The invention relates to an organic electroluminescent device which contains 2,5-diaminoterephthalic acid derivatives of formula 1a as emitter substances in one or several emitter layers in a pure or doped manner. The ring A is a triple unsaturated benzene ring wherein R.sup.4' and R.sup.8' are zero or ring A is a double unsaturated ring respectively provided with a double bond in the 1,2 position and 4,5 position, and wherein R.sup.10 is a nitrile radical --CN or a radical C(.dbd.X.sup.1)--X.sup.2R.sup.1, R.sup.11 is a nitrile radical --CN or a radical --C(.dbd.X.sup.3)--X.sup.4R.sup.5, X.sup.1 and X.sup.3 are oxygen, sulfur or imino, X.sup.2 and X.sup.4 are oxygen, sulfur or optionally substituted amino, R.sup.1 R.sup.8, R.sup.4' and R.sup.8' are H, C1 20-alkyl, aryl, heteroaryl, R.sup.4 and R.sup.8 can be halogen, nitro, cyanogen or amino, R.sup.2 R.sup.4, R.sup.6 R.sup.8, R.sup.4' and R.sup.8' can be trifluoromethyl or pentafluorophenyl, and wherein certain radicals can form a saturated or unsaturated ring. The devices are characterized by narrow emission bands, low driver voltages, high photometric efficiency and high thermal stability within a broad spectral range ##STR00001##