Fluorescent diketopyrrolopyrroles

The present invention relates to fluorescent diketopyrrolopyrroles (“DPPs”) of the formula A 1 and A 2 independently from each other stand for characterized in that that at least two adjacent substituents R 5 to R 11 form an aromatic or aliphatic fused ring system, or at least one substituent R 5 to R 11 is cycloalkyl, aralkyl, alkenyl, cycloalkenyl, alkynyl, a hydroxyl group, a mercapto group, alkylthio, an aryl thioether group, a heterocyclic group, halogen, haloalkyl, haloalkenyl, haloalkynyl, a cyano group, an aldehyde group, a carbonyl group, a carboxyl group, an ester group, a carbamoyl group, a nitro group, a silyl group, a siloxanyl group, a substituted or unsubstituted vinyl, arylamino or diarylamino group; a process for their preparation and their use for the preparation of inks, colorants, pigmented plastics for coatings, non-impact-printing material, color filters, cosmetics, or for the preparation of polymeric ink particles, toners, dye lasers and electroluminescent devices. The fluorescent diketopyrrolopyrroles (“DPPs”) of the formula I exhibit a high lightfastness, a high heat stability, especially in plastics. A luminescent device comprising a DPP compound of formula I is high in the efficiency of electrical energy utilisation, high in luminance and high in colour purity.