Simple hydrazinium salts

Neutralization of hydrazine hydrate with the corresponding acids yields simple hydrazinium salts. However, the pH of the solution is very important in the preparation of the required salt for this acid-base neutralization ... 

The structures of many simple hydrazinium salts have been determined using single-crystal X-ray crystallography. Neutron diffraction studies have shown that, besides normal hydrogen bonds, bifurcated and probably trifurcated bonds are also common in some of the hydrazinium salts. Table 1.4 lists some of the compounds along with their crystal data and N-N bond distances [6,19]. 

All simple hydrazinium salts are prepared by the reaction of respective ammonium salts with hydrazine hydrate. The general equation for the formation of these hydrazinium salts is ... 

Hydrazinium salts form by simple neutralization using the corresponding acid. Two series of salts are possible, containing the hydrazinium(I) ion,, ... 

The simple acid salts, MHY, conform to these rules, and with rather greater regularity in that malonic acid is no longer exceptional its hydrogen-anion is nearly planar, though the oxygen atoms just maintain a proper van der Waals separation. Hydrazinium hydrogen oxalate conforms to the rules, but the potassium salt — as we have seen — is obdurately unorthodox. Acid salts of adipic acid have not yet been studied. 

The sulfate ion (S04 ), though a simple dianionic ligand, exhibits a rather flexible symmetry and variable mode of binding with metal ions in the crystalline state. Interest in metal sulfate interactions with the hydra-zinium cation arises from the fact that these compounds exhibit one- and three-dimensional magnetic interactions of a linear-chain antiferromag-net. Dihydrazinium sulfate forms a series of double sulfates with divalent and trivalent cation that are well crystallized and, in a few instances, are even less soluble than hydrazinium sulfate itself. The most easily prepared double sulfates are those of Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Li, Mg, Al, La, Ce, Pr, Nd, and Sm. These salts are similar to the ammonium alums obtained with some metal sulfates. In contrast to the ammonium double salts, the hydrazinium metal sulfates of first row transition elements and lithium crystallize without water, whereas the lighter lanthanides and aluminum form hydrated salts. 

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