Transition metals are known to cause toxic effects through their interaction with oxygen, but toxicity under anoxic conditions is poorly understood. Here we investigated the effects of iron (Fe) and copper (Cu) on the anaerobic growth and gene expression of the purple phototrophic bacterium Rhodopseudomonas palustris TIE-1. We found that Fe(II) and Cu(II) act synergistically to delay anaerobic ...

The most important pollutants in wastewater are heavy metal ions. In this paper, the effects of various parameters such as pH, contact time, initial concentration, and temperature on the adsorption of Cu (II) by nanochitosan (NCS) was investigated in batch experiment. Nanochitosan was prepared based on ionic gelation and charac­terized by means of Fourier Transform Infrared Spectroscopy (FTIR),...

Fluorescence quenching properties of copper(II) ions have been used for designing Cu(II) sensitive fluorescent molecular probes. In this paper, we demonstrate that static quenching plays a key role in free Cu(II)-mediated fluorescence quenching of a near infrared (NIR) fluorescent dye cypate. The Stern-Volmer quenching constant was calculated to be KSV = 970,000 M in 25 mM MES buffer, pH 6.5 at...

Glyphosate (N-(phosphonomethyl)glycine) is the active ingredient in a range of popular broad-spectrum herbicide formulations. Glyphosate is a chelating agent that can form stable complexes with divalent metal ions including Cu(II). Little is known about the bioavailability and ecotoxicity of glyphosate-Cu(II) complexes to aquatic organisms. In this study, we used video tracking and behavior ana...

The batch sorption capability of Romanian pine bark for the removal of Cu(II) and Zn(II) ions from diluted aqueous solutions was investigated as a function of initial pH, contact time, and temperature. The metal sorption sequence is Cu > Zn. The experimental data for Cu(II) and Zn(II) ions retention on the tested bark of Pinus sylvestris L. showed a better compliance with the pseudo–second orde...

The chemically crosslinked metal-complexed chitosans were synthesized by using the ion-imprinting method from a chitosan with four metals (Cu(II), Zn(II), Ni(II) and Pb(II)) as templates and glutaraldehyde as a crosslinker. The influences of adsorption conditions, including molar ratios of crosslinker/chitosan and pH changes, were studied. They were used to investigate for comparative adsorptio...

To improve understanding of copper at the active site of Type 1 copper proteins, Cu(I) and Cu(II) complexes of 1,8-dithia-4,11-diazacyclotetradecane, shown in , have been successfully isolated and structurally characterized by X-ray crystallography. In these compounds, both Cu(I) and Cu(II) are centered in the plane of the macrocycle containing two sulphur and two nitrogen heteroatoms comprisin...

   In this study, cadmium sulfide nanoparticles (CdS NPs) were prepared, characterized and used as a new adsorbent for simultaneous removal of Pb(II) and Cu(II) ions from aqueous solutions. Using a batch adsorption method, the effects of solution pH, contact time, adsorbent dose, and temperature were studied and optimized. Removal efficiencies, higher than 98% were obtained for both the met...

Two C₂-symmetrical dipyrrole-polyamide dimers 2 and 3 that were tethered with triethylenetetramine and spermine, respectively, and their corresponding Cu(II) complexes 2@Cu(2+) and 3@Cu(2+), were synthesized and fully characterized. Agarose gel electrophoresis studies on pBR322 DNA cleavage indicated that both Cu(II) complexes exhibited potent DNA-cleaving activities under physiological conditi...

Threaded complexes like pseudorotaxanes, rotaxanes based on Cu(I)/Cu(II) ions have shown to be promising for the construction of mechanically interlocked molecular-level architectures. In this short review, we focus on the synthetic strategies developed to construct pseudorotaxanes and rotaxanes using Cu(I)/Cu(II) ions as template. Further, brief discussions on chemical and mechanical propertie...