NOVELTY - Substituted indole compounds (I) are new.    USE - (I) are useful in preparing polymer and in photoactive semiconductive material (polymer thin film) and for forming polymer thin film. The polymer thin film is useful in device comprising solar cell, transistor, fuel cell, lighting device, or display screen (all claimed), light emitting diodes such as polymeric light emitting diodes and organic light emitting diodes, various sensors and biosensors, circuitry, thermoelectrics and organic electronics, pigment particles for a variety of coating materials e.g. conductive coatings, metal remediation of drinking water, actuators, electrostatic shields, and electromagnetic shields and in semiconductive ink composition.    ADVANTAGE - (I) provide robust, processable synthetic eumelanin polymers with desired ranges of light absorption, charge mobility, film forming properties, reactivity, durability and longevity. The polymer thin film is prepared without the use of petroleum starting materials/feedstocks.    DETAILED DESCRIPTION - Substituted indole compounds of formula (I) are new.    R1-R4 = alkyl, alkylester, alkoxy, aryloxy, polyethylene glycol (PEG) (all optionally substituted), H, macroinitiator, polymer or crosslinker;    A1, A2 = halo, R3Sn, B(OR)2, triflate, SiR3, or Si(OR) 3; and    P1 = H or protecting moiety.    INDEPENDENT CLAIMS are also included for:    (1) preparing (I);    (2) substituted polyindole compounds of formula (II);    (3) forming polymer comprising reacting 4,7-dibromo-5,6-dimethoxy-N-methyl- I H-indole-2-carboxylate (DBI) with compound of formula (X1-UCP1-X2), and forming a covalent bond at positions 4 and 7 of the DBI or reacting DBI with substituted phenyl compounds of formula (37a);    (4) solution comprising many polymers, and/or many unpolymerized or partially polymerized repeat units of it and a solvent;    (5) making a photoactive semiconductive material comprising applying the solution to a substrate, allowing the solvent to evaporate from substrate, thus forming photoactive semiconductive material on substrate; and    (6) composition comprising the polymer and fullerene.    UCP = (if present) unsaturated carbon pair which is connected directly to a repeat unit of the polymer or is connected indirectly to a repeat unit of the polymer through a optionally substituted aromatic;    n = 10-1000;    P2 = H or protecting moiety where protecting moiety is methyl, ethyl, PEG, carbamate, an acetamides, benzyl, or tosylamide;    UCP1 = unsaturated carbon pair;    X1, X2 = chemical groups capable of displacing Br, preferably X1 and X2 are Bu3Sn;    Y1-Y4 = H or optionally saturated, optionally branched, optionally substituted 1-30C alkyl or OR; and    R = H or optionally saturated, optionally branched, optionally substituted 1-30C alkyl, preferably if UCP is double bond, Y1, Y4 is H, and Y2, Y3 are RO and R is dodecyl or if UCP is triple bond, Y1, Y4 is H, Y2, Y3 is RO and R is dodecyl or 2-ethylhexyl.