DE4009309A1 - Soluble polycondensates of carbaldehyde deriv(s). - for conversion into insol. electroconductive poly:hetero-arylene-vinylene - Google Patents

Abstract

Polycondensation prods. of 5-membered 5-methyl-heteroaryl-2-carbaldehydes or their Schiffs bases are made up of units (II) and opt. units of formula (I), with the proviso that the ratio of the number of units (II) to the number of units (I) is greater than 0.3, pref. greater than 0.35. X = -O-, -S- or -NR-; R = H, alkyl or ayrl; Y -N(R1) (R2) or -OR3; R1 and R2 = H, 1-8C alkyl, acyl or alkali(ne earth) ion and R2 may also = opt. substd. aryl gp.; and R3 = H, acyl residue or alkali(ne earth) ion. The polycondensates are prepd. by alkaline or acid condensn. of the corresp. aldehydes or Schiff's base opt. in an organic diluent, following the polycondensation analytically and terminating the reaction when the desired ratio of units (II) to units (I) has been achieved, and opt. acylating the polycondensation prod. USE/ADVANTAGE - The polycondensation prods. resulting from polycondensation of the corresponding aldehydes or their Schiffs bases to a stage where a large proportion of units (II) are present, have good solubility in water and/or organic solvents, which allows easy processing e.g. by casting into films or application as a thin film to a substrate, after which the prods. can easily be converted e.g. by heating or by treatment with conventional dopants into electrically conductive polyhetero-arylenevinylenes made up of units (I).

Description

The invention relates to new soluble polycondensation products of 5-membered 5-methyl-hetaryl-2-carbaldehydes, Process for their preparation and their use for the production of electrically conductive polyheteroarylene vinylenes.

Polyheteroarylenvinylenes and their production by Polycondensation of 5-membered 5-methyl-hetaryl-2- carbaldehydes are known (see e.g. Makromol. Chem. 182: 3419 (1981); Semiconducting and Conducting Polymers with Aromatic and Heteroaromatic Units, in "Handbook of Conducting Polymers "Vol. 1, M. Dekker, New York 1986, Page 351).

Polyheteroarylenvinylenes are electrical semiconductors interesting properties. Your application in practice so far, however, due to its disadvantageous property complicates that they are insoluble and not undecomposed  are meltable and therefore only with great difficulty processable, e.g. B. in a thin layer on third-party materials can be applied, or to shaped articles such as foils, are processable.

One has therefore tried the polyheteroarylenevinylenes from soluble, easier to process precursors Basis of sulfonium salts of these polyheteroarylene vinylenes (see J. Polym. Sci. Part C, 24, 503 (1986); Polymeric Materials Science and Engineering, 56, Denver Meeting 1987; Polymer 27, (1986); DE-PS 37 43 443). However, these precursors have the disadvantage that when they are converted into the polyheteroarylenevinylenes Sulfides are split off and therefore there is an intense odor nuisance. Furthermore the preparation of the precursors requires several reaction stages and those necessary for the manufacture Starting products are sometimes difficult to access.

Surprisingly, it was found that if one the polycondensation of the 5-membered 5-methyl-hetaryl 2-carbaldehydes or their Schiff bases on one certain stage continues, namely the stage where the polycondensation products some amount of hydroxy or have amino groups, polycondensation products receives, which may be after alkylation or acylating their OH or NH groups in water and / or organic solvents that dissolve can be processed easily, e.g. B. by shedding to moldings, e.g. B. cast films, or by application  in a thin layer on third-party materials, and that itself after processing, also in a simple manner, e.g. B. Heating or by treatment with conventional dopants, in electrically conductive polyheteroarylene vinylenes get transferred.

The invention therefore relates to polycondensation products of 5-membered 5-methyl-hetaryl-2-carbaldehydes or whose Schiff bases, which consist of structural units of the Formula (II) and optionally of formula (I)

are built in which

X represents an oxygen or sulfur atom or a

with R = H, alkyl or aryl,
Y represents an -NR₁R₂- or an -OR₃ group in which R₁ and R₂ independently of one another are hydrogen, C₁- C₈-alkyl, an acyl radical or an alkali or alkaline earth metal ion and R₂ can additionally represent optionally substituted aryl and R₃ is hydrogen, represents an acyl radical or an alkali or alkaline earth metal ion,

with the proviso that the ratio number of structural units of formula (II) / number of structural units of formula (I) has a value <0.3, preferably <0.35.

