WO2010115623A1

WO2010115623A1 - Oligomeric and polymeric semiconductors based on thienothiazoles

Info

Publication number: WO2010115623A1
Application number: PCT/EP2010/002195
Authority: WO
Inventors: Timo Meyer-Friedrichsen
Original assignee: H.C.Starck Clevios Gmbh
Priority date: 2009-04-08
Filing date: 2010-04-08
Publication date: 2010-10-14
Also published as: EP2417177A1; TW201038619A; DE102009016502A1

Abstract

The invention relates to novel organic semiconducting compounds containing thienothiazole units, the preparation thereof and their use in electronic components.

Description

Oligomeric and polymeric semiconductors based on thienothiazoles

The invention relates to novel organic semiconducting compounds containing thienothiazole units, the preparation thereof and their use in electronic compo- nents.

The field of molecular electronics has developed rapidly in the last 15 years with the discovery of organic conducting and semiconducting compounds. During this time a large number of compounds which have semiconducting or electro-optical properties have been found. It is general understanding that molecular electronics will not displace conventional semiconductor units based on silicon. Instead, it is assumed that molecular electronic components will open up novel fields of use in which suitability for coating large areas, structural flexibility, processability at low temperatures and low costs are required. Semiconducting organic compounds are currently being developed for fields of use such as organic field effect transistors (OFETs), organic light-emitting diodes (OLEDs), sensors and photovoltaic elements. By simple structuring and integration of OFETs in integrated organic semiconductor circuits, inexpensive solutions for intelligent cards (smart cards) or price tags, which could not be realized hitherto with the aid of silicon technology because of the price and lack of flexibility of the silicon units, become possible. OFETs could likewise be used as circuit elements in large-area flexible matrix displays. An overview of organic semiconductors, integrated semiconductor circuits and uses thereof is given, for example, in H. Klauk (editor), Organic Electronics, Materials, Manufacturing and Applications, Wiley- VCH 2006.

A field effect transistor is a three-electrode element in which the conductivity of a narrow conduction channel between two electrodes (called "source" and "drain") is controlled by means of a third electrode (called "gate") separated from the conduction channel by a thin insulating layer. The most important characteristic properties of a field effect transistor are the mobility of the charge carriers, which decisively determine the circuit speed of the transistor, and the ratio between the cur- rents in the switched and unswitched state, the so-called "On/Off ratio".

In organic field effect transistors, two large classes of organic compounds have been used hitherto. The organic compounds of both classes have continuous conjugated units and are classified into conjugated polymers and conjugated oli- gomers, depending on the molecular weight and structure.

Oligomers as a rule have a uniform molecular structure and a molecular weight below 10,000 Dalton. Polymers as a rule are made up of chains of uniform repetitive units with a molecular weight distribution. However, there is a fluid transition between oligomers and polymers.

The distinction between oligomers and polymers is often made to express the fact that there is a fundamental difference in the processing of these compounds. Oligomers often can be vaporized and are applied to substrates via vapour deposition processes. Compounds which can no longer be vaporized and are therefore applied via other processes are often called polymers, regardless of their molecular structure. In the case of polymers, as a rule compounds are sought which are soluble in a liquid medium, for example in organic solvents, and can then be applied via appropriate application processes. A very widely used application process is e.g. the "spin coating" process. Application of semiconducting compounds via the ink-jet process is a particularly elegant method. In this process, a solution of the semiconducting compound is applied to the substrate in the form of very fine droplets and dried. This process allows structuring to be carried out during the application. A description of this application process for semiconducting compounds is described, for example, in Nature, volume 401, p. 685.

A greater potential for arriving at inexpensive organic integrated semiconductor circuits by a simple method and manner is generally attributed to the wet chemistry processes.

An important prerequisite for the production of high quality and at the same time inexpensive organic semiconductor circuits are compounds with the highest possible storage and operating stability, in order to avoid expensive encapsulation against oxygen in the atmosphere and moisture. The purity of the semiconductors is to be mentioned as a parameter which influences the stability. Impurities, for example, can inject charges into the semiconducting compound ("doping") and thus reduce the On/Off ratio, or serve as charge traps and thus drastically reduce the mobility. Impurities can furthermore also initiate the reaction of the semiconducting compounds with oxygen or moisture, and oxidizing impurities may oxidize the semiconducting compounds and thus shorten possible storage, processing and operating times. A further parameter is the oxidation potential of the com- pounds. A low oxidation potential leads to a higher sensitivity towards oxidation of the compound by, for example, oxygen in the atmosphere.

Order phenomena furthermore play a major role in the electrical properties of the compounds in organic semiconductors. Impeding a uniform alignment of the compounds and emphasizing of grain boundaries lead to a dramatic drop in the macroscopic semiconductor properties. Currently the most important representative of semiconducting polymers is the regioregular poly(3-hexylthiophene-2,5-diyl) (P3HT) (A-I)

which reaches mobilities of up to 0.1 cm²/Vs (Science, 1998, volume 280, p. 1741). In formula (A-I) and the formulae shown below, linkage with the other units takes place via the positions labelled with *.

Like almost all long-chain polymers, poly(3-hexylthiophene-2,5-diyl) forms good films after application from solution and is therefore easy to process. The hexyl chains ensure on the one hand adequate solubility, and on the other hand, due to their regioregular alignment, a substantial macroscopic order of the chains in the film. A decisive weak point of this compound is the relatively low oxidation po- tential of approx. 4.8 eV. This leads to a slow oxidative doping of the semiconductor layers of P3HT by oxygen in the atmosphere (Chemistry of Materials, 2007, volume 19, p. 1472).

There have therefore been attempts to improve, by modification of the polymer skeleton, both the stability to oxygen in the atmosphere and the ability to form ordered structures. The reduction of the alkyl chains, for example, in poly(3,3'"- dialkyl quater thiophene) (PQT) (A-III)

leads to an increased ionization potential of 4.9 eV and mobilities of 0.07 - 0.12 cm²/Vs (Journal of the American Chemical Society, 2004, volume 126, p. 3378). By fusing the middle thiophenes to give the thienothiophene, with poly(2,5-bis(3- alkylthiophen-2-yl)thieno[3,2-b]thiophenes) (pBTTT) (A-IV)

mobilities of 0.2 - 0.6 cmVVs and an ionization potential of 5.1 eV are achieved (Nature Materials, 2006, volume 5, p. 328). A comparison of the properties of polymers of the conceptional structures described above is described in Chemistry - A European Journal, 2008, volume 14, p. 4766.

Finally, it has recently also been possible to obtain polymers which contain the thiazolothiazole group, which has a lower electron density, compared to the thie- nothiophene unit. However, the poly(2,5-bis(3-dodecylthiophen-2-yl)- thiazolo[5,4-d]thiazole) obtained, (A-V),

is insoluble. Poly(2,5-bis(3-dodecyl-5-(3-dodecylthiophen-2-yl)thiophen-2-yl)- thiazolo[5,4-d]thiazole) (A-VI)

on the other hand, is soluble and has an ionization potential of 5.1 eV at mobilities of 0.1 cm²/Vs (Advanced Materials, 2007, volume 19, p. 4160). The synthesis of the polymer poly(2,5-bis(3-hexylthiophen-2-yl)-thiazolo[5,4-d]thiazole), which is analogous to (A-V), was reported in Macromolecules, 2008, volume 41, edition 9, p. 3169, but without experimental data on the electrical properties and the ionization potential. WO 2006131185 Al describes the use of thieno[3,4-d]thiazole-2,5- diyls in semiconductor polymers. In these, however, the thiazole part of the thie- nothiazole group is not a direct constituent of the polymer backbone, but influences the electronic structure only indirectly as a 3,4-fused ring on the 2,5-thiophene monomer.

The object of the present invention was therefore to provide organic compounds which can be processed from the usual solvents, which result in semiconducting films with good properties and which remain sufficiently stable during storage in air. Such compounds would be outstandingly suitable for application of organic semiconducting layers over large areas.

It would be desirable in particular for these compounds to form high quality layers of uniform thickness and morphology and to be suitable for electronic uses.

It has now been found, surprisingly, that oligomeric or polymeric organic compounds with continuously conjugated double bonds containing one or more optionally substituted units of thienothiazole-2,5-diyl groups have the desired properties.

In particular, the stability and the film morphology and the macroscopic electrical properties thus obtained in the films of oligomeric or polymeric organic com- pounds containing one or more optionally substituted units of thienothiazole-2,5- diyl groups are improved.

