NOVELTY - Substituted heteroaryl compounds (I) are new.    USE - (I) are useful: in an electronic device, which is organic LED, organic field-effect transistors, organic thin-film transistors, organic light-emitting transistors, organic integrated circuits, organic solar cell, organic field-quench devices, light emitting electrochemical cell, organic photoreceptors or organic laser diode; and as a matrix material for phosphorescent dopant in an emitting layer, an electron transport material in an electron transport layer, a hole transport material in a hole transport layer and/or a hole block material in a hole block layer (all claimed).    ADVANTAGE - (I): exhibit high thermal stability; and provide increased life time, efficiency and low operating voltages to the electronic devices.    DETAILED DESCRIPTION - Substituted heteroaryl compounds of formula (I) are new.    W1 = N or CR1;    Y1 = N or CR2;    E = a covalent bond or a bivalent unit comprising N(R3), C(R3)2, Si(R3)2, C=O, C=NR3, C=C(R3)2, S, S=O, SO2, P(R3) or P(=O)R3;    X = a bivalent unit comprising C(R3)2, N(R3), Si(R3)2, C=O, C=NR3, C=C(R3)2, S, O, S=O, SO2, P(R3) or P(=O)R3, provided that if E is a covalent bond, then X is a bivalent unit comprising C(R3)2, Si(R3)2, C=O, C=NR3, C=C(R3)2, S, O, S=O, SO2, P(R3) or P(=O)R3;    n, m = 0 or 1, provided that the sum of n and m is 1 (preferred) or 2;    Ar1 = a bivalent or trivalent, mono- or polycyclic (hetero)aryl unit with 5-40 aromatic ring atoms (optionally substituted by R4a);    Ar2 = a mono- or polycyclic heteroaryl group with 5-40 ring atoms (optionally substituted by R4b), preferably pyridine, pyrazine, pyrimidine, pyridazine, 1,2,4-triazine, 1,3,5-triazine, quinoline, isoquinoline, quinoxaline, pyrazole, imidazole, benzimidazole, thiazole, benzothiazole, oxazole or benzooxazole;    L = a covalent bond or a bivalent unit comprising -C(O)-, -Ar3-C(O)- or -Ar2, provided that when the bivalent unit is -Ar3-C(O)-, then the group Ar3 is bonded to N and C(O) is bonded to Ar2;    Ar3 = a bivalent mono- or polycyclic (hetero)aryl unit with 5-40 aromatic ring atoms (optionally substituted by R4a or R4b);    R1, R2 = 1-40C-alkyl, 1-40C-alkoxy, 1-40C-thioalkoxy, cyclic 3-40C-alkyl, 3-40C-alkoxy, 3-40C-thioalkoxy, 2-40C-alkenyl, 2-40C-alkynyl (all optionally substituted by R5, where one or more non-adjacent CH2 groups are optionally replaced by R5C=CR5, C?=C, C=O, C=S, P(=O)(R5), SO, SO2, NR5, O, S or CONR5 and one or more H atoms are optionally replaced by D, F, Cl, Br, I, CN or NO2), H, D, F, Cl, Br, I, N(Ar4)2, C(=O)Ar4, P(=O)(Ar4)2, S(=O)Ar4, S(=O)2Ar4, CN, or a mono- or polycyclic (hetero)aryl with 5-40 ring atoms (optionally substituted by R6), or (hetero)aryloxy with 5-40 ring atoms (optionally replaced by R5), where two or more adjacent R1 and/or R2 are optionally bonded over a covalent bond or a bivalent group Z;    R3 = 1-40C-alkyl, 1-40C-alkoxy, 1-40C-thioalkoxy, cyclic 3-40C-alkyl, 3-40C-alkoxy, 3-40C-thioalkoxy, 2-40C-alkenyl, 2-40C-alkynyl (all optionally substituted by R5, where non-adjacent CH2 groups are optionally replaced by R5C=CR5, C?=C, Si(R5)2, Ge(R5)2, Sn(R5)2, C=O, C=S, C=Se, C=NR5, P(=O)(R5), SO, SO2, NR5, O, S or CONR5 and one or more H atoms are replaced by D, F, Cl, Br, I, CN or NO2), a mono- or polycyclic (hetero)aryl ring system with 5-40 aromatic ring atoms (optionally replaced by R6), or (hetero)aryloxy with 5-40 ring atoms (optionally replaced by R5), H, D, F, Cl, Br, I, N(Ar3)2, C(=O)Ar3, P(=O)(Ar3)2, S(=O)Ar3, S(=O)2Ar3, CR5=CR5Ar3, CN, NO2, Si(R5)3, B(OR5)2 or OSO2R5, where two or more adjacent R3 are bonded over a covalent bond or a bivalent group Z;    R4a, R4b = 1-40C-alkyl, 1-40C-alkoxy, 1-40C-thioalkoxy, cyclic 3-40C-alkyl, 3-40C-alkoxy, 3-40C-thioalkoxy, 2-40C-alkenyl, 2-40C-alkynyl (all optionally substituted by R5, where one or more non-adjacent CH2 groups are optionally replaced by R5C=CR5, C?=C, C=O, C=S, P(=O)(R5), SO, SO2, NR5, O, S or CONR5, and one ore more H atoms are replaced by D, F, Cl, Br, I, CN or NO2), or a mono- or polycyclic (hetero)aryl ring system with 5-40 ring atoms (optionally substituted by R6), (hetero)aryloxy with 5-40 ring atoms (optionally replaced by R5), D, F, Cl, Br, I, N(Ar4)2, C(=O)Ar4, P(=O)(Ar4)2, S(=O)Ar4, S(=O)2Ar4 or CN, where two or more adjacent R4a or R4b are bonded over a covalent bond or a bivalent group Z;    Ar4 = a mono- or polycyclic (hetero)aryl ring with 5-40 ring atoms (optionally replaced by R6);    R5 = 1-20C-alkyl, cyclic 3-20C-alkyl (where one or more non-adjacent CH2 groups are optionally replaced by NH, O or S and one or more H atoms are optionally replaced by F), or a mono- or polycyclic (hetero)aryl ring system with 5-20 atoms (optionally replaced by R6), H or D, where two or more R5 are bonded over a covalent bond or a bivalent group Z;    R6 = 1-20C-alky, cyclic 3-20C-alkyl (where one or more non-adjacent CH2 groups are optionally replaced by NH, O or S and one or more H atoms are replaced by F), H, D, F or CN, where two or more R6 are bonded over a covalent bond or a bivalent group Z;    Z = a bivalent group (CH2)q; and    q = 1-5, preferably 1 or 2.    INDEPENDENT CLAIMS are included for:    (1) the preparation of (I);    (2) a polymer, oligomer or dendrimer comprising (I), where one or more H atoms of (I) are bonded to the polymer, oligomer or dendrimer;    (3) a mixture comprising (I) and/or polymer, oligomer and/or dendrimer with one or more emitting compounds; and    (4) a formulation comprising (I) and/or polymer, oligomer and/or dendrimer or the mixture, and an organic solvent.