Ethane, reaction with iron

Now let me come back to primary substitutions at the ferrocene nucleus. Together with Vil chevskaya, we phosphorylated ferrocene and its derivatives to triferrocenylphosphine oxides [263, 264). An unusual reaction, discovered in collaboration with Perevalova and Yur eva, was the direct cyanation of ferrocene with hydrocyanic acid in the presence of ferric chloride [265,272). Initially, cyanide attacks the iron atom of the ferricinium cation, then the cyanide group transfers to the ring while the iron is simultaneously reduced. The reaction was termed by us as the ricochet (from the metal to the nucleus) substitution it may be applied to many substituted ferrocenes and to the ruthenocenium cation [273), and it is now the simplest route to ferrocene carboxylic acids through their nitriles. Further, ferrocene was studied in acid-medium reactions with oxo compounds. With aldehydes [274), the reaction was complicated by the transformation of ferro-cenylalkyl carbinol formed Initially via the carbonium ion, followed by transformation to a radical which, in its turn, was coupled to 1,2-bis-(ferrocenylalkyl)ethane (27.5). The reaction with acetone led to 2,2-di-ferrocenylpropane (276). 

Bis(diisopropylamino)triafulvene (7) yields an iron carbonyl complex upon reaction with cyclopentadicnyl(dicarbonyl)iron iodide and l,2-bis(2,3-diisopropylaminocyclopropenylium)-ethane dication by coupling upon oxidation with iodine. 

In the present macro-scale experiments the filaments have been formed following reaction of ethane with iron and iron oxides. The decomposition of ethane to elemental carbon and hydrogen is endothermic (27) and so, at first sight, it appears that the experimental results are in conflict with the above mechanism of filament growth. However, earlier work (28) has shown that the majority of carbon formed from ethane arises from the decomposition product ethylene. The latter decomposes exothermically (27) (- A H for C2H4 at 725°C is 9.2 kcal. mole- ) so that this mechanism is not contravened. A similar rationale was used by Keep, Baker and France (29) to account for the formation of carbon filaments during the nickel catalyzed decomposition of propane. 

Apparent SMSI effects have also been reported with non-Transition Metal oxide supports.Those obtained with magnesia were almost certainly due to evolution of traces of hydrogen sulfide, or of iron ions, from the bulk at the high temperatures used, but real effects have been seen with silica when very high pre-treatment temperatures were employed the rate of the ethane reaction decreased more quickly than that of hydrogen chemisorption, pointing clearly to the need for multiatomic sites in hydrogenolysis. 

The preparation of bis (r 3-aiiyi)iron(II) complexes of the type [Fe(ri3-C3H5)2(PMe3)2] has been reported and their reactions with 1,3-dienes to form a mixture of products were described. The reaction of allyl halides with salts of [Fe(CO)3(NO)]- afforded [PeCli -allyl)(CO)2(NO)] complexes, which on treatment with l,2-bis(diphenylphosphino)ethane gave P,Y-unsaturated acyl iron complexes in good yields via regioselective carbonylation with retention of configuration of the allylic double bond. The same [Fe(Ti3-allyl)(CO)2(NO)] complexes were... 

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