The invention provides oligomeric or polymeric compounds with continuously conjugated double bonds containing one or more optionally substituted units of thieno[2,3-cT|thiazole-2,5-diyl groups of the general formula (M-I) or/and optionally substituted units of thieno[3,2-d]thiazole-2,5-diyl groups of the general formula (M-2),

wherein

R represents linear or branched C]-C₂o-alkyl radicals, C₃-C₈-cycloalkylene radicals, mono- or polyunsaturated C₂-C₂o-alkenyl radicals, Ci-C₂₀-alkoxy radicals, C₁-C₂₀-aralkyl radicals, optionally substituted aryl or heteroaryl radicals, C₂-C₂o-oligo- or C₂-C₂₀-polyether radicals or H, preferably linear or branched d-C^-alkyl radicals, C₁-C₂₀-alkoxy radicals, optionally substituted aryl radicals or H, particularly preferably linear or branched C₄- C]₂-alkyl radicals, C₄-Ci₂-alkoxy radicals, optionally substituted phenyl radicals or H.

In the formulae (M-I) and (M-2) and the formulae shown below, linkage with the other units takes place via the positions labelled with "*". A preferred embodiment of the invention is represented by the oligomeric or polymeric compounds according to the general formulae (N-I) and (N-2)

wherein

R has the meaning given above,

A, B independently of each other represent optionally substituted ethenylene, arylene, heteroarylene, thieno[2,3-cT|thiazole-5,2-diyl groups, thieno[3,2-cT]thiazole-5,2-diyl groups or ethynylene or di- azo groups, preferably arylene, heteroarylene, thieno[2,3-

<f|thiazole-5,2-diyl and thieno[3,2-d]thiazole-5,2-diyl groups and a and b independently of each other represent an integer from 0 to 10, preferably an integer from 0 to 4, m represents an integer from 1 to 10, preferably an integer from 1 to

4, and n represents an integer > 1.

In a further preferred embodiment of the invention, at least two optionally substi- tuted units of thieno[2,3-d]thiazole-2,5-diyl groups of the general formula (M-I) and/or thieno[3,2-d]thiazole-2,5-diyl groups of the general formula (M-2), wherein R, A, B, a, b, m and n have the meaning given above, are linked with each other through the 2-position of their respective thiazole ring. A particularly preferred embodiment has a core structural unit in the form of a dimer comprising two units of formula (M-I) or two units of formula (M-2), wherein each (M-I) or (M-2) unit is linked through the 2-position of the thiazole ring to the 2-position of the thiazole ring of the other (M-I) or (M-2) unit. One or both of the (M-I) or (M- 2) units forming the core structural dimer unit can be substituted with one or more R, A and/or B groups, wherein R, A and B have the meaning given above.

A particularly preferred embodiment of the invention is represented by the oli- gomeric or polymeric compounds according to the general formula (N-Ia) and (N-2a)

wherein R, A, B, a, b, m and n have the meaning given above and

R¹ and R² independently of each other represent one of the meanings of R or Sn(R^al)(R^a2)(R^a3), -Si(R^al)(R^a2)(R^a3), -B(OR^bl)(OR^b2), aldehyde, -

CH=CH₂ or a halogen, preferably Br or I,

R^al, R^ώ, R⁸³ independently of each other represent Ci-C₁₂-alkyl, aryl or H and R^bl, R^b2 independently of each other represent H, d-Cn-alkyl or OR^bl and

OR^b2 with the B atom form a ring consisting of 2 - 20 C atoms.

In a very particularly preferred embodiment of the present invention, in the organic compounds of the general formulae (N-I) and (N-2) A and B independently of each other represent optionally substituted phenylene-l,4-diyl, fluorene-2,7- diyl or thiophene-2,5-diyl, preferably thiophene-2,5-diyl. In the context of the invention, linear or branched C]-C₂₀-alkyl radicals represent alkyl radicals, such as, for example, methyl, ethyl, n- or iso-propyl, n-, iso-, sec- or tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1- ethylpropyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, n- hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n- tridecyl, n-tetradecyl, n-hexadecyl or n-octadecyl, preferably n-hexyl, n-heptyl, n- octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n- hexadecyl or n-octadecyl; Q-Cπ-alkyl radicals represent the corresponding choice from the C₁-C_2O-ShCyI radicals, where here methyl, ethyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-decyl, n-undecyl or n-dodecyl are preferred; C₃-C₈- cycloalkylene radicals represent cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl, preferably cyclohexyl; mono- or polyunsaturated C₂- C₂₀-alkenyl radicals represent the abovementioned CrC₂o-alkyl radicals containing at least one double bond; Q-C^-alkoxy radicals represent the abovemen- tioned d-C₂o-alkyl radicals containing an alkoxy group; Q-C^-aralkyl radicals represent benzyl, o-, m-, p-tolyl, 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, 3,5-xylyl or mesityl, preferably benzyl or o-, m-, p-tolyl; and C₂-C₂o-oligo- or C₂-C₂o-polyether radicals represent the C₁-C₂₀-alkyl radicals given above, where here the straight-chain or branched alkyl chain is interrupted by at least one oxygen atom. In the context of the invention, an oligoether is understood as meaning, for example, that some ether groups are present, i.e. that e.g. a C₂₀-alkyl chain is interrupted by an O atom three times, whereas in a C₂o-polyether radical, for example, an oxygen bridge is present regularly every two C atoms (= polyethylene oxide), i.e. a total of 9 O atoms are present here.

In the context of the invention, arylene is understood as meaning optionally substituted aromatic carbon rings, for example phenyl, tolyl or xylyl, preferably phenyl, and heteroarylene is understood as meaning aromatic carbon rings containing at least one hetero atom, for example pyrrole, thiazole, thiophene, oxadia- zole, pyridine, pyrimidine or triazine.

In a preferred aspect of the compounds according to the invention, at least one of R, A and B represents linear or branched CrC^-alkyl radicals, preferably linear or branched C₂-C₁₈-alkyl radicals, preferably linear or branched C₄-C₁₂-alkyl radicals, preferably linear or branched C₄-Cio-alkyl radicals, preferably linear or branched C_δ-Cio-alkyl radicals. In another preferred aspect of the compounds ac- cording to the invention, at least one of R, A and B represents C₄-C₁₈-aryl and/or C₄-C₁₈-aralkyl radicals, preferably Q-Q_ό-aryl and/or C₄-C₁₆-aralkyl radicals, preferably C₄-C₁₄-aryl and/or C₄-C₁₄-aralkyl radicals, preferably C₄-C₁₂-aryl and/or C₄-Ci₂-aralkyl radicals, preferably C₄-C₁₀-aryl and/or C₄-C₁o-aralkyl radicals. Substituents for the arylenes and heteroarylenes are, for example, linear or branched Q-C^-alkyl radicals, C₃-C₈-cycloalkylene radicals, mono- or polyunsaturated C₂-C₂₀-alkenyl radicals, d-C₂o-alkoxy radicals, C]-C₂₀-aralkyl radicals, optionally substituted aryl or heteroaryl radicals, C₂-C₂o-oligo- or C₂-C₂₀- polyether radicals. The R₅ A and B groups mentioned above can also be substituted with any one or more of these substituents.

In the context of the invention, numerous organic compounds are possible optional further substituents for R, A and B, such as benzothiadiazole, optionally substituted thiophene or selenophene, optionally substituted fluorene, cyanovinyl, dicyanovinyl, optionally substituted acenes, such as, for example, anthracene, pentacene or bis(triisopropylethynyl)-pentacene, in particular benzothiadiazole, optionally substituted fluorene or optionally substituted thiophene. Accordingly, in preferred aspects of the compounds according to the invention, any one or more of A, B, R, R¹, R²,R^al, R*², R^a3, R^bl, R^b2, independently of each other, can be substituted with at least one group selected from linear or branched C₁-C₂o-alkyl radicals, C₃-C₈-cycloalkylene radicals, mono- or polyunsaturated C₂- C₂₀-alkenyl radicals, d-C^-alkoxy radicals, d-C₂o-aralkyl radicals, optionally substituted aryl or heteroaryl radicals, C₂-C₂₀-oligo- or C₂-C₂₀-polyether radicals, benzothiadiazole, optionally substituted thiophene or selenophene, optionally substituted fluorene, cyanovinyl, dicyanovinyl, anthracene, pentacene and bis(triisopropylethynyl)-pentacene.

The compounds according to the invention can be prepared by means of various processes which as such are known in principle to the person skilled in the art. All the limitations given above for the compounds are also preferred embodiments of compounds, starting materials and intermediates used and/or formed in the proc- esses according to the invention.

