Mono complexes cyclopentadienyl compounds

Mono-n-cyclopentadienylmagnesium compounds have so far only been isolated in the form of adducts with oxygen or nitrogen bases. The bis-(tetrahydrofuran) complexes of cyclopentadienyl(phenyl)- and -(methyl)-magnesium have been synthesized by Whitesides and co-workers (96) according to Eq. (4). 

In addition to the di-r -cyclopentadienyl compounds, there are many mono-r -cyclopentadienyls, such as CpMn(CO)3, CpCo(CO)2, and [CpFe(CO)2]2. Substituted Cp rings, such as indenyl and coupled rings, as in fulvalenes are also known to form metal complexes, examples being (16-XLI) and (16-XLII). 

These complexes also undergo many of the reactions shown for ferrocene, particularly the aromatic substitution reactions. An additional outline of some reactions of mono-7r-cyclopentadienyl complexes are shown in Fig. 6-5. These compounds also undergo carbonyl substitution reactions. 

The crystal structure of a mono(cyclopentadienyl)zirconium complex containing a novel Me2Si-linked bis(amidinate) ligand was reported (Scheme 203). In this compound the central Zr atom is octahedrally coordinated with the bis(amidi-nate) acting as a tridentate ligand. ... 

Mono(cyclooctatetraenyl) lanthanide(III) compounds, synthesis and characteristics, 4, 124 Mono(cyclooctatetraenyl) zirconium(III) compounds, preparation and reactions, 4, 743 Mono(cyclopentadienyl) amido complexes alkane elimination, 4, 446 amine elimination, 4, 442 HCL elimination, 4, 446 metathesis reactions, 4, 438 miscellaneous reactions, 4, 448 properties, 4, 437... 

A number of facile procedures were developed for the synthesis of mono and bis cyclopentadienyl derivatives of titanium, e.g., the (tt-CsH )-trialkoxytitanium derivatives, (77-C5H5)-titanium trihalides (406, 407-409), (77-C5H5)-titanium internal complexes (409), triaroxytitanium cyclopentadienyls (410), compounds containing different groups (alkoxy, aryloxy. 

Whereas complexes of unsubstituted and substituted cyclopentadienyl ligands represent the vast majority of all published compounds in organolanthanide chemistry, examples of isolated and fully characterized (including X-ray structural analyses) compounds containing only cr-bonded alkyl and aryl ligands are still fairly rare. The first structurally characterized homoleptic lanthanide alkyls became available through the use of bulky mono-, bis-, and tris(trimethyl-silyl)-substituted methyl ligands. Simple unsolvated alkyls of the rare earth elements have not yet been synthesized. 

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