If O2 is available at circumneutral pH, Fe(2+) is rapidly oxidized to Fe(3+), which precipitates as FeO(OH). Neutrophilic iron oxidizing bacteria have evolved mechanisms to prevent self-encrustation in iron. Hitherto, no mechanism has been proposed for cyanobacteria from Fe(2+)-rich environments; these produce O2 but are seldom found encrusted in iron. We used two sets of illuminated reactors c...

[Fe-Fe]-hydrogenases are enzymes that reversibly catalyze the reaction of protons and electrons to molecular hydrogen, which occurs in anaerobic media. In living systems, [Fe-Fe]-hydrogenases are mostly used for H(2) production. The [Fe-Fe]-hydrogenase H-cluster is the active site, which contains two iron atoms. The latest theoretical investigations1,2 advocate that the structure of di-iron air...

We have measured dielectronic recombination (DR) resonance strengths and energies for carbon-like Fe xxi forming Fe xx and for boron-like Fe xxii forming Fe xxi via N 1⁄4 2 ! N 0 1⁄4 2 core excitations. All measurements were carried out using the heavy-ion Test Storage Ring at the Max-Planck-Institute for Nuclear Physics in Heidelberg, Germany. We have also calculated these resonance strengths ...

First principles studies on the ground state structure, binding energy, spin multiplicity, and the noncollinearity of local spin moments in Fe(n) and Fe(n) (-) clusters and their oxides, viz., Fe(n)O(2) and Fe(n)O(2) (-) have been carried out within a density functional formalism. The ground states of Fe(n) and Fe(n) (-) clusters have collinear spins with a magnetic moment of around 3.0 micro(B...

To achieve cellular iron deprivation by chelation, it is important to develop chelators with selective metal-binding properties. Selectivity for iron has long been the province of certain oxygen-donor chelators such as desferrioxamine, which target Fe(III) and exploit the strength of a relatively ionic Fe(III)-O interaction. We have been studying novel chelators that possess mechanisms to selec...

The title compound, [Fe(C(12)H(8)N(2))(3)][Fe(2)Cl(6)O]·0.5CH(3)CH(2)OH, consists of one [Fe(phen)(3)](2+) cation (phen = 1,10-phen-anthroline), one [Fe(2)Cl(6)O](2-) anion and one half-mol-ecule of ethanol. In the cation, the Fe(II) atom is coordinated by six N atoms from three phen ligands in a distorted octa-hedral geometry. In the bent anion, two Fe(III) atoms are connected by a bridging ox...

The title compound, [Fe(4)(C(6)H(6)NS)(CH(3)S)S(CO)(11)], com-prises two butterfly-shaped sub-cluster cores, Fe(2)S(2)N and Fe(2)S(2), joined together by a spiro-type μ(4)-S atom. The (pyridin-2-yl)methane-thiol-ate ligand is attached to the Fe(2)(CO)(5) unit in a μ-κN:κ(2)S mode, and the methane-thiol-ate ligand is coordinated to the Fe(2)(CO)(6) unit in a μ-κ(2)S fashion.

The weak-field ligand environments at the metal nodes of metal-organic frameworks (MOFs) mimic the electronic environment of metalloenzyme active sites, but little is known about the reactivity of MOF nodes toward small molecules of biological relevance. Here, we report that the ferrous ions in Fe(2+)-exchanged MOF-5 disproportionate nitric oxide to produce nitrous oxide and a ferric nitrito co...

In the centrosymmetric dimeric title complex, [Fe(2)(C(14)H(10)N(2)O(4))(2)Cl(2)(C(2)H(6)OS)(2)]·2C(2)H(6)OS, two {Fe(L)Cl(DMSO)} units (L is the tridentate ligand 4-nitro-2-{[2-(oxidometh-yl)phen-yl]imino-meth-yl}phenolate; DMSO is dimethyl sulfoxide) are bridged by two O atoms, with an Fe⋯Fe separation of 3.1838 (8) Å. The coordination polyhedron of the Fe(III) atoms can be described as disto...