Ferrocenophane complexes

Ferrocenophanes Complexes 104-106 have been synthesized by intramolecular coupling of ferrocenedicarbaldehydes [142-144] (Figure 6.18). Other isomers of 105, in vhich the ethylene moiety bridges the o- or m-positions, have also been... 

Binuclear ferrocenophane complexes have been prepared, such as 1,12-dimethyl[l,r]-ferrocenophane, 4.31c [3246]. 

Other [AuCIL] complexes with monophosphines are those derived of o-carborane (427),2506 pyr-anoside group (428),2507 a-dimethylamino(3)ferrocenophan-2-yl,2508 calix[4]arene derived phosphites,25 or aminoxyl radical-substituted phosphines (429),2510 for which ferromagnetic interactions have been observed. 

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 number of molecular mechanics studies of metal-cyclopentadienyl complexes have been reported recently. The systems studied include linear metallocenes (in particular ferrocene), ferrocene derivatives (such as complexes with substituted cy-clopentadienyl ligands, bis(fulvalene)diiron complexes, ferrocenophanes and mixed-ligand complexes with carbonyls and phosphines), and nonlinear cyclopentadienyl complexes 8,153,221 231]. 

Aza[3]ferrocenophanes, synthesis, 6, 187 Azaheterocycles, alkynylation with Ir catalysts, 7, 340 7-Azaindole, in trinuclear Ru and Os clusters, 6, 725 Azametallacyclobutane, tantalum complexes, 5, 168 Azametallacyclopropane, with niobium, 5, 87 Aza-oxo ligands, chromium complexes, 5, 353 Azaphosphirenes, with tungsten carbonyls, 5, 623 2H-Azaphosphirenes, with tungsten carbonyls, 5, 679 Aza-titanacyclopentenes, synthesis, 4, 407-408 Azavinylidenes... 

Diphosphaferrocene, with chromium carbonyls, 5, 220 l,l -Diphospha[2]ferrocenophane, synthesis, 6, 210 Diphosphazanes, in dinuclear Ru complexes, 6, 674 l,l -Diphosphetanylferrocenes, preparation, 6, 200-201 Diphosphine borane complex, polypyrrole support for,... 

Although a selection of ferrocene crown ethers (Scheme 4) were initially reported by Biernat and Wilczewski (44), Saji (45) described the first evidence of anodic shifts in the oxidation potential of pentaoxa[13]-ferrocenophane (6) resulting from the addition of alkali metal salts. Two distinct electrochemical CV waves corresponding to complexed and uncomplexed (6) were observed for both Na+ and Li+ guest cations (Fig. 4). The respective anodic shifts correspond to a decrease of the... 

Besides the ferrocene crown ether ligands described earlier, a variety of related macrocyclic ferrocenophanes containing various sulfur, oxygen, and nitrogen heteroatoms have been reported by a number of groups (110-115) (Scheme 21). These ligands complex transition metal guest cations such as Ag(I), Cu(I), and Pd(II) (116,117). Of particular... 

As in the case of [3] ferrocenophanes, there are numerous examples of [4]- and [5]ferrocenophanes. While the saturated complexes may be prepared from the usual route of treating the corresponding dicyclopentadienide with FeCl2, other approaches may be taken. For example, the reaction of keto[3]ferrocenophane (296) with diazomethane results in ring-expanded keto[4]ferrocenophanes (406a,406b) (equation 89). 

Considering the high efficiency of enzymes, model compounds have been developed that mimic their functions (Fig. 4-21). Among them, -cyclodextrin occupies a prominent place, as it forms inclusion complexes with suitably constructed ferrocene derivatives that then may undergo kinetic resolution (Fig. 4-21 d). An ester of an unsaturated acid derived from a 1,2-ferrocenophane is the best substrate for this technique the rate of hydrolysis of one enantiomer is enhanced by 3.2 x 10 [133]. 

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]). 

On the other hand, transition metal compounds with chelating l,l -ferrocenylene, i.e., l-metalla-[l]ferrocenophanes, are rare, the best-known representatives being the group 4 metal complexes (Fig. 5-11) derived from the di(cyclopentadienyl) metal dichlorides, fc[MCp2] and fc[M(C5H4tBu)2] (M = Ti, Zr, Hf) [188, 212]. 

With respect to intramolecular metal-metal interactions, a series of 1,3-dichalco-gena-[3]ferrocenophanes has been investigated that contain a transition metal complex fragment in the center between the two ring-attached chalcogens (Table 5-5). Hetero-bimetallic complexes of this kind can be considered as either 1,3-dichal-... 

Table 5-5. l,3-Dichalcogena-[3]ferrocenophanes, fc(E2M), containing a transition metal complex fragment (M)... 

---