For R₁ and R₂, the methyl, ethyl, propyl and butyl radicals may be mentioned as C₁-C₈ alkyl radicals; optionally substituted aryl radicals for R₂ are preferably the phenyl, tolyl and p-chlorophenyl radical;
for R₁, R₂ and R₃, aliphatic acyl radicals such as the acetyl and propionyl radical, aromatic acyl radicals such as the benzoyl and in particular the tosyl radical may be mentioned as acyl radicals.

The polycondensation products according to the invention from Structural units of the formula (I) and (II) are represented by Condensation of aldehydes or aldehyde derivatives formula

received in the

X has the meaning given under formulas (I) and (II) and
Z represents oxygen or a = NR₂ group, in which R₂ has the meaning given under formula (II).

The aldehydes of the formula (III) are commercially available. The aldehydes can be in their by known methods Derivatives, the Schiff bases (Z = NR₂) transferred will.

The production of the polycondensation products according to the invention from these aldehydes or their Schiff's Bases can be done in different ways:

• a) by condensation of the aldehydes of the formula (III) in an alkaline medium in the presence of diluents. The condensation can occur at temperatures of 0 to 180 ° C are carried out. The response times depend on the selected condensation temperature in the sense that the lower the condensation temperature the longer the response time must be chosen.
• b) by condensation of the aldehydes of the formula (III) with alkali or alkaline earth hydroxides in the absence of diluents at temperatures from 100 to 300 ° C, preferably at temperatures from 150 to 250 ° C.
• c) by condensation of the aldehydes of the formula (III) in a strongly acidic medium (pH <1) at temperatures of 0 to 50 ° C.  
• d) by electrochemically initiated condensation of the Aldehydes of formula (III) in the presence of a solvent and a suitable conductive salt Temperatures from 10 to 40 ° C.

Suitable solvents for electrochemical oxidation are aprotic solvents such as dimethylformamide, Acetonitrile, methylene chloride, acetone, ethylene carbonate, Propylene carbonate, dimethyl sulfoxide, tetramethylene sulfone, N-methyl pyrrolidone, N-methyl caprolactam.

Suitable conductive salts are e.g. B. the halides of quaternary Ammonium salts such as tetraethylammonium iodide and Tetrabutylammonium chloride.

• e) Radical induced condensation of the Aldehydes of the formula (III) with the help of radical formers. This polycondensation can if necessary be made in a solvent. The radical initiated polycondensation obtained polycondensation mixtures can immediately for the production of films, castings or fibers are used. As a radical generator have in particular halogens such as chlorine, bromine and iodine, as well as azo compounds such as bisazoisobutyronitrile and peroxides such as dibenzoyl peroxide proven.

The polycondensation products obtained in process (a) to (e) can be reacted with acylating agents in the polycondensation products according to the invention  transfer from structural units of the Formula (I) and (II) are constructed in which Y is OR₁ stands and R₁ is an acyl radical.

Deliver the electrochemical and radical condensation the polycondensation products according to the invention, without having to take any action, so the relationship Number of structural units of the formula (II) / <Number of structural units of formula (I) the value <0.3. Require alkaline and acidic condensation against it as a special measure, so the value this ratio is achieved that the course the condensation reaction is followed analytically and the Reaction stops when the ratio of number of structural units of formula (II) / number of structural units of the formula (I) reaches the desired value <0.3 Has.

The invention therefore also relates to a method for Preparation of the polycondensation products according to the invention, which consist of structural units of the formulas (I) and (II) are constructed, which is characterized in that aldehydes or aldehyde derivatives of the formula (III) are made alkaline, acidic, electrochemical or radical, if appropriate in diluents, condensed, one the course of alkaline and acidic condensation analytically followed the reaction and terminated the reaction, if the ratio number of structural units  of the formula (II) / number of structural units of the formula (I) has reached the desired value <0.3, and the Polycondensation products then optionally acylated.

The polycondensation products according to the invention are in Water and / or organic solvents, e.g. B. protic Solvents such as ethanol or aprotic solvents such as ketones, e.g. B. acetone, ethers such as tetrahydrofuran, Amides such as dimethylformamide, dimethylacetamide, N-methylcaprolactam, N-methylpyrrolidone and hexamethylphosphoric triamide, Sulfoxides such as dimethyl sulfoxide; Sulfones such as tetramethylene sulfone and in chlorinated hydrocarbons such as methylene chloride, chloroform and Tetrachloromethane good to very soluble if the