The standard coupling reactions, such as cross-coupling polymerizations catalyzed by transition metals (described, for example, in J. Chem. Soc, Chem. Commun. 1992, p. 70, J. Am. Chem. Soc. 1992, volume 1 14, p. 10087, Adv. Ma- ter. 1999, volume 11, p. 250), dehalogenating coupling polymerization (described, for example, in Adv. Mater. 2006, volume 18, p. 3029), Stille coupling (for example in Nature Mat. 2006, volume 5, p. 328) or Suzuki coupling (described, for example, in J. Polym. Sci., part A: Polym Chem. 2005, volume 43, p. 1845) can be used for the preparation of the compounds according to the invention. The present invention provides a process for the preparation of compounds of the general formula (N-Ia) or of the general formula (N-2a), at least comprising the process steps: i) providing a compound of general formula (I) or of general formula (II)

(I) (H),

wherein R³ and R⁴ , independently of each other, have the meaning given for R, A and B above, halogen, and Si(CH₃)₃; ii) reacting the compound of general formula (I) or the compound of general formula (II) with ii-a) an organolithium reagent, and ii-b) sulphur, and iii) combining the reaction mixture obtained in step ii) with water.

According to a further embodiment of the present invention, mixtures of the compounds with the general formula (Nl -a) and (N2-a) can be obtained in providing mixtures of the compounds with the genera formula (I) and (II).

According to an embodiment of the present invention, the above process can form a part of the process for forming an oligomeric or polymeric compound of the present invention. This holds in particular, if the one or more compounds of the general formula (N-2a) are used.

The preferred embodiments of R, A and B above are also preferred embodiments for R³ and R⁴ in the compound of general formula (I). In particularly preferred embodiments of the compound of general formula (I), R³ and R⁴, independently of each other, represent an optionally substituted linear or branched C₁-C₂₀ alkyl, an optionally substituted arylene, an optionally substituted heteroarylene, an optionally substituted thieno[2,3-d]thiazole-5,2-diyl and an optionally substituted thieno[3,2-d]thiazole-5,2-diyl groups, most preferably an optionally substituted C₂-Ci_S, C₂-Ci₂ or C4-C10 alkyl, an optionally substituted C₄-Ci₂, C₅-CiO or C₆-C₈ arylene, for example an optionally substituted phenylene, an optionally substituted thiophene, an optionally substituted thiazole, an optionally substituted thieno[2,3- d]thiazole-5,2-diyl or an optionally substituted thieno[3,2-d]thiazole-5,2-diyl group. In further preferred embodiments of the compound of general formula (I), R⁴ represents a halogen, in particular Cl, Br, I, preferably Br, or Si(CHs)₃ (SiMe₃). In this case, the halogen or SiMe₃ can also act as a leaving group in the ring- formation step, so that the resulting ring is unsubstituted and carries an H at this position.

The compound of general formula (II) can be prepared, for example, as described in Heterocycles 2000, 52, 349. In an alternative preparation, the compound of general formula (II) can be prepared according to scheme i) or scheme ii):

Scheme i) (H)

Scheme ii) (H)

The first step of schemes i) and ii) is preferably carried out in organic solvent, for example in aprotic polar or non-polar solvent, preferably halogenated solvent, particularly preferably dichloromethane or chloroform, preferably at least partly at temperatures in the range of from -40 °C to 30 ⁰C, more preferably at least partly at temperatures in the range of from -20 °C to 20 ⁰C, more preferably at least partly at temperatures in the range of from -10 °C to 10 ⁰C, most preferably at least partly at temperatures in the range of from -5 °C to 5 °C, i.e. at least a part of the reaction is carried out at these temperatures. The product of the first step is preferably worked up, washed, dried and isolated before being subjected to the second step of schemes i) and ii). In the second step of schemes i) and ii) the product of the first step is reacted with a thioamide as shown. The reaction conditions depend on the thioamide and on its substituents. The reaction can be carried out at room temperature or at elevated temperature, or partly at room temperature and partly at elevated temperature. Reduced temperatures can also be envisaged, as described for the first step, for example for addition or mixing of reagents. At least a period of elevated temperature in the range of from 40-100 °C, preferably from 50-100 °C, preferably from 50-90 °C, more preferably from 60-80 ⁰C is preferred.

In process step ii) of the process according to the invention for preparation of compounds of general formula (N-Ia) and/or (N-2a) the compound of general formula (I) or of general formula (II) is reacted first with an organolithium compound and then with elemental sulphur. The reaction is preferably carried out in an organic solvent, preferably at least comprising one aprotic polar solvent, whereby other solvents, for example non-polar organic solvents can also be pre- sent. Preferred solvents are ethers, for example diethyl ether, dibutyl ether, tetra- hydrofurane (THF), and alkanes, such as pentane, hexane, heptanes, and mixtures thereof. At least a part, preferably all of process step ii) of this process is carried out at reduced temperature, preferably at temperatures in the range of from -80 °C to 10 °C, more preferably at least partly at temperatures in the range of from -80 °C to 0 ⁰C, whereby at least the combining with the organolithium reagent is carried out at temperatures in the range of from about -80 °C to -50 °C, and the subsequent stages of this process step ii) can be carried out at temperatures in the range of from -50 °C to 10 °C, more preferably at temperatures in the range of from -40 °C to 10 °C, most preferably at least partly at temperatures in the range

In process step iii) of the process according to the invention for preparation of compounds of general formula (N-Ia) and/or (N-2a), the reaction mixture obtained in step ii) is combined with water. This combination is preferably carried out by adding water to the reaction mixture. The combination can take place at temperatures in the range of from about -40 °C to 25 °C, preferably at tempera- tures in the range of from -20 °C to 20 °C, more preferably at temperatures in the range of from -10 °C to 20 °C. After combination the resulting mixture can be subjected to a period of elevated temperature, preferably in the range of from 40- 100 °C, preferably from 50-100 °C, preferably from 50-90 °C, more preferably from 60-80 °C is preferred, preferably after a period of stirring at room tempera- ture or reduced temperatures in the preferred ranges given for the combination step.

If the compound of general formula (I) according to scheme (i) or a corresponding compound of general formula (II) is used, which has two alkyne groups, the ring- closing reaction carried out in the process according to the invention for preparing compounds of general formula (Nl -a) and/or (N-2a) can be carried out on both alkyne groups at the same time, or first on one alkyne group and subsequently on the second alkyne group, optionally isolating the intermediate before the second ring-closing reaction.

The reaction mixture obtained from process step iii) can be worked up using procedures known to the skilled person, for example by washing, drying, evaporation of solvent, filtration, preferably filtration over silica gel or the like, and purified, for example by chromatography, crystallisation, distillation, or the like.

In order to obtain product (Nl -a) or (N-2a), the ring-closed product, optionally after work-up and/or purification, can be reacted in order to substitute one or more thiophene rings, preferably at the position adjacent to the sulphur atom, with a -Sn(R³¹XR²²XR^*3), -Si(R³¹XR³²XR³³), -B(OR^bl)(OR^b2), aldehyde, -CH=CH₂ or a halogen, in processes which are in principle known to the skilled person. For example, a reaction with N-bromosuccinimide (NBS) can be carried out to bromi- nate the thiophene ring or rings or a reaction with a dioxoborolan to substitute with a boron-heteroring. In principle, any reagents and/or substitutents known to the skilled person can be employed, to substitute one or more thiophene rings in such a way that they can subsequently be reacted to form inventive oligomers or polymers by means of coupling and/or polymerisation reactions, as described above. In this way, the products (Nl -a) and (N-2a) can be obtained.

The present invention also provides a process for the preparation of the compounds according to the general formulae (N-I) and (N-2) according to the invention, in which the compounds of the general formulae (N-Ia) or (N-2a) respec- tively are reacted, optionally in the presence of at least one catalyst, optionally in solution and optionally at elevated temperature. This reaction preferably takes place in the presence of at least one solvent. In a preferred aspect of the process according to the invention for preparation of the compounds according to the invention, the compounds of the general formulae (N-Ia) or (N-2a) are reacted in the presence of at least one metal-comprising compound, as catalyst. The at least one metal-comprising compound preferably comprises at least one ligand selected from the group consisting of at least one ligand which interacts with the metal through at least one of a carbon, a nitrogen, a phosphorus, an oxygen and a sulfur, a halide, and any combination of two or more of these ligands, whereby preferably at least one ligand is present which interacts with the metal through at least one of a carbon, an oxygen, a phosphorus and a halide. Chelating ligands capable of interacting with the metal through more than one group, for example di- phosphines, acetates, diamines, or mixed chelating ligands such as phosphino- amines, can also be used. Particularly preferred ligands are phosphines, di- phosphines, acetates. Possible catalysts are in principle all suitable compounds which contain a metal of the platinum group (nickel, palladium, platinum).

