Magnetic, Mössbauer, and I.R. studies of nanosize particles of Fe and Co species dispersed in a cage of aluminosilicates structure, in relation to syngas (CO+H2) Fischer Tropsch conversion. The difference in the catalytic activity of such species have shown dependancy on their degree of dispersion. The carbonyl impregnation gave ultra-fine Super Paramagnetic Fe3O4, whereas the nitrate impregnat...

The spectroscopic studies of transition metal complexes of iron. metal complexes, are characterized by XRD, FTIR, H NMR, Mössbauer and VSM (vibrating sample magnetometer) measurements, are reported in the present paper. The XRD analysis reveals the crystalline nature of all the compounds. Mössbauer study interprets paramagnetic nature of complexes at room temperature. VSM measurements also reve...

We have used Mössbauer emission spectroscopy to study an oxygenated heme complex, produced in a frozen solution by nuclear decay from the isomorphous (57)Co-labeled compound. The Mössbauer parameters agree with those obtained by Mössbauer absorption spectroscopy of oxyhemoglobin. Thus, a nonprotein environment for iron can duplicate the unique oxyhemoglobin Mössbauer spectrum. The electronic st...

Benzoyl-CoA reductase catalyzes the two-electron transfer from a reduced ferredoxin to the aromatic ring of benzoyl-CoA; this reaction is coupled to stoichiometrical ATP hydrolysis. A very low reduction potential (less than -1 V) is required for the first electron transfer to the aromatic ring. In this work the nature of the redox centers of purified benzoyl-CoA reductase from Thauera aromatica...

  In this research, a low temperature in-field 57Fe Mössbauer spectroscopy is used for investigation of anomalous magnetic properties of MnZn nanoferrite. Based on Mössbauer spectroscopy results, the reduced saturation magnetization of MnZn nanoferrite in respect to that of bulk sample is due to nonequilibrium cation distribution and spin disorder. The enhanced Curie temperature of MnZn nanofer...

Cytochrome c-554 functions in the ammonia oxidizing system of Nitrosomonas europaea. We have investigated its molecular and ligand binding properties and studied the protein with optical, EPR, and Mössbauer spectroscopies in the pH range from 2 to 13. Amino acid, heme, and metal analyses show that the protein has Mr = 25,000 and that it contains four c-type hemes per molecule. Optical spectra r...