The potentially tridentate ligand 2-pyridinecarbaldehyde isonicotinoyl hydrazone (HPCIH) and its analogues are an emerging class of orally effective Fe chelators that show great promise for the treatment of Fe overload diseases. Herein, we present an extensive study of the Fe coordination chemistry of the HPCIH analogues including the first crystallographically characterised Fe(II) complex of t...

Bacterial reduction of a hematite-rich natural coastal sand was studied in flow-through column reactors at flow rates which varied from 0.62 to 11 pore volumes d(-1). Sand columns were wet-packed with the dissimilatory metal-reducing bacterium (DMRB) Shewanella putrefaciens CN32, and a PIPES-buffered, lactate-containing growth medium was pumped through the columns for over 20 days. Soluble Fe(I...

The enrichment of Fe, relative to alpha-elements such as O and Mg, represents a potential means to determine the age of quasars and probe the galaxy formation epoch. To explore how Fe II emission in quasars is linked to physical conditions and abundance, we have constructed a 830-level Fe II model atom and investigated through photoionization calculations how Fe II emission strengths depend on ...

A noticeable increase in molecular complexity of drug targets has created an unmet need in the therapeutic agents that are larger than traditional small molecules. Macrocycles, which are cyclic compounds comprising 12 atoms or more, are now recognized as molecules that "are up to the task" to interrogate extended protein interfaces. However, because macrocycles (particularly the ones based on p...

Formation of Fe(II)-As(III) solids is suspected to limit dissolved As concentrations in anaerobic environments. Iron(II) precipitates enriched in As(III) have been observed after microbial reduction of As(V)-loaded lepidocrocite (γ-FeOOH) and symplesite (Fe(II)(As(V)O)]·8HO) and upon abiotic reaction of Fe(II) with As(III). However, the conditions favorable for Fe(II)-As(III) precipitation and ...

A steel-slag/compost fertilizer can be useful in supplying complex Fe(II) species to barren coastal regions. Seawater extractable organic matter (SWEOM) was examined for use as a novel chelator of Fe(II) in the compost. The dissociation kinetics for Fe(II)-SWEOM were evaluated, based on the rate of ligand-exchange with ortho-phenanthroline. The ΔH(‡) for the Fe(II)-SWEOM (19 kJ mol(-1)) was sig...

{Cp*(dppe)Fe(C≡C-)}(2)(1,3-C(6)H(4)) is studied both as a neutral molecule, Fe(II)-Fe(II), and as a mixed-valence complex, Fe(II)-Fe(III). Scanning tunneling microscopy (STM) is used to image these species at 77 K under ultrahigh-vacuum conditions. The neutral molecule Fe(II)-Fe(II) has a symmetric, "dumbbell" appearance in STM images, while the mixed-valence complex Fe(II)-Fe(III) demonstrates...

Seven reported xanthate ligands and their new Fe(II) complexes of formulaNa[Fe(R-OCSS)3], where R is ethyl-, propyl-, butyl-, pentyl-, Hexyl-, heptyl- and octyl-xanthate have been synthesized. They have been characterized using elemental analysis, molar conductance, FT-IR, UV-Vis and 1H NMR spectroscopic techniques and melting-, decomposition-points for ligand...

Abiotic reduction of 0.1 mM U(VI) by Fe(II) in the presence of synthetic iron oxides (biogenic magnetite, goethite, and hematite) and natural Fe(III) oxide-containing solids was investigated in pH 6.8 artificial groundwater containing 10 mM NaHCO3. In most experiments, more than 95% of added U(VI) was sorbed to solids. U(VI) was rapidly and extensively (> or = 80%) reduced in the presence of sy...

Ferritin is a nanocage protein made of 24 subunits. Its major role is to manage intracellular concentrations of free Fe(ii) and Fe(iii) ions, which is pivotal for iron homeostasis across all domains of life. This function of the protein is regulated by a conserved di-iron catalytic center and has been the subject of extensive studies over the past 50 years. Yet, it has not been fully understood...