Ferrocenophane Fe

Figure 8 X-Ray structures of (a) 1,2,3-trithia[3]ferrocenophane. Fe-C average bond length 2.044 A. (b) [3](1,] )[3J(2,2/)(l,2,3)trithia-ferrocenophane. Fe-C average bond length 2.043 A...

For example, for the trimethylene-bridged derivative [Fe( 75, 5-C5H4(CH2)3C5H4)] (also known as [3]ferrocenophane) the oxidation... 

Braunstein and coworkers have shown (vide supra) that in the bimetallic Fe—Pt complex (CO)3(SiR3)Fe(yU.-PPh2)Pt(PPh3)CO(Fe—Pt), a silyl migration occurred from the Fe to the Pt center (Scheme 17)102. Remarkably, the first example of a well-characterized insertion of a transition-metal fragment into a strained silicon-carbon bond of a silicon-bridged [l]ferrocenophane was recently reported by Sheridan, Lough and Manners. The... 

A series of [n,n]-ferrocenophanes is listed in Scheme 20 together with their AE1/2 values. The introduction of a second bridge enforces the c/.v-con figuration and a comparatively shorter Fe—Fe distance. Thus, the geometrical restrictions enhance the possibility... 

Another topologically chiral K5 molecule is the chiral ferrocenophane ketone derivative 51 (Fig. 8), which is an intermediate in the synthesis of tetrabridged ferrocenophanes [79]. It is important to notice that in order to obtain a non-planar molecular graph, at least four of the ten Fe —C bonds must be taken into account. The K5 subgraph (52) also contains an oriented edge ( —CH2CH2CH2CO-fragment) and a coloured vertex (Fe atom). 

Figure 7.30 Ferrocenophanes and ferrocenyl ligands derived from dilithioferrocene. (i) Fe(CO)5 (ii) Mo(CO)6, (CF3C0)20 ...

A great deal of effort has been devoted to the study of linked metallocene units in order to probe the redox properties of compounds containing two or more identical electron-transfer sites much of the interest in these systems stems from the fact that one-electron changes lead formally to mixed-valence species. Iron compounds, including biferrocene 1 (M = Fe), bridged biferrocenes 2 [X = (CH2) , S, Hg, etc.], bis(ful-valene)diiron 3 (M = Fe), ferrocenophane 4 (M = M = Fe), and their derivatives, have attracted the most attention. 

In addition, fc(OH)2 [76] or its potassium salt generated in situ [77, 78] may also be used to prepare crown-ether type polyoxa ferrocenophanes [76 - 78], which show interesting complex forming ability for metal cations. Two examples of simple [3]ferrocenophanes are Fe(C5H4-0)2Pd(PPhj) [79] and Fe(C5H4-0)2C = 0 ( ferro-cenylene carbonate ) (Scheme 5-14 cf. Sect. 5.7.1 [80]). 

In l,3-dichalcogena-[3]ferrocenophanes of the type fc(E2M) (E = O, S, Se, Te), a transition metal complex fragment (M) is held firmly between the two chalcogen atoms (E) (Table 5-5). Although both the ferrocene iron and the transition metal are essential parts of the cyclic structure, the two metals generally remain isolated from each other. Only a few examples have been found where an intramolecular, transannular interaction between Fe and M can be taken into consideration, as in the palladium(ii) and platinum(ii) complexes fc[E2M(PPh3)] (E = O, M = Pd E = S, M = Pd and Pt) (Sect. 5.7.1). 

Fe or Ru, substituted in the 1- and 1 -positions by 2 nitronyl nitroxide radicals.182 Similar data were also used to study cationic organometallic polymers, such as cyclopentadienyl-iron polyether-imines.183 13C and 29Si MAS-NMR spectra were reported for l,5,3,2,4-diazooxadisila[5]ferrocenophane.184... 

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