Trichromyl Chloride, Cr₃O₆Cl₂

Trichromyl Chloride, Cr₃O₆Cl₂, also known as chromium chlorochromate, is formed, together with chromyl chloride, when potassium chlorochromate, Cl.CrO₂.OK, is distilled with concentrated sulphuric acid; by distilling a solution of iodine in chromyl chloride; and by the action of chlorine upon chromium chromate (chromium dioxide). It is prepared by heating chromyl chloride in a closed tube for several hours at 180° C. as a black, amorphous, deliquescent powder, the aqueous solution of which evolves chlorine. It is readily reduced by hydrogen and is decomposed on heating in air. With hydrochloric acid, chlorine and chromic chloride are produced, while ammonia yields ammonium chloride and chromium chromate.