NOVELTY - Pyrimidine derivatives (I), are new.    USE - (I) are useful: in an electronic device, preferably organic electroluminescent device; in an electron transport layer, electron injection layer, hole blocking layer and/or as a matrix material for fluorescent emitters in an emitting layer; and in an electron transport layer or electron injection layer in combination with another electron transport- or electron injection-material, preferably with an organic alkali metal compound (all claimed).    DETAILED DESCRIPTION - Pyrimidine derivatives of formula (I), are new.    Pym = a compound of formula (II) or (III);    Ar = fused aryl or heteroaryl group having 10-30 aromatic ring atoms, which may be substituted with one or more radicals R12;    R1-R8, R12 = H, halo, CHO, N(R13)2, N(Ar1)2, B(Ar1)2, Si(R13)2, Si(Ar1)2 , C(=O)Ar1, P(=O)(Ar1)2, S(=O)Ar1, S(=O)2Ar1, CR13=CR13Ar1, CN, NO2, Si(R13)3, B(OR13)2, B(R13)2, B(N(R13)2)2, OSO2R13, a straight chain alkyl, alkenyl, alkinyl, alkoxy or 1-40C thioalkoxy or branched or cyclic alkyl, alkenyl, alkinyl, alkoxy or 3-40C thioalkoxy, which may be substituted with one or more radicals R13, where one or more non-adjacent CH2 groups are replaced by R13C-CR13, C-C, Si(R13)2, Ge(R13)2, Sn(R13)2, C=O, C=S, C=Se, C=NR13, P(=O)(R13), SO, SO2, NR13, O, S or CONR13, one or more H-atoms are replaced by halo, CN or NO2, or an aromatic or heteroaromatic ring system containing 5-60 aromatic ring atoms, which are substituted by one or more radicals R13 and/or an aryloxy or heteroaryloxy group with 5-60 aromatic ring atoms, which are substituted by one or more radicals R13, which form two or more adjacent substituents R1-R8, R12 also a mono- or polycyclic, aliphatic or aromatic ring system;    Ar1 = aromatic or heteroaromatic ring system with 5-30 aromatic ring atoms, which may be substituted with one or more radicals R13, where two radicals Ar1, which bind to the same nitrogen, phosphorus, silicon or boron, are linked by a single bond or a bridge, comprising B(R13), C(R13)2, Si(R13)2, C=O, C=NR13, C-C(R13)2, O, S, S=O, SO2, N(R13), P(R13) or P(=O)R13; and    R13 = H or an aliphatic, aromatic and/or hetero-aromatic 1-20C hydrocarbyl, in which H-atom is replaced by F, thus form two or more adjacent substituents R13 and also a mono- or polycyclic, aliphatic or aromatic ring system.    R9-R11 = R1-R8, R12, where the dotted bond indicates the bond of the anthracene.    INDEPENDENT CLAIMS are included for:    (1) the preparation of (I);    (2) an electronic device, preferably organic electroluminescent devices, organic integrated circuits, organic field-effect transistors, organic thin film transistors, organic light-emitting transistors, organic solar cells, dye-sensitized organic solar cells, organic optical detectors, organic photoreceptors, organic field-quench devices, light-emitting electrochemical cells, organic laser diodes or organic plasmon-emitting devices, comprising (I); and    (3) a formulation comprising (I) and at least one solvent.