Diiron dodecacarbonyl

Diiron dodecacarbonyl has also been used as a reagent for the reduction of nitro-benzenes to anilines [47]. The two-phase reduction reaction which is believed to involve phase transfer of the HFe3(CO)ri anion occurs rapidly at room temperature and requires one half equivalent of Fe3(CO)i2. The reaction takes place as formulated in equation 9.18 and affords yields of 85%, 92%, 88%, and 60% with 4-methyl-, 4-methoxy-, 4-chloro- and 4-acetylnitrobenzenes. It is interesting that these reactions are so successful in benzene solution, a medium in which BTEAC is an ineffectual catalyst under other circumstances [48]. 

Diene iron tricarbonyl complexes are prepared by thermal or photochemical reaction of conjugated dienes with iron pen-tacarbonyl in the presence of TMANO, triiron dodecacarbonyl, ()]" -benzylidenacetone)iron tricarbonyl, diiron nonacarbonyl, or diiron nonacarbonyl absorbed on silica gel in the absence of solvent. The latter method is particnlarly usefiil for the preparation of complexes from polar electron-rich dienes and heterodienes. A reductive complexation of cycloheptatrienes using iron tricarbonyl and sodium borohydride to give cyclo-heptadiene iron tricarbonyl has been developed (Scheme 126). 

Diiron enneacarbonyl, synthesis 46 Triiron dodecacarbonyl, synthesis 46 Tricarbonyl(cyclooctatetraene)iron, synthesis 47 Iron carbonyl complexes of triphenylphosphine, triphenyl-arsine, and triphenylstibine, synthesis 48 cis-Dinitrobis(ethylenediamine)cobalt(III) nitrite and nitrate, synthesis 60... 

Pentacarbonyl iron is fairly inert to substitution reactions, and attempts to prepare Fe(CO)5- (CNR) (n = 1-5) by the direct reaction of Fe(CO)5 with isocyanides in Carius tubes has produced only the complexes Fe(CO)s (CNR) (n = 1 and 2). The products were obtained as mixtures that required separation. Other syntheses, including photochemical and trimethylamine N-oxide-promoted displacement of carbonyl groups, or other means, give the same products in variable yield. Procedures based on diiron nonacarbonyl and triiron dodecacarbonyl have produced similar results. The only zero-valent iron complex Fe(CO)5 (CNR) where n > 2 is the complex Fe(CNR)5 prepared either by metal vapor synthesis techniques or by sodium amalgam reduction of iron(II) bromide in the presence of isocyanide. ... 

An example of sonochemical switching was found with the sonolysis of iron pentacarbonyl (Fig. 23).Pyrolysis and photolysis form pyrophoric iron and diiron nonacarbonyl respectively, in contrast to sonolysis, which gives triiron dodecacarbonyl, a compound not easily accessible by other methods. A pyrolytic... 

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