Cyclopentadienyl ligands iron complexes with

Iron complexes with organic ligands are widely used as such reservoirs. For example, the stable 19-electron complex cyclopentadienyl benzene iron(I) is a clean electron reservoir that has a sufficiently negative oxidation potential and can be easily made, stored, and handled and can be weighed accurately (Alonso Astruc 2000). 

A. R. Kudinov, A. A. Filchikov, P. V. Petrovskii, and M. I. Rybinskaya, 30-Electron Cationic Iron- and Cobalt-containing Triple-Decker Complexes with a Central Cyclopentadienyl Ligand. The First Synthesis of the Parent Triple-Decker Iron Complex with Cyclopentadienyl Ligands, [( 5-C5H5)Fe(p-jy jy-C5H5)Fe(jy5-C5H5)]PFg, Russ. Chem. Bull. 48, 1352-1355(1999). 

Nesmeyanov, Volkenau et al. were the first to replace cyclopentadienyl with another ligand in ferrocene, preparing cyclopentadienyl-arene iron complexes by reaction of ferrocene with aromatic compounds in the presence of AICI3 255-259). 

Half-Sandwich Iron Complexes with a Silanol-Functionalized Cyclopentadienyl Ligand ... 

A chiral metal center, as is found in a pseudotetrahedral iron complex with cyclopentadienyl, carbonyl, triphenylphosphine, and ethyl ligands, has also been u,sed to address the question of alkyl migration versus carbonyl insertion. Inversion of... 

Another route to complexes with a,/i-unsaturated acyl ligands involves reaction of the dicar-bonyl(r/5-cyclopentadienyl)iron anion of 12 with a,/ -unsaturated acyl halides38. 

Applying the pseudo-atom convention to the iron complex in Figure 8, the iodine atom is priority 1, the t1S-C5H3R2 ligand is priority number 2, the phosphorus atom is priority number 3, and carbon is priority number 4.15 When the iron is viewed from the side opposite the priority number 4, the sequence is 1,2,3 in the anticlockwise or 5 direction. The highest priority carbon in the cyclopentadienyl ligand, indicated by an asterisk, is designated with the R chirality symbol by application of the extended CIP sequence rule. 

Ferrocene is an iron(II) sandwich complex with two cyclopentadienyl ligands (Figure 1.3). Since its discovery in 1951 [4], ferrocene has been the subject of extensive investigations due to its reactivity, structural features and potential for applications [73]. 

A. R. Kudinov, M. I. Rybinskaya, Yu. T. Struchkov, A. I. Yanovskii, and P. V. Petrovskii, Synthesis of the First 30-Electron Triple-Decker Complexes of the Iron Group Metals with Cyclopentadienyl Ligands. X-Ray Structure of [(/ -C5H5)Ru (p,jy-C5Me5)Ru(jy-C5Me5)]PF6, J. Organomet. Chem. 336, 187-197 (1987). 

This type of sandwich complex, first reported with iron as the central metal, has now become widespread with ruthenium as well. Early routes to ruthenium complexes were modeled on iron chemistry, and used the AICI3-catalyzed exchange of a cyclopentadienyl ligand for an arene in ruthenocene, or reaction of CpRu(CO)2Cl with AlCb/arene. These methods are less successful with ruthenium than with iron, however, owing to the greater stability of ruthenocene. A mixture of arene, pentamethylcyclopentadiene, and RuCls in the Zn reduction method gives good yields of the mixed-sandwich cations. A... 

Some cyclopentadienyltitanium complexes react with FeClj or iron acetylacetonate with transfer of the cyclopentadienyl ligand from titanium to iron. The yield of ferrocene also depends on the other ligands on titanium. The yield increases with decreasing number of electron-attractive halogen atoms in the molecule (see Table IV). 

Probably substitution of the cyclopentadienyl ligand on alcoholysis and hydrolysis, and its transfer in reactions of di- and monocyclopentadienyl-titanium derivatives with FeClj or iron(II) acetylacetonate, follows a mechanism common for 77-ligand exchange in other metal 77-complexes (see later). 

Hundreds of iron hydride complexes with phosphine ligands have been isolated and characterized. These complexes are almost always diamagnetic. For example, a spectacularly active electrocatalyst for dihydrogen oxidation is the cyclopentadienyl iron... 

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