Triiron complexes

CO species in the adducted triiron complexes, the propargylidene-ketene compoimd has e same structure as compound 5 (ii) desilylation by the substitution of the silyl termin species with the ion originating from H2O or the solvent gives the hydrogen-ketene form. 

We cite here two examples of triiron complexes which can depict well the possible intramolecular electronic interactions in polymetallic complexes. First of all we take into account that, as discussed in Chapter 2, Section 1.5.1 and Chapter 4, Section 1.3, from the electrochemical viewpoint, the existence of a mutual electronic (through-space or through-bond) interaction in molecules containing two or more redox-active centres leads to the appearance of separate electron transfer processes. There are, however, two main classes of polynuclear molecules ... 

Reactions between salts of [m Jo-7-CBioHi3] and [Fc3(CO)i2] afford the mononuclear anionic iron compound [2,2,2-(CO)3-c/o5o-2,l-FeCBioHn], typically isolated as its [N(PPh3)2] salt (11) (Chart 4). No anionic triiron complex analogous to 5 and 7 is formed in this reaction. The anionic mononuclear iron, ruthenium and osmium complexes and the previously mentioned neutral mononuclear ruthenium dicarbollide complex 4, obtained from [Ru3(CO)i2] and /Jo-7,8-C2BgHi3, are iso-lobal with the cyclopentadienide species [Mn(CO)3(ri-C5H5)] and [Fe(CO)3 (il-CsHs)]. ... 

Other aspects of the report (42) on [Fe3S2(NO)5] are surprising. Elemental analysis of the ammonium salt was reported to distinguish between iron(II) and iron(III) in [Fe3S2(NO)5] , but to find these two types of iron present in equal numbers is most unusual for a triiron complex. Second, the molecular weight of the potassium salt was measured as 420 by mass spectrometry. This value is close to the M/Z of 421 calculated for the most abundant isotopic form of the ion-pair cation [KFe3S2(NO)5] +. Finally, the ESR spectrum reported is that of a dini-trosyliron species, which bears a remarkable resemblance to that reported (22) for a complex formed from Fe(II) and nitric oxide in aqueous alkaline solution. 

Pentafluoropyridine, with Ni(0) complexes, 8, 47 -8 Pentagonal bipyramidal complexes, triiron complexes, 6, 310 Pentahapto germolyl complexes, with Hf(IV), 4, 987-989 Pentahapto siloyl complexes, with Hf(IV), 4, 987-989 Pentakis(acetoxymercurio)pentamethylruthenocene, preparation, 6, 630... 

The insertion of CS2 occurs at the Fe-C bond of the tetramethylfulvene-bridged diiron complex 36, producing the triiron complex 37 and the monoiron complex 38 (Scheme 9) [82]. A dithiocarboxylato ligand in 37 bridges three iron fragments in a novel coordination mode. One iron atom adopts the distorted-piano-stool geometry, while the other two iron atoms are distorted octahedral. 

Scheme 9 Formation of a triiron complex and a monoiron complex bearing a dithiocar-boxylato ligand...

Tl -bismolyl derivative [Mn(CO)jL] (81) (L=2,5-Me2C4H2Bi). Two papers describe the formation of triiron complexes [ Fe(CO)4 3(p -BiR)] in which bismuth is tetrahedral, addition of acetic acid to which affords rectangular complexes [Fc(CO)4(p-BiR)]2 . Another publication details the preparation of a whole range of complexes in which a bismuth nitrate unit is linked to two metal centres , while thermolysis of NaBi03 and [Mo(CO)J in methanol for a day, followed by addition of Et4NBr yields the unusual cluster [Mo3(CO)9(p -Bi) p -(OMej)Mo(CX))3 ][NEt4]2, which contains a naked bismuth atom (82) . ... 

Ermert DM, GordonJB, Abboud KA, Murray LJ. Nitride-bridged triiron complex and its relevance to dinitrogen activation. Inorg Chem. 2015 54 9282-9289. 

The di(/x-disulfido)diiron complex 243 (L = Gp ) is converted into the di(/U3-sulfido)triiron complex 244 by thermal reaction with iron carbonyls. Selective mono-GO substitution of 244 by PPh3 is accelerated by photolysis or by treatment with reductant (benzophenone ketyl) or oxidant (ferrocenium cation). ... 

Triiron Complexes Bound through Carbon and Oxygen 307... 

Reactivity of triiron complexes containing capping chalcogens (and related complexes) 311... 

The stepwise formation of tropones upon insertion of GO into alkyne dimers coordinated to diiron centers is a commonly found process in iron carbonyl chemistry no triiron complexes are isolated during these processes (e.g., see Refs 14 and 14a). Finally, GO insertion is observed when diiron dimers linked by diacetylene moieties are reacted with diethylamine to give the complexes 6 and 7 (Figure 2) these complexes also contain iron-carbon-nitrogen and iron-carbon-phosphorus bonds. 

Other recent examples are the reactions of 2-methyl-3-butyn-2-ol with Fe3(GO)i2 which afforded, among others, a triiron complex containing a partially dehydrated alkyne dimer 14 " and the related pentagonal bipyramidal complex 15 with nitrogen-containing ligands (Figure 4). 

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