NOVELTY - Substituted pyrene compounds (I) are new.    USE - (I) or their oligomers, polymers or dendrimers are useful: in an electronic device comprising organic integrated circuits, organic field-effect transistors, organic thin film transistors, organic light-emitting transistors, organic solar cells, organic optical detectors, organic photoreceptors, organic field-quench devices, light-emitting electrochemical cells, organic laser diodes or organic light emitting diodes; as emitter material in an emitting layer, as a matrix material in an emitting layer and/or as a hole transport material in a hole transport layer and/or a hole injection layer; and as an emitter material in combination with one or more matrix materials in an emitting layer or electronic device (all claimed).    ADVANTAGE - (I) provide electronic devices with improved efficiency, operation voltage and service life.    DETAILED DESCRIPTION - Substituted pyrene compounds of formula (I) are new.    Y1 = -N(Ar1)-, -P(Ar1)-, -P(=O)(Ar1)-, -S-, -S(=O)- or -S(=O)2-;    Ar1 = 6-30 membered aromatic ring system or 5-30 membered (hetero)aromatic ring system (optionally substituted with one or more R2), where two Ar1 groups are optionally bonded together by a single bond or a divalent group comprising -C(R2)2-, -R2C=CR2-, -Si(R2)2-, -C(=O)-, -C(=NR2)-, -O-, -S- or -NR2-;    Ar2 = 6-30 membered aromatic ring system or 5-30 membered (hetero)aromatic ring system (both optionally substituted with one or more R2);    R1 = linear 1-20C-alkyl or -alkoxy or a branched or cyclic 3-20C-alkyl or -alkoxy or 2-20C-alkenyl or -alkynyl (all optionally substituted with one or more R3, where one or more adjacent or non-adjacent CH2-groups are optionally replaced by Si(R3)2, C=O, C=NR3, -C(=O)O-, -C(=O)NR3-, NR3, -O-, -S-, SO or SO2, and one or more H atoms are optionally replaced by D, F, Cl, Br, I, CN or NO2), 6-20 membered aryl or 5-20 membered heteroaryl (both optionally substituted with one or more R3), F, D, C(=O)R3, CN, Si(R3)3, N(R3)2 or NO2, where R1 is bonded to one or more of the position 6, 7 and 8 of the pyrene ring, and 1-3 R1 groups are present; either    R2 = linear 1-20C-(thio)alkyl or -alkoxy or a branched or cyclic 3-20C-alkyl or -alkoxy or 2-20C-alkenyl or -alkynyl (all optionally substituted with one or more R3, where one or more adjacent or non-adjacent CH2-groups are optionally replaced by -R3C=CR3-, -CC-, Si(R3)2, Ge(R3)2, Sn(R3)2, C=O, C=S, C=Se, C=NR3, -C(=O)O-, -C(=O)NR3-, NR3, P(=O)(R3), -O-, -S-, SO or SO2, and one or more H atoms are optionally replaced by D, F, Cl, Br, I, CN or NO2), or 5-60 membered (hetero)aromatic ring system or 5-60 membered (hetero)aryloxy (both optionally substituted by one or more R3), H, D, F, Cl, Br, I, B(OR3)2, CHO, C(=O)R3, CR3=C(R3)2, CN, C(=O)OR3, C(=O)N(R3)2, Si(R3)3, N(R3)2, NO2, P(=O)(R3)2, OSO2R3, OR3, S(=O)R3 or S(=O)2R3; or    two or more R2 bonded together = (hetero)aliphatic or (hetero)aromatic ring, where the pyrene ring is optionally substituted by one or more R2 at any of its free positions; either    R3 = linear 1-20C-(thio)alkyl or -alkoxy or a branched or cyclic 3-20C-(thio)alkyl or -alkoxy or 2-20C-alkenyl or -alkynyl (all optionally substituted with one or more R4, where one or more adjacent or non-adjacent CH2-groups are optionally replaced by -R4C=CR4-, -CC-, Si(R4)2, Ge(R4)2, Sn(R4)2, C=O, C=S, C=Se, C=NR4, -C(=O)O-, -C(=O)NR4-, NR4, P(=O)(R4), -O-, -S-, SO or SO2, and one or more H atoms are optionally replaced by D, F, Cl, Br, I, CN or NO2), 5-60 membered (hetero)aromatic ring system or 5-60 membered (hetero)aryloxy (both optionally substituted by one or more R4), H, D, F, Cl, Br, I, B(OR4)2, CHO, C(=O)R4, CR4=C(R4)2, CN, C(=O)OR4, C(=O)N(R4)2, Si(R4)3, N(R4)2, NO2, P(=O)(R4)2, OSO2R4, OR4, S(=O)R4 or S(=O)2R4; or    two or more R3 bonded together = (hetero)aliphatic or (hetero)aromatic ring; and either    R4 = H, D, F or 1-20C-aliphatic or (hetero)aromatic organic residue, in which one or more H-atoms are optionally replaced by D or F; or    two or more R4 bonded together = (hetero)aliphatic or (hetero)aromatic ring.    Provided that: the groups Ar1 are not substituted with a residue comprising B, Si, Ge or P; the groups Ar1 are not heteroaryl groups containing one or more nitrogen atoms in the aromatic ring; and when R1 is N(R3)2, then R1 is not bonded to one or more of the bonding positions 6 and 8 of the pyrene ring. INDEPENDENT CLAIMS are included for:    (1) the preparation of (I);    (2) oligomers, polymers or dendrimers comprising one or more (I); and    (3) formulation comprising (I) or their oligomers, polymers or dendrimers and at least one solvent.