In this study we use ab initio molecular dynamics simulations to analyze the structure and dynamics of the oxygen ligand in models of the oxymyoglobin active site and its cobalt-substituted analog. Our calculations are performed for iron-porphyrin and cobalt-porphyrin complexes with imidazole and oxygen as axial ligands, and we investigate the effect of the distal histidine in the structure and...

Molybdenum-containing enzymes catalyze basic metabolic reactions in the nitrogen, sulfur, and carbon cycles. With the exception of the nitrogenase cofactor, molybdenum is incorporated into proteins as the molybdenum cofactor that contains a mononuclear molybdenum atom coordinated to the sulfur atoms of a pterin derivative named molybdopterin. Certain microorganisms can also utilize tungsten in ...

the solvent extraction of rare earth metal ions from nitrate solutions by 5.11.17.23-tetra-tert-butyl-25,27-bis(diethylcarbamoylmethoxy)-26,28-dihydroxycalix[4]arene (l) in 1,2-dichloroethane has been investigated. the alalysis of the extraction equilibrium obtained from a mixture of la3+, eu3+, er3+ and y3+ revealed that the extracted species have a 1:1 metal/ligand ratio. the intra-group sepa...

The isolation and cloning of the cDNA coding for myoglobin (Mb) from the mollusc Aplysia limacina is reported here. Five amino acid differences from the previously published protein sequence have been found in positions 22, 26, 27, 77 and 80 by back transplanting the cDNA; some of these may be relevant for overall structure stabilization in this Mb. High-level expression of the holoprotein in E...

Organic ligand facilitated in situ exsolution of CoFe alloys over Ba 0.5 Sr Co 0.8 Fe 0.2 O 3 perovskite toward enhanced oxygen electrocatalysis for rechargeable Zn-air batteries.

A family of iron(II) carbonyl hydride complexes supported by either a bifunctional PNP ligand containing a secondary amine, or a PNP ligand with a tertiary amine that prevents metal–ligand cooperativity, were found to promote the catalytic hydrogenation of CO2 to formate in the presence of Brønsted base. In both cases a remarkable enhancement in catalytic activity was observed upon the addition...

the present work describes the studies on the coordination behaviour of 4[n-(benzalidene) amino]antipyrine semicarbazone (baaps) (i), 4[n-(furfural)amino]antipyrine semicarbazone (ffaaps) (ii) and 4[n-(cinnamalidene)amino]antipyrine semicarbazone (caaps) (iii) in presence of dimethyl sulfoxide (dmso) or diphenyl sulfoxide (dpso) towards th4+ and uo22+ salts. all the complexes were isolated in n...

In this paper we report the synthesis and characterization of two new binuclear Cd(II) macrocyclic Schiff base complexes [CdL23pydfp(NO3)], (1), and [CdL33pydfp(NO3)], (2). [1+1] cyclocondensation of L23py = N-(2-pyridylmethyl)-N-(3-aminpropyl)-1,3-diaminoethane and L33py = N-(3-pyridylmethyl)-N-(3-aminpropyl)-1,3-diaminopropane and 2,6-diformyl-4-methylphenol, dfp, in the presence of Cd(NO3)2....