Method for the production of thiophene oligomers

1. Process for polymerizing at least one thiophene derivative having at least two leaving groups to oligomers having molecular weights of from 1,000 to 3,000, the polymerization proceeding by means of an organometallic thiophene compound and of at least one catalyst at a catalyst concentration, based on the molar amount of the thiophene derivative used, of ≧0.05-≦0.85 mol %, a pressure of 4 to 15 bars and a temperature of ≧120° C.-≦140° C.

2. Process according claim 1 , wherein said at least one thiophene derivative contains at least one leaving group selected from the group consisting of halogens, sulphates, sulphonates and diazo groups.

3. Process according to claim 1 , wherein the leaving groups of the at least one thiophene derivative are identical.

4. Process according to claim 1 , wherein the organometallic thiophene compound contains at least one metal selected from the group consisting of zinc, magnesium, tin and boron.

5. Process according to claim 1 , wherein said at least one catalyst comprises nickel, palladium or both nickel and palladium.

6. Process according to claim 1 , wherein said at least one thiophene derivative comprises at least one compound of the formula:

where R is selected from the group consisting of hydrogen, hydroxyl, halogen, pseudohalogen, formyl, carboxyl derivatives, carbonyl derivatives, alkyl, long-chain alkyl, alkoxy, long-chain alkoxy, cycloalkyl, haloalkyl, aryl, arylene, haloaryl, heteroaryl, heteroarylene, heterocycloalkylene, heterocycloalkyl, haloheteroaryl, alkenyl, haloalkenyl, alkynyl, haloalkynyl, keto, ketoaryl, haloketoaryl, ketoheteroaryl, ketoalkyl, haloketoalkyl, ketoalkenyl, haloketoalkenyl, phosphoalkyl, phosphonates, phosphates, phosphine, phosphine oxide, phosphoryl, phosphoaryl, sulphonyl, sulphoalkyl, sulphoarenyl, sulphonate, sulphate, sulphone, amine, polyether, silylalkyl and silylalkyloxy, where, in the case of radicals having one or more nonadjacent CH 2 groups, one or more of said nonadjacent CH 2 groups are optionally independently replaced by —O—, —S—, —NH—, —NR—, —SiRR—, —CO—, —OOO—, —OOO—, —OOO—O—, —SO 2 —, —S—OO—, —CO—S—, —CY 1 ═CY 2 or —C≡C—, and in such a way that oxygen and/or sulphur atoms are not bonded directly to one another, with terminal CH 3 groups being interpreted as CH 2 groups in the sense of CH 2 —H

and where X and X′ are each independently a leaving group.

7. Process according to claim 5 , wherein said at least one catalyst comprises at least one compound selected from the group consisting of nickel and palladium catalysts with ligands selected from the group consisting of tri-tert-butylphosphine, triadamantylphosphine, 1,3-bis(2,4,6-trimethylphenyl)imidazolidinium chloride, 1,3-bis(2,6-diisopropylphenyl)-imidazolidinium chloride or 1,3-diadamantylimidazolidinium chloride or mixtures thereof; bis(triphenylphosphino)palladium dichloride (Pd(PPh 3 )Cl 2 ), palladium(II) acetate (Pd(OAc) 2 ), tetrakis(triphenylphosphine)palladium (Pd(PPh 3 ) 4 ), tetrakis(triphenylphosphine)nickel (Ni(PPh 3 ) 4 ), nickel(II) acetylacetonate Ni(acac) 2 , dichloro(2,2′-bipyridine)nickel, dibromobis(triphenylphosphine)nickel (Ni(PPh 3 ) 2 Br 2 ), bis(diphenylphosphino)propanenickel dichloride (Ni(dppp)Cl 2 ) or bis(diphenylphosphino)ethanenickel dichloride Ni(dppe)Cl 2 and mixtures thereof.

8. Process according to claim 1 , wherein said catalyst concentration is ≧0.15-≦0.75 mol %.

9. Process according to claim 8 , wherein said catalyst concentration is ≧0.25-≦0.55 mol %.

10. Process according to claim 9 , wherein said catalyst concentration is, ≧0.35-≦0.45 mol %.

11. Process according to claim 1 , wherein said pressure is in the range of ≧4-≦10 bar.

12. Process according to claim 6 , wherein said leaving groups are selected from the group consisting of Cl, Br and I.