NOVELTY - Substituted pyrene compounds (I), are new.    USE - (I) is useful: as organic semiconductor; and in transistors and electronic devices (all claimed). (II) is useful in solar cell, a memory device, an organic light emitting diode, a photosensor and a laser device.    ADVANTAGE - (I) has excellent coplanarity and easily transfers charge between molecules to provide good semiconductor, and improves miscibility with carbon nanotube, fullerene and graphene and has good oxidation stability and electrical reliability.    DETAILED DESCRIPTION - Substituted pyrene compounds of formula (I), are new.    X1-X4 = S, N or CR50;    R50 = 1-20C alkyl, 6-20C aryl (both optionally substituted) or H; either    R1-R6 = 1-20C alkyl, 3-20C cycloalkyl, 1-20C alkoxy, 3-20C cycloalkyloxy, 6-30C aryl, 6-30C aryloxy, 2-30C heteroaryl (all optionally substituted), H, halo, 2-30C heteroaromatic ring including at least one electron withdrawing imine nitrogen atom or 2-30C heteroaromatic ring including at least one sulfur atom, NR51R52, C(O)OR53 or C(O)NR54R55; or    two adjacent substituents of R1-R6 = linked to each other to provide one of a thiophenyl ring group fused with a pyrene moiety and a thiazolyl ring group fused with a pyrene moiety;    R51-R55 = 1-20C alkyl, 3-20C cycloalkyl, 6-30C aryl, 2-30C heteroaryl (all optionally substituted) or H; and    R7, R8 = 1-20C alkyl, 3-20C cycloalkyl, 1-20C alkoxy, 3-20C cycloalkyloxy, 6-30C aryl, 6-30C aryloxy, 2-30C heteroaryl (all optionally substituted), H, halo, 2-30C heteroaromatic ring including at least one electron withdrawing imine nitrogen atom or 2-30C heteroaromatic ring including at least one sulfur atom, NR51R52, C(O)OR53 or C(O)NR54R55.    Provided that (i) when at least one of X1 and X2 is S, and the other one of X1 and X2 is CR50, and (ii) when at least one of X3 and X4 is S, and the other one is CR50, at least one of R1-R6 is one of a 2-30C heteroaromatic ring group including at least one electron withdrawing imine nitrogen atom, and two adjacent substituents of R1-R6 are linked to each other to provide one of a thiophenyl ring group fused with a pyrene moiety and a thiazolyl ring group fused with a pyrene moiety. INDEPENDENT CLAIMS are included for:    (1) substituted pyrene polymer of formula (II); and    (2) a transistor (10) comprising (I) and (II).    Ar1, Ar2 = 6-30C aromatic ring, 4-14C heteroaromatic ring or 6-30C condensed polycyclic (all optionally substituted); and    p, q = 0-10, when p or q are each 2 or more, many of Ar1 and Ar2 are the same or different from each other.    DESCRIPTION OF DRAWING(S) - The figure shows a cross-sectional view of a transistor.    Transistor (10)    Substrate (12)    Gate electrode (14)    Insulation layer (16)    Source electrode. (17a)