The distance between the two metal binding sites of human serum transferrin is calculated from measurements made of the paramagnetic broadening of the EPR spectrum of Cu2+ bound at the NH2-terminal (B) site from Fe3+ bound at the COOH-terminal (A) site. Complexes of monoferric(A)-monocupric(B) transferrin, monocupric(B) transferrin, and monogallium(A)-monocupric(B) transferrin were prepared und...

An amperometric sensor was constructed, by using humic acids to immobilize Fe3+ ions on a carbon paste electrode (CPE-HA-Fe), and used for ascorbic acid (H2A) determination. The cyclic voltammogram of the electrode showed electrochemical response due to the Fe3+/Fe2+ couple at E1/2=+0.78 V vs SCE, using 0.5 mol L-1 KCl and 0.2 mol L-1 acetate/0.020 mol L-1 phosphate buffer, at pH = 5.4, as supp...

A Synechococcus sp. PCC 7942 bioreporter strain capable of sensing bioavailable Fe was constructed by fusing the Fe-responsive isiAB promoter to the Vibrio harveyi luxAB genes. Monitoring luxAB-dependent luminescence through the growth curve demonstrated that in Fe-replete media, transcription from the isiAB promoter was induced transiently in the mid-exponential phase of growth. The initiation...

Li2O·0.25Fe2O3·0.25NiO·1.5SiO2 glass was prepared with and without 5 wt % sulfur (S) while melting the mixture of the starting materials at 1350 C for 1 h in air. A part of the as-prepared glass was heat treated for 1 h near its crystallization temperature (Tc) as determined from differential thermal analysis. Each glass was also investigated by means of Mössbauer spectroscopy, X-ray diffracti...

Reaction of Fe3(CO)12 with 1,2-dithiolene HSC6H2Cl2SH affords a mixture of complexes [Fe2(CO)6(μ-SC6H2Cl2S)] 1, [Fe2(SC6H2Cl2S)4] 2 and [Fe3(CO)7(μ3-SC6H2Cl2S)2] 3. In the course of the reaction the trimetallic cluster 3 is first formed and then converted into the known dinuclear compound 1 to afford finally the neutral diiron tetrakis(dithiolato) derivative 2. Compounds 2 and 3 have been studi...

Reaction of a trinuclear iron(II) complex, Fe3 Br3 L (1), with KC8 under N2 leads to dinitrogen activation products (2) from which Fe3 (NH)3 L (2-1; L is a cyclophane bridged by three β-diketiminate arms) was characterized by X-ray crystallography. (1) H NMR spectra of the protonolysis product of 2 synthesized under (14) N2 and (15) N2 confirm atmospheric N2 reduction, and ammonia is detected b...

Injectable materials often have shortcomings in mechanical and drug-eluting properties that are attributable to their high water contents. A water-free, liquid four-armed PEG modified with dopamine end groups is described which changed from liquid to elastic solid by reaction with a small volume of Fe3+ solution. The elastic modulus and degradation times increased with increasing Fe3+ concentra...

We present results of first-principles calculations of structural, magnetic, and electronic properties of small Fe clusters. It is shown that, while the lowest-energy isomers of Fe3 and Fe4 obtained in the framework of density functional theory within the generalized gradient approximation (GGA) are characterized by Jahn-Teller-like distortions away from the most regular shapes (which is in agr...

The weak mechanical properties of hydrogels due to the inefficient dissipation energy in intrinsic structures limit their practical applications. Here, a double-network (DN) hydrogel has been developed by integrating an ionically cross-linked agar network, covalently acrylic acid (AAC) and dynamic reversible coordination between AAC chains Fe3+ ions. proposed model reveals mechanisms improved p...