Iron enneacarbonyl

Iron enneacarbonyl reacts smoothly with 1,1-dimethylsilacyclobutane to insert into the ring Si—C bond with complete regiospecificity (76JCS(D)910). The ferrosilacyclopentane (54) is thermally stable but reacts with HCl, and can also be prepared from 3-chIoropropyI-dimethylchlorosilane and Fe(CO)42. Carbonyl anions will substitute at silicon if this atom bears chlorine, and platinum will insert into the Si—H bond (Scheme 79) (72CC445, 78JOM( 144)317). 

The bis(77-allyl)nickel, -palladium, and -platinum complexes also react with iron enneacarbonyl under analogous conditions. In the presence of iodine, 77-allyliron tricarbonyl iodide has been isolated (158). 

It has been noted that unlike the palladium and platinum complexes, the nickel derivatives afford nickel iodide instead of the free metal. The reaction is accompanied by carbon monoxide evolution, which is increased in the presence of iodine. Independently of the stoichiometric ratio of Pd to Fe employed, the reaction consumes approximately half the amount of allyl-palladium compound. Hence the present authors assume that iron enneacarbonyl produces two moieties under the conditions of reaction ... 

It has been shown that Fe(CO)s accumulates in solution (GLC and polarography), and it reacts considerably more slowly with 7r-allylpalladium chloride than does iron enneacarbonyl (155). 

Iron enneacarbonyl, see Diiron nonacarbonyl Iron pentacarbonyl, 259,519-520 Iron pentacarbonyl-dimethylacetylene complex, 519-520... 

Diiron nonacarbonyl (Iron enneacarbonyl), Fe2(CO)8(l).MoLwt. 363.79. Preparation. ... 

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. 

Page 250. Read Diethyl ethoxycarfconylmethyl phosphonate, see Triethyl phosphonoacetate. Page 251. Second formulation, over first arrow. For (C02CH3)j read (COsCHjV Page 259, line 5. Read 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. ... 

Iron enneacarbonyl, Fe2(CO)9, was found to have C—O stretching frequencies at 2080 and 2034 cm due to the terminal carbonyl groups, and an absorption at 1828 cm due to the bridged group [ ]. The structure proposed for this compound was that shown in Fig. 1. 

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. 

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