Murexide (MX) - organic dye purpurat ammonium, ammonium salt of 5,5'-nitrilodibarbiturovoy (purple) acid. Gross formula S8N8N6O6 * H2O (Extendedly: NH4C8H4N5O6, or C8H5N5O6.NH3). Has a purple-red color.
Dark red, purple or brownish fine crystals with a greenish sheen, poorly soluble in water and soluble in ethanol, diethyl ether. The molecular weight of 238.18.