Although the crystals of coordination polymer {[CuCl(μ-O,O\'-L-Br2Tyr)]}n (1) (L-Br2Tyr = 3,5-dibromo-L-tyrosine) were formed under basic conditions, crystallographic studies revealed that the OH group of the ligand remained protonated. Two adjacent [CuCl(L-Br2Tyr)] monomers, bridged by the carboxylate group of the ligand in the syn-anti bidentate bridging mode, are differently oriented to form a polymeric chain; this specific bridging was detected also by FT-IR and EPR spectroscopy. Each Cu(II) ion in polymeric compound 1 is coordinated in the xy plane by the amino nitrogen and carboxyl oxygen of the parent ligand and the oxygen of the carboxyl group from the symmetry related ligand of the adjacent [Cu(L-Br2Tyr)Cl] monomer, as well as an independent chlorine ion. In addition, the Cu(II) ion in the polymer chain participates in long-distance intermolecular contacts with the oxygen and bromine atoms of the ligands located in the adjacent chains; these intramolecular contacts were also supported by NCI and NBO quantum chemical calculations and Hirshfeld surface analysis. The resulting elongated octahedral geometry based on the [CuCl(L-Br2Tyr)] monomer has a lower than axial symmetry, which is also reflected in the symmetry of the calculated molecular EPR g tensor. Consequently, the components of the d-d band obtained by analysis of the NIR-VIS-UV spectrum were assigned to the corresponding electronic transitions.

Two copper(II) complexes containing diplacone (H4dipl), a naturally occurring C-geranylated flavanone derivative, in combination with bathophenanthroline (bphen) or 1,10-phenanthroline (phen) with the composition [Cu3(bphen)3(Hdipl)2]⋅2H2O (1) and {[Cu(phen)(H2dipl)2]⋅1.25H2O}n (2) were prepared and characterized. As compared to diplacone, the complexes enhanced in vitro cytotoxicity against A2780 and A2780R human ovarian cancer cells (IC50 ≈ 0.4-1.2 μM), human lung carcinoma (A549, with IC50 ≈ 2 μM) and osteosarcoma (HOS, with IC50 ≈ 3 μM). Cellular effects of the complexes in A2780 cells were studied using flow cytometry, covering studies concerning cell-cycle arrest, induction of cell death and autophagy and induction of intracellular ROS/superoxide production. These results uncovered a possible mechanism of action characterized by the G2/M cell cycle arrest. The studies on human endothelial cells revealed that complexes 1 and 2, as well as their parental compound diplacone, do possess anti-inflammatory activity in terms of NF-κB inhibition. As for the effects on PPARα and/or PPARγ, complex 2 reduced the expression of leukocyte adhesion molecules VCAM-1 and E-selectin suggesting its dual anti-inflammatory capacity. A wide variety of Cu-containing coordination species and free diplacone ligand were proved by mass spectrometry studies in water-containing media, which might be responsible for multimodal effect of the complexes.

A novel cationic complex, bromido-tetra-kis-[5-(prop-2-en-1-ylsulfan-yl)-1,3,4-thia-diazol-2-amine-κN 3]copper(II) bromide, [CuBr](C5H7N3S2)4Br, was synthesized. The complex crystallizes with fourfold mol-ecular symmetry in the tetra-gonal space group P4/n. The CuII atom exhibits a square-pyramidal coord-ination geometry. The Cu atom is located centrally within the complex, being coordinated by four nitro-gen atoms from four AAT mol-ecules, while a bromine anion is located at the apex of the pyramid. The amino H atoms of AAT inter-act with bromine from the inner and outer spheres, forming a two-dimensional network in the [100] and [010] directions. Hirshfeld surface analysis reveals that 33.7% of the inter-mol-ecular inter-actions are from H⋯H contacts, 21.2% are from S⋯H/H⋯S contacts, 13.4% are from S⋯S contacts and 11.0% are from C⋯H/H⋯C, while other contributions are from Br⋯H/H⋯Br and N⋯H/H⋯N contacts.

