Browse
Submit Data
Databases
API
Help

Dataset Information

11 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Identification of a Two-Coordinate Iron(I)-Oxalate Complex.

ABSTRACT: Exotic oxidation states of the first-row transition metals have recently attracted much interest. In order to investigate the oxidation states of a series of iron-oxalate complexes, an aqueous solution of iron(III) nitrate and oxalic acid was studied by infrared free liquid matrix-assisted laser desorption/ionization as well as ionspray mass spectrometry. Here, we show that iron is not only detected in its common oxidation states +II and +III, but also in its unusual oxidation state +I, detectable in both positive-ion and in negative-ion modes, respectively. Vibrational spectra of the gas phase anionic iron oxalate complexes [Fe^III (C₂ O₄ )₂ ]^- , [Fe^II (C₂ O₄ )CO₂ ]^- , and [Fe^I (C₂ O₄ )]^- were measured by means of infrared photodissociation spectroscopy and their structures were assigned by comparison to anharmonic vibrational spectra based on second-order perturbation theory.

SUBMITTER: Mayer M

PROVIDER: S-EPMC9303725 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Synthesis and magnetic characterization of a dinuclear complex of low-coordinate iron(II).

Project description:Low-coordinate ions possess exciting magnetic, optical, and reactive properties that may afford novel material physics. Hence, it is important to test both synthetic methods for realizing extended solids of such ions as well as the properties of smaller molecular fragments of envisioned future materials. Herein, we report the synthesis and characterization of a new dinuclear Fe species, [{(Me3Si2)2N}Fe{μ-p-{HN(SiMe3)}(C6Me4){N(SiMe3)}}2Fe{N(SiMe3)2}] (1), formed through a transamination reaction between [Fe{N(SiMe3)2}2]2 and the bulky diamine p-{HN(SiMe3)}2(C6Me4) (L). The Fe centers of this dimer assume a pseudo-trigonal-planar, three-coordinate conformation in 1, bridged by two aromatic diamines. Single-crystal X-ray diffraction, IR spectroscopy, and Mössbauer spectroscopy enable the assignment of both Fe centers as the 2+ oxidation state. Magnetic studies show that 1 displays a weak antiferromagnetic exchange interaction (J = -2.33 cm-1) and moderate zero-field splitting (D = 7.51 cm-1). Importantly, these studies demonstrate the viability of using transamination to bridge high-spin low-coordinate metal ions and hence the technique may, in the future, produce new extended structures.

| S-EPMC8174817 | biostudies-literature

Mesoporous Iron(III)-Doped Hydroxyapatite Nanopowders Obtained via Iron Oxalate.

Project description:Mesoporous hydroxyapatite (HA) and iron(III)-doped HA (Fe-HA) are attractive materials for biomedical, catalytic, and environmental applications. In the present study, the nanopowders of HA and Fe-HA with a specific surface area up to 194.5 m2/g were synthesized by a simple precipitation route using iron oxalate as a source of Fe3+ cations. The influence of Fe3+ amount on the phase composition, powders morphology, Brunauer-Emmett-Teller (BET) specific surface area (S), and pore size distribution were investigated, as well as electron paramagnetic resonance and Mössbauer spectroscopy analysis were performed. According to obtained data, the Fe3+ ions were incorporated in the HA lattice, and also amorphous Fe oxides were formed contributed to the gradual increase in the S and pore volume of the powders. The Density Functional Theory calculations supported these findings and revealed Fe3+ inclusion in the crystalline region with the hybridization among Fe-3d and O-2p orbitals and a partly covalent bond formation, whilst the inclusion of Fe oxides assumed crystallinity damage and rather occurred in amorphous regions of HA nanomaterial. In vitro tests based on the MG-63 cell line demonstrated that the introduction of Fe3+ does not cause cytotoxicity and led to the enhanced cytocompatibility of HA.

| S-EPMC8005114 | biostudies-literature

Mechanistic insight into N=N cleavage by a low-coordinate iron(II) hydride complex.

Project description:The reaction pathways of high-spin iron hydride complexes are relevant to the mechanism of N2 reduction by nitrogenase, which has been postulated to involve paramagnetic iron-hydride species. However, almost all known iron hydrides are low-spin, diamagnetic Fe(II) compounds. We have demonstrated that the first high-spin iron hydride complex, LtBuFeH (LtBu = bulky beta-diketiminate), reacts with PhN=NPh to completely cleave the N-N double bond, giving LtBuFeNHPh. Here, we disclose a series of experiments that elucidate the mechanism of this reaction. Crossover and kinetic experiments rule out common nonradical mechanisms, and support a radical chain mechanism mediated by iron(I) species including a rare eta2-azobenzene complex. Therefore, this high-spin iron(II) hydride can break N-N bonds through both nonradical and radical insertion mechanisms, a special feature that enables novel reactivity.

| S-EPMC2548314 | biostudies-literature

Two mechanisms coordinate replication termination by the Escherichia coli Tus-Ter complex.

