NOVELTY - A 2,7-disubstituted carbazole is new.    USE - The invention is for making oligomer, polymer and/or co-polymer film used as fluorescent coating, electronic protective layer and in polymeric light-emitting diode for electronic device, particularly electroluminescent device such as light emitting diode, photocell (e.g. photovoltaic device, solar cell, photodiode or photodetector), photo conductor or metal-insulator-semi conductor field effect transistor. All claimed.    ADVANTAGE - The oligomers, polymers and copolymers of the invention do not contain misformed polynuclear structures or bonding through positions other than the 2- and 7'-positions. The polymers have good solubility characteristics and relatively high glass transition temperatures, which facilitate their fabrication into coatings and films that are relatively, thermally stable and free of defects. If the polymers contain end groups which are capable of being cross-linked, the cross linking of such groups after the films or coating is formed increases the solvent resistance, which is beneficial in applications where one or more solvent-based layers of material are deposited. The polymers and copolymers have excellent solubility (greater than 1 g/L) in common organic solvents, has the ability to form pin-hole free films and has weight-average molecular weights of at least3000 g/mole relative to polystyrene standard, preferably at least20000 g/mole. They have polydispersity of less than 10, preferably less than 3, and high fluorescence quantum efficiencies. The polymer exhibits photoluminescent emission of 350-1000 nm and an absorption of 200-600 nm.    DETAILED DESCRIPTION - A 2,7-disubstituted carbazole of formula (I) is new.    R1, R2 = halo, B(OH)2, B(OR7)2, Sn(R8)3, 1-20C hydrocarbyl or 1-20C hydrocarbyl comprising heteroatom(s);    R3 = H, 1-20C hydrocarbyl, 1-20C hydrocarbyl comprising heteroatom(s), or cyano;    R4, R5 = H, halo, 1-20C hydrocarbyl, 1-20C hydrocarbyl comprising heteroatom(s) or cyano;    R7, R8 = 1-20C hydrocarbyl provided that R4 and R5 are not both H when R3 is n-octyl.    INDEPENDENT CLAIMS are also included for the following:    (a) a conjugated oligomer or polymer comprising at least10% of the repeating unit of formula (II);    (b) production of oligomer or polymer comprising subjecting a carbazole to a polycondensation reaction in the presence of a transition metal;    (c) a conjugated co-polymer of formula (III);    (d) a polymer blend comprising 1-99 wt.% carbazole(s)-containing polymer of (II) or (III);    (e) a film comprising at least0.1 wt.% oligomer, polymer or co-polymer of (I), and;    (f) production of compounds of formula(I).    R3 (for (II)) = 1-20C hydrocarbyl, 1-20C hydrocarbyl comprising heteroatom(s) or cyano;    n (for (II)) = degree of polymerization which is greater than 4 as measured by gel permeation chromatography;    R6 = aryl or heteroaryl repeating unit;    x = greater than 0.1 but less than 0.9;    y = greater than 0.01 but less than 0.9;    x+y = 1;    n (for (III)) = greater than 1.