In a further preferred aspect of the process according to the invention for preparing compounds according to the invention the compounds of the general formulae (N-Ia) or (N-2a) are reacted in the presence of at least one base. In a particularly preferred aspect, the compounds of the general formulae (N-Ia) or (N-2a) are re- acted in the presence of at least one base and at least one metal-comprising compound, as catalyst. Suitable bases according to the invention are compounds comprising at least one metal selected from group 1 or group 2 of the periodic table, for example lithium, sodium, potassium, cesium, magnesium, calcium, barium, preferably in the form of their carbonates, hydrogencarbonates, sulphates, halides, amides, oxides, alkoxides, hydroxides, alkyls, halides, or combinations thereof.

In an aspect of the invention, the compounds of the general formulae (N-Ia) or (N-2a) are reacted in a solution comprising at least one aprotic solvent, preferably at least one aprotic polar solvent. In the context of the invention, suitable solvents are aromatic hydrocarbons, such as, for example, toluene, xylenes, benzene, or solvents comprising at least one heteroatom selected from O and N, such as ethers, such as, for example, diethyl ether, tetrahydrofuran, dioxane,methyl tert- butyl ether, or dimethylformamide.

In a preferred embodiment of the process according to the invention, the prepara- tion of the compounds according to the general formulae (N-I) and (N-2) according to the invention is carried out at a temperature of from 0 to 150 ⁰C, preferably from 60 to 130 ⁰C. The temperature is preferably selected such that the reaction is carried out in refluxing solvent.

The invention also relates to the compounds which are obtainable by the process according to the invention.The preparation of the monomers containing thienothi- azole units, of the general formulas M-I and M-2, required for the compounds according to the invention can be carried out by various routes. Possible synthesis routes for the preparation are described in the following. In this context, in equa- tions 1 to 5 R represents a radical according to the general definition for M-I and M-2.

One possibility for the preparation of thienothiazoles according to the general formula M-I is synthesis from thiazolidine-2,4-dione. In accordance with equa- tion 1 , thiazolidine-2,4-dione is first reacted as described, for example, in Journal of the Chemical Society Perkin Transactions 1, 1992, p. 973 to give the thienothi- azole T-I. Bromination with N-bromosuccinimide in N,N-dimethylformamide and subsequent hydrolysis and decarboxylation then lead to the brominated thie- nothiazole monomer T-2. The monomer can be processed further by appropriate coupling reactions to give oligomeric structures, which are then polymerized further.

Equation 1

Another possibility for the synthesis of monomers according to the general formula M-I starts from 2,2'-bithiazoles. In accordance with equation 2, 4,4'- dibromo-2,2'-bithiazole, which is described, for example, in Heterocycles, 2000, volume 52, p. 349, is first silylated in the 5-position and then reacted with an acid halide in accordance with the reaction described in Journal of Organic Chemistry, 1988, volume 53, p. 1748 to give the substituted bithiazole S-I. Ring closure, hydrolysis and decarboxylation in accordance with Journal of the Chemical Society Perkin Transactions 1, 1992, p. 973 (see equation 1) then leads to the bi- thienothiazole monomer T-3. This can be polymerized directly by oxidative coupling, or first halogenated to give, for example, T-4.

Equation 2

For the preparation of unsubstituted bi-thienothiazoles, a formylation of 4,4'- dibromo-2,2'-bithiazole in accordance with Heterocycles, 2000, volume 52, p. 349 to give the bithiazole S-2 according to equation 3 is suitable. A corresponding ring closure reaction, hydrolysis and decarboxylation as described for equation 2 then leads to the bi-thienothiazole T-5, or to T-6 after halogenation.

T-5 T-6

Equation 3

Another route for the synthesis of monomers M-I starts from 5,5'-dicarboxy-2,2'- bithiophenes. For this, the carboxylic acids are reacted in accordance with, for example, Journal of Medicinal Chemistry 2002, volume 45, p. 4513 and Synthesis, 1977, p. 255 to give the corresponding amides B-I. Thiocyanation in the 4- position is then carried out in accordance with Chemistry of Heterocyclic Com- pounds (English translation), 1974, volume 10, p. 1045 and the product is then reacted by means of ethyl benzoate to give the bi-thienothiazole T-7. The free amine T-8 is obtained by deprotection of the amide functions, and can be halo- genated by diazotization in a Sandmeyer reaction to give, for example, T-9, or reacted with compounds which are capable of coupling to give corresponding azo compounds.

T-7 T-8

T-9

Equation 4

An example for the preparation of monomers according to the general formula M- 2 is shown in equation 5. The bithiazole S-3 is first obtained by a condensation reaction in accordance with Chemistry of Materials, 1995, volume 7, p. 2232. After hydrolysis, the carboxylic acid is reacted with lithium organyls in a Gilman- van-Ess reaction to give S-4. Subsequent halogenation of the 5-position and a ring closure reaction corresponding to the reaction described in Journal of the Chemical Society Perkin Transactions 1, 1992, p. 973 leads to the bi-thienothiazole T- 10. Hydrolysis and decarboxylation lead further to T-11, and halogenation thereof to T- 12. 2^{1 4} H₂ ^RO^"

1 KOH 2 HCI

THF ^™^iHi^: ~ -CO₂ bx T-11 ύ Έ- ~b*x y ~s

T-12

Equation 5

The compounds according to the invention are typically readily soluble in the usual organic solvents and are therefore outstandingly suitable for processing from solution. Solvents which are suitable in particular are aromatics, ethers or halogenated aliphatic hydrocarbons, such as, for example, chloroform, toluene, benzene, xylenes, diethyl ether, methylene chloride, chlorobenzene, dichloroben- zene or tetrahydrofuran, or mixtures of these.

The compounds according to the invention are soluble in conventional solvents, such as e.g. aromatics, ethers or halogenated aliphatic hydrocarbons, e.g. in chloroform, toluene, benzene, xylenes, diethyl ether, methylene chloride, chloroben- zene, dichlorobenzene or tetrahydrofuran, to the extent of at least 0.1 wt.%, preferably at least 1 wt.%, particularly preferably at least 5 wt.%. The compounds according to the invention form high quality layers of uniform thickness and morphology from evaporated solutions and are therefore suitable for electronic uses.

The invention also relates to a process for preparing an electronic component, comprising the process steps: a) providing a substrate, preferably in the form of a sheet, film, wafer or the like, which has a surface comprising at least one face; b) providing the substrate with at least one layer of a dielectric mate- rial to form a dielectric layer on the substrate, whereby the dielectric layer optionally covers at least 80%, at least 90% or at least 95% of the surface of the substrate, or the dielectric layer preferably covers at least 80%, preferably at least 90%, preferably at least 95%, more preferably at least 99%, most preferably 100% of the at least one face of the substrate,; c) applying at least one layer of a compound according to the present invention onto the dielectric layer, to form an organic semiconductor layer; d) applying at least one electrode to at least one of the organic semi- conductor layer and the substrate.

The electronic component is preferably a field effect transistor, a light-emitting component, in particular organic light-emitting diodes, or photovoltaic cells, lasers and sensors.

Suitable substrates, are, for example silicon wafers, polymer films or glass panes, which can be provided with electrical or electronic structures. The electrical or electronic structures, if present, can be provided in the form of at least one organic semiconducting polymer layer, which can be applied with or without a mask, depending on the intended use of the electrical component. If the electronic component is a field effect transistor, the substrate preferably comprises a semi- conducting material.

The dielectric layer provided in process step b) preferably comprises an organic material, and more preferably consists of an organic material, preferably a silicon- comprising organic material and/or a carbon-based polymer. Suitable organic ma- terials for the dielectric layer are known to the skilled person and can be purchased commercially, such as octyldimethylchlorosilane, hexamethyldisilazane or polystyrene. The material from which the dielectric layer is formed or which is comprised in the dielectric layer is preferably provided in the form of a vapour, a liquid or a solution. The vapour, the liquid or the solution preferably come into contact with the substrate, optionally at elevated temperature, for example at a temperature in the range of from 0 °C to 100 °C, preferably at a temperature in the range of from about 20 °C to about 80 °C, for a time in the range of from about 1 second to about 24 hours, preferably for a time in the range of from about 20 seconds to about 12 hours, preferably for a time in the range of from about 20 sec- onds to about 4 hours, preferably for a time in the range of from about 20 seconds to about 1 hour, depending on the material used for the dielectric layer. Hexamethyldisilazane, for example, requires longer contact times than octyldimethylchlorosilane or polystyrene. The substrate provided with the dielectric layer can be dried or tempered, optionally at elevated temperatures as for the above contact temperatures, after application of the dielectric material. In process step c) of the process according to the invention for preparing an electronic component, all application processes are possible in principle for the application. Preferably, the compounds and mixtures according to the invention are applied from a liquid phase, i.e. from a solution or a dispersion, and the solvent is then evaporated. The application from solution or dispersion can be carried out by known processes, for example by spraying, dipping, printing and knife-coating. Application by spin coating and by ink-jet printing is particularly preferred. According to this aspect of the process, in process step c) the compound is applied in the form of at least one layer from solution. Following the application, the com- pound can be dried or tempered, optionally at elevated temperatures, for example at a temperature in the range of from 0 °C to 200 °C, preferably at a temperature in the range of from about 20 ⁰C to about 150 °C, more preferably at a temperature in the range of from about 20 °C to about 100 °C.

