NOVELTY - Heterocyclic compounds (I) are new.    USE - (I), oligomer, polymer or dendrimer or the composition is useful in an electronic device as a hole-blocking material, electron injection material and/or electron transport material.    ADVANTAGE - (I ) can be processed in an easy manner and exhibits good solubility and film formation. The electronic device exhibits improved efficiency, operating voltage and improved durability and is cost efficient.    DETAILED DESCRIPTION - Heterocyclic compounds of formula (I), are new.    X=X, O, NR, S, SO, SO2, PR, POR or BR;    X1, X=CR (preferred) or N, where X1 comprises no benzene derivative of formula (XIV); either    Y1=CR11;    R, R11=H, D, F, Cl, Br, I, N(R1)2, CN, NO2, OH, COOH, C(=O)N(R1)2, Si(R1)3, B(OR1)2, C(=O)R1, P(=O)(R1)2) S(=O)R1, S(=O)2R1, OSO2R1, straight chain 1-20C alkyl, 1-20C alkoxy, 1-20C thioalkoxy, 2-20C alkenyl, 2-20C alkynyl, branched or cyclic 3-20C alkyl, 3-20C alkoxy, 3-20C thioalkoxy (which is substituted with R1, where at least one non adjacent CH2 is replaced by R1C=CR1, CC, Si(R1)2, C=O, NR1, O, S or CONR1 and at least one H is replaced by D, F, Cl, Br, I or CN), aromatic or heteroaromatic ring system with 5-60 aromatic ring atoms (which is substituted by R1), aryloxy or heteroaryloxy with 5-40 aromatic ring atoms (which is substituted by R1), aralkyl- or heteroaralkyl with 5-40 aromatic ring atoms (which is substituted by R1), diarylamino, diheteroarylamino or arylheteroarylamino with 10-40 aromatic ring atoms (which is substituted by R1); or    2R=mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system;    R11+Y1+C = cyclopentene derivative of formula (V) or (VI), cyclohexene derivative of formula (VII) or (VIII), cycloheptene derivative of formula (IX), (X) or (XI);    2Y1 = cyclohexadiene of formula (XII) or cyclohexene of (XIII);    R1 = H, D, F, Cl, Br, I, N(R2)3, CN, NO2, Si(R2)3, B(OR2)2, C(=O)R2, P(=O)(R2)2, S(=O)R2, S(=O)2R2, OSO2R2, straight chain 1-20C alkyl, 1-20C alkoxy, 1-20C thioalkoxy, 2-20C alkenyl, 2-20C alkynyl, branched or cyclic 3-40C alkyl, 3-40C alkoxy, 3-40C thioalkoxy (which is substituted with R2, where at least one non adjacent CH2 is replaced by R2C=CR2, CC, Si(R2)2, C=O, NR2, O, S or CONR2 and at least one H is replaced by D, F, Cl, Br, I, CN or NO2, aromatic or heteroaromatic ring system with 5-60 aromatic ring atoms which is substituted with R2), aryloxy- or heteroaryloxygruppe with 5-40 aromatic ring atoms (which is substituted with R2), aralkyl- or heteroaralkyl with 5-40 aromatic ring atoms (which is substituted with R2), diarylamino, diheteroarylamino- or arylheteroarylamino with 10-40 aromatic ring atoms (which is substituted with R2); or    2R, R1R = mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system; either    R2 = H, D, F or aliphatic, aromatic and/or heteroaromatic 1-20C hydrocarbon (where at least one H is replaced by H); or    2R2 = mono- or polycyclic, aliphatic ring system;    A1, A2 = C(R3)2, O, S, NR3 or C(=O);    A3 = C(R1)2) O, S, NR3 or C(=O);    G = O, S, N (R2), B(R2), Si (R2)2, C=O, C=NR2, C=C(R2)2, S=O, SO2, P(R2) or P(= O)R2, 1, 2, or 3C alkylene which is substituted with R2, -CR2=CR2 or ortho-linked arylene or heteroarylene with 5-14 aromatic ring atoms which is substituted with R2;    R3 = F, straight chain 1-10C alkyl, 1-10C alkoxy, branched or cyclic 3-10C alkyl, 3-10C alkoxy (which is substituted with R2, where at least one non adjacent CH2 is replaced by R2C=CR2, C=C, Si(R2)2, C=O, NR2, O, S or CONR2 and at least one H is replaced by D or F), aromatic or heteroaromatic ring system with 5-24 aromatic ring atoms (which is substituted with R2), aryloxy- or heteroaryloxy with 5-24 aromatic ring atoms (which is substituted with R2), or aralkyl- or heteroaralkyl with 5-24 aromatic ring atoms (which is substituted with R2);    2R3C = aliphatic or aromatic ring system, where 2R3 is clamped to spirosystem; and    R3+adjacent R, R3+R1 = aliphatic ring system.    INDEPENDENT CLAIMS are also included for:    (1) an oligomer, dendrimer or polymer comprising (I), where at least one bond is present from the (I) to the polymer, oligomer or dendrimer;    (2) a composition comprising (I) and/or the oligomer, polymer or dendrimer and at least one additional organic functional material;    (3) a formulation comprising (I), the oligomer, polymer or dendrimer, at least one composition and at least one solvent;    (4) preparing (I); and    (5) an electronic device comprising (I), oligomer, polymer or dendrimer or the composition, where the electronic device is organic integrated circuits, organic field-effect transistors, organic thin film transistors, organic electroluminescent devices, organic solar cells, organic optical detectors or organic photoreceptors.