrum of biological activities and water-soluble amino acid ligands into copper complexes can regulate their amphiphilic properties and biological activity, so as to obtain highly efficient copper-based therapeutics.

This paper reports a practical and versatile oxidative cyclization of 2-arylethynylanilines towards 2-hydroxy-2-substituted indol-3-ones via a copper-catalyzed radical approach in the presence of O 2 . The transformation of 2-hydroxy-2-arylindol-3-ones to 3-hydroxy-3-arylindol-2-ones proceeds well with good yields and highlights the practicability and utility of this catalytic system. Mechanistic investigations showed that the acetyl substituent on 2-arylaethynylanilines played an important role in the formation of the cyclic products and the reaction proceeded via an N -center radical-based 5-endo-dig aza-cyclization pathway.

This paper describes the recognition process of tetrahedral [CuII(tnz)2X2] (X = Cl, Br) complexes by a DNA chain, analyzing the specific interaction between the DNA bases and backbone with the metal and the tinidazole (tnz) ligand. We identified the coordination of the copper metal center with one or two phosphates as the first recognition site for the tinidazole copper(II) complexes, while the ligands present partial intercalation into the minor groove. Also, we discuss a novel trigonal copper(I) tnz bromide complex, obtained by reducing the previously reported [Cu(tnz)2Br2]. This complex sheds light on the mechanism of action of tnz metal complexes as one of the most stable DNA-complex adducts depicts a trigonal geometry around the copper ion. [ABSTRACT FROM AUTHOR]

The rapid and sensitive detection of ultra-trace marker molecules from biological samples is of great significance for the wide application of surface-enhanced Raman spectroscopy (SERS) methods in clinical diagnosis and disease monitoring. However, the cumbersome biological sample processing procedures and the poor enrichment of target analytes in hot spots hinder the practical applications of SERS methods. In this paper, we synthesized a novel floating SERS substrate by a simple one-step oxidation process, annealing and in situ chemical etching to form Ag-NPs@Cu-NW bundles on copper mesh (CM). In particular, under spontaneous bottom-up capillary action, the pressure difference at different nanogaps drives uric acid molecules to actively enter hot spots, so that the Ag-NPs@Cu-NW bundle nanostructure with the advantages of a light weight CM is capable of preventing the common coffee-ring effect and enhancing the spatial enrichment of analytes. Therefore, this SERS substrate realizes highly sensitive detection of uric acid at a level of 50 nM in pretreatment-free urine. Currently, this portable, flexible, simple, fast and cost-effective SERS substrate has great potential for early screening and clinical diagnosis of diseases in different biofluids. [ABSTRACT FROM AUTHOR]

Justicia adhatoda is commonly known as Malabar nut or adulsi and extensively used for various medicinal applications such as bleeding disorders, piles, and hemorrhage, particularly musculoskeletal and cardiac diseases. Development of medicinal plant extract-derived metal nanoclusters for the detection of biomolecules has received great attention in recent years. In this paper, bluish-green fluorescent copper nanoclusters (Cu NCs) are synthesized with a quantum yield of 17.12% via green chemistry using Justicia adhatoda plant extract as a template. The morphology, size, surface chemistry and elemental oxidation states of the J. adhatoda–Cu NCs are confirmed by high-resolution transmission electron microscopy (HR-TEM), Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopic techniques. In the presence of myoglobin, the emission peak of J. adhatoda–Cu NCs at 478 nm was drastically quenched and similarly the emission peak was greatly enhanced with the addition of L -thyroxine. Moreover, the J. adhatoda–Cu NC-based fluorescent probe exhibited high sensitivity for myoglobin and L -thyroxine with detection limits of 1.92 and 7.4 nM, respectively. Moreover, the J. adhatoda–Cu NCs acted as probes for the imaging of Saccharomyces cerevisiae cells. This method was successfully applied to quantify myoglobin in biofluids and L -thyroxine in pharmaceutical samples. [ABSTRACT FROM AUTHOR]

This paper describes the recognition process of tetrahedral [Cu II (tnz) 2 X 2 ] (X = Cl, Br) complexes by a DNA chain, analyzing the specific interaction between the DNA bases and backbone with the metal and the tinidazole (tnz) ligand. We identified the coordination of the copper metal center with one or two phosphates as the first recognition site for the tinidazole copper(II) complexes, while the ligands present partial intercalation into the minor groove. Also, we discuss a novel trigonal copper(I) tnz bromide complex, obtained by reducing the previously reported [Cu(tnz) 2 Br 2 ]. This complex sheds light on the mechanism of action of tnz metal complexes as one of the most stable DNA-complex adducts depicts a trigonal geometry around the copper ion.

In this article, a novel triphenylamine-modified salicylaldehyde Schiff base 2-(((4-(diphenylamino)phenyl)imino)methyl)-4-(pyridine-4-yl)phenol (HL) was synthesized and structurally characterized. HL possessed D-π-A structure and exhibited typical AIE property in THF/H 2 O. It was applied to selectively recognize Cu 2+ through an on-off mode in THF/H 2 O (1/9, v/v), and the fluorescence attenuation was attributed to a paramagnetic quenching effect of Cu 2+ together with the abatement of HL aggregates. Hence, the detection limit achieved was as low as 1.32 × 10 -7 M. The spectroscopic and ESI-HRMS results revealed a 1 : 2 complexation ratio of Cu 2+ with HL. The mechanism for sensing Cu 2+ was further confirmed by performing DFT calculations. Owing to the large affinity between Cu 2+ and His, the resultant CuL2 system was further used to detect His via the off-on method based on the displacement of ligands. The detection limit for His reached 5.14 × 10 -8 M. Furthermore, HL was available to prepare handy indicator papers for the on-site recognition of Cu 2+ and His. Confocal fluorescent imaging demonstrated that HL could sequentially respond to intracellular Cu 2+ and His.

