Bis-cyclopentadienyl iron

See 1,3-Di[bis(cyclopentadienyl)iron]-2-propen-1-one Perchloric acid, etc. See other organometallic perchlorates... 

The discovery in 1951 of the transition metal rr-complex, ferrocene or bis-cyclopentadienyl-iron, Fe(Cp)2, (1, 2) led to enormous interest being shown in the possible structures of such compounds and in the nature of the metal-ring bonding. Within a year the sandwich type structure (Fig. 1) had been proposed (2), and an outline treatment of the metal 3d-ligand 7r-orbital interaction by Jaffe (4) was soon followed by a more detailed molecular... 

Another example of a complex that obeys the 18-electron rule is ferrocene or bis(cyclopentadienyl) iron. The cyclopentadienyl anion is generated by the reaction of cydopentadiene with sodium, and ferrocene is obtained by the subsequent reaction with ferrous chloride,... 

Cyclopentadienylsodium, 1855 //-Cyclopcntadicnyltrimcthyl titanium. 3038 Diaquabis(cyclopentadienyl)titanium dichromate, 3327 1,3 -Di[bis(cyclopentadienyl)iron] -2-propen-1 -one, 3840... 

Di[bis(cyclopentadienyl)iron]-2-propen-l-one, 3840 =K Dicarbonyl- /r-cycloheptatrienyltungsten azide, 3123... 

The original concepts of metal-ligand bonding were essentially related to the dative covalent bond the development of organometallic chemistry has revealed a further way in which ligands can supply more than one electron pair to a central atom. This is exemplified by the classical cases of bis(benzene)chromium and bis(cyclopentadienyl)iron, trivial name ferrocene. These molecules are characterised by the bonding of a formally unsaturated system (in the organic chemistry sense, but expanded to include aromatic systems) to a central atom, usually a metal atom. 

Formula (C5H5)2Fe or (ri-C5H5)2Fe MW 186.04 a metal n sandwich complex in which the six n electron system of the cyclopentadienidide ion CsHf is bound to Fe2+ ion Fe—C distance 2.045 A and C—C bond distance 1.4 A. Synonyms bis(cyclopentadienyl)iron ferrocene dicyclopentadienyliron... 

Both in acetonitrile and in other non-aqueous solvents, a major problem arises in terms of the manner in which the potential values are reported by various investigators. Koepp, Wendt, and Strehlow [6] noted that hydrogen ion is the poorest reference material on which to base nonaqueous potentials because of the extreme differences in its solvation in various solvents. On the basis of an investigation of the solvent dependence of 18 redox couples, these investigators concluded that ferrocene/ferrocenium ion (i.e. bis(cyclopentadienyl)iron(III/II), abbreviated as Fc+ /Fc°) and/or cobal-tocene/cobalticenium ion represented optimal potential reference materials for nonaqueous studies. On the basis of their minimal charge (+1, 0) and their symmetry (treated as though they were roughly spherical), the potentials of these two redox couples are presumed to be relatively independent of solvent properties. 

The classic (if not classical) metal sandwich species bis(cyclopentadienyl)iron has the formula [(CH)5]2Fe (CpaFe) and the semisystematic name ferrocene, and so the related magnesium-containing species [(CHfsJaMg (CpaMg) is often accompanied by the name magnesocene. We commence our discussion with this species. 

The behavior of ferrocene, bis(cyclopentadienyl)iron(II), as an aromatic molecule under conditions for electrophilic substitution has received much attention by both organic and inorganic chemists (59, 63). The Friedel-Crafts acylation may illustrate the reactivity of this very stable compound. 

D. Optical Reflectance Probe Bis(cyclopentadienyl)iron(II) Size Exclusion and Intrazeolite Chemistry... 

J. D. Dunitz, and L. E. Orgel, Bis-cyclopentadienyl Iron a Molecular Sandwich, Nature... 

The chemistry in this chapter originates from Pauson s discovery of bis(cyclopentadienyl)iron(II). Pauson had attempted the synthesis of the 1 Otc aromatic hydrocarbon fulvalene via an oxidative coupling/dehydro-genation of the cyclopentadienyl anion (Figure 7.24). However, Pauson... 

In > , >y -bis(cyclopentadienyl)iron dicarbonyl the <7-bonded ligand is easily attacked by HFA with conservation of the a bond. Photochemical treatment of 147 affords 146d, in which both cyclopentadienyl rings become n bonded (76). 

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