Project description:The Escherichia coli replication terminator protein (Tus) binds to Ter sequences to block replication forks approaching from one direction. Here, we used single molecule and transient state kinetics to study responses of the heterologous phage T7 replisome to the Tus-Ter complex. The T7 replisome was arrested at the non-permissive end of Tus-Ter in a manner that is explained by a composite mousetrap and dynamic clamp model. An unpaired C(6) that forms a lock by binding into the cytosine binding pocket of Tus was most effective in arresting the replisome and mutation of C(6) removed the barrier. Isolated helicase was also blocked at the non-permissive end, but unexpectedly the isolated polymerase was not, unless C(6) was unpaired. Instead, the polymerase was blocked at the permissive end. This indicates that the Tus-Ter mechanism is sensitive to the translocation polarity of the DNA motor. The polymerase tracking along the template strand traps the C(6) to prevent lock formation; the helicase tracking along the other strand traps the complementary G(6) to aid lock formation. Our results are consistent with the model where strand separation by the helicase unpairs the GC(6) base pair and triggers lock formation immediately before the polymerase can sequester the C(6) base.

| S-EPMC4499146 | biostudies-literature

A Two-Coordinate Iron(II) Imido Complex with NHC Ligation: Synthesis, Characterization, and Its Diversified Reactivity of Nitrene Transfer and C-H Bond Activation.

Project description:Iron terminal imido species are typically implicated as reaction intermediates in iron-catalyzed transformations. While a large body of work has been devoted to mid- and high-valent iron imidos, to date the chemistry of iron(II) imidos has remained largely unexplored due to the difficulty in accessing them. Herein, we present a study on the two-coordinate iron(II) imido complex [(IPr)Fe(NArTrip)] (3; IPr = 1,3-bis(2',6'-diisopropylphenyl)imidazol-2-ylidene; ArTrip = 2,6-bis(2',4',6'-triisopropylphenyl)phenyl) prepared from the reaction of an iron(0) complex with the bulky azide ArTripN3. Spectroscopic investigations in combination with DFT calculations established a high-spin S = 2 ground spin state for 3, consistent with its long Fe-N multiple bond of 1.715(2) Å revealed by X-ray diffraction analysis. Complex 3 exhibits unusual activity of nitrene transfer and C-H bond activation in comparison to the reported iron imido complexes. Specifically, the reactions of 3 with CH2?CHArCF3, an electron-deficient alkene, and CO, a strong ? acid, readily afford nitrene transfer products, ArCF3CH?CHNHArTrip and ArTripNCO, respectively, yet no similar reaction occurs when 3 is treated with electron-rich alkenes and PMe3. Moreover, 3 is inert toward the weak C(sp3)-H bonds in 1,4-cyclohexadiene, THF, and toluene, whereas it can cleave the stronger C(sp)-H bond in p-trifluoromethylphenylacetylene to form an iron(II) amido alkynyl complex. Interestingly, intramolecular C(sp3)-H bond functionalization was observed by adding ( p-Tol)2CN2 to 3. The unique reactivity of 3 is attributed to its low-coordinate nature and the high negative charge population on the imido N atom, which render its iron-imido unit nucleophilic in nature.

| S-EPMC6750749 | biostudies-literature

Crystal structures of two new six-coordinate iron(III) complexes with 1,2-bis(diphenyl-phosphane) ligands.

Project description:Structural characterization of the ionic complexes [FeCl2(C26H22P2)2][FeCl4]·0.59CH2Cl2 or [(dppen)2FeCl2][FeCl4]·0.59CH2Cl2 (dppen = cis-1,2-bis-(di-phenyl-phosphane)ethyl-ene, P2C26H22) and [FeCl2(C30H24P2)2][FeCl4]·CH2Cl2 or [(dpbz)2FeCl2][FeCl4]·CH2Cl2 (dpbz = 1,2-bis-(di-phenyl-phosphane)benzene, P2C30H24) demonstrates trans coordination of two bidentate phosphane ligands (bis-phosphanes) to a single iron(III) center, resulting in six-coordinate cationic complexes that are balanced in charge by tetra-chlorido-ferrate(III) monoanions. The trans bis-phosphane coordination is consistent will all previously reported mol-ecular structures of six coordinate iron(III) complex cations with a (PP)2X2 (X = halido) donor set. The complex with dppen crystallizes in the centrosymmetric space group C2/c as a partial-occupancy [0.592?(4)] di-chloro-methane solvate, while the dpbz-ligated complex crystallizes in the triclinic space group P1 as a full di-chloro-methane monosolvate. Furthermore, the crystal studied of [(dpbz)2FeCl2][FeCl4]·CH2Cl2 was an inversion twin, whose component mass ratio refined to 0.76?(3):0.24?(3). Beyond a few very weak C-H?Cl and C-H?? inter-actions, there are no significant supra-molecular features in either structure.

| S-EPMC6002827 | biostudies-other

Electronic, magnetic, and structural characterization of the five-coordinate, high-spin iron(II) nitrato complex [Fe(TpivPP)(NO3)]-.

