A series of tetranuclear grid-type complexes were prepared by the reaction of the asymmetric multidentate ligand HL (HL = 2-[3-(2-hydroxyphenyl)-1H-pyrazol-5-yl]-6-pyridine carboxylic acid ethylester) with different metal sources. The tetranuclear copper complex, [Cu4(L1)4(NO3)4(H2O)4] Et2O 2MeOH (1, HL1 = 2-[3-(2-hydroxyphenyl)-1H-pyrazol-5-yl]-6-pyridine carboxylic acid methyl ester) consists...

This study investigated the impact of atmospheric metal deposition on natural phytoplankton communities at open-ocean and coastal sites in the Sargasso Sea during the spring bloom. Locally collected aerosols with different metal contents were added to natural phytoplankton assemblages from each site, and changes in nitrate, dissolved metal concentration, and phytoplankton abundance and carbon c...

Optimization of the hydrated Cu(II)(N7-guanine) structures revealed a number of minima on the potential energy surface. For selected structures, energy decompositions together with the determination of electronic properties (partial charges and electron spin densities) were performed. In the complexes of guanine with the bare copper cation and that with the monoaqua ligated cation, an electron ...

There has been considerable discussion on the question of determining total sulphur in urine. Folinl has suggested the use of sodium peroxide as oxidizing agent in determining total urinary sulphur. Benedict,2 by the use of copper nitrate and potassium chlorate, obtains results comparable with those of the Folin method. Ritson3 by using barium peroxide, obtains somewhat higher values than are g...

Besides being a naturally occurring element and an essential micronutrient, copper is used as a pesticide, but at generally higher concentrations. Copper, unlike organic pesticides, does not degrade, but rather enters a complex biogeochemical cycle. In the water column, copper can exist bound to both organic and inorganic species and as free or hydrated copper ions. Water column chemistry affec...

The physicochemical qualities of a refinery effluent and water and sediment of an effluent receiving water body were investigated. The treated refinery effluent contained very high concentrations of phenol (11.06 mg/l), oil and grease (7.52 mg/l), ammonia (8.52 mg/l), COD (91.76 mg/l), TDS (390.6 mg/l) and phosphate (6.2 mg/l), but low in sulphide, nickel, lead, copper and chromium, which were ...

Metal-aqua ion ([M(H2O)n](X+)) formation is a fundamental step in mechanisms that are central to enzymatic and industrial catalysis. Past investigations of such ions have yielded a wealth of information regarding their properties, however questions still exist involving the exact structures of these complexes. A prominent example of this is hexaaqua copper(II) ([Cu(H2O)6](2+)), with the solutio...

The electrosorption of U(VI) and NO3 from waste water was carried out by using an activated carbon fiber(ACF) felt electrode. Electrosorption experiments showed that the applied negative potential increased the adsorption kinetics and capacity in comparison to the open circuit potential(OCP) adsorption for uranium ions. The absolute value of the applied negative potential controlled the adsorpt...