3.1. Carbon−Nitrogen Bond Formation 14 3.1.

The deposition of the cerium conversion layer on aluminum alloy 7075-T6 proceeds by a simple procedure immersion, but it is affected several factors which govern its corrosion protectiveness. study aimed to investigate two crucial relationships: (i) how type salt used for affects composition, thickness, and electrochemical characteristics deposited layers, (ii) depends intermetallic particles. ...

Some nitrate- and Fe(III)-reducing microorganisms are capable of oxidizing Fe(II) with nitrate as the electron acceptor. This enzymatic pathway may facilitate the development of anaerobic microbial communities that take advantage of the energy available during Fe-N redox oscillations. We examined this phenomenon in synthetic Fe(III) oxide (nanocrystalline goethite) suspensions inoculated with m...

The first synthesis of the racemic 8-deoxy WP3688-2 angucycline antibiotic (3), with characteristic cis-hydroxy groups at C-4 a and C-12b, is reported. Key steps involve the coupling, mediated by samarium diiodide, of the bicyclic trione 37 to the tricyclic cis-diol 39. Biomimetic aldol cyclization of the corresponding dione 41 gave a mixture of the tetracyclic cis- and trans-3,4a-diols 42 and ...

We propose a model for the water-oxidation and recovery systems of the oxygen-evolving complex (OEC) of the photosystem II (PSII) enzyme. The whole system is constructed from two catalytic cycles, conducted as a tandem reaction: (i) a water-oxidation loop uses cerium(IV) ammonium nitrate as an oxidant to activate a dimanganese complex for water-oxidation and thereby liberate a molecule of O2 an...

Studies towards the biomimetic synthesis of cardinalin 3 are described. Despite the successful enantioselective synthesis of the monomeric pyranonaphthoquinone ventiloquinone L, it subsequently failed to undergo a proposed biomimetic homodimerisation to cardinalin 3 using a range of oxidants. However, treatment of a related naphthopyran with cerium ammonium nitrate (CAN) facilitated a tandem bi...

Chitosan based membranes to be applied on wound healing as topical drug delivery systems were developed by graft copolymerization of acrylic acid (AA) and 2-hydroxyethyl methacrylate (HEMA) onto chitosan using cerium ammonium nitrate as chemical initiator. Evidence for graft copolymerization of the vinyl monomers onto chitosan was obtained by FTIR and DMTA. Swelling degree, cytotoxicity, thromb...

the complex of ce(iii), [ ce (phensc) (h 0) ] (c10 ) , was synthesized using the phensc, a hexadentate ligand,2,9-diformyl-1,lo- phenanthroline bis (semicarbazone), and characterized by x-ray diffraction. the cerium atom has an unusual coordination number of ten involving six donor atoms of the planar ligand in the equatorial plane and four oxygen atoms from four axial water molecules. the comp...

On the basis of optimized grinding/heating cycles developed for several phosphate-based ceramics, the preparation of brabantite and then monazite/brabantite solid solutions loaded with tetravalent thorium, uranium, and cerium (as a plutonium surrogate) was examined versus the heating temperature. The chemical reactions and transformations occurring when heating the initial mixtures of AnO2/CeO2...