NOVELTY - Heterocyclic compounds (I)-(IV), excluding 8-oxo-8H-7,12b-diaza-benzo(a)aceanthrylene-6-carboxylic acid, 7,7b-diaza-indeno(1,2,3-jk)fluorene, 2,7b-diaza-indeno(1,2,3-jk)fluorene and 4,7,7b-triaza-indeno(1,2,3-jk)fluorene, are new.    USE - (I), (II), (III) or (IV) or oligomers, polymers or dendrimers comprising (I), (II), (III) or (IV) are useful in electronic devices, preferably organic electroluminescent devices (organic light emitting diodes or polymer light-emitting diodes), 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 and organic plasmon-emitting devices (all claimed).    ADVANTAGE - (I), (II), (III) or (IV): exhibits high thermal stability; and is suitable as matrix material for blue phosphorescent compounds, along with red and green phosphorescent compounds. The fluorescent or phosphorescent emitter comprising (I)-(IV) as matrix material, exhibits very high efficiency and long service life. The organic electroluminescent device comprising (I)-(IV) exhibits: high efficiency and steep current-voltage curves with low threshold voltages; and good operating voltage.    DETAILED DESCRIPTION - Heterocyclic compound of formulae (I)-(IV), excluding 8-oxo-8H-7,12b-diaza-benzo(a)aceanthrylene-6-carboxylic acid, 7,7b-diaza-indeno(1,2,3-jk)fluorene, 2,7b-diaza-indeno(1,2,3-jk)fluorene and 4,7,7b-triaza-indeno(1,2,3-jk)fluorene, are new.    A=CR or N;    W 1=C (when W 1is bonded to Y 1) or CR or N (when W 1is not bonded to Y 1);    X=N, P or P=O;    Y 1=C(R1)2, NR 1, O, S, C(O), C(S), C=NR 1, C=C(R 1) 2, Si(R1) 2, BR 1, PR 1, AsR 1, SbR 1, BiR 1, P(=O)R 1, As(=O)R 1, Bi(=O)R 1, SO, SeO, TeO, SO 2, SeO 2, TeO 2or a combination of two of these groups, which may be same or different, or chemical bond (with the condition that all three Y 1in a unit will not simultaneously represent single bond); either    R, R 1=straight chain 1-40C alkyl, 1-40C alkoxy or 1-40C thioalkyl, or branched or cyclic 3-40C alkyl, 3-40C alkoxy or 3-40C thioalkyl, or 2-40C alkenyl or 2-40C alkynyl (all optionally substituted by at least one R 2, and at least one non-adjacent CH 2group may be replaced by R 2C=CR 2, CC, Si(R 2) 2, Ge(R 2) 2, Sn(R 2) 2, C=O, C=S, C=Se, C=NR 2, P(=O)(R 2), SO, SO 2, NR 2, O, S or CONR 2, and at least one H may be replaced by D, F, Cl, Br, I, CN or NO 2), or (hetero)aromatic ring with 5-80 aromatic ring atoms, preferably 5-60 aromatic ring atoms, (hetero)aryloxy with 5-60 aromatic ring atoms or (hetero)aralkyl with 5-60 aromatic ring atoms (all optionally substituted by at least one R 2), or H, D, F, Cl, Br, I, CN, NO 2, N(A1) 2, N(R 2) 2, C(=O)A1, C(=O)R 1or P(=O)(A1) 2; or    at least two adjacent R or R1R1 which are bonded to same Y 1=monocyclic or polycyclic, aliphatic or (hetero)aromatic ring (optionally substituted by at least one R 2); either    R 2=straight chain 1-40C alkyl, 1-40C alkoxy or 1-40C thioalkyl, or branched or cyclic 3-40C alkyl, 3-40C alkoxy or 3-40C thioalkyl or 2-40C alkenyl or 2-40C alkynyl (all optionally substituted by at least one R 3, and at least one non-adjacent CH 2group may be replaced by R 3C=CR 3, CC, Si(R 3) 2, Ge(R 3) 2, Sn(R 3) 2, C=O, C=S, C=Se, C=NR 3, P(=O)(R 3), SO, SO 2, NR 3, O, S or CONR 3, and at least one H may be replaced by Z), or (hetero)aromatic ring with 5-60 aromatic ring atoms, (hetero)aryloxy with 5-60 aromatic ring atoms or (hetero)aralkyl with 5-60 aromatic ring atoms (all optionally substituted by at least one R 3), or H, D, F, Cl, Br, I, CN, NO 2, N(A1) 2, N(R 3) 2, C(=O)A1, C(=O)R 3or P(=O)(A1) 2; or    at least two adjacent R 2=monocyclic or polycyclic, aliphatic or (hetero)aromatic ring (optionally substituted by at least one R 3); either    R 3=(hetero)aromatic ring with 5-30 aromatic ring atoms (at least one H may be replaced by D, F, Cl, Br, I or CN), 1-20C aliphatic hydrocarbon, H, D, F or CN; or    at least two adjacent R 3=mono- or polycyclic, aliphatic or (hetero)aromatic ring;    A1=(hetero)aromatic ring with 5-30 aromatic ring atoms (optionally substituted by at least one non-aromatic R 3), where 2 residues A1, which is bonded to same N or P are linked with each other through a single bond or a bridge comprising N(R 3), C(R 3) 2, O or S; either    L=branched or cyclic 3-40C alkylene, 3-40C alkylidene or 3-40C (thio)alkyleneoxy, or 2-40C alkenylene or 2-40C alkynylene (both optionally substituted by at least one R 2), bi-, tri-, tetra-, penta- or hexavalent straight chain 1-40C alkylene, 1-40C alkylidene or 1-40C (thio)alkyleneoxy (in all groups at least one non-adjacent CH 2group may be replaced by -R 2C=CR 2-, -CC-, Si(R 2) 2, Ge(R 2) 2, Sn(R 2) 2, C=O, C=S, C=Se, C=NR 2, P(=O)(R 2), S=O, SO 2, -O-, -S- or CONR 2, and at least one H may be replaced by D, F, Cl, Br, I, CN or NO 2), bi-, tri-, tetra-, penta- or hexavalent (hetero)aromatic ring with 5-80, preferably 5-40 aromatic ring atoms (optionally substituted by at least one R 2), P(R 2) 3-p, P(=O)(R 2) 3-p, C(R 2) 4-p, Si(R 2) 4-p, N(A1) 3-por a combination of two, three, four or five of these groups; or    L=chemical bond;    n=0 or 1;    p=2-6 (with a condition that p is not greater than the maximum valency of L); and    Z=D, F, Cl, Br, I, CN or NO 2.    Provided that at least one group A and/or at least one group W 1is N.    INDEPENDENT CLAIMS are also included for:    (1) the preparation of (I), (II), (III) or (IV);    (2) oligomers, polymers or dendrimers comprising at least one compound (I)-(IV), where instead of at least one residue R, R 1and/or R 2at least one bond to the polymer, oligomer or dendrimer is present; and    (3) electronic devices, preferably organic electroluminescent devices (organic light emitting diodes or polymer light-emitting diodes), 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 and organic plasmon-emitting devices.