NOVELTY - Phenyl-cyclopentane compounds (A), are new.    USE - (A) are useful in electronic devices such as an organic electroluminescence device (organic light-emitting diode, polymer light-emitting diode), organic field-effect-transistors, organic thin-film transistors, organic light-emitting transistors, organic integrated control, organic solar cells, organic field-quench-device, light-emitting electro-chemical cells, organic laser diode or organic photon receptor. (A) (where R1 is a simple or condensed aryl- or heteroaryl group) are useful as a host for a fluorescent dopant. (A) (where R1 and/or X are C=O, P(=O) and/or SO2) are useful as a matrix for phosphorescent dopant. (A) (where R1 is vinylaryl unit, at least a vinylarylamine unit and/or at least an arylamino unit) are useful as an emitting material. (A) (where R1 is N(Ar)2) optionally recouped with an electron withdrawing compound are useful as a hole carrier material or as a hole injection material, preferably as a hole-transport- or as a hole injection layer. (A) (where R1 is C=O, P(=O) and/or SO2) optionally recouped with an electron donor compound are useful as an electron transport material (all claimed).    ADVANTAGE - (A) is thermally stable, highly efficient, easily accessible and exhibits high lifetime.    DETAILED DESCRIPTION - Phenyl-cyclopentane compounds (A) of formulae (1)-(4), are new.    Y1 = CR1 or N;    Z = C, if Z is bound by a bridge X, or Y1, if Z not bound by a bridge X;    X = a bivalent bond, such as B(R1), C(R1)2, Si(R1)2, C = O, C=NR1, C=C(R1)2, O, S, S=O, SO2, N(R1), P(R1) or P(O)R1; either    R1 = H, F, Cl, Br, I, CHO, N(Ar)2, C(=O)Ar, P(=O)Ar2, S(=O)Ar, S(=O)2Ar, CR2=CR2Ar, CN, NO2, Si(R2)3, B(OR2)2, OSO2R2, alkyl-, alkoxy- or thioalkoxy group with 1-40C atoms or a branched or cyclic alkyl-, alkoxy- or thioalkoxy group with 3-40C atoms, which is substituted with one or more residues of R2, where one or more non-adjacent CH2-group is substituted by R2C=CR2, C=C, Si(R2)2, Ge(R2)2, Sn(R2)2, C=O, C=S, C=Se, C=NR2, P(=O)(R2), SO, SO2, NR2, O, S or CONR2, and one or more H atom is substituted by F, Cl, Br, I, CN or NO2, or 5-40 membered aromatic or heteroaromatic ring system is substituted with one or more residues of R2, and/or an aryloxy- or heteroaryloxy group with 5-40 aromatic rings that is substituted with one or more residues of R2; or    two or more adjacent R1 = a mono- or polycyclic aliphatic ring system;    Ar = an aromatic or heteroaromatic ring system with 5-30 aromatic ring atoms that is substituted with one or more non-aromatic residues R1, where two residues of Ar are bonded to the same N or P-atom, through a single bond or a bridge, such as B(R1), C(R1)2, Si(R1)2, C=O, C=NR1, C=C(R1)2, O, S, S=O, SO2, N(R1), P(R1) or P(=O)R1; either    R2 = H or an aliphatic, aromatic and/or heteroaromatic 1-20C hydrocarbon residue, in which H is substituted by F; or    two or more adjacent R2 = a mono- or polycyclic, aliphatic or aromatic ring system; and either    a-d = 0 (preferred) or 1; or    a+b, c+d = 1 or 2.    Where X is not available in the corresponding bridge. INDEPENDENT CLAIMS are included for:    (1) a polymer, oligomer or dendrimer containing (A);    (2) the preparation of (A);    (3) the preparation of a functionalized (A);    (4) a device containing an anode, cathode and at least an organic layer containing (A); and    (5) an organic electroluminescence device comprising cathode, anode, one or more emitting layer and optionally further layer such as hole injection layer, hole carrier layer, electron carrier layer, electron injection layer and/or charge-generation layer.