In a further aspect of the process according to the invention for preparing an electronic component, in process step c) the compound is applied by vapour deposition. Suitable techniques and equipment are known to the skilled person, and described in the Examples.

The organic semiconducting layer produced from the compounds according to the invention can be modified further after the application, for example by a heat treatment, e.g. passing through a liquid crystal phase, or for structuring e.g. by laser ablation.

If the electronic component is a field effect transistor, in process step d) at least two electrodes are applied to the organic semiconductor layer. At least one electrode can also be applied to the substrate. If the electronic component is a light- emitting component, in process step d) at least one electrode is applied to the organic semiconductor layer and at least one electrode is applied to the substrate, if this is not already provided with an electrode. The electrodes are preferably applied in process step d) by vapour deposition or by application of a suitable paste, solution or dispersion, for example a commercially available silver paste known to the skilled person. The electrodes can be applied using a mask or template.

The invention also provides the use of the compounds according to the invention as semiconductors in electronic components, such as field effect transistors, light- emitting components, such as organic light-emitting diodes, or photovoltaic cells, lasers or sensors.

In order to be able to ensure appropriately a functionality as semiconductors, the compounds and mixtures according to the invention have an adequate mobility, e.g. at least 10^"4 cm²/Vs. It is preferred according to the invention that the compound has a linear mobility of at least 1 x 10³ cm²/Vs, preferably in the range of from 1 x 10^ to 10,000 cm²/Vs, preferably in the range of from 1 x 10^"3 to 1000 cm²/Vs, preferably in the range of from 1 x 10^"3 to 100 cm²/Vs, preferably in the range of from 1 x 10² to 100 cmVVs, preferably in the range of from 1 x 10² to 10 cm²/Vs. Charge mobilities can be determined, for example, as described in M. Pope and CE. Swenberg, Electronic Processes in Organic Crystals and Polymers, 2nd ed., p. 709 -713 (Oxford University Press, New York Oxford 1999).

For use, the compounds according to the invention are applied to suitable sub- strates, for example to silicon wafers, polymer films or glass panes provided with electrical or electronic structures. All application processes are possible in principle for the application. Preferably, the compounds and mixtures according to the invention are applied from a liquid phase, i.e. from solution, and the solvent is then evaporated. The application from solution can be carried out by the known processes, for example by spraying, dipping, printing and knife-coating. Application by spin coating and by ink-jet printing is particularly preferred.

The layers produced from the compounds according to the invention can be modified further after the application, for example by a heat treatment, e.g. passing through a liquid crystal phase, or for structuring e.g. by laser ablation.

The invention furthermore provides electronic components comprising the compounds and mixtures according to the invention as semiconductors.

The following examples serve to illustrate the invention by way of example and are not to be interpreted as a limitation.

Examples

The compounds of the formulae (M-I) and (M-2) according to the invention can be prepared, for example, analogously to the synthesis as shown in Examples 1 to 14

All the reaction vessels were heated thoroughly and flooded with nitrogen by the conventional inert gas technique before use. Exclusively dry and degassed solvents were used.

Bromoacetyl bromide, dithioxamide, thiobenzamide, isopropoxy-4,4,5,5- tetramethyl-l,3,2-dioxoborolane, N-bromosuccinimide and bistrimethyl- silylethyne were purchased from Aldrich. Hexyl-2-thiophenethioamide was syn- thesised analogously to the procedure in Bio. Med. Chem. Lett., 2002, 12, 2317. The product obtained consisted of the two isomers 3 -hexyl-2-thiophenethioamide and 4-hexyl-2-thiophene thioamide in the ratio 3 : 1 and was used without further separation.

Example 1

2.25 g (6.3 mmol) 4,4'-Bis(trimethylsilyethynyl)-2,2'-bithiazole {Heterocycles, 2000, 52, 349) was dissolved in 300 ml dry THF and reacted at -78°C with 5 ml of a 2.5 M solution of n-butyllithium in hexane. The reaction mixture was then warmed to -20°C and stirred for a further 30 minutes. After cooling to -30°C 0.90 g (28 mmol) sulfur was added. The cooling bath was then removed and the temperature allowed to increase to -5°C. 60 ml Water was added to the dark red solution and the mixture was stirred for 2.5 hours at room temperature. The organic phase was separated and the aqueous phase extracted with toluene. The combined organic phases were dried over Na₂SO₄, filtered and concentrated. The crude product was purified by chromatography (silica gel, eluent: toluene) Yield: 0.59 g (33.7% of theoretical yield). ¹H NMR (CDCl₃): 7.53 (2H, d, J= 5,35), 7.51 (2H, m) ppm. GC-MS: 99.04% (m/z = 280).

Example 2:

2.33 g (17.5 mmol) AlCl₃ was suspended in 17,5 ml dry dichloromethane. To this was added dropwise at 0⁰C a solution of 3.19 g (17.5 mmol) 1-trimethylsilyloct-l- yne (J. Org. Chem., 2008, 73, 3258) and 1.52 ml (17.5 mmol) bromoacetylbro- mide in 30 ml dry dichloromethane over 2 hours. The resulting mixture was then stirred for 45 minutes at 0°C, then warmed to room temperature and stirred for a further hour. It was then cooled again to 0°C and 43.75 ml IM HCl slowly added. The organic phase was separated, the aqueous phase extracted with diethylether, the combined organic phases dried over MgSO₄, filtered and concentrated. The product obtained was dissolved in 30 ml dry dimethylformamide (DMF) and 0.9 g (7.5 mmol) dithioxamide added. Stirring was then carried out for 1 hour at room temperature and 16 hours at 80⁰C. After cooling 300 ml ethylacetate and 150 ml 0,1 M HCl were added. The organic phase was separated, washed twice, each time with 150 ml water, dried over MgSO₄, filtered, and the solvent removed. The crude product was purified by chromatography (silica gel, eluent: ethylacetat :n- hexane 1 :9). Yield: 0.92 g (32 % of theoretical yield).

¹H NMR (CDCl₃): 7.42 (2H, s), 2.43 (4H, t, J= 7.21 Hz), 1.63 (4H, m), 1.45 (4H, m), 1.31 (8H, m), 0.90 (6H, t, J = 6.96 Hz) ppm.

Example 3:

0.67 g (1.7 mmol) 4,4'-Bis(octynyl)-2,2'-bithiazole was dissolved in 20 ml dry THF and 2.79 ml (7 mmol) of a 2,5M butyllithium solution in n-hexane added dropwise at -78°C over 1 hour. The mixture was then stirred for 30 minutes at - 20°C, then cooled to -30°C and 0.25 g (7.9 mmol) sulfur added. The cooling bath was then removed, the temperature allowed to rise to -5 °C and stirring carried out for 1 hour at -5°C. 20 ml Water was then added and the mixture was stirred for 30 minutes at room temperature and 1.5 hours at 70°C. After cooling the solvent was evaporated and the residue taken up in chloroform and filtered over 70 ml silica gel with chloroform as eluent. The thus-obtained crude product was purified by chromatography (silica gel, eluent: ethylacetate:n-hexane 1 :20). Yield: 0.05 g (6 % of theoretical yield). ¹H NMR (CDCl₃): 7.19 (2H, s), 2.91 (4H, t, J = 7.47 Hz), 1.74 (4H, dt, J= 7.54 Hz, J= 15.23 Hz), 1.31 (12H, m), 0.90 (6H, t, J= 6.97 Hz) ppm.

