New Findings in the Chemistry of Iron Carbonyls: The Previously Unreported [H4−nFe4(CO)12]n− (n = 1, 2) Series of Clusters,
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- 作者：Cristina Femoni ; Maria Carmela Iapalucci ; Giuliano Longoni ; Stefano Zacchini ; Salvatore Zarra
- 刊名：Inorganic Chemistry
- 出版年：2009
- 出版时间：February 16, 2009
- 年：2009
- 卷：48
- 期：4
- 页码：1599-1605
- 全文大小：180K
- 年卷期：v.48,no.4(February 16, 2009)
- ISSN：1520-510X
文摘
The new [HFe4(CO)12]3− cluster anion has been obtained in high yields by reduction of [Fe4(CO)13]2− or [HFe3(CO)11]− with a 6 M methylalcoholic KOH solution under a nitrogen atmosphere and isolated with miscellaneous tetrasubstituted ammonium salts. The [NEt4]3[HFe4(CO)12] salt has been characterized by IR, 1H and 13C NMR, electrospray ionization mass spectrometry, and X-ray studies. Investigation of its protonation reaction afforded spectroscopic proof for the existence of its unstable isomeric [HFe4(CO)11(CO-H)]2− and [H2Fe4(CO)12]2− conjugated acids. The latter is probably isostructural with the [H2Ru4(CO)12]2− congener. The nature of the first protonation product as a [HFe4(CO)11(CO-H)]2− adduct, involving an oxygen-bound proton, has been corroborated by the preparation and spectroscopic characterization of the corresponding [HFe4(CO)11(CO-Me)]2− dianion. The above findings demonstrate that protonation of a CO-shielded polynuclear metal anion initially occurs on one oxygen atom and then the oxygen-bound proton migrates to the metal cage. Finally, [HFe4(CO)12]3− and its [H2Fe4(CO)12]2− conjugate acid fill the previously existing gap between the chemistry of iron carbonyls and ruthenium and osmium congeners.