Na2Fe

Carbonylate anions are the most suitable starting material for the synthesis of silylmetal compounds. A prerequisite for the preparation of compounds with a formal M = Si double bond is the use of metallate dianions like Na2Fe(CO)4 (Collman s reagent) together with the respective dichlorosilanes [96]. 

It is known that Na2Fe(CO)4 can be silylated twice to form cri-[(H3C)3Si]2Fe(CO)4 [109]. Also the reaction of Na2Fe(CO)4 with 1.1-dichlorosilanes has been described and leads exclusively to the dimeric compounds [110, 111], In polar solvents the formation of dimers can be suppressed and monomeric base-stabilized compounds are obtained. A very elegant procedure is the in-situ generation of the carbonylate anions in solution by deprotonation of H2Fe(CO)4. 

The reaction (Eq. (5)) in THF yields labile THF adducts which are converted into the more stable HMPA adducts by addition of HMPA. The various equilibria existing between Na2Fe(CO)4 and several donor solvents are described in a detailed paper by Collman in HMPA, the solvent-separated supernucleophilic ion pair [Na+x HMPA x Fe(CO)4 ] is the kinetically dominant species, with no kinetic contribution from free [Fe(CO)J2 . In THF, Na2Fe(CO)4 is much less dissociated, with tight-ion paired [NaFe(CO)4] as the kinetically important species [96],... 

Whether these results will also have an impact on the theory of metallaallenes is difficult to predict at least for the compounds Cp (CO)2Mn = M = Mn(CO)2Cp, (M = Ge, Sn, Pb) a linear structure is established and also linear p-carbido complexes are known [198], Recently, a germanium compound has been synthesized which is directly comparable with 22. In this case, the starting material for the synthesis is not a monomeric base adduct, but a dimeric germylene complex which is cleaved by Na2Fe(CO)4 in pyridine to form 72 [199],... 

Anhydrides, both aliphatic and aromatic, as well as mixed anhydrides of carboxylic and carbonic acids, have been reduced to aldehydes in moderate yields with disodium tetracarbonylferrate Na2Fe(CO)4. Heating a carboxylic acid, presumably to form the anhydride, and then reaction with Na/EtOH leads to the aldehyde. 

Treatment of Na2Fe(CO)4 with an alkyl halide in the absence of PhjP gives rise to a solution of 142. Addition of a second alkyl halide produces a ketone 142+R X RCOR. ... 

Still another method for the conversion of halides to acid derivatives makes use of Na2Fe(CO>4. As described in 10-112, primary and secondary alkyl halides and tosylates react with this reagent to give the ion RFefCO) (142) or, if CO is present, the ion RCOFe(CO)4 (143). Treatment of 142 or 143 with oxygen or sodium hypochlorite gives, after hydrolysis, a carboxylic acid. " Alternatively, 142 or 143... 

Grignard reagents react with ethyl chloroformate to give carboxylic esters, EtOCOCl -I- RMgX — EtOCOR. Acyl halides can also be converted to ketones by treatment with Na2Fe(CO)4 followed by R X (10-112, method 4). 

A dramatic example of photolysis is the photodegradation of sodium nitroprusside in aqueous solution. Sodium nitroprusside, Na2Fe(CN)5NO-2 H20, is administered by intravenous infusion for the management of acute hypertension. If the solution is protected from light it is stable for at least one year if exposed to normal room light, it has a shelf life of only 4 hours [35]. 

The imidazolide and the catalyst are combined in a molar ratio of 1 2. Without catalyst the formylation of Na2Fe(CO)4 yielded only NaFeH(CO)4 and carbon monoxide quantitatively. 107 ... 

Sodium nitroprusside (for sulfur detection) dissolve about 1 g of sodium nitroprusside in 10 mL of water as the solution deteriorates on standing, only freshly prepared solutions should be used. This compound is also called sodium nitroferricyanide and has the formula Na2Fe(NO)(CN)5 2H20. 

Cyanide compounds have been prescribed by physicians for treatment of hypertension and cancer (Sprine et al. 1982). Sodium nitroprusside (Na2Fe(CN)5NO 2H20) was widely used for more than 30 years to treat severe hypertension and to minimize bleeding during surgery (Solomon-son 1981 Vesey 1987). Laetrile, an extract of ground apricot kernels, has been used for cancer chemotherapy and, in deliberate high intakes, as an attempted suicide vehicle (Gee 1987). 

The reaction of o-halomethylene benzyl halides, l,4-dihalobut-2-enes, cyclo-2-hexenols or 2,5-dihydrothiophene-l,1-dioxides with Na2Fe(CO)4 or Fe2(CO)9 results in the formation of (diene)Fe(CO)3 complexes108. In each case, the precursor is transformed in situ into the free diene ligand, followed by complexation. 

Give a plausible reason for the irreproducibility of substitution reactions of Fe (CN)5H20 . The ion had been prepared in solution from a sample of solid Na2Fe(CN)5H20 which had not been overly purified. Addition of a small amount of Brj slowed down the substitution reaction and gave more consistent data. 

Increasing concentrations of Na give rise to NaFe(CN)6 and Na2Fe(CN)g and changing slope of plot may arise in terms of a reactive NaFe(CN) and a non-reactive... 

Sodium Nitroprusside, Na2Fe(CN)5NO (22.6.7) It is synthesized by successive reactions including the reaction of potassium ferrocyanide with nitric acid, which forms potassium nitroprusside (22.6.5), which is further transformed to copper nitroprusside (22.6.6), and reaction of this with sodium carbonate gives sodium nitroprusside (22.6.7). 

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