Sulfide-bridge iron complex

There are many important mixed valence and fractional formal oxidation state compounds (e.g., Fc304) and complexes of iron. Mixed valence trinuclear /.t-oxo-carboxylato-complexes are dealt with in Section 5.4.5.4.2, polynuclear complexes held together by sulfide bridges in Section 5.4.5.9.2. 

The first example of iron-catalyzed asymmetric oxidation of sulfides was described by Fontecave and coworkers in 1997 [163]. An oxo-bridged diiron complex, which contained (—)-4,5-pinenebipyridine as chiral ligand, was reported to catalyze sulfide oxidations with H202 in acetonitrile, having the potential to transfer an oxygen atom directly to the substrates. However, the enantioselectivity of this process remained rather low (<40% ee, Scheme 3.53). 

A wide variety of synthetic binuclear iron complexes (39) bridged by sulfide, disulfide and/or thiolate groups are known. They have proven to be good models for the two-iron ferredoxin proteins, as demonstrated by comparisons of structure and properties. Early attempts to isolate two-iron complexes by direct reaction of a monothiol with FeCl3, NaSH and NaOMe afforded only four-iron products suggesting that a particularly high stability is associated with the tetrameric... 

Lu TT, Huang HW, Liaw WF (2009) Anionic mixed thiolate-sulfide-bridged Roussin s red esters [(NO)2Fe(p-SR)(p-S)Fe(NO)2] (R = Et, Me, Ph) a key intermediate for transformation of dinitrosyl iron complexes (DNICs) to [2Fe-2S] clusters. Inorg Chem 48 9027-9035... 

Reactivity of dinuclear iron complexes with simple bidentate ligands such as 2,2 -bipyridine and 1,10-phenanthroline for oxidation of alkanes, toluene, dimethyl sulfide, trans-stilbene and adamantane was studied in CHjCN under Ar in the presence of oxidants (TBHP, CHP or H2O2). The effect of the number of the bridging ligand was found remarkable monobridged Fe20(L)4(X)2(C104)4 >... 

The mass spectrum of Fe2(CO)9, long assumed to be completely involatile, shows a parent ion, but the base peak is Fe2(CO) J, with a structure retaining the three bridging carbonyl groups [Fe(CO)3Fe]+ (70). Similar bridged ions containing iron have been postulated in the spectra of some phosphine and sulfide complexes (Section VI). 

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