Cyclopentadienyl carbonyl complexes carbonylation

Mono( 17-cyclopentadienyl) carbonyl complexes of Ti, Zr, and Hf have been noted only in the patent literature. A U.S patent issued to Ethyl Corporation in 1962 described the use of such complexes as anti-knock agents and lubricant additives. Two examples of complexes purported to have been made are shown below (115). 

The 18-electron rale is not obeyed as consistently by these types of oiganome-tank compounds a by the carbonyl and nitrosyl complexes and their derivatives. For example, in addition to ferrocene. M(i 5-CsHs)2 compounds are known for most of the other elements of the first transition series (M — V, Cr, Mn.Co, Ni) and these cannot obey ihe 18-electron rule. However, only ferrocene shows exceptional thermal stability (stable to 500 C) and is not oxidized by air. Furthermore, cobaltocene, a 19-electron species, is readily oxidized to the 18-electron cobaltocenium ion. (Co(ip-CsH )3)4 , which reflects much of the thermal stability of ferrocene. Mixed cyclopentadienyl carbonyl complexes are common K -CjHjMCO) ]. [(if-CjH )-Cr(CO), . [( -CjHOMnCCOjJ, [(>r-C,H,>Fe(CO ,, . [fo -CjiyCoCoy. and (ip-CsH,)Ni(CO) 2. Of interest is the fact that among these compounds, the odd-atomic-number elements (V. Mn, and Co) form monomers and the even-atomic-number elements (Cr. Fe. and Ni) Ibrm dimers, which is in direct contrast to the behavior shown by the simple carbonyl complexes. Cyclopentadienyl derivatives are now known for every main group and transition metal of the periodic table and for most of the -block metals.89... 

Binding energy, pentacarbonyliron, 6, 3 Binuclear complexes bis-Cp titanium halides, 4, 522 with Ni-M and Ni-C cr-bonds heterometallic clusters, 8, 115 homometallic clusters, 8, 111 Binuclear dicarbonyl(cyclopentadienyl)hydridoiron complexes, with rand C5 ligands, 6, 178 Binuclear iridium hydrides, characteristics, 7, 410 Binuclear monoindenyl complexes, with Ti(IV), 4, 397 Binuclear nickel(I) carbonyl complexes, characteristics, 8, 13 Binuclear osmium compounds, with hydrocarbon bridges without M-M bonds, 6, 619... 

Cyclopentadienones, in molybdenum carbonyls, 5, 451 Cyclopentadienyl alkenes, with niobium, 5, 76 Cyclopentadienyl-alkoxo complexes, with Ti(IV), 4, 495 Cyclopentadienyl alkyl complexes, with niobium, 5, 66 Cyclopentadienyl-amido complexes, with Ti(IV), via dehalosilylation, 4, 448... 

Cyclopentadienyl carbonyl complexes, with niobium, 5, 64 Cyclopentadienyl chromium bis(Ti-allyl) complexes, with chromium, 5, 305-306 Cyclopentadienyl chromium carbonyls... 

Mononuclear dicarbonyl(cyclopentadienyl)hydridoiron complexes, characteristics, 6, 173 Mononuclear a-donor ligands, in molybdenum carbonyls,... 

C-H bond dissociation energies, 1, 298 C-N triple bond additions, 10, 427 C02, ketene, ketenimine complexes, 5, 84 CO and CNR reductive coupling, 5, 66 cyclopentadienyl alkyl and aryls, 5, 66 cyclopentadienyl carbonyl complexes, 5, 64 cyclopentadienyl hydrides, 5, 69 cyclopentadienyl isocyanide complexes, 5, 65 rf-acyl and rj2-iminoacyl complexes, 5, 82 fj3-complexes, 5, 87... 

In this case (compare with Ref. 268), the Te — Te bond remains. This bond is not destroyed also under interaction of diphenylditellurides with cyclopentadienyl-carbonyl complexes of manganese (3.99a) [272] and iron (3.99b) [273] ... 

Similarly protonation of diphenylfulveneiron tricarbonyl generates a substituted 7r-cyclopentadienyl cation (241, 242). Hydride abstraction from cyclopentadieneiron tricarbonyl releases the 77-cyclopentadienyl cation complex (172). The Mossbauer spectra of the [CpFe(CO)3]1 cation and related iron carbonyl cations have been determined (121). 

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