Example 4:

0.896 g (2.3 mmol) 4,4'-Bis(octynyl)-2,2'-bithiazole was dissolved in 100 ml dry THF, 1.86 ml (4.6 mmol) of a 2,5M butyllithium solution in n-hexane added dropwise at -78°C over 10 minutes and the resulting mixture then stirred for 1 hour at -78°C. 0.187 g (5.8 mmol) sulfur was then added at -78°C. The cooling bath was removed, the temperature allowed to increase to -5°C, then the mixture was cooled to -30°C and 20 ml water added, it was stirred for 30 minutes at room temperature and 2 hours at 70°C. After cooling the solvent was evaporated and the residue taken up in chloroform and filtered over 60 ml silica gel with chloroform as eluent. The thus-obtained crude product was used in Example 5 without further purification. Yield: 0.98 g with a content of 90.3% product according to GC-MS. Example 5:

0.97 g (2.9 mmol) 2-(4-Oct-l-yn-l-yl-l,3-thiazol-2-yl)thieno[3,2-d][l,3]thiazole was dissolved in 100 ml dry THF, 2.3 ml (5.7 mmol) of a 2,5M butyllithium solution in n-hexane added dropwise over 10 minutes at -78°C and the resulting mixture then stirred for 1 hour at -78°C. 0.18 g (5.7 mmol) Sulfur was then added. The cooling bath was removed, the temperature allowed to increase to -5°C, then the reaction mixture was cooled to -30°C, 20 ml water added, and stirring was carried out for 30 minutes at room temperature and 2 hours at 70°C. After cooling, the solvent was evaporated and the residue taken up in chloroform and filtered over 60 ml silica gel with chloroform as eluent. The thus-obtained crude product was recrystallized from ethyl acetate. Yield: 0.34 g (26% of theoretical yield).

¹H NMR (CDCl₃): 7.19 (2H, s), 2.91 (4H, t, J = 7.53 Hz), 1.74 (4H, dt, J = 7.55 Hz, J= 15.24 Hz), 1.41 (4H, m), 1.32 (8H, m), 0.90 (6H, t, J= 7.05 Hz) ppm. MS (EI): m/z (%) = 448 (100) M.

Example 6:

7.47 g (56 mmol) AlCl₃ was suspended in 60 ml dry dichloromethane. To this was added dropwise at 0°C a solution of 9.54 g (56 mmol) bistrimethylsilylethyne und 4.88 ml (56 mmol) bromoacetylbromide in 100 ml dry dichloromethane over 2 hours. The resulting mixture was stirred for 45 minutes at 0°C, then warmed to room temperature and stirred for a further hour. It was then cooled to O⁰C and 140 ml IM HCl slowly added. The organic phase was separated, the aqueous phase extracted with diethyl ether and the combined organic phases dried over MgSO₄, filtered and concentrated. The thus-obtained product was dissolved in 100 ml dry DMF and 6.37 g (28 mmol) 3-hexyl-2-thiophenethioamide was added. The mixture was then stirred for 48 hours at room temperature. 500 ml Ethyl acetate was added to the solution and the resulting mixture was washed with 240 ml 0.1M HCl and then washed with 2x120 ml water. The organic phase was dried over MgSO₄, filtered, and the solvent removed. The crude product was purified by chromatography (silica gel, eluent: ethyl acetate : n-hexane 1:4). Yield: 8.88 g (91% theoretical yield). The product consists of two isomers (6A and 6B) in the ratio 3:1.

6A 6B

¹H NMR (CDCl₃): 7.45 (IH, s, Isomer A+B), 7.38 (0.3H, d, J= 1.40 Hz, Isomer B), 7.36 (0.3H, s, Isomer B), 7.30 (IH, d, J = 5.21 Hz, Isomer A), 6.99 (0.3H, s, Isomer B), 6.95 (IH, d, J = 5.12Hz, Isomer A), 2.90 (2H, t, J = 7.74Hz, Isomer A), 2.59 (0.,6H, t, J = 7.43 Hz, Isomer B), 1.67 (2.6H, m, Isomer A +B), 1.40 (2.6H, m, Isomer A+B), 1.30 (5.2H, m, Isomer A+B), 0.88 (3.9H, m, Isomer A+B), 0.27 (9H, s, Isomer A), 0.26 (2.7H, s, Isomer B) ppm.

Example 7:

0.97 g (2.8 mmol) of the isomer mixture of 6A and 6B was dissolved in 30 ml dry THF and 1.12 ml (2.8 mmol) of a 2.5M butyllithium solution in n-hexane added dropwise over 1 hour at -78°C. The resulting mixture was then stirred for 30 minutes at -20 °C, then cooled to -30 °C and 0.10 g (3.2 mmol) sulfur added. The cooling bath was then removed, the temperature allowed to increase to -5°C and the mixture stirred for further 1 hour at -5°C. 30 ml Water was added and the mixture stirred for 30 minutes at room temperature and 1.5 hours at 70 °C. After cooling the solvent was evaporated and the residue taken up in chloroform and filtered over 70 ml silica gel with chloroform as eluent. The thus-obtained crude product was purified by chromatography (silica gel, eluent: ethyl acetate : n-hexane 1:10). The pure isomer 7 A was obtained. Yield: 0.38 g (44 % of theoretical yield).

7A 7B

¹H NMR (CDCl₃): 7.48 (IH, d, J= 5.28 Hz), 7.43 (IH, d, J= 5.36 Hz), 7.32 (IH, d, J= 5.06 Hz), 6.98 (IH, d, J= 5.21 Hz), 2.97 (2H, t, J= 7.79 Hz), 1.70 (2H, m), 1.43 (2H, m), 1.33 (4H, m) 0.89 (36H, t, J= 6.88 Hz) ppm.

Alternatively, the product mixture of both isomers can be used without purification.

Example 8:

0.80 g (2.6 mmol) of the isomer mixture of 7A and 7B was dissolved in 20 ml dry DMF and, at 0°C, a solution of 0.94 g (5.3 mmol) N-bromosuccinimide in 10 ml dry DMF added dropwise over 30 minutes. The resulting mixture was stirred for a further 4 hours at room temperature. The solution was added to 60 ml water, extracted with chloroform, the organic phase washed with water, dried over MgSO₄, filtered and the solvent evaporated. The thus obtained crude product was taken up in toluene and filtered over silica gel (eluent: toluene). The isomer mixture of 8A and 8B in the ratio 3:1 was obtained. Yield: 1.13 g (93% of theoretical yield).

8A 8B

¹H NMR (CDCl₃): 7.48 (IH, s, Isomer A), 7.45 (0.3H, s, Isomer B), 7.22 (0.3H, s, Isomer B), 6.94 (IH, s, Isomer A), 2.86 (2H, t, J = 7.79 Hz, Isomer A), 2.57 (0.6H, t, J = 7.46 Hz, Isomer B), 1.66 (2.6H, m, Isomer A+B), 1.41 (2.6H, m, Isomer A+B), 1.32 (5.2H, m, Isomer A+B) 0.89 (3.9H, m, Isomer A+B) ppm. Example 9:

0.93 g (2.0 mmol) of the isomer mixture of 8A and 8B was dissolved in 20 ml dry THF and, at room temperature, 1.44 ml (2.0 mmol) of a 1.4M methylmagnesium- bromide solution in THF added dropwise over 10 minutes. The resulting mixture was then heated under reflux for 1 hour. After cooling, 0.015 g (0.02 mmol) bis[(diphenylphosphino)propane]-dichloronickel(II) was added and the solution heated again under reflux for 2 hours. After cooling the solution was added to 150 ml methanol, the precipitated residue filtered and extracted in a Soxhlett first with hexane, then with methanol and finally with chloroform. The product was obtained by concentration of the chloroform phase. Yield: 0.37 g (60% of theoretical yield).

¹H NMR (CDCl₃): 7.70 (IH, br s), 7.43 (IH, br s), 2.94 (2H, br t), 1,68 (2H, br m), 1.30 (6H, br m), 0.89 (3H, br m) ppm.

