苯六甲酸 517-60-2 用途

It crystallizes in fine silky needles and is soluble in water and alcohol.It is a very stable compound,chlorine,concentrated nitric acid and hydriodic acid having no action upon it.It is decomposed,on dry distillation,into carbon dioxide and pyromellitic acid,C10H6O3; when distilled with lime it gives carbon dioxide and benzene.Long digestion of the acid with excess of phosphorus pentachloride results in the formation of the acid chloride,which crystallizes in needles,melting at 190 °C.By heating the ammonium salt of the acid to 150-160 °C as long as ammonia is evolved,a mixture of paramide (mellimide),C6(CONH)3,and ammonium euchroate is obtained.The mixture may be separated by dissolving out the ammonium euchroate with water.Paramide is a white amorphous powder,insoluble in water and alcohol.
The high stability of mellitic acid salts and that they are the endproduct of the oxidation of polycyclic aromatic hydrocarbons,which are present in the solar system,made them a possible organic substance in Martian soil.[4]