Cu(II) precursors ligated to phenanthrolines are reduced in situ by alcohols or amines in the presence of a base (Cs(2)CO(3)) to generate Cu(I) species which are active catalysts in C-N and C-O cross-coupling reactions. The conversion Cu(II) --> Cu(I) has been evidenced and monitored by UV-vis and NMR spectroscopy.

Optimization of Cd (II), Zn (II) and Cu (II) biosorption from contaminated water were performed as function of parameters (pH, contact time, initial metal ions concentration and yeast dose). The experimental results showed that the highest equilibrium adsorption capacity at the optimum pH were 8.5 for Cd (II) and 6 for Zn (II) and 6 for Cu (II). Optimum pH values were carried out to evaluate ot...

Earlier we reported the tendency of ferrocenylmethyl substituted amino acids to organize around Cu(ii) in a C(2) symmetry. In this paper we have utilized this property to form a chiral cavity using a l-tyrosine derivative. Structural characterization of [Cu(II)(S-fTyr)(2)(MeCN)(2)] (), where S-fTyr(1-) is ferrocenylmethyl-l-tyrosinate, showed that the alignment of two tyrosine aromatic rings ar...

The natural product jadomycin B, isolated from Streptomyces venezeulae ISP5230, has been found to cleave DNA in the presence of Cu(II) ions without the requirement for an external reducing agent. The efficiency of DNA cleavage was probed using supercoiled plasmid DNA in buffered solution as a model environment. EC₅₀ and t(½) values for cleavage were 1.7 μM and 0.75 h, respectively, and varied ±...

The L,L-Phe-Leu-Cu(II), L,L-Leu-Phe-Cu(II), L,L-Phe-Met-Cu(II), and L,L-Met-Phe-Cu(II) systems were studied using molecular modelling. The results obtained, which are in good agreement with results obtained by potentiometric studies show a significant increase in stability of copper complexes, when an aromatic residue is located in C-terminal (compared to the L,L-dipeptides containing the same ...

A Ni-Cu ion exchange has been observed for (5,15-dibromo-10,20-diphenylporphyrinato)nickel(II) (NiDBrDPP) and (5,10,15,20-tetrakis(4-bromophenyl)porphyrinato)nickel(II) (NiTBrPP) on Cu(111). The ion exchange proceeds at a faster rate for the NiDBrDPP/Cu(111) system compared to NiTBrPP/Cu(111). This is explained in terms of the macrocycle-substrate distance and the distortions that occur when th...

The human small heat-shock protein αB-crystallin (αB) rescues misfolded proteins from irreversible aggregation during cellular stress. Binding of Cu(II) was shown to modulate the oligomeric architecture and the chaperone activity of αB. However, the mechanistic basis of this stimulation is so far not understood. We provide here first structural insights into this Cu(II)-mediated modulation of c...

New silica supported Schiff base ligands were prepared by the condensation reaction of 4,6-diacetylresorcinol with silica-gel derivatives, which modified with 3-aminopropyltriethoxysilane and N-(2-aminoethyl) -3-aminopropyltrimethoxysilane. Metal ion uptake capacities of these compounds were studied towards of selected transition metal (Cd(II), Cu(II), Co(II), Mn(II), Pb(II) and Ni(II)) cations...

In the title complex, {[Cu3[W(CN)8]2(C5H6N2)4(H2O)2]·2H2O} n , the coordination polyhedron of the eight-coordinated W(V) atom is a bicapped trigonal prism, in which five CN groups are bridged to Cu(II) ions, and the other three CN groups are terminally bound. Two of the Cu(II) ions lie on a centre of inversion and each of the three independent Cu(II) cations is pseudo-octahedrally coordinated. ...