NOVELTY - Preparing conjugated polymers, comprises adding a solution of at least one organometallic complex in a solvent, to a nickel or palladium catalyst. The organometallic complex is prepared by adding metallic zinc or magnesium to a solution of at least one monomer in a solvent, or by adding at least one reducing agent comprising lithium naphthalenide, sodium naphthalenide or potassium naphthalenide, to a solution of at least one monomer and a salt containing zinc(II) or magnesium(II) ions, in a solvent. The monomer comprises pi -conjugated hydrocarbon compounds (I).    USE - The conjugated polymer is useful for producing flexible and lightweight optoelectronic components, preferably polymer light-emitting diodes, polymer solar cells and organic thin film transistors.    ADVANTAGE - The method has less technological steps, which reduces the energy consumption, and thus it is economic, and produces the conjugated polymers in high yields.    DETAILED DESCRIPTION - Preparing conjugated polymers, comprises adding a solution of at least one organometallic complex in a solvent, to a nickel or palladium catalyst. The organometallic complex is prepared by adding metallic zinc or magnesium to a solution of at least one monomer in a solvent, or by adding at least one reducing agent comprising lithium naphthalenide, sodium naphthalenide or potassium naphthalenide, to a solution of at least one monomer and a salt containing zinc(II) or magnesium(II) ions, in a solvent. The monomer comprises pi -conjugated hydrocarbon compounds of formula (X-B1-A-B1-X) (I).    A = core based on electron acceptor materials, preferably naphthalene-1,4,5,8-tetracarboxylic acid bisimide-, perylenetetracarboxylic bisimide-, pyromellitic bisimide- or diketopyrrolopyrrole moiety;    B1 = (hetero)aromatic moiety or fused (hetero)aromatic moiety (both substituted), preferably benzene-, fluorene-, thiophene-, bithiophene-, pyrrole-, thieno(2,3-b)thiophene-, 4H-cyclopenta(2,1-b:3,4-b')dithiophene- or dithieno(3,2-b:2',3'-d)silole moiety (all optionally substituted); and    X = halo.