Metal Sulfate Hydrazines

Metal sulfate hydrazines MSO4 XN2H4 (M = Mn, Co, Ni, Zn, and Cd X = 2-3) are prepared by the addition of alcoholic hydrazine hydrate to an aqueous saturated solution of metal sulfates. The complexes precipitate instantaneously they are then filtered, washed with alcohol, and dried 

Chemical analysis revealed that all the metals form metal sulfate hydrazines except manganese, which forms a hydrated complex. Further, the number of hydrazine molecules in the complexes varies from two to three. 

Infrared spectra of the complexes show a i n-n stretching frequency of N2H4 in the region 960-980 cm , indicating the presence of bridged hydrazine. The sulfate ion appears to be free (ionic) as seen by the infrared absorption bands at 1100 (1/3) and 600 cm (1/4). Coordination of the sulfate groups of the metal ion lowers the Tj symmetry of the S04 ion and, hence, the splitting of these bands occurs. 

Compound Thermogravimetry Temperature % Weight loss Obsd. Calcd. DTA peak temperature Product 

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The most adequately characterized hydrazinium complexes consisting of coordinated metal ions are (N2H5)2M(S04)2 (M = Mg, Mn, Fe, Co, Ni, Cu, Zn, Cd, and the halides) [31]. In addition, single crystals have been analyzed of Co and Ni double sulfates synthesized under hydrothermal conditions using metal sulfates, hydrazine hydrate, and HF [32]. Table 1.8 lists various hydrazinium compounds along with their crystal data and N—N bond distances. 

Govindarajan, S., Babu, P.J., and Patil, K.C. (1986) Thermal analysis of metal sulfate hydrazinates and hydrazinium metal sulfates. Thermochimica Acta, 97, 287-293. 

Hydrazinium metal sulfate hydrazines of the formula (N2H5)2M(S04)2-3N2H4 are prepared by reaction of the corresponding ammonium metal sulfate hexahydrates with stoichiometric amounts of hydrazine hydrate ... 

The reaction is instantaneous with the evolution of ammonia and color change. After complete removal of ammonia, the products are washed with ethanol and diethyl ether, and dried over P2O5. However, the above reaction with Mn gives only the hydrazinium metal sulfate (N2H5)2Mn(S04)2 and not the hydrazinium metal sulfate hydrazine as expected. The corresponding hydrazinium metal sulfate hydrazine of copper is also not obtained because of its instant reduction to copper metal on addition of hydrazine hydrate. 

Table 5.1 Infrared absorption frequencies (cm of hydrazinium metal sulfates and hydrazinium metal sulfate hydrazines.

The compounds MS04(N2H4)2, where M " " = Fe, Co, Ni, and Cd, are prepared either by mixing hydrazine hydrate with aqueous solutions of metal sulfates or by dissolving the corresponding metal powders in a solution of ammonium sulfate in hydrazine hydrate. 

Jia, L.H., Li, R.Y., Duan, Z.M. et al. (2011) Hydrothermal synthesis, structures and magnetic studies of transition metal sulfates containing hydrazine. Inorganic Chemistry, 50, 144-154. 

A solid compound separates out initially, which is washed with 50% alcohol until free from sulfate it is then washed with diethyl ether and dried in a vacuum desiccator over P2O5. Chemical analyses of the mixed metal sulfite hydrazine hydrates confirms a stoichiometry of MFe2(S03)3 6N2H4 2H20. The reaction can be written as follows ... 

Similar to hydrazinium metal sulfates, hydrazinium metal sulfite complexes can be synthesized the procedure is, though, slightly different. Hydrazinium transition metal sulfite dihydrate complexes of the formula (N2H5)2M(S03)2(H20)2 where M = Fe, Co, Ni, Cu, and Zn are prepared from metal hydrazine carboxylates (described in Chapter 4) as the starting material. In this method, the anhydrous metal hydrazine carboxylate, M(N2H3C00)2, is added to distilled water previously saturated with sulfur dioxide gas. The complex decomposes with the liberation of carbon... 

Patil, K.C., Govindarajan, S., Soundararajan, R., and Pai Verneker, V.R. (1981) Thermal analysis of hydrazinium metal sulfates and their hydrazinates. Proceedings of the Indian Academy of Sciences - Chemical Sciences, 90, 421 26. 

Gravimetric methods more suitable for general use involve the precipitation of metallic gold from tetrachloraurate solutions by reduction with oxaUc acid, SO2, or hydroquinone. Formaldehyde, hydrazine, ferrous sulfate, and hypophosphorous acid also have been used but are considered less efficient (40). 

A silver-containing solution was basified with sodium hydroxide, and after filtration, ammonia solution was used to wash residual silver from the filter. Hydrazine sulfate was then added to precipitate metallic silver and when the mixture was heated it exploded. This may have been caused by formation of silver nitride and/or hydrazine-silver complexes, both of which are explosively unstable. 

Hydrazine sulfate is used as a reducing agent in analytical chemistry for gravimetric measurement of nickel, cobalt, and other metals, and in peptide analysis in the separation of polonium from tellurium as an antioxidant in... 

NAGu consists of wh monocl crysts(ftom w), apparent d 0.22 g/cc, mp 184°(decomp) expl ca 190°. When heated on a metallic spatula near a flame, each particle of NAGu expl as it is ignited by the flame. It may be ground in a mortar without producing an expln. One of the methods for its prepn is the interaction of nitroguanidine with hydrazine sulfate in ammonia. This and other methods are described in Refs 1,2,3,4a,6,... 

One gram of U.S.P. gum arabic is dissolved in 70ml of hot water. After cooling, O.lg of copper sulfate 5-hydrate ia dissolved in the liquid and 30ml of concentrated ammonia are added. The blue solution is warmed to 50°C and a few milliliters of a 0.0005% hydrazine hydrate solution are added. A copper sol ia produced which ia the color of the metal by reflected light and blue by transmitted light The colloidal suspension must be dialyzed for several days immediately after it is prepared and it ia stable for only a short time. 

Analysis of the compound for platinum is accomplished gravimetrically by reduction of a known weight of the anhydrous salt to metallic platinum with formic acid.3 For the determination of chloride, 0.3 g. of the anhydrous salt is dissolved in 40 ml. of distilled water containing 250 mg. of hydrazine sulfate the solution is boiled gently until platinum metal is formed and coagulated. Then, without removal of the platinum, the solution is made 1 f in nitric acid and is titrated potentiometrically with standard 0.2 F silver nitrate solution. Anal. Calcd. for Na2PtCl6 Pt, 42.99 Cl, 46.88. Found Pt, 42.78 Cl, 46.73. 

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