Diehloro Complex

Oxalato-diethylenediamino- Diehloro-dietliyfenediamino- Dibromo-diethylcncdianiino-chromic complex. chromic complex. chromic complex . 

The crude substance is their recrystallised from water containing acetic acid. The compound was originally believed to exist in two isomeric forms, but Jorgensen found the crystalline form depends on the concentration of acetic acid used for crystallisation, inasmuch as rhombic leaflets separate from hot dilute acetic acid, and from hot concentrated acid the substance separates in yellow-brown needles. The complex is sparingly soluble in water, and gives no precipitate in aqueous solution with silver nitrate or potassium chromate. If treated with cold hydrochloric acid it is transformed into chloro-dinitro-triammino cobalt, [Co(NH3)3(N02)2Cl], and if warmed with concentrated hydrochloric acid gives diehloro-aquo-triammino-cobaltic chloride. 

The m and tram dinitrotetrammine salts may be readily distinguished by gently boiling 0.5g of each salt with 10ml of concent rated hydrochloric acid. The ds salt gives a green precipitate of tram diehloro chloride, and the tram complex yields red chloronitro chloride (see next section). 

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