Cobalt ammonium chlorides double salts

The cadmium salt, [Cr(NH3)2(SCN)4]2Cd.H20, is a red, sparingly soluble, crystalline powder, and the ferric salt crystallises in golclen-yellow leaflets. Double salts may also be formed for example, the hexammino-cobaltic salt, [Cr(NH3)s(SCN)4]3[Co(NH3)6], on addition of hexammino-cobaltic chloride to ammonium tetrathioeyanato-diammino-chromium, crystallises in very sparingly soluble plates. Other salts of this type have been prepared.4... 

Ammonium Tetranitrito - diammino - cobaltate, [Co(XH3)2 (N02)4]NH4, is prepared from cobaltous chloride by mixing an aqueous solution of the salt with aqueous ammonium-chloride solution, sodium nitrite, and ammonia, and oxidising the mixture by passing air through it for several hours. The solution is allowed to stand in air for some days, when crystals gradually separate. These are collected, washed, and reerystallised from water.3 The substance crystallises in brown rhombic prisms. It is decomposed on treatment with potassium hydroxide with evolution of ammonia, and a cold solution reacts with ammonia in presence of ammonium salts, with formation of flavo-dinitro double salts, of which [Co(NH3)4(N02)2][Co(NH3)2(N02)4] is typical. Oxalic acid transforms it into the oxalato-dinitrito-diammino-salt, [Co(NH3)2(N02)2(C204)]NH4. 

Ammonium Cobalti-nitrite, 4(NH4)3Co(N02)s.3Ha0, was first prepared in 1856 by Gibbs and Genth. Erdmann 2 obtained it by the action of ammonium nitrite upon cobalt chloride solution acidulated with acetic acid. It may also be obtained by adding semicarbazide to a solution of sodium cobalti-nitrite 3 and by double decomposition of solutions of ammonium chloride and sodium cobalti-nitrite or by addition of nitrous acid to a suspension of cobalt carbonate in the requisite quantity of ammonium nitrite solution.4 In all three cases the salt is precipitated out. 

Ammonium quaternary salt containing a double bond such as [2-hydroxy-3-(methacryloyloxy)propyl]trimethylammonium chloride can be used as a grafting reagent to improve the hydrophylic properties of polyamides (63). Still other compounds as vinyl pyrrolidone (23) and methacryloxy stannane (64), seem to be useful for Nylon grafting under cobalt-60 irradiation. 

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