Manganese -dicyclopentadienyl

Wilkinson et al. 196) were the first to discover C5H5 ligand transfer from one transition metal to another. Thus a number of cyclopentadienyl compounds react with FeCl2 to give ferrocene. This is an important criterion for some ionic character in the metal-cyclopentadienyl bond. Only in solutions of the alkali metal cyclopentadienides is there a noticeable concentration of CjHj- ions 197). It is questionable whether even the so-called ionic magnesium and manganese dicyclopentadienyls produce CjHj" ions in solution 198). Thus it may be assumed that in all cases investigated... 

Unlike manganese, rhenium is reported to form an alkyl compound, dimethyl rhenium. Re(CH )3. Like manganese, it forms a dirhenium compound with carbon monoxide, (CO)5ReRe(CO)5, as well as hydrogen-halogen and alkyl-carbonyl compounds. It also forms a dicyclopentadienyl compound, (CsHjJReH. 

Dicyclopentadienyl manganese was first obtained by thermal decomposition of the ammine [MnfNHsle] (CbHb)2 (50, 111). Shortly afterward, it was made in good yield by the reaction between manganese bromide and cyclopentadienyl sodium in tetrahydrofuran (214), and it may also be prepared by the interaction of manganese chloride and an ethereal solution of the Grignard reagent, followed by sublimation (60). At ordinary temperatures it forms brown crystals. 

These were made on the uncharged dicyclopentadienyls of vanadium, chromium, iron, cobalt, nickel, ruthenium, manganese, and magnesium,... 

The possibility of calculating thermodynamic functions from infrared and Raman frequencies has been exploited for Fe(05115)2, Ni(OsH5)2, and Ru(OsH6)2 (124)- The vapor-pressure curve of ferrocene was also reported soon after its discovery (112). Vapor-pressure measurements for dicyclopentadienyl manganese are also available (216). The heats of formation of Fe(05Hs)2 and Ni (05115)2 from the O5H6 radical and the... 

Many 7i-cyclopentadienyl complexes may be prepared from the reaction of alkali metal cyclopentadienides with ammonia-soluble transition metal salts such as nitrates and thiocyanates in liquid ammonia (2-30). The amine complexes, [M(NH3) ] (C5H5)2, lose ammonia when heated in vacuo, and the uncharged dicyclopentadienyl complexes of iron, cobalt, nickel, chromium, and manganese are obtained. 

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