Three bonding modes of bis(2-picolyl)phenylphosphine at iron: isolation of a dinuclear iron complex featuring dearomatized pyridine moieties

2015 ◽  
Vol 44 (16) ◽  
pp. 7500-7505 ◽  
Author(s):  
G. Jin ◽  
L. Vendier ◽  
Y. Coppel ◽  
S. Sabo-Etienne ◽  
S. Bontemps
Keyword(s):  
Iron Complexes ◽  
Iron Complex ◽  
Coordination Modes ◽  
Dinuclear Iron

Three iron complexes displaying different coordination modes of the NPN ligand were isolated, including one dinuclear compound featuring dearomatized pyridine moieties.

scholarly journals Water oxidation catalyzed by molecular di- and nonanuclear Fe complexes: importance of a proper ligand framework

2016 ◽  
Vol 45 (34) ◽  
pp. 13289-13293 ◽  
Author(s):  
Biswanath Das ◽  
Bao-Lin Lee ◽  
Erik A. Karlsson ◽  
Torbjörn Åkermark ◽  
Andrey Shatskiy ◽  
...  
Keyword(s):  
Water Oxidation ◽  
Iron Complexes ◽  
Iron Complex ◽  
Oxidation Catalysts ◽  
Dinuclear Iron ◽  
Fe Complexes

The synthesis of two molecular iron complexes, a dinuclear iron(iii,iii) complex and a nonanuclear iron complex, and their use as water oxidation catalysts is described.

scholarly journals Neutrophil Gelatinase-Associated Lipocalin Expresses Antimicrobial Activity by Interfering with l-Norepinephrine-Mediated Bacterial Iron Acquisition

2010 ◽  
Vol 54 (4) ◽  
pp. 1580-1589 ◽  
Author(s):  
Marcus Miethke ◽  
Arne Skerra
Keyword(s):  
Iron Acquisition ◽  
Primary Source ◽  
Iron Complexes ◽  
Iron Complex ◽  
Immune Defense ◽  
Uptake System ◽  
Iron Chelate ◽  
Neutrophil Gelatinase Associated Lipocalin ◽  
Bacterial Uptake ◽  
Neutrophil Gelatinase

ABSTRACT l-norepinephrine (NE) is a neuroendocrine catecholamine that supports bacterial growth by mobilizing iron from a primary source such as holotransferrin to increase its bioavailability for cellular uptake. Iron complexes of NE resemble those of bacterial siderophores that are scavenged by human neutrophil gelatinase-associated lipocalin (NGAL) as part of the innate immune defense. Here, we show that NGAL binds iron-complexed NE, indicating physiological relevance for both bacterial and human iron metabolism. The fluorescence titration of purified recombinant NGAL with the FeIII·(NE)3 iron complex revealed high affinity for this ligand, with a K D of 50.6 nM. In contrast, the binding protein FeuA of Bacillus subtilis, which is involved in the bacterial uptake of triscatecholate iron complexes, has a K D for FeIII·(NE)3 of 1.6 μM, indicating that NGAL is an efficient competitor. Furthermore, NGAL was shown to inhibit the NE-mediated growth of both E. coli and B. subtilis strains that either are capable or incapable of producing their native siderophores enterobactin and bacillibactin, respectively. These experiments suggest that iron-complexed NE directly serves as an iron source for bacterial uptake systems, and that NGAL can function as an antagonist of this iron acquisition process. Interestingly, a functional FeuABC uptake system was shown to be necessary for NE-mediated growth stimulation as well as its NGAL-dependent inhibition. This study demonstrates for the first time that human NGAL not only neutralizes pathogen-derived virulence factors but also can effectively scavenge an iron-chelate complex abundant in the host.

Nucleophilic addition to di- and poly-iron arene complex cations

1996 ◽  
Vol 74 (11) ◽  
pp. 2073-2082 ◽  
Author(s):  
Alaa S. Abd-Ei-Aziz ◽  
Debbie A. Armstrong ◽  
Shelly Bernardin ◽  
Harold M. Hutton
Keyword(s):  
Nucleophilic Addition ◽  
Iron Complexes ◽  
Iron Complex ◽  
Cyanide Anion ◽  
Meta Position ◽  
Arene Complex ◽  
Nmr Techniques ◽  
Cyano Groups ◽  
Predominant Effect

