Hydrazonium perchlorate

5 Hydrazine Perchlorates - Hydrazinium Perchlorate (N2H5CIO4), Hydrazinium Perchlorate Monohydrate (N2H5CIO4 H2O), Hydrazinium Perchlorate Hemihydrate (N2H5CIO4 O.5H2O), and Hydrazonium Perchlorate [N2Hg(C104)2] 

Hydrazine perchlorates are of interest due to their possible use as solid propellant oxidizers. Hydrazine forms two different perchlorates, depending on the degree of protonization. Hydrazinium (l-E) perchlorate (N2H5CIO4) forms N2H5CIO4 monohydrate and hemihydrate. The divalent (2-I-) perchlorate forms hydrazonium perchlorate, N2H6(C104)2. Because both salts are high explosives, their preparation has to proceed with extreme precaution. Hydrazinium perchlorates can be sublimed under vacuum without decomposition. 

The synthesis of anhydrous hydrazinium perchlorate (N2H5CIO4), hydra-zinium perchlorate monohydrate (N2H5CIO4 H2O), and hydrazinium perchlorate hemihydrate (N2H5CIO4 O.5H2O) has been discussed in Section 2.2.2.1. 

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The DTA of hydrazinium perchlorate hydrate shows an endotherm at 132 °C, which is attributed to its partial dehydration and melting. The second endothermic peak at 263 °C is due to decomposition. However, DTA in vacuum (Figure 2.18b) gives anhydrous hydrazinium perchlorate which further decomposes at 226 °C to ammonium perchlorate. The two endotherms at 240 and 290 °C have been assigned to ammonium perchlorate phase change and sublimation, respectively. This behavior is similar to that of hydrazonium perchlorate, which is known to decompose initially to hydrazinium perchlorate. 

Hydrazine Diperchlorate (Hydrazinium Diperchlorate in Gmelin it is called Hydrazonium Hydroperchlorate, HDP). N2H4.2HCIO4, mw 232.97, OB +34.3% white crysts, mp 191°, d 2.21 g/cc (Ref 4) CA Registry No 13812-39-0 Preparation. HDP was first prepd by the interaction of equimolar amts of aq Ba perchlorate and hydrazine sulfate, the pptd Ba sulfate filtered off, and the filtrate evapd on a w bath until crystn occurs (Ref 2). It has also been prepd by the interaction of 2 moles of aq perchloric ac and 1 mole of hydrazine hydrate followed by evapn of the w or its azeotropic removal by distn with trichloroethylene (Ref 6), or by sweeping hydrazine vapors into 70% perchloric ac with dry N (Ref 7)... 

Accordingly, the TG-DTA studies (Table 2.11) of N2H6(C104)2-2H20 show a partial weight loss of 5.33% at 100 °C complete dehydration would have resulted in a weight loss of 15.65%. Therefore, infrared and DTA studies appear to indicate the presence of some oxonium ions in hydrazonium (2-I-) perchlorate dihydrate. 

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