Example 10:

4.67 g (35 mmol) AlCl₃ was suspended in 35 ml dry dichloromethane. To this was added dropwise at 0°C a solution of 5.96 g (35 mmol) bistrimethylsilylethyne und 3.05 ml (35 mmol) bromoacetylbromide in 60 ml dry dichloromethane over 1 hour. The resulting mixture was stirred for 45 minutes at 0 °C, then warmed to room temperature and stirred for a further hour. It was then cooled to O⁰C 90 ml IM HCl was added slowly. The organic phase was separated, the aqueous phase extracted with diethyl ether, the combined organic phases dried over MgSO₄, filtered and concentrated. The thus-obtained product was dissolved in 60 ml dry DMF and 4.80 g (35 mmol) thiobenzamide was added. The mixture was then stirred for 17 hours at room temperature. To the solution was added 300 ml ethyl acetate and the resulting mixture was then washed with 150 ml 0.1M HCl and then with 2x150 ml water. The organic phase was dried over MgSO₄, filtered and the solvent removed. The crude product was purified by chromatography (silica gel, eluent: ethyl acetate :n-hexane 1 :20). Yield: 6.06 g (67% of theoretical yield). ¹H NMR (CDCl₃): 7.97 (2H, m), 7.48 (IH, s), 7.44 (3H, m), O.,28 (9H, s, - Si(CH₃)₃) ppm. Example 11 :

5.15 g (20 mmol) 4-Trimethylsilylethynyl-2-phenyl-l,3-thiazole (Example 10) was dissolved in 300 ml dry THF and added dropwise over 1 hour at -78°C to 8.2 ml (20.5 mmol) of a 2.5M butyllithium solution in n-hexane. The resulting mixture was then stirred for 1 hour at -78°C, then 0.82 g (25.5 mmol) sulfur was added. The cooling bath was then removed and the temperature allowed to rise to - 5°C. 40 ml water was then added and the mixture was stirred for 30 minutes at room temperature and 2 hours at 70⁰C. After cooling the solvent was evaporated and the residue taken up in chloroform and filtered over 60 ml silica gel with chloroform as eluent. 4.12 g of crude product with a purity of 68% (GC-MS) were obtained. The crude product was purified by chromatography (silica gel, eluent: ethyl acetate : n-hexane 1:20). Yield: 1.24 g (28.5% of theoretical yield).

¹H NMR (CDCl₃): 7.99 (2H, m), 7.50 (IH, d, J = 5.34 Hz), 7.46 (3H, m), 7.45 (lH, d, J = 5.44Hz) ppm.

Example 12:

1 BuLi

2 -V

' ". X

// w wa> ^~v~"

THF - ^{S^S} ° ^^'<

To a solution of 0.85 g (3.9 mmol) 2-phenylthieno[3,2-d][l,3]thiazole (Example 11) in 60 ml dry THF was added dropwise at -78°C in total 1.72 ml (4.3 mmol) of a 2,5 M butyllithium solution in hexane and the mixture was stirred for 1 hour at - 78°C. Then 0.871 g (4.7 mmol) isopropoxy-4,4,5,5-tetramethyl- 1,3,2- dioxoborolane was added in one portion, the solution warmed to room tempera- ture and stirred overnight. The solution was stirred into 200 ml water and extracted with methylene chloride. The organic phase was washed with saturated NaCl solution, dried over MgSO₄, filtered and the solvent removed by rotary evaporation. 1.17 g crude product was obtained, consisting of 79.1% product und 19.4% starting material according to GC-MS analysis. This was used in Example 14 without further purification.

Example 13:

To a solution of 0.80 g (3.7 mmol) 2-phenylthieno[3,2-ύf|[l,3]thiazole (Example 11) in 30 ml dry DMF was added dropwise over 30 minutes at 0°C a solution of 0.66 g (3.7 mmol) N-bromosuccinimide in 12 ml dry DMF. The resulting mixture was warmed to room temperature and then stirred for 4 hours. The solution was stirred into 200 ml ice water and extracted with methylene chloride. The combined organic phases were washed with water, dried over Na₂SO₄, filtered and solvent removed by rotary evaporation. 1.02 g crude product was obtained as a white solid, consisting of 95.1% product and 4.9% starting materials according to GC-MS analysis. This was used in Example 14 without further purification.

Example 14:

Pd[PPh₃J₄

=J S"^S \=/ S-^S O"\ THF ^=⁷ S"^S ^-"^N ^-U

0.77 g (purity: 95.1%, 2.6 mmol) 5-Bromo-2-phenylthieno[3,2-<f|[l,3]thiazole (Example 13) und 1.12 g (purity: 79.1%, 2.6 mmol) 5-[4,4,5,5-tetramethyl-[ 1,3,2- dioxoborolan]-2-phenylthieno[3,2-</][l,3]thiazole (Example 12) were dissolved in 40 ml THF and degassed. Then 38.3 mg (0.03 mmol) tetra- kis(triphenylphosphine)palladium was added and 14.36 ml (28.7 mmol) of a degassed 2M Na₂CO₃ aqueous solution added. The solution was stirred overnight at 67°C. The solution was then added to a solution of 50 ml water and 30 ml hydrochloric acid. The precipitated solid was vacuum-filtered, washed with water and dried. The crude product was dissolved in hot chloroform and filtered at 55 ⁰C over 50 ml silica gel. The filtrate was concentrated and the product which crystallized therefrom filtered and dried. 0.065 g (6% of theoretical yield) of pure product was obtained as a pale yellow solid.

¹H NMR (CDCl₃): 8.00 (4H, m), 7.63 (2H, s), 7.49 (6H, m) ppm. MS (FD): m/z (%) = 432 (100) M. Example 15

OFET preparation:

a) Substrate for OFET and cleaning

P-doped silicon wafers polished on one side and with a thermally grown oxide layer 300 nm thick (Sil-Chem) were cut into substrates 25 mm x 25 mm in size. The substrates were first cleaned thoroughly. The adhering silicon splinters were removed by rubbing with a clean-room wipe (Bemcot M-3, Ashaih Kasei Corp.) under running distilled water and the substrates were then cleaned in an aqueous 2 % strength water/Mucasol solution at 60 ⁰C for 15 min in an ultrasound bath. Thereafter, the substrates were rinsed with distilled water and spin-dried in a centrifuge. Immediately before coating, the polished surface was cleaned for 10 min in a UV/ozone reactor (PR-100, UVP Inc., Cambridge, GB).

b) Dielectric layer

i. Octyldimethylchlorosilane (ODMC): The ODMC used for the dielectric intermediate layer (Aldrich, 246859) was poured into a Petri dish so that the base is just covered. Onto this was placed the magazine containing the cleaned Si substrates standing upright. Everything was covered with an upturned glass beaker and the Petri dish was heated to 70 ⁰C. The substrates remained in the octyldimethylchlorosilane-rich atmosphere for 15 min. ii. Hexamethyldisilazane (HMDS): The hexamethyldisilazane (Aldrich, 37921-2) used for the dielectric intermediate layer was poured into a glass beaker containing the magazine with the cleaned Si substrates standing up- right. The silazane covered the substrates completely. The glass beaker was covered and heated to 70 ⁰C on a hot-plate. The substrates remained in the silazane for 24 h. The substrates were then dried in a dry stream of nitrogen. iii. Polystyrene (PS): the polystyrene used for the dielectric intermediate layer (Aldrich, 182435) was dissolved as a 0.5 wt.% solution in toluene, filtered through a 0:45 μm filter and then spun on the substrate with an open lid and 2000 rpm for 30 seconds The substrate was then tempered for 3 minutes at 70 °C.

c) Organic semiconductor

In a vaporisation device (Univex 350, Leybold), the semiconductor was vapor- coated onto the substrate at 0.1 A/s with a total layer thickness of 70 A.

A general concept for an alternative application of the semiconductor layer is as follows: For application of the semiconductor layer, a solution of the compounds in a suitable solvent was prepared. In order to achieve a complete solution of the components, the solution was placed in an ultrasound bath at 60 ⁰C for approx. 1 min. The concentration of the solution was 0.3 wt.%.

The substrate provided with the dielectric intermediate layer was laid with the polished side up in the holder of a lacquer spin coater (Carl Suss, RC8 with Gyrset^®) and heated to approx. 70 ⁰C with a hair dryer. Approx. 1 ml of the still hot solution was dripped on to the surface and the solution with the organic semiconductor centrifuged on the substrate at 1,200 rpm for 30 sec with an acceleration of 500 rps² and an open Gyrset^®. The film produced in this way was dried on a hot-plate at 70 ⁰C for 3 min. The layer was homogeneous and showed no clouding.

In the present Example the vaporisation method was used.

d) Application of the electrodes

The electrodes for the source and drain were then vapour-deposited on this layer. A shadow mask which comprised a galvanically produced Ni foil with 4 recesses of two interlocking combs was used for this. The teeth of the individual combs were 100 μm wide and 4.7 mm long. The mask was laid on the surface of the coated substrate and fixed with a magnet from the reverse.

