The rare earth iron garnets RE3Fe5O12 (REIG hereafter) have been discovered at Grenoble (France) (Bertaut & Forrat, 1956; Bertaut et al., 1956) then independently at Murray Hill (USA) (Geller & Gilleo, 1957a, 1957b). These most studied ferrimagnetic materials have a general formula {RE3+3}[Fe3+2](Fe3+3)O12 where RE3+ can be any trivalent rare earth ion or the Yttrium Y3+. The crystal structure ...

Growth of Bacteroides fragilis under anaerobic conditions in the presence of either haemin or protoporphyrin IX was inhibited by the ferrous iron chelator bipyridyl. The ferric-iron chelator desferrioxamine inhibited growth in the presence of protoporphyrin but not haemin, suggesting that even under anaerobic conditions Fe3+ is involved in uptake of non-haem iron, which is required in the absen...

The title compound, [FeCl2(C12H26N4)]PF6, is the first mononuclear Fe3+ complex of an ethylene cross-bridged tetraaza-macrocycle to be structurally characterized. Comparison with the mononuclear Fe2+ complex of the same ligand shows that the smaller Fe3+ ion is more fully encapsulated by the cavity of the bicyclic ligand. Comparison with the mu-oxo dinuclear complex of an unsubstituted ligand o...

Highly dispersed Fe3+-doped layered double hydroxide (LDH-Fe) nanorings were obtained by a simple coprecipitation-acid etching approach. The morphology, structure, magnetic resonance imaging (MRI) performance in vitro, drug loading and releasing, Fe3+ leakage, and cytotoxicity of the as-prepared LDH-Fe nanorings were characterized. The LDH-Fe nanorings showed good water dispersity and a well-cr...

A new sorbent was synthesized by anchoring 7-amino-4-azaheptyltrimetoxisilane, freshly prepared, to silica gel, producing 7-amino-4-azaheptyl anchored silica gel (AAHSG). This material was characterized by infrared spectroscopy (IR), elemental analysis (CHN), and nitrogen adsorption-desorption isotherms. Isotherms of the adsorption of Fe3+, Fe2+ and Cu2+ on AAHSG were recorded, which indicated ...

In this work, we report a novel iridium(III)-based luminescent switch on-off-on probe, for the in vitro and in vivo detection of sulfide ion. The mechanism of this platform is based on the effective charge transfer quenching of the iridium(III) complex 1 by Fe3+, followed by the restoration of luminescence upon the addition of Na2S. The probe, hereinafter referred to as 1-Fe3+, exhibited a line...

The active site of superoxide reductase SOR consists of an Fe2+ center in an unusual [His4 Cys1] square-pyramidal geometry. It specifically reduces superoxide to produce H2O2. Here, we have reacted the SOR from Desulfoarculus baarsii directly with H2O2. We have found that its active site can transiently stabilize an Fe3+-peroxo species that we have spectroscopically characterized by resonance R...

The cytochrome P450 superfamily of enzymes is ubiquitous, being responsible for the metabolism of a wide range of endogenous and xenobiotic compounds. However, the detailed mechanism of the catalytic cycle of these enzymes is still not fully understood. We describe results, obtained from first principles molecular simulations, which indicate that the low-spin state of the Fe3+ ion, present in t...

The biosynthesis of a yellow-green, fluorescent, water-soluble pigment by Pseudomonas jluorescens occurred only when the bacteria were iron-deficient and was not directly influenced by the nature of the organic carbon source. The pigment formed a very stable Fe3+ complex and was purified in this form. Pseudomonasfluorescens produced only one molecular species of fluorescent pigment; however, it...

Studies were carried out to determine the actions of and interactions between ascorbate, NADPH, Fe2+, and Fe3+ on lipid peroxidation in adrenal and testicular microsomes. Ascorbate-induced malonaldehyde production was maximal in adrenal and testicular microsomes at an ascorbate concentration of 1 X 10(-4)M. Fe2+, at levels between 10(-6) and 10(-3)M, produced concentration-dependent increases i...