Hydrazinium chloride

With tellurium, precipitation of the element with sulphur dioxide is slow in dilute hydrochloric acid solution and does not take place at all in the presence of excess of acid moreover, the precipitated element is so finely divided that it oxidises readily in the subsequent washing process. Satisfactory results are obtained by the use of a mixture of sulphur dioxide and hydrazinium chloride... 

B. Determination of tellurium Procedure. The solution should contain not more than 0.2 g tellurium in 50 mL of 3M hydrochloric acid (ca 25 per cent by volume of hydrochloric acid). Heat to boiling, add 15 mL of a freshly prepared, saturated solution of sulphur dioxide, then 10 mL of a 15 per cent aqueous solution of hydrazinium chloride, and finally 25 mL more of the saturated solution of sulphur dioxide. Boil until the precipitate settles in an easily filterable form this should require not more than 5 minutes. Allow to settle, filter through a weighed filtering crucible (sintered-glass, or porcelain), and immediately wash with hot water until free from chloride. Finally wash with ethanol (to remove all water and prevent oxidation), and dry to constant weight at 105 °C. Weigh as Te. 

Electrolysis of chloride solutions may be carried out provided that a sufficient amount (1 —5 g) of either hydrazinium chloride or of hydroxylammonium chloride is added as an anodic depolariser ... 

The solution should be free from the following, which either interfere or lead to an unsatisfactory deposit silver, mercury, bismuth, selenium, tellurium, arsenic, antimony, tin, molybdenum, gold and the platinum metals, thiocyanate, chloride, oxidising agents such as oxides of nitrogen, or excessive amounts of iron(III), nitrate or nitric acid. Chloride ion is avoided because Cu( I) is stabilised as a chloro-complex and remains in solution to be re-oxidised at the anode unless hydrazinium chloride is added as depolariser. 

In a similar determination described by Lingane and Jones,11 an alloy containing copper, bismuth, lead, and tin is dissolved in hydrochloric acid as described above, and then 100 mL of sodium tartrate solution (0.1 M) is added, followed by sufficient sodium hydroxide solution (5M) to adjust the pH to 5.0. After the addition of hydrazinium chloride (4 g), the solution is warmed to 70 °C and then electrolysed. Copper is deposited at —0.3 volt, and then sequentially, bismuth at —0.4 volt, and lead at —0.6 volt all cathode potentials quoted are vs the S.C.E. After deposition of the lead, the solution is acidified with hydrochloric acid and the tin then deposited at a cathode potential of — 0.65 volt vs the S.C.E. 

In the application of the polarographic method of analysis to steel a serious difficulty arises owing to the reduction of iron(III) ions at or near zero potential in many base electrolytes. One method of surmounting the difficulty is to reduce iron(III) to iron(II) with hydrazinium chloride in a hydrochloric acid medium. The current near zero potential is eliminated, but that due to the reduction of iron(II) ions at about - 1.4 volts vs S.C.E. still occurs. Other metals (including copper and lead) which are reduced at potentials less negative than this can then be determined without interference from the iron. Alternatively, the Fe3 + to Fe2+ reduction step may be shifted to more negative potentials by complex ion formation. 

A yellowish precipitate was obtained from the chloride and hydrazinium chlorides when basified with sodium acetate. It had N—Hg bonds and was perhaps CIHgNHNHHgCl. It exploded on heating or shock. A similar compound resulted from the bromides. 

Diphenylhydrazinium chloride, 3519 Hydrazinium azide, 4550 Hydrazinium chlorate, 4010 Hydrazinium chloride, 4007 Hydrazinium chlorite, 4008 Hydrazinium dinitrate, 4561 Hydrazinium diperchlorate, 4068... 

Hydrazinium azide, 4545 Hydrazinium chlorate, 4004 Hydrazinium chloride, 4001 Hydrazinium chlorite, 4002 Hydrazinium dinitrate, 4556 Hydrazinium diperchlorate, 4062... 

Hydrazinium chloride, 4001 5-Hydrazino-1,2,3,4-thiatriazole, 0461 5,5 -Hydrazotetrazole, 0822 l-Hydroxy-2-hydroxylamino-l,3,4-triazole, 0813 1-Hydroxybenzotriazole, 2265... 

Although good results may be obtained by conducting the preparation in the open with reagents and solvents as received from the supplier, a product of enhanced stability is obtained if the reagents are dried in vacuo (sodium tetra-hydroborate at 100°, hydrazinium chloride at room temperature), the solvent is dried with calcium hydride, and the entire procedure is carried out under dry nitrogen. The use of an excess of the hydrazine salt also leads to a more stable product. 

Preparation. Sisler and co-workers developed a technique for obtaining chloramine by gas-phase reaction of chlorine with excess ammonia and showed that the reagent combines with tertiary amines to form the corresponding 1,1,1-trisubstituted hydrazinium chlorides (1) in good yield, and with tertiary phosphines to form aminophosphonium chlorides (2). The product of reaction (2) can be dehydrohalo-genated with magnesium hydride to triphenylphosphine amine. 

Fig. 5. Low temperature (90 °K) Raman spectra of polycrystalline (a) pyrrole, C5H4NH (b) hydrazinium chloride N2H5CI (c) triazole, C2N3H2...

Synonyms Hydrazine HCI Hydrazine hydrochloride Hydrazinium chloride Hydrazinium monochloride... 

Seward, R.P., The conductance and viscosity of highly concentrated aqueous solutions of hydrazinium chloride and hydrazinium nitrate, J. Am. Chem. Soc. 77, 905-907 (1955). 

Sakurai, K. and Tomiie, Y, The crystal structure of hydrazinium chloride, N2H5CI, Acta Crystallogr. 5, 293 (1952). 

Repeat the series of experiments above replacing sulphite by a solution of hydrazinium chloride or sulphate. 

---