Project description:The preparation and characterization of the five-coordinate iron(II) porphyrinate derivative [Fe(TpivPP)(NO3)]- (TpivPP = picket-fence porphyrin) is described. Structural and magnetic susceptibility data support a high-spin state (S = 2) assignment for this species. The anionic axial nitrate ligand is O-bound, through a single O atom, with an Fe-O bond length of 2.069(4) A. The planar nitrate ligand bisects a N(p)-Fe-N(p) angle. The average Fe-N(p) bond length is 2.070(16) A. The Fe atom is located 0.49 A out of the 24-atom mean porphyrin plane toward the nitrate ligand. From solid-state Mössbauer data, the isomer shift of 0.98 mm/s at 77 K is entirely consistent with high-spin iron(II). However the quadrupole splitting of 3.59 mm/s at 77 K is unusually high for iron(II), S = 2 systems but within the range of other five-coordinate high-spin ferrous complexes with a single anionic axial ligand. Crystal data for [K(222)][Fe(TpivPP)(NO3)] x C6H5Cl: a = 17.888 (5) A, b = 21.500 (10) A, c = 22.514 (11) A, beta = 100.32 (3) degrees, monoclinic, space group P2(1)/n, V = 8519 A3, Z = 4.

| S-EPMC1501086 | biostudies-literature

Two mechanisms coordinate the recruitment of the chromosomal passenger complex to the plane of cell division.

Project description:During cytokinesis, the chromosomal passenger complex (CPC) promotes midzone organization, specifies the cleavage plane, and regulates furrow contractility. The localizations of the CPC are coupled to its cytokinetic functions. At the metaphase-to-anaphase transition, the CPC dissociates from centromeres and localizes to midzone microtubules and the equatorial cortex. CPC relocalization to the cell middle is thought to depend on MKlp2-driven, plus end-directed transport. In support of this idea, MKlp2 depletion impairs cytokinesis; however, cytokinesis failure stems from furrow regression rather than failed initiation of furrowing. This suggests that an alternative mechanism(s) may concentrate the CPC at the division plane. We show here that direct actin binding, via the inner centromere protein (INCENP), enhances CPC enrichment at the equatorial cortex, thus acting in tandem with MKlp2. INCENP overexpression rescues furrowing in MKlp2-depleted cells in an INCENP-actin binding-dependent manner. Using live-cell imaging, we also find that MKlp2-dependent targeting of the CPC is biphasic. MKlp2 targets the CPC to the anti-parallel microtubule overlap of the midzone, after which the MKlp2-CPC complex moves in a nondirected manner. Collectively, our work suggests that both actin binding and MKlp2-dependent midzone targeting cooperate to precisely position the CPC during mitotic exit, and that these pathways converge to ensure successful cleavage furrow ingression.

| S-EPMC5706991 | biostudies-literature

Persistent four-coordinate iron-centered radical stabilized by ?-donation.

Project description:Dinuclear iron carbonyl complex 2, which contains an elongated unsupported Fe-Fe bond, was synthesized by the reaction between Fe2(CO)9 and phosphinyl radical 1. Thermal Fe-Fe bond homolysis led to the generation of a four-coordinate carbonyl-based iron-centered radical, 3, which is stabilized by ?-donation. Complex 3 exhibited high reactivity toward organic radicals to form diamagnetic five-coordinate Fe(ii) complexes.

| S-EPMC5515065 | biostudies-literature

Diazoalkanes in Low-Coordinate Iron Chemistry: Bimetallic Diazoalkyl and Alkylidene Complexes of Iron(II).

Project description:The addition of (trimethylsilyl)diazomethane and its conjugate base to iron ?-diketiminate precursors gives novel dinuclear complexes in which the bridges are either diazomethane derivatives or an alkylidene. One product is an unusual bridging alkylidene complex containing two three-coordinate iron(II) centers. On the other hand, syntheses using the deprotonated diazomethane give two bridging diazomethyl species with binding modes that have not been observed in iron complexes previously. In the presence of a coordinating tetrahydrofuran solvent, a diiron(II) compound with ?-N bridges rearranges to a more stable isomer with ?-N,C bridges, a process that is accompanied by a 1,3-shift of a silyl group.

| S-EPMC5499981 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data