The substrates were subjected to vapour deposition with gold in a vapour deposi- tion unit (Univex 350, Leybold). The electrode structure produced in this way had a length of 14.85 cm at a separation of 100 μm.

e) Capacitance measurement

The electrical capacitance of the arrangements was determined by subjecting a substrate, prepared in an identical manner but without the organic semiconductor layer, to vapour deposition in parallel behind the same shadow mask. The capacitance between the p-doped silicon wafer and the vapour-deposited electrodes was determined with a multimeter (MetraHit 18S, Gossen Metrawatt GmbH). The capacitance measured was C = 0.7 nF for this arrangement, and on the basis of the electrode geometry a capacitance per unit area of C = 6.8 nF/cm² resulted. f) Electrical characterization

The characteristic lines were measured with the aid of two current-voltage sources (Keithley 238). One voltage source applies an electrical potential to the source and drain and thereby determines the current which flows, while the second applies an electrical potential to the gate and source. The source and drain were contacted with printed-on gold pins, the highly doped Si wafer formed the gate electrode and was contacted via the reverse side, scratched free from oxide. The characteristic lines were plotted and evaluated by the known method, as described e.g. in "Organic thin- film transistors: A review of recent advances" , C. D. Dimitra- kopoulos, D. J. Mascara, IBM J. Res. & Dev. vol. 45 no. 1 January 2001.

The electrical characterization (Fig. 1) gave the following relevant parameters for this transistor construction:

i. Mobility ii. On/Off ratioI_D(U_G=-60 V)/ I_D(U_G=0V)

Note: The sensitivity of the Off current measurement I₀(U_G=O V) is limited to approx. 1 nA due to an incompletely shielded cable. iii. Threshold voltage

The results of the transistor measurements are summarised in Table 1.

Table 1:

Claims

Claims:

1. Oligomeric or polymeric compounds with continuously conjugated double bonds comprising one or more optionally substituted units of thieno[2,3- <f]thiazole-2,5-diyl groups of the general formula (M-I) and/or thieno[3,2- J]thiazole-2,5-diyl groups of the general formula (M-2),

wherein

R represents linear or branched d-C₂o-alkyl radicals, C₃-C₈- cycloalkylene radicals, mono- or polyunsaturated C₂-C₂₀-alkenyl radicals, Q-C^-alkoxy radicals, Q-C^-aralkyl radicals, optionally substituted aryl or heteroaryl radicals, C₂-C₂₀-oligo- or C₂-C₂₀- polyether radicals, or H.

2. The compounds according to claim 1, characterized in that they correspond to the general formula (N-I) or (N-2),

wherein R has the meaning given in claim 1 ,

A, B independently of each other represent optionally substituted ethenylene, arylene, heteroarylene, thieno[2,3-f/]thiazole- 5,2-diyl groups, thieno[3,2-<f|thiazole-5,2-diyl groups or ethynylene or diazo groups and a, b independently of each other represent an integer from 0 to

10, m represents an integer from 1 to 10 and n represents an integer > 1.

3. The compounds according to claim 1 or 2, characterized in that at least two optionally substituted units of thieno[2,3-<i]thiazole-2,5-diyl groups of the general formula (M-I) and/or thieno[3,2-d]thiazole-2,5-diyl groups of the general formula (M-2) are linked with each other through the 2-position of their respective thiazole ring.

4. The compounds according to any one of claims 1 to 3, characterized in that they correspond to the general formula (N-Ia) or (N-2a),

wherein R, A, B, a, b, m and n have the meaning given in claim 2 and R¹ and R² independently of each other represent one of the meanings of R or Sn(R³¹XR³²XR³³), -Si(R³¹XR³²XR^*3), - B(OR^bl)(OR^b2), aldehyde, -CH=CH₂ or a halogen, R^al, R³², R^ independently of each other represent Q-Cn-alkyl, aryl or

H and

R^M, R^b2 independently of each other represent H, Q-C^-alkyl or

OR^bl and OR^b2 with the B atom form a ring consisting of 2 - 20 C atoms.

5. The compounds according to at least one of claims 1 to 3, characterized in that A and B independently of each other represent optionally substituted phenylen-l,4-diyl, fluorenyl-2,7-diyl or thiophen-2,5-diyl.

6. The compounds according to at least one of the preceding claims, characterized in that R represents linear or branched Q-Qo-alkyl radicals.

7. The compounds according to at least one of the preceding claims, characterized in that R represents at least one of Q-Qo-aryl radicals and C₄-Ci₀- aralkyl radicals.

8. The compounds according to at least one of the preceding claims, characterized in that R is substituted with at least one group selected from linear or branched Ci-C₂₀-alkyl radicals, C₃-C₈-cycloalkylene radicals, mono- or polyunsaturated C₂-C₂o-alkenyl radicals, Ci-C₂₀-alkoxy radicals, C₁-C₂₀- aralkyl radicals, optionally substituted aryl or heteroaryl radicals, C₂-C₂₀- oligo- or C₂-C₂o-polyether radicals, benzothiadiazole, optionally substi- tuted thiophene or selenophene, optionally substituted fluorene, cyanovi- nyl, dicyanovinyl, anthracene, pentacene and bis(triisopropylethynyl)- pentacene.

9. The compounds according to at least one of claims 2 to 8, characterized in that at least one of R, A and B represents linear or branched C₄-C₁₀-alkyl radicals.

10. The compounds according to at least one of claims 2 to 8, characterized in that at least one of R, A and B represents at least one of C₄-C₁ o-aryl radicals and C₄-Cio-aralkyl radicals.

1 1. The compounds according to at least one of claims 2 to 10, characterized in that, independently of each other, any one or more of A, B, R, R¹, R²,R^al, R³², R^a3, R^bl, R^b2, is substituted with at least one group selected from linear or branched C₁-C₂₀-alkyl radicals, C₃-C₈-cycloalkylene radicals, mono- or polyunsaturated C₂-C₂₀-alkenyl radicals, Ci-C₂o-alkoxy radicals, d-C₂o-aralkyl radicals, optionally substituted aryl or heteroaryl radicals, C₂-C₂₀-oligo- or C₂-C₂₀-polyether radicals, benzothiadiazole, op- tionally substituted thiophene or selenophene, optionally substituted fluorene, cyanovinyl, dicyanovinyl, anthracene, pentacene and bis(triisopropylethynyl)-pentacene.

12. A process for the preparation of compounds of the general formula (N-Ia) or (N-2a), at least comprising the process steps: i) providing a compound of general formula (I) or of general formula

(H)

(I) (H),

wherein R³ and R⁴, independently of each other, have the meaning given for R, A and B in any one of claims 1 to 11, halogen, and

Si(CH₃)₃; ii) reacting the compound of general formula (I) or the compound of general formula (II) with ii-a) an organolithium reagent, and ii-b) sulphur, and iii) combining the reaction mixture obtained in step ii) with water.

13. A process for the preparation of the compounds according to at least one of claims 1 or 2, characterized in that the compounds of the general formulae (N-Ia) or (N-2a), wherein R, A, B, a, b, m, n, R¹, R², R^al, R³², R^a3, R^bl and R^b2 have the meaning given in claims 2 and 3 are reacted, optionally in the presence of catalysts, optionally in solution and optionally at elevated temperature.

14. The process according to claim 13, characterized in that the compounds of the general formulae (N-Ia) or (N-2a) are reacted in the presence of at least one metal-comprising compound, as catalyst.

15. The process according to claim 14, characterized in that the at least one metal-comprising compound comprises at least one ligand selected from the group consisting of at least one ligand which interacts with the metal through at least one of a carbon, a nitrogen, a phosphorus, an oxygen and a sulfur, a halide, and any combination of two or more of these ligands.

16. The process according to any one of claims 13 to 15, characterized in that the compounds of the general formulae (N-Ia) or (N-2a) are reacted in the presence of at least one base.

17. The process according to any one of claims 13 to 16, characterized in that the compounds of the general formulae (N-Ia) or (N-2a) are reacted in a solution comprising at least one aprotic polar solvent.

18. A compound obtainable by a process according to any one of claims 13 to 17.

19. A process for preparing an electronic component, comprising the process steps: a) providing a substrate; b) providing the substrate with at least one layer of a dielectric material to form a dielectric layer; c) applying at least one layer of a compound according to any one of claims 1 to 11 or 18 onto the dielectric layer, to form an organic semiconductor layer; d) applying at least one electrode to at least one of the organic semi- conductor layer and the substrate.

20. The process according to claim 18, characterized in that in process step c) the compound is applied in the form of at least one layer from solution.

21. The process according to claim 18, characterized in that in process step c) the compound is applied by vapour deposition.

22. Use of the compound according to at least one of claims 1 to 11 or 18 as a semiconductor in electronic components.

23. Use according to claim 22, characterized in that the components are field effect transistors, light-emitting components, in particular organic light- emitting diodes, or photovoltaic cells, lasers and sensors.

24. Electronic components comprising a compound according to at least one of claims 1 to 11 or 18 as semiconductors or obtainable by the process according to any one of claims 19 to 21.

25. Electronic components according to claim 24, characterized in that the component has a linear mobility determined as described herein of at least

1 x 10^"3 cm²/Vs.