NOVELTY - Nitrogen containing heterocyclic compounds (I) are new.    USE - (I) or the polymer, oligomer or the dendrimer is useful in an electronic device including 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 electroluminescent devices; and in an organic electroluminescent device as a matrix material in an emitting layer, as an electron transporting material in an electron transporting- or electron injecting layer, and/or as a hole blocking material in a hole blocking layer (all claimed).    ADVANTAGE - (I): exhibits high temperature stability and high oxidation stability in solution, high glass transition temperature, and improved quantum efficiency, and thus it is well-processable, and improved storage property and formation of color coordinates; and provides improved service-life to the electronic devices.    DETAILED DESCRIPTION - Nitrogen containing heterocyclic compounds of formula (I) are new. An aromatic group of formula (II) is bonded over at least one of the bonds denoted with asterisk, where asterisk in (II) characterizes further the bond for (I). In (I), if t he bond denoted with asterisk is not bonded to (II), than a residue R2 is bonded. (I) excludes (2-(9,9-dimethylacridin-10(9H)-yl)phenyl)(phenyl)methanone and (2-(10H-phenothiazin-10-yl)phenyl)(phenyl)methanone.    A = heteroaryl with 5-20 aromatic ring atoms, which is optionally substituted with at least one R1 and contains at least one heteroaromatic five-membered ring having at least two heteroatoms comprising N, O and S, at least one heteroaromatic six membered ring having at least one heteroatoms comprising N, O and S, a keto optionally substituted with at least one R1, phosphorus oxide optionally substituted with at least one R1, or sulfoxide optionally substituted with at least one R1;    Y1 = BR2, C(R2)2, C=O, Si(R2)2, NR2, O, S, S=O or S(=O)2;    X = CR1 or N and/or C bonded with A;    Z = CR2 or N;    Ar1 = aromatic or heteroaromatic ring having 5-30 aromatic ring atoms optionally substituted with at least one R1; either    R1 = 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, NO2, P(=O)(R3)2, OSO2R3, OR3, S(=O)R3, S(=O)2R3, straight chain alkyl, alkoxy or thio alkyl having 1-20C, branched or cyclic alkyl, alkoxy or thioalkyl having 3-20C, alkenyl or alkynyl having 2-20C, where the above mentioned groups are optionally substituted with at least one R3 and at least one CH2 groups mentioned in the above groups can be replaced by -R3C=CR3-, -CC-, Si(R3)2, C=O, C=S, C=NR3,-C(=O)O, -C(=O)NR3-, NR3, P(=O)(R3)-O-, -S-, SO or SO2 and at least one H mentioned above is replaced by D, F, Cl, Br, I, CN or NO2, aromatic ring with 6-30 aromatic ring atoms optionally substituted by at least one R3, or aryloxy with 6-30 aromatic ring optionally substituted by at least one R3; or    2 or more R1 = a ring; either    R2 = 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, S(=O)2R3, straight chain alkyl, alkoxy or thioalkyl having 1-20C, branched or cyclic alkyl, alkoxy or thioalkyl having 3-20C, alkenyl or alkynyl having 2-20C, where the above groups are substituted with at least one R3 residue, and at least one CH2 group mentioned in the above groups can be replaced by -R3C=CR3-, -CC-, Si(R3)2, C=O, C=S, C=NR3, -C(=O)O-, -C(=O)NR3-, NR3, P(=O)(R3), -O-, -S-, SO or SO2, and at least one H atom in the above mentioned groups is replaced by D, F, Cl, Br, I, CN or NO2, aromatic or heteroaromatic ring with 5-30 aromatic ring atoms optionally substituted by at least one R3, or aryloxy or heteroaryloxy with 5-60 aromatic ring optionally substituted by at least one R3; or    two or more R2 = a ring; either    R3 = H, D, F, Cl, Br, I, B(OR 4)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, S(=O)2R4, straight chain alkyl, alkoxy or thioalkyl having 1-20C, branched or cyclic alkyl, alkoxy or thioalkyl having 3-20C, alkenyl or alkynyl having 2-20C, where the above-mentioned groups are substituted by at least one R4 and at least one CH2 group mentioned in the above groups can be replaced by -R4C=CR4-, -CC-, Si(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 at least one H atom in the above-mentioned groups can be replaced by D, F, Cl, Br, I, CN or NO2, aromatic or heteroaromatic ring with 5-60 aromatic ring optionally substituted by at least one R4, or aryloxy or heteroaryloxy group with 5-60 aromatic ring atoms, which is substituted by at least one R4; or    two or more R3 = a ring; either    R4 = H, D, F or aliphatic, aromatic or heteroaromatic organic group with 1-20C, in which at least one H atom is replaced by D or F; or    two or more R4 = ring; and    n = 0-3.    Provided that: the residue R2 does not form a condensed ring with the ring system of (I); the group A is bonded in a meta or an ortho position at the aromatic six-membered ring, when the group (II) is attached to the nitrogen atom in (I). INDEPENDENT CLAIMS are also included for:    (1) an oligomer, polymer or dendrimer comprising (I), where the bonds to the polymer, oligomer or the dendrimer are localized at any position in (I), which is substituted with R1 or R2;    (2) a formulation comprising (I) or the polymer, oligomer or dendrimer, and at least one solvent; and    (3) preparing (I).