The coordination environment of the type 2 (nonblue) copper in native ascorbate oxidase (L-ascorbate:oxygen oxidoreductase, EC 1.10.3.3) and of a derivative of the enzyme having the type 1 (blue) copper reversibly bleached has been examined by electron paramagnetic resonance (EPR) spectroscopy. In the g[unk] region of the spectrum of bleached ascorbate oxidase, a seven-line superhyperfine patte...

Intensive efforts for the transformation of dinitrogen using transition metal-dinitrogen complexes as catalysts under mild reaction conditions have been made. However, limited systems have succeeded in the catalytic formation of ammonia. Here we show that newly designed and prepared dinitrogen-bridged dimolybdenum complexes bearing N-heterocyclic carbene- and phosphine-based PCP-pincer ligands ...

A computational method targeted to Werner-type complexes is developed on the basis of quantum mechanical effective Hamiltonian crystal field (EHCF) methodology (previously proposed for describing electronic structure of transition metal complexes) combined with the Gillespie-Kepert version of molecular mechanics (MM). It is a special version of the hybrid quantum/MM approach. The MM part is res...

The cyclo-dipeptide substrates of the essential M. tuberculosis (Mtb) enzyme CYP121 were deconstructed into their component fragments and screened against the enzyme. A number of hits were identified, one of which exhibited an unexpected inhibitor-like binding mode. The inhibitory pharmacophore was elucidated, and fragment binding affinity was rapidly improved by synthetic elaboration guided by...

there has been a considerable interest in platinum group metal complexes of thiaoxa-donor macrocycles because of their unusual properties. 1 As an extension of our studies involving mixed-donor cyclic 2a and acyclic 2b ligands incorporating thiaoxa mixed-donors, we became interested in exploring their coordination chemistry of platinum group metal ions. The S2O-donor macrocycle of the title com...

Current interests in the chemistry of high-nuclearity transition-metal complexes draw from their utility in the emerging science of nanomaterials, as models for the multimetal active sites of metal-storage proteins, and as single molecule magnets (SMMs). In addition, such super-sized molecules often show a variety of supramolecular interactions. The “self-assembly” process of generating a high-...

The processes that convert bioavailable inorganic nitrogen to inert nitrogen gas are prominent in continental shelf sediments and represent a critical global sink, yet little is known of these pathways in the Arctic where 18% of the world's continental shelves are located. Moreover, few data from the Arctic exist that separate loss processes like denitrification and anaerobic ammonium oxidation...

Experimental da ta on ligand effects in the chemistry of main group elements are less extensive than in the coordination chemistry of transition elements. The relation between the donor properties of ligands L and the halogen ligands in tin(IV) complexes of the type SnHal 4 L 2 being often uncertain, we performed a systematic N Q R study of tin(IV) complexes of the type Alk„SnHal4_„L2 , where o...

introduction:nitrate entrance to water bodies can cause eutrophication and decrease quality of them, furthermore it can effect on human health so concentration of nitrate must be at defined standard level. there are several methods for reduction or removal of nitrate in water such as ion exchange, reverse osmosis, electrodialysis and denitrification. microbial denitrification of nitrate in anox...