Two new copper(II) complexes (1 and 2) with reduced L -histidine Schiff bases were synthesized and characterized using single-crystal X-ray diffraction, powder X-ray diffraction, UV-visible spectroscopy, and thermal analysis. Single-crystal analysis reveals that 5-methyl-containing 1 possesses a simple phenoxo-bridged binuclear unit, while 5-bromine-substituted 2 possesses a metal–organic cage (MOC) structure. The as-prepared complexes as artificial metallohydrolases displayed catalytic activity towards the hydrolysis of both PNPP (p-nitrophenyl picolinate) and PNPA (p-nitrophenyl acetate). These two complexes provided 28-fold (for 1) and 39-fold (for 2) rate enhancements in comparison with spontaneous hydrolysis of PNPA, respectively. With regard to PNPP, its hydrolysis was accelerated by two orders of magnitude in the presence of 1 or 2. Additionally, positive micellar effects of bis(hexadecyldimethylammonium)hexane bromide (16-6-16) and N-octyldocosylammonium bromide (C22H45N(CH3)2C8H17Br, abbr. C22/8) were observed for the PNPA hydrolysis by 1 or 2, resulting in 1.3 to 3.9 times acceleration compared to that in buffered aqueous solution. In micellar solution of N,N-dimethyl-n-lauroylsarcosine sodium (LSS), no obvious rate enhancement was observed for the PNPA hydrolysis by 1 or 2. [ABSTRACT FROM AUTHOR]

In this study, three excellent yellow emissive Cu(I) complexes were synthesized, namely [Cu2I2(bipy)(POP)2]·4CH2Cl2 (1), [Cu2Br2(bipy)(POP)2]·4CH2Cl2 (2), and [CuCl(bipy)(POP)]·CH2Cl2·CH3OH (3) [bipy = 4,4′-bipyridine, POP = bis(2-diphenylphosphino-phenyl)ether]. The synthesis and characterization of three complexes are introduced. Complexes 1–3 have luminescent emission peaks of 529–532 nm, belonging to yellow light emission, and their quantum yield is 72–88%. Complex 2 exhibits an exceptionally high quantum yield of 88% and its lifetime is 9.6 μs. Among the available data, this result is one of the best luminescence results for yellow luminescent cuprous complexes. This study enriches the understanding of the photophysical properties of Cu(I) complexes and offers new insights for the development of efficient OLED materials. [ABSTRACT FROM AUTHOR]

Three new examples of covalently linked bis(3-pyrrolyl BODIPY)s were prepared as key precursors for the synthesis of rare hexapyrrolic ligands by treating readily available 3-pyrrolyl BODIPY with different ketones under acid-catalyzed conditions. The new bis(3-pyrrolyl BODIPY) complexes were thoroughly characterized using HR-MS, NMR spectroscopy, absorption, fluorescence, electrochemistry, and theoretical methods. The bis(3-pyrrolyl BODIPY) complexes were treated with AlCl3 in CH3OH at reflux for 2 h to demask BF2 units to afford novel hexapyrrolic ligands. The hexapyrrolic ligands without isolating were treated with Zn(CH3COO)2 in CH3CN at room temperature for 2 h followed by repeated recrystallization to afford crystalline bis-Zn(II) complexes. The X-ray crystallographic structure obtained for one of the bis-Zn(II) complexes revealed that it was a double-stranded bimetallic helicate containing two non-superimposable M and P enantiomers in equal amounts, which were nonseparable. Each Zn(II) ion in the bis-Zn helicate complexes was coordinated to four nitrogen atoms of two dipyrrin units from two hexapyrrolic ligands in a distorted tetrahedral geometry. The distance between two Zn(II) ions (Zn1–Zn2) in bis-Zn(II) helicate was 8.211 Å, which was longer than the distance between two Cu(II) ions (Cu1–Cu2) in our previously reported bis-Cu(II) helicate complex (7.330 Å). NMR studies indicated that the bis-Zn(II) complexes were highly symmetric. The bis-Zn(II) helicates showed broad absorption bands in the region of 400–700 nm and were nonfluorescent. DFT/TD-DFT studies were in agreement with the experimental observations. [ABSTRACT FROM AUTHOR]

Optimizing methanol reforming for hydrogen production is crucial, in which the regulation of the catalyst structure has a significant impact on improving catalytic activity. LaCoO3 perovskite is a promising catalyst for this application due to its tunable structure and exceptional thermal stability. This work reports the modulation of the active phase in the perovskite LaCo1−xCuxO3 (x = 0, 0.03, 0.06, 0.12) by annealing under a H2 atmosphere. The results of XPS, XRD, and H2-TPR reveal that Cu doping and hydrogen reduction can modify the chemical states of B-site elements. Consequently, the activity of methanol reforming for hydrogen production is considerably enhanced. The optimal performance for methanol hydrogen production observed in LaCo0.97Cu0.03O3 suffered from H2 reduction at 300 °C. This is due to the modulation of the active phase structure with appropriate redox pairs of Cu2+/Cu+, Co3+/Co2+ and O2−/Ov. This work offers valuable insights in the development of efficient catalysts for methanol reforming and hydrogen production. [ABSTRACT FROM AUTHOR]