IRIS – Institutional Research Information System
IRIS è il sistema di gestione della ricerca dell’Università degli Studi di Milano-Bicocca.Il repository BOA è il modulo del sistema dedicato alla raccolta e alla disseminazione della produzione scientifica di Ateneo. Le pubblicazioni sono ricercabili per parola chiave attraverso il box nella barra orizzontale in alto oppure, mediante il pulsante Sfoglia, per "Afferenza", "Autore", "Titolo", "Tipologia" o "Settore scientifico-disciplinare".
IRIS contiene inoltre alcuni moduli dedicati alla registrazione dei progetti e dei contratti, e alla reportistica avanzata per le attività di valutazione della ricerca
EnglishThe reaction of Fe<sub>2</sub>(S<sub>2</sub>C<sub>2</sub>H <sub>4</sub>)(CO)<sub>6</sub> with cis-Ph<sub>2</sub>PCH=CHPPh<sub>2</sub> (dppv) yields Fe<sub>2</sub>(S<sub>2</sub>C<sub>2</sub>H<sub>4</sub>)(CO) <sub>4</sub>(dppv), 1(CO)<sub>4</sub>, wherein the dppv ligand is chelated to a single iron center. NMR analysis indicates that in 1(CO)<sub>4</sub>, the dppv ligand spans axial and basal coordination sites. In addition to the axial-basal isomer, the 1,3-propanedithiolate and azadithiolate derivatives exist as dibasal isomers. Density functional theory (DFT) calculations indicate that the axial-basal isomer is destabilized by nonbonding interactions between the dppv and the central NH or CH<sub>2</sub> of the larger dithiolates. The Fe(CO) <sub>3</sub> subunit in 1(CO)<sub>4</sub> undergoes substitution with PMe <sub>3</sub> and cyanide to afford 1(CO)<sub>3</sub>(PMe<sub>3</sub>) and (EttN)[1(CN)(CO)<sub>3</sub>], respectively. Kinetic studies show that 1(CO)<sub>4</sub> reacts faster with donor ligands than does its parent Fe <sub>2</sub>(S<sub>2</sub>C<sub>2</sub>H<sub>4</sub>)(CO)<sub>6</sub>. The rate of reaction of 1(CO)<sub>4</sub> with PMe<sub>3</sub> was first order in each reactant, k = 3.1 × 10<sup>-4</sup> M<sup>-1</sup> s<sup>-1</sup>. The activation parameters for this substitution reaction, ΔH‡ = 5.8(5) kcal/mol and ΔS‡ = -48(2) cal/deg·mol, indicate an associative pathway. DFT calculations suggest that, relative to Fe <sub>2</sub>(S<sub>2</sub>C<sub>2</sub>H<sub>4</sub>)(CO)<sub>6</sub>, the enhanced electrophilicity of 1(CO)<sub>4</sub> arises from the stabilization of a "rotated" transition state, which is favored by the unsymmetrically disposed donor ligands. Oxidation of MeCN solutions of 1(CO) <sub>3</sub>(PMe<sub>3</sub>) with Cp<sub>2</sub>FePF<sub>6</sub> yielded [Fe<sub>2</sub>(S<sub>2</sub>C<sub>2</sub>H<sub>4</sub>)(μ-CO)(CO) <sub>2</sub>(dppv)(PMe<sub>3</sub>)(NCMe)](PF<sub>6</sub>)<sub>2</sub>. Reaction of this compound with PMe<sub>3</sub> yielded [Fe<sub>2</sub>(S <sub>2</sub>C<sub>2</sub>H<sub>4</sub>)-(μ-CO)(CO)(dppv)(PMe <sub>3</sub>)<sub>2</sub>(NCMe)](PF<sub>6</sub>)<sub>2</sub>. © 2007 American Chemical Society.
| Citazione: | Justice, A.K., Zampella, G., De Gioia, L., Rauchfuss, T.B., van der Vlugt, J.I., & Wilson, S.R. (2007). Chelate control of diiron(I) dithiolates relevant to the [Fe-Fe]-hydrogenase active site. INORGANIC CHEMISTRY, 46(5), 1655-1664. |
| Tipo: | Articolo in rivista - Articolo scientifico |
| Carattere della pubblicazione: | Scientifica |
| Titolo: | Chelate control of diiron(I) dithiolates relevant to the [Fe-Fe]-hydrogenase active site |
| Autori: | Justice, AK; Zampella, G; De Gioia, L; Rauchfuss, TB; van der Vlugt, JI; Wilson, SR |
| Autori: | |
| Data di pubblicazione: | 5-mar-2007 |
| Lingua: | English |
| Rivista: | INORGANIC CHEMISTRY |
| Digital Object Identifier (DOI): | http://dx.doi.org/10.1021/ic0618706 |
| Appare nelle tipologie: | 01 - Articolo su rivista |
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