Search results for "coordination complex"
showing 10 items of 381 documents
CO-releasing binuclear rhodium complexes as inhibitors of nitric oxide generation in stimulated macrophages.
2013
Nontoxic CO-releasing dirhodium complexes act as inhibitors of NO in stimulated macrophage cells, suggesting that novel antiinflammatory treatments could involve the use of these types of binuclear complexes.
Synthesis, structural and magnetic characterizations of new complexes of di-2,6-(2-pyridylcarbonyl)pyridine (pyCOpyCOpy) ligand
2013
International audience; Using the di-2,6-(2-pyridylcarbonyl)pyridine ligand (L1) as starting framework, five new mononuclear complexes were obtained: [Cu(L1)(MeCN)(ClO4)2] (1) [Co(L1)(MeCN)(Br)2]*MeCN (2), [Fe(L1)2](BF4)2*MeOH*H2O (3), [Cr(L2a)Cl2]*2MeOH (where HL2a is (6-(hydroxyl(methoxy)(pyridin-2-yl)methyl)pyridin-2-yl)(pyridin-2-yl)methanone) (4) and one trinuclear [NiII3] complex, [Ni3(L2b)2(Bz)2(EtOH)2](ClO4)2*2EtOH (where HL2b is (6-(hydroxyl(ethoxy)(pyridin-2-yl)methyl)pyridin-2-yl)(pyridin-2-yl)methanone; Bz = benzoato) (5). Their structural and magnetic characterizations are herein reported. All the metal ions show octahedral coordination geometry, which is slightly unusual for t…
Complexes of organometallic compounds
1974
Abstract Several new complexes formed by PhTlCl 2 with tridentate ligands (with ONO and SNO donor atoms) and a tetradentate ligand (with ONNO donor atoms), have been prepared. The complexes show 1/1 organothallium(lll)/Ligand ( = L 2− ) stoichiometry. Their nature and configuration are investigated in the solid state by vibrational spectroscopy, and in solution by electronic spectroscopy. The existence of chelation by the dianionic ligands on Tl III is inferred, and suggestions are made concerning the Tl III coordination number and the stereochemistry of the complexes.
NaI/CuI–II heterometallic cages interconnected by unusual linear 2-coordinate OCN-Cu(I)-NCO links: synthesis, structural, magnetostructural correlati…
2009
A new Na(I)/Cu(I-II) heterometallic coordination complex [Cu(2)L(2)Na(NCO)(2)Cu](n) (1) with an unusual architecture has been synthesised. In 1 cyclic Na-O-Cu-O-Cu cages constructed by the tetradentate N(2)O(2) donor Schiff base ligand (H(2)L = N, N'-bis(2-hydroxyacetophenone) propylenediimine) are interconnected to each other by a rare singly end-to-end bridged OCN-Cu(I)-NCO link generating 1D chain. The complex has been characterised by elemental, spectral and structural analysis. The cyclic voltammogram of 1 has been compared with the analogous complexes. Cryomagnetic susceptibility studies indicate the copper(II) centers in the cyclic Na-O-Cu-O-Cu cages are antiferromagnetically coupled…
Binding Mode and Selectivity of a Scorpiand-Like Polyamine Ligand to Single- and Double-Stranded DNA and RNA: Metal- and pH-Driven Modulation
2017
The interaction of a polyazacyclophane ligand having an ethylamine pendant arm functionalized with an anthryl group (L), with the single-stranded polynucleotides polyA, polyG, polyU, and polyC as well as with the double-stranded polynucleotides polyA-polyU, poly(dAT)(2), and poly(dGC)(2) has been followed by UV/Vis titration, steady state fluorescence spectroscopy, and thermal denaturation measurements. In the case of the single-stranded polynucleotides, the UV/Vis and fluorescence titrations permit to distinguish between sequences containing purine and pyrimidine bases. For the double-stranded polynucleotides the UV/Vis measurements show for all of them hypochromicity and bathochromic shif…
DNA interaction of CuII, NiII and ZnII functionalized salphen complexes: studies by linear dichroism, gel electrophoresis and PCR.
2013
The interaction of salphen-type NiII, CuII and ZnII complexes with native DNA was investigated by exploiting linear dichroism experiments. The NiII complex behaves as a typical intercalator, binding strongly and stiffening and unwinding the DNA. The strength of the DNA interaction is slightly weaker for the copper complex and much weaker for the zinc complex. Plasmid-DNA gel electrophoresis experiments indicated that while CuII and ZnII complexes do not induce the unwinding of supercoiled DNA, the NiII complex has a nuclease activity without the addition of external agents. On the other hand, as shown in the PCR assays, we demonstrate that, at the used concentrations, only the CuII complex …
Triplet of cysteines – Coordinational riddle?
2020
Polythiol binding of metal ions plays crucial role in the proper functioning of cysteine-rich proteins that are responsible for metal homeostasis and defending processes against metal toxicity (including heavy metals detoxification). The coordination properties of cysteine residues involved in specific sequencional patterns in proteins (like those present in e.g. metallothioneins) are interesting not only from a chemical point of view but may also lead to a better understanding of the purpose and allocation of metal ions in various biomolecules. In this study, the interaction of Zn2+, Cd2+ and Ni2+ ions with four peptides containing cysteine triplet motif were studied by potentiometric and …
Ferrocenyl-Coupled N-Heterocyclic Carbene Complexes of Gold(I)
2016
Four gold(I) carbene complexes featuring 4-ferro-cenyl-substituted imidazol-2-ylidene ligands were investigated for antiproliferative and antivascular properties. They were active against a panel of seven cancer cell lines, including multidrug-resistant ones, with low micromolar or nanomolar IC50 (72 h) values, according to their lipophilicity and cellular uptake. The delocalized lipophilic cationic complexes 8 and 10 acted by increasing the reactive oxygen species in two ways: through a genuine ferrocene effect and by inhibiting the thioredoxin reductase. Both complexes gave rise to a reorganization of the F-actin cytoskeleton in endothelial and melanoma cells, associated with a G1 phase c…
Gold(I) Biscarbene Complexes Derived from Vascular-Disrupting Combretastatin A-4 Address Different Targets and Show Antimetastatic Potential
2014
Gold N-heterocyclic carbene (NHC) complexes are an emerging class of anticancer drugs. We present a series of gold(I) biscarbene complexes with NHC ligands derived from the plant metabolite combretastatin A-4 (CA-4) that retain its vascular-disrupting effect, yet address different cellular and protein targets. Unlike CA-4, these complexes did not interfere with tubulin, but with the actin cytoskeleton of endothelial and cancer cells. For the highly metastatic 518A2 melanoma cell line this effect was accompanied by a marked accumulation of cells in the G1 phase of the cell cycle and a suppression of active prometastatic matrix metalloproteinase-2. Despite these mechanistic differences the co…
Fluoroquinolone–metal complexes: A route to counteract bacterial resistance?
2014
Abstract Microbial resistance to antibiotics is one of the biggest public health threats of the modern world. Antibiotic resistance is an area of much clinical relevance and therefore research that has the potential to identify agents that may circumvent it or treat resistant infections is paramount. Solution behavior of various fluoroquinolone (FQ) complexes with copper(II) in the presence and absence of 1,10-phenanthroline (phen) was studied in aqueous solution, by potentiometry and/or spectrophotometry, and are herein described. The results obtained showed that under physiological conditions (micromolar concentration range and pH 7.4) only copper(II):FQ:phen ternary complexes are stable.…