Hydride and cyanide addition to a series of di- and polycyclopentadienyliron arene complex cations with etheric bridges is described. Reaction of the di-iron complexes with sodium borohydride resulted in the formation of a number of adducts.p-Methyl- and o,o-dimethylphenoxybenzene cyclopentadienyliron complexes were used as models in this study to allow for the characterization of the analagous di-iron complexes. The use of HH COSY and CH COSY NMR techniques enabled us to identify the isomeric nature of these adducts. The hydride addition results indicated that the etheric substituent had the predominant effect over the methyl group, leading to a higher addition ratio to the meta-, followed by the ortho-, then the para-positions. It was also clear that in the di-iron system, the hydride addition to each complexed arene ring took place independently. The addition of the cyanide anion to di- and poly-iron arene systems was more selective than that of the hydride anion. Reaction of sodium cyanide with p-methyl- or o-methyl-substituted arene complexes led to the formation of one adduct, with the cyanide being added to the meta position to the etheric bridges. However, cyanide addition to the di-iron complex, with a methyl substituent attached at the meta position of each complexed arene, led to the formation of a mixture of adducts. Cyanide addition to the poly-iron system with p-substituted arenes proved to be very selective, allowing for the formation of one adduct. Oxidative demetallation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) produced the uncomplexed polyaromatic ethers with cyano groups in a very good yield. Key words: cyclopentadienyliron, arene, nucleophilic addition, hydride, cyanide.

A water-oxidizing dinuclear iron complex as an efficient catalyst toward organic sulfide oxidation

2014 ◽  
Vol 67 (18) ◽  
pp. 3026-3032 ◽  
Author(s):  
Mojtaba Amini ◽  
Mohammad Mahdi Najafpour ◽  
Maryam Zare ◽  
Małgorzata Hołyńska ◽  
Atefeh Nemati Moghaddam ◽  
...  
Keyword(s):  
Sulfide Oxidation ◽  
Iron Complex ◽  
Efficient Catalyst ◽  
Organic Sulfide ◽  
Dinuclear Iron

Synthesis of coupling dinuclear iron complexes from μ-N-(2-oxo-2-methylethanaminato)-μ-N′-(dimethylamino)-Fe2(CO)5 complex with acetylene derivatives

2000 ◽  
Vol 613 (1) ◽  
pp. 132-135 ◽  
Author(s):  
Cecilio Alvarez Toledano ◽  
Arturo Rodrı́guez Jiménez ◽  
Mónica Moya Cabrera ◽  
Elena I Klimova ◽  
Noé Rosas Espinosa ◽  
...  
Keyword(s):  
Iron Complexes ◽  
Dinuclear Iron ◽  
Acetylene Derivatives

β-Acylvinyl-dicarbonyl-η5-cyclopentadienyl-eisen-Komplexe / β-Acylvinyl-dicarbonyl-η5-cyclopentadienyl-iron Complexes

1990 ◽  
Vol 45 (6) ◽  
pp. 833-847 ◽  
Author(s):  
Rudolf Gompper ◽  
Eduard Kottmair
Keyword(s):  
Spectral Data ◽  
Oxalyl Chloride ◽  
Iron Complexes ◽  
Iron Complex ◽  
Cyclopentadienyliron Complexes ◽  
Binuclear Iron

Reactions of β-chlorovinylcarbonyl compounds 10, 14, 16, 18, 20, 22, with sodium dicarbonyl-η5-cyclopentadienyl-ferrate (NaFp) furnish β-acylvinyl-dicarbonyl-η5-cyclopentadienyliron complexes 15, 17, 19, 21, 23 and binuclear iron complexes 26-29. Spectral data demonstrate the donor effect of the Fp group. Irradiation of these complexes in the presence of triphenylphosphane delivers β-acylvinyl-carbonyl-η5-cyclopentadienyl-triphenylphosphane-iron complexes 34, 35. Reaction of glutarimides with oxalyl chloride gives rise to oxazolo-[3,2 a]pyridines 13. Benzylidenemalonyl chloride reacts with FpCS2Na to form benzylidenethietane-2,4-dione (32). A β-acylethinyl-carbonyl-η5-dicyclopentadienyl-iron complex 43 has been prepared.

scholarly journals Low-molecular-mass iron complexes in blood plasma of iron-deficient pigs do not originate directly from nutrient iron

Metallomics ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1900-1911 ◽  
Author(s):  
Nathaniel Dziuba ◽  
Joanne Hardy ◽  
Paul A. Lindahl
Keyword(s):  
Blood Plasma ◽  
Molecular Mass ◽  
Iron Complexes ◽  
Iron Complex ◽  
Iron Deficient ◽  
In Blood Plasma

This study aims to detect a nutrient-derived iron complex called NTBI in blood but detected complexes originate from internal stores.

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