Crystal Phase Study of Pigment Red 254 in the Presence of Ionic ‎Liquids

Polymorphism is difined as different ‎crystalline phases with the same ‎chemical structure. ‎Diketopyrrolopyrrole (DPP) ‎derivatives, as the innovative ‎heterocyclic pigments, follow this ‎pattern and most of times exist in ‎two crystalline forms of alpha and ‎beta with various application in ‎different industries. Herein, ‎synthesis of 3, 6-Bis (4-‎chlorophenyl) -2, 5-dihydropyrrolo ‎‎[3,4-c] pyrrole-1,4-dione called ‎Pigment Red 254 (PR 254) with ‎selected crystalline phase using ‎ionic liquids was achieved without ‎any further need to conventional ‎methods for crystalline phase ‎separation after synthesis. ‎Observed different physical ‎properties such as melting points ‎and color properties of the ‎obtained pigment (PR 254 in ? and ‎B crystalline phases) are ‎clarified.‎Prog. Color Colorants Coat. ‎‎5(2012), 1-6. © Institute for Color ‎Science and Technology.‎