The dinuclear title compound, [Fe(2)(C(2)H(4)S(2))(C(24)H(20)OP(2))(CO)(5)] or (μ-SCH(2)CH(2)S-μ)Fe(2)(CO)(5)[Ph(2)PP(O)Ph(2)], con-tains a butterfly-shaped Fe(2)S(2) core in which the Fe⋯Fe separation is 2.5275 (6) Å. One of the Fe atoms is also coordinated to three carbonyl ligands and the other to two carbonyl ligands and one phosphane ligand [Ph(2)PP(O)Ph(2)]. Both Fe-atom geometries could ...

The superoxide dismutase (SOD) activity of iron(II) tetrakis-N,N,N',N'(2-pyridylmethyl)ethylenediamine complex (Fe-TPEN) was reexamined using a pulse radiolysis method. In our previous study (J. Biol. Chem., 264, 9243-9249 (1989)), we reported that this complex has a potent SOD activity in a cyt. c (cytochrome c)-based system (IC50 = 0.8 microM) and protects E. coli cells against paraquat toxic...

Cross-couplings of alkyl halides and organometallic species based on single electron transfer using Ni and Fe catalyst systems have been studied extensively, and separately, for decades. Here we demonstrate the first couplings of redox-active esters (both isolated and derived in situ from carboxylic acids) with organozinc and organomagnesium species using an Fe-based catalyst system originally ...

A crystal structure of the anaerobic Ni-Fe-S carbon monoxide dehydrogenase (CODH) from Rhodospirillum rubrum has been determined to 2.8-A resolution. The CODH family, for which the R. rubrum enzyme is the prototype, catalyzes the biological oxidation of CO at an unusual Ni-Fe-S cluster called the C-cluster. The Ni-Fe-S C-cluster contains a mononuclear site and a four-metal cubane. Surprisingly,...

Single crystals of the iron tetrapolyvanadate Fe(2)V(4)O(13) and the iron polyvanadomolybdate Fe(2)V(3.16)Mo(0.84)O(13.42) were grown from Fe(2)O(3)/V(2)O(5) and Fe(2)O(3)/V(2)O(5)/MoO(3) melts, respectively. Single-crystal X-ray diffraction revealed that the two structures are closely related. Both contained isolated Fe(2)O(10) octahedral dimers with similar orientations. The unusual U-shaped ...

A series of monocarbonyl iron complexes in the formal oxidation states 0, +1, and +2 are accessible when supported by a tetradentate tris(phosphino)silyl ligand (SiP(iPr)(3) = [Si(o-C(6)H(4)PiPr(2))(3)](-)). X-ray diffraction (XRD) studies of these carbonyl complexes establish little geometrical change about the iron center as a function of oxidation state. It is possible to functionalize the t...

Proposed electrocatalytic proton reduction intermediates of hydrogenase mimics were synthesized, observed, and studied computationally. A new mechanism for H(2) generation appears to involve Fe(2)(CO)(6)(1,2-S(2)C(6)H(4)) (3), the dianions {[1,2-S(2)C(6)H(4)][Fe(CO)(3)(μ-CO)Fe(CO)(2)](2-) (3(2-)), the bridging hydride {[1,2-S(2)C(6)H(4)][Fe(CO)(3)(μ-CO)(μ-H)Fe(CO)(2)]}(-), 3H(-)(bridging), and ...

An iron-based ionic liquid, Fe((OHCH(2)CH(2))(2)NH)(6)(CF(3)SO(3))(3), is synthesized in a single-step complexation reaction. Infrared and Raman data suggest NH(CH(2)CH(2)OH)(2) primarily coordinates to Fe(iii) through alcohol groups. The compound has T(g) and T(d) values of -64 degrees C and 260 degrees C, respectively. Cyclic voltammetry reveals quasi-reversible Fe(iii)/Fe(ii) reduction waves.

The effect of prolonged consumption of guar gum on iron absorption and Fe status was investigated in rats. Experiments with closed loops of duodenum, isolated in situ, were designed to reveal changes in the short-term regulation of duodenal Fe uptake, induced by challenge with low- and high-Fe meals. In separate experiments, the effect of guar gum on the capacity of intact rats to maintain Fe s...