Specificity of hexarhenium cluster anions for synthesis of Mn2+-based nanoparticles with lamellar shape and pH-induced leaching for specific organ selectivity in MRI contrasting.

The present work demonstrates the structure variation of hexarhenium anionic cluster units [{Re6S8}(CN)(6-n)(OH)n]4- (n = 0, 2, 4) as the strategy to develop Mn2+-containing nanoparticles (NPs) exhibiting pH-dependent leaching. The dicyanotetrahydroxo complex [{Re6S8}(CN)2(OH)4]4- is the optimal for the synthesis of the Mn2+-based NPs with a lamellar shape exhibiting the pH-dependent aggregation and magnetic relaxation behavior. The pH-dependent behavior of the NPs derives from the easy protonation of the apical hydroxo ligands of [{Re6S8}(CN)2(OH)4]4- cluster, which triggers partial leaching of Mn2+ ions and aggregation of the NPs driven by the surface neutralization. The in vivo MRI scanning of the mice intravenously injected with the NPs indicates the preferable accumulation of the lamellar NPs within mouse intestine over liver and kidneys. This differs from the spherical NPs constructed from [{Re6Se8}(CN)6]4- units, which provide the preferable brightening of mouse liver over kidneys and intestine.

External oxidant-free cross-coupling: electrochemically induced aromatic C-H phosphonation of azoles with dialkyl-H-phosphonates under silver catalysis.

A convenient external oxidant-free method of phosphorylation of azole derivatives (benzo-1,3-azoles, 3-methylindole, 4-methyl-2-acetylthiazole) by using dialkyl-H-phosphonates through the catalytic oxidation of their mixture under electrochemical mild conditions (room temperature, normal pressure) in the presence of silver salts or oxide (1%) is proposed. This method allows us to obtain the desired azole dialkylphosphonates with good yield (up to 75%). The transformations of silver and phosphorus precursors and intermediates using cyclic voltammetry, ESR, and NMR spectroscopy were investigated, and a radical process mechanism was proposed. It has been found that AgP(O)(OEt)2 is oxidized earlier than other components of the reaction mixture with the elimination of a radical. The ESR spectrum of this radical's adduct was obtained in the presence of the radical trap PBN. Ag2+ is out of the catalytic cycle.

Oxygen reduction reaction catalyzed by nickel complexes based on thiophosphorylated calix[4]resorcinols and immobilized in the membrane electrode assembly of fuel cells.

The catalytic activity of the nickel complexes of thiophosphorylated calix[4]resorcinols for oxygen reduction in a polymer electrolyte membrane fuel cell (PEMFC) has been studied. The conformation of the macrocyclic ligand determines the morphology and catalytic properties of the resulting organometallic species.

Complexation of pectin with macro- and microelements. Antianemic activity of Na, Fe and Na, Ca, Fe complexes.

New water-soluble pectin complexes with Ca(2+), Mg(2+), Co(2+), Cu(2+), Fe(2+), Mn(2+), Zn(2+) on the basis of pectin biopolymer have been synthesized and successfully tested on white rats. For a starting, we have obtained a sodium pectate to enhance solubility of target complexes as a whole. Shortly afterwards, running the reaction of ligand exchange of Nа(+) ions with corresponding s-, d- metal cations we were able to synthesize new pectin complexes. The ranges of s-, d-metals salts concentrations were detected experimentally, in which the selective formation of water-soluble complexes occurred. Antianemic effect of new pectin complexes with Na, Fe and Na, Ca, Fe was investigated on white rats with posthemorrhagic anemia. Under the effect of complexes, the improvement of animals and prevention of erythropoiesis disorders were observed. Antianemic effect of the complexes manifested itself in the doses equivalent to 25% or 50% of the iron daily rate, recommended in the treatment of iron-deficiency anemia with the drugs based on iron sulphate.

Accessing perfluoroalkyl nickel(II), (III), and (IV) complexes bearing a readily attached [C4F8] ligand.

The [C4F8] ligand was shown to support well-defined terpyridyl nickel complexes in the +2 and +3 oxidation states. Notably, a cyclic voltammetry study of the nickel(iii) species indicates that an additional oxidation is accessible, providing a family of related fluoroalkyl nickel complexes spanning the +2 to +4 oxidation states.