Di-iron enneacarbonyl

Cyclopropa[fe]naphthalene gives rise to (345) by formal addition of an Fe—C bond of di-iron enneacarbonyl to one edge of the three-membered ring the nature of the process is unknown. ... 

It is interesting to contrast the reaction of di-iron enneacarbonyl with butadiene at 40°C. Here a different product is formed, in which butadiene is acting as a 2-electron rather than as a 4-electron ligand. 

Intermediates in Reactions.—Attempts to prepare metal complexes of thiirens resulted in the formation of complexes of thioketocarbenes instead. Treatment of 1,2,3-thiadiazoles and -selenadiazoles with di-iron enneacarbonyl gives thioketo- and selenoketo-carbene complexes. The formation of two carbene complexes from unsymmetrically substituted thia- or selena-diazoles suggests the intermediacy of a thiiren or seleniren complex. ... 

Treatment of thiets with di-iron enneacarbonyl yields complexes, e.g. (177), of thioacrolein. X-Ray analysis of thioacrolein triphenylphosphine dicarbonyliron (178) established the structure. ... 

A full paper by Alper and Chan, describing in detail the formation of sulphur-donor ligand ortho-metallated complexes (74) by the reaction of substituted thiobenzophenones with di-iron enneacarbonyl, Fe2(CO)>, has appeared. The complexes (74) appeared to be valuable starting materials in the synthesis of the little-known isobenzothiophen heterocycles. Related ortho-metallated thiobenzophenone complexes of ruthenium were found to have a different structure (75). Some non-aromatic thioketones also react with di-iron enneacarbonyl, but these reactions appear to be more complicated. Thus adamantanethione yielded no less than four different complexes, of which (76) was the prevailing one (71%). Thiocamphenilone (77) formed a complex analogous with (76), but such a complex could not be obtained with thiofenchone (78), presumably for steric reasons. Two... 

Metal Complexes.—In order to determine the effect of the presence of a nitrogen donor on the ortho-metallation of the thiobenzoyl function, Alper and Chan treated NN-dimethylthiobenzamide with di-iron enneacar-bonyl. However, no sulphur-donor ligand ortho-metallated complex was obtained, as happens in the case of thiobenzophenone, but instead the complexes (245) and (246) were formed. - NN-Dimethylthioacetamide similarly yielded the complexes (247) and (248), whereas the unsubstituted thiobenzamide on treatment with di-iron enneacarbonyl gave the complexes (249) and (250). The synthesis and properties of metal complexes of dithio-oxamides, dithiomalonamides, 2-thiocarbamoyl-l,10-phenan-throlines, thiomorpholine-3-thione, and 2,4-dithiouracil have also been described recently. 

Iron enneacarbonyl (di-iron nonacarbonyl) [15321-51-4] M 363.7, m 100"(dec). Wash it with EtOH and Et20, then dry it in air. It sublimes at 35° at high vacuum. It forms dark yellow plates which are stable for several days when kept in small amounts. Large amounts, especially when placed in a desiccator, spontaneously ignite in a period of one day. It decomposes in moist air. It is insoluble in hydrocaibon solvents but forms complexes with several organic compounds. [Sheline Pitzer J Am Chem Soc 72 1107 1950, Speyer Wolf Chem Ber 60 1424 1927.] TOXIC. 

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