Synthesis and characterization of new Co(III) mixed-ligand complexes, containing 2-hydroxy-aryloximes and α-diimines. Crystal and molecular structure of [Co(saox)(bipy)2]Br

Lalia‐Kantouri, Maria; Papadopoulos, Christos D.; Quirós, Miguel; Hatzidimitriou, Antonios G.

doi:10.1016/j.poly.2006.10.047

Cited by 23 publications

(11 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…ZINDO has been successfully applied to simulate the spin states and the electronic spectra of transition metal complexes with an accuracy comparable to that of DFT (time-dependent DFT for spectra) (21)(22)(23). The Heisenberg spin Hamiltonian and the resulting spin states of polynuclear transition metal complexes computed with ZINDO agree well with the experimental data (24).…”

mentioning

confidence: 73%

Electron tunneling in respiratory complex I

Hayashi

Stuchebrukhov

2010

Proc. Natl. Acad. Sci. U.S.A.

119

120

View full text Add to dashboard Cite

NADH:ubiquinone oxidoreductase (complex I) plays a central role in the respiratory electron transport chain by coupling the transfer of electrons from NADH to ubiquinone to the creation of the proton gradient across the membrane necessary for ATP synthesis. Here the atomistic details of electronic wiring of all Fe/S clusters in complex I are revealed by using the tunneling current theory and computer simulations; both density functional theory and semiempirical electronic structure methods were used to examine antiferromagnetically coupled spin states and corresponding tunneling wave functions. Distinct electron tunneling pathways between neighboring Fe/S clusters are identified; the pathways primarily consist of two cysteine ligands and one additional key residue. Internal water between protein subunits is identified as an essential mediator enhancing the overall electron transfer rate by almost three orders of magnitude to achieve a physiologically significant value. The identified key residues are further characterized by sensitivity of electron transfer rates to their mutations, examined in simulations, and their conservation among complex I homologues. The unusual electronic structure properties of Fe 4 S 4 clusters in complex I explain their remarkable efficiency of electron transfer.electron transfer in proteins | respiratory chain | iron-sulfur clusters N ADH:ubiquinone oxidoreductase (complex I) is a large L-shaped membrane-bound enzyme involved in cellular respiration that catalyzes the oxidation of NADH and the reduction of ubiquinone in mitochondria and respiring bacteria (1-3). This reaction involves the transfer of electrons over approximately 90 Å from NADH bound to the hydrophilic domain to ubiquinone in or near the hydrophobic membrane-bound domain of complex I (4). In turn, the reaction provides the driving force for translocation of four protons across the membrane, thus generating, in part, the proton gradient necessary for ATP synthesis (5). Complex I defects are the cause of several neurodegenerative diseases including Parkinson disease, Alzheimer's disease, and Huntington disease (6).The transfer of electrons from NADH to ubiquinone is facilitated by flavin mononucleotide (FMN), two binuclear (2Fe-2S) iron-sulfur clusters (N1a and N1b), and six tetranuclear (4Fe-4S) iron-sulfur clusters (N3, N4, N5, N6a, N6b, and N2) (Fig. 1A). NADH, a two-electron donor, initially passes both electrons, as hydride, to the FMN cofactor. From FMN one electron enters a transport chain leading to the ubiquinone-binding site; the second electron enters a side path to N1a that appears to serve as a control mechanism to prevent generation of superoxide ions (4).The crystal structure of hydrophilic domain of complex I from Thermus thermophilus was reported in 2006 (4), and recently the whole architecture of the enzyme has been revealed (7); however, until now, the atomistic details of electron transfer along the chain of Fe/S metal clusters have remained unknown. Recently, a hopping (stepwise) electron transfer (...

show abstract

mentioning

confidence: 73%

Electron tunneling in respiratory complex I

Hayashi

Stuchebrukhov

2010

Proc. Natl. Acad. Sci. U.S.A.

119

120

View full text Add to dashboard Cite

show abstract

“…[95][96][97] For [Co III (saox)(bipy) 2 ] + (22; H 2 saox = salicylaldoxime), specific solvent-solute interactions cause changes in Δ oct that in turn, affect the energies of the 1 A 1g → 3 T 1g and 1 A 1g → 3 T 2g transitions. 98 In this case, the band wavelengths do not correlate with any of the solvatochromic parameters discussed earlier. When a correlation can be made, it is possible to draw insights into the solvent-solute interactions, for example, in the case of [Co III nonane-N,N′,N″-tripropionate), in which the dependency of ν max on the solvent acceptor number was attributed to effects in the second coordination sphere.…”

Section: Solvatochromism In Non-redoxisomeric Cobalt Complexesmentioning

confidence: 65%