Nitroso ferrous sulphate

Complexes are also known in which the co-ordination numbers- are one, two, three, five, seven, and even eight respectively, but these are less frequent. As examples may be mentioned sulphito-coppcr potassium, [Cu(S03)]K, and the unstable nitroso-ferrous sulphate, [Fe(N0)]S04, each of which possess unit co-ordination number. l)i-ammino-silvcr chloride, [Ag(NH3)2]Cl, and triammino-silver chloride. [Ag(NIT3)3]Cl, possess co-ordination numbers two and three respectively. In penta-phenylhydrazino-zine sulphate, [Zn(NHa.NH.C6II5)5JS04, and octammino-strontium chloride, [Sr(NH3)8]Cl2, the co-ordination numbers are five and eight respectively. 

Nitric oxide is absorbed by unreacted ferrous sulphate to form a dark brown ring nitroso ferrous sulphate. 

In an aqueous solution, nitroso ferrous sulphate is in penta aqua form [Fe(N0)(H20)5]. It is a paramagnetic complex with three unpaired electrons showing a magnetic moment of 3.90 bohr magneton (BM). This value of magnetic moment supports the +1 oxidation state of iron (d ) in a high-spin complex ion. 

In which test is nitroso ferrous sulphate produced ... 

Liebermann s reagent) with ferrous sulphate a green lake Nitroso-co louring matters... 

Nitroso derivatives of a more complex and more stable character than the foregoing were discovered by Roussin in 1858.2 This investigator observed that a black voluminous precipitate is obtained when a mixture of ammonium sulphide and alkali nitrite is added to an aqueous solution of ferrous sulphate. On boiling, the precipitate passes into solution. The liquid is filtered, and, upon cooling, black crystals separate out, the composition of which has been the subject of considerable discussion. The reaction does not proceed in perfectly neutral solution, a green liquor only being produced, consisting of sulphides of iron and sodium, entirely free from any nitroso derivative. The presence of a small quantity of acid, however, results in the formation of the nitroso derivative, probably because it liberates nitrous acid, which acts direct upon the ferrous salt. 

Potassium ferro-heptanitroso sulphide, KFe4(N0)7S3.H20.—To prepare this salt, Pavel 4 raised a solution of potassium nitrite to boiling, added sodium sulphide, and, finally, with repeated shaking, a solution of ferrous sulphate in small quantities at a time. Upon crystallisation the nitroso derivative separated out m monoclinic crystals which were purified by recrystallisation from warm water and carbon disulphide in succession, and finally dried over phosphorus pentoxide. 

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