The central ion Mg2+ is responsible for the differences between chlorophyll a and its free base in their reactivity toward metal ions and thus their resistance to oxidation. We present here the results of spectroscopic (electronic absorption and emission, circular dichroism, and electron paramagnetic resonance), spectroelectrochemical, and computational (based on density functional theory) investigations into the mechanism of pheophytin, a degradation that occurs in the presence of Cu ions and O2. The processes leading to the formation of the linear form of tetrapyrrole are very complex and involve the weakening of the methine bridge due to an electron withdrawal by Cu(II) and the activation of O2, which provides protection to the free ends of the opening macrocycle. These mechanistic insights are related to the naturally occurring damage to the photosynthetic apparatus of plants growing on metal-contaminated soils.

A new mononuclear copper(II) complex, [Cu(C7H5O3)(HCO2)(C10H9N3)], containing mixed N- and O-donor ligands, 2,2\'-di-pyridyl-amine (dpyam) and m-hy-droxy-benzoate (m-OHbenz), has been obtained from a solvent mixture. The coordination environment of the CuII ion is distorted square-pyramidal with a [N2O3] coordination set originating from the chelating dpyam and m-OHbenz ligands in the basal plane and the O atom of a formato ligand at the apical position. The crystal structure of the title complex is stabilized by N-H⋯O, O-H⋯O, C-H⋯O hydrogen-bonding, π-π and C-H⋯π inter-molecular inter-actions, which were qu-anti-fied by Hirshfeld surface analysis.

Photodeposited TiO2/Ag nanocomposites were generally used to be a friendly catalyst for degrading organic contaminant in environmental field. However, electrochemiluminescence (ECL) sensing analysis based on photocatalysts remains a significant challenge. Herein, polyvinylimide (PEI)-TiO2/Ag nanocomposites (PEI-TiO2/AgNCPs) film with reduced graphene oxide(r-GO) was constructed as a sensing interface for copper(II) ECL detection. TiO2/Ag nanocomposites was prepared by reversed phase microemulsion method and photodeposition technique. Moreover, it was discovered that a small amount of Cu2+ could obviously boost the ECL signal of ninhydrin-hydrogen peroxide system. Signal amplification was achieved by using the synergistic effect between r-GO and TiO2/Ag nanocomposites, and the efficiently concentrated effect of PEI to Cu2+. Furthermore, the investigation showed that ECL mechanism of ninhydrin-hydrogen peroxide system was attributed to the generated hydroxyl radical and superoxide anion during the several type of reactions. Thus for the first time, an ultrasensitive ECL approach for detecting Cu2+ could be performed using ninhydrin as an ECL signal probe and hydrogen peroxide as a co-reaction reagent. Under the suitable circumstances, the proposed method showed an excellent linear relationship in the concentration range of Cu2+ from 1.0 fM to 5.0 nM. Detection limit was estimated to be as low as 0.26 fM. The sensing interface expanded the application of photodeposited TiO2/Ag nanocomposites in ultrasensitive ECL detection. It has potential applications in other components and biological analysis.

A bis(chalcone) molecule (H2L) was synthesized via Aldol\'s condensation from terephthalaldehyde and 2\'-hydroxyacetophenone and it was used as bridging ligand for the preparation of five dinuclear copper(II) complexes of the composition [Cu(NN)(μ-L)Cu(NN)](NO3)2⋅nH2O (n = 0-2) (1-5), where NN stands for a bidentate N-donor ligand such as phen (1,10-phenanthroline, 1), bpy (2,2\'-bipyridine, 2), mebpy (5,5\'-dimethyl-2,2\'-dipyridine, 3), bphen (bathophenanthroline, 4) and nphen (5-nitro-1,10-phenanthroline, 5). The compounds were characterized by different suitable techniques to confirm their purity, composition, and structure. Moreover, the products were evaluated for their in vitro cytotoxicity on a panel of human cancer cell lines: ovarian (A2780), ovarian resistant to cisplatin (A2780R), prostate (PC3), osteosarcoma (HOS), breast (MCF7) and lung (A549), and normal fibroblasts (MRC-5), showing significant cytotoxicity in most cases, with IC50 ≈ 0.35-7.8 μM. Additionally, the time-dependent cytotoxicity and cellular uptake of copper, together with flow cytometric studies concerning cell-cycle arrest, induction of cell death and autophagy and induction of intracellular ROS/superoxide production in A2780 cells, were also performed. The results of biological testing on A2780 cells pointed out a possible mechanism of action characterized by the G2/M cell cycle arrest and induction of apoptosis by triggering the intrinsic signalling pathway associated with the damage of mitochondrial structure and depletion of mitochondrial membrane potential. SYNOPSIS: Dinuclear Cu(II) complexes bearing a bridging bis(chalcone) ligand revealed high in vitro cytotoxicity, initiated A2780 cell arrest at G2/M phase and efficiently triggered intrinsic pathway of apoptosis.

Neutral (l-histidinato)(l-glutaminato)copper(II) [Cu(His)(Gln)] has been established as the most abundant ternary copper(II) amino acid compound of the exchangeable copper(II) pool in blood plasma. The experimental studies of Cu(His)(Gln) and bis(glutaminato)copper(II) [Cu(Gln)2] in solutions did not specify their complete geometries. To determine the geometries, this paper investigates the conformers, energy landscapes, and a structure-magnetic parameters relation of Cu(Gln)2 and Cu(His)(Gln) by the density functional theory (DFT) calculations. We assume a glycine-like coordination of Gln (other coordination patterns are dismissed because of steric reasons), and three His in-plane copper(II) binding modes. The conformational analyses are performed in the gas phase and implicitly modeled aqueous solution. The reliability of the DFT relative electronic and Gibbs free energies of the Cu(His)(Gln) conformers is confirmed by benchmarking against the corresponding energies obtained by the domain-based local pair natural orbital coupled-cluster method with singles, doubles, and perturbative triples [DLPNO-CCSD(T)]. Several cis- and trans-Cu(His)(Gln) conformers with His in the histaminate-like and glycine-like modes have low Gibbs free energies, and the greatest estimated metal-binding affinities. The DFT-calculated magnetic parameters of the low-energy conformers reproduce best the experimental electron paramagnetic resonance parameters measured in aqueous solutions for trans- and cis-Cu(Gln)2 conformers having two oxygen atoms (either from Gln or water molecules) at the apical positions, and Cu(His)(Gln) conformers having His in the histaminate-like mode with an apically placed carboxylato oxygen atom. The predicted conformational flexibility of His‑copper(II)-amino acid compounds may be connected with their physiological abundance, and the role in copper(II) exchange reactions in blood plasma.

Novel fluorescent probes were constructed for the convenient and rapid analysis of Cu2+ ions, taking advantages of the the triphenylamine backbone as chromophore and acylhydrazone group as the Cu2+ recognition site. Especially, probe T2 could act as a dual-channel probe towards Cu2+ through both fluorescent and colorimetric method. Through the fluorescent method, the detection limit of probe T2 was calculated to be as low as 90 nmol/L and there was a good linear relationship between the intensity change and the concentration of Cu2+ ions. By virtue of the two-phase liquid-liquid extraction method, probe T2 could be successfully applied in practical extraction and separation of Cu2+. Furthermore, by applying a \"turn-off-turn-on\" circle, compound T2 could act as a sensitive probe towards S2- anions through the indirect approach and the detection limit of complex T2-Cu2+ for S2- anion was found to be 110 nmol/L.

In the title compound, {[Cu2(C10H8O4)2(C14H14N4O2)]·5H2O}n, the CuII cations are coordinated in a square-pyramidal fashion, with four 3-(2-carb-oxy-phen-yl)propionate (cpp) carboxyl-ate O-atom donors in the basal plane, along with an N-atom donor from a N-[2-(pyridin-3-yl-amino)-eth-yl]nicotinamide (pen) ligand in the apical position. [Cu2(cpp)2]n coordination polymer layer motifs with embedded {Cu2(OCO)4} paddlewheel clusters are thereby constructed. These layer motifs are connected into a three-dimensional [Cu2(cpp)2(pen)]n coordination polymer network by tethering pen ligands. Treating the {Cu2(OCO)4 paddelwheel clusters as 6-connected nodes reveals an underlying cross-pillared self-penetrated rob network with 48668 topology. The water mol-ecules of crystallization are held to the coordination polymer network by N-H⋯O and O-H⋯O hydrogen-bonding patterns.