NOVELTY - Piperidine derivatives (I) are new.    USE - (I) are useful: in electronic devices, preferably 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-quenching devices, light-emitting electrochemical cells, organic laser diodes and organic electroluminescent devices; as hole transport material in hole transport layer and/or in hole injection layer of organic electroluminescent device; as an emitting material in an emitting layer of organic electroluminescent device, preferably in combination with a host material (all claimed).    ADVANTAGE - The use of (I) in electronic devices ensures the operation of the device at low voltage and the device exhibits a long life time. (I) exhibits flexible geometry and lower tendency to crystallize.    DETAILED DESCRIPTION - Piperidine derivatives of formula (I) are new.    X = divalent bridge comprising 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;    A1 = aromatic ring with 10-40 aromatic ring atoms or heteroaromatic ring with 5-40 aromatic ring atoms (both optionally substituted by at least one R1);    A2-A5 = aromatic or heteroaromatic ring with 5-40 aromatic ring atoms (both optionally substituted by at least one R1);    R1 = H, D, halo, CHO, N(R3)2, N(A6)2, C(=O)A6, P(=O)(A6)2, S(=O)A6, S(=O)2A6, CR3=CR3A6, CN, NO2, Si(R3)3, B(OR3)2, OSO2R3, straight chain 1-40C alkyl, 1-40C alkenyl, 1-40C alkoxy or 1-40C thioalkoxy and branched monocyclic or polycyclic 3-40C alkyl, 3-40C alkenyl, 3-40C alkoxy and 3-40C thioalkoxy, which can be substituted with at least one R3, where at least one non-adjacent CH2 can be replaced by R3C=CR3, C=C, Si(R3)2, Ge(R3)2, Sn(R3)2, C=O, C=S, C=Se, C=NR2, P(=O)(R3), SO, SO2, NR3, O, S or CONR3, and where at least one H can be replaced by F, Cl, Br, I, CN or NO2 or (hetero)aromatic ring with 5-40C aromatic ring atoms, which can be substituted with at least one R2 and/or (hetero)aryloxy with 5-40 aromatic ring atoms which can be substituted with at least one R2 or two or more adjacent R1 together forms a mono- or polycyclic, aliphatic or aromatic ring;    R2 = H, D, F, Cl, Br, I, CHO, N(R3)2, N(A6)2, C(=O)A6, P(=O)(A6)2, S(=O)A6, S(=O)2A6, CR3=CR3A6, CN, NO2, Si(R3)3, B(OR3)2, OSO2R3, straight chain 1-40C alkyl, 1-40C (thio)alkoxy and/or branched monocyclic or polycyclic 3-40C alkyl, 3-40C (thio)alkoxy, which can be substituted with at least one R3, where at least one non-adjacent CH2 can be replaced by R3C=CR3, C=C, Si(R3)2, Ge(R3)2, Sn(R3)2, C=O, C=S, C=Se, C=NR2, P(=O)(R3), SO, SO2, NR3, O, S or CONR3, and where at least one H can be replaced by halo, CN or NO2; or two or more adjacent R2 together forms a mono- or polycyclic, aliphatic or aromatic ring;    R3 = H, F or aliphatic, aromatic and/or heteroaromatic 1-20C hydrocarbon in which H can be replaced by F; or two or more adjacent R3 together forms a mono- or polycyclic, aliphatic or aromatic ring;    A6 = (hetero)aromatic ring with 5-30 aromatic ring atoms (optionally substituted with at least one R3); or    two residues A6 = single bond or bridge comprising B(R3), C(R3)2, Si(R3)2, C=O, C=NR3, C=C(R3)2, O, S, S=O, SO2, N(R3), P(R3) or P(=O)R3, forms bond with the same N or P;    m1-6 = 0 or 1; and    n = 1-3.    Provided that: if m is 0, then X is H or R1 is present, and where at least one of the indices m1, m3, m4 and/or m6 is 1. INDEPENDENT CLAIMS are also included for:    (1) an oligomer, polymer or dendrimer comprising at least one (I), where at least one substituent of (I) forms a bond with the oligomer, polymer or dendrimer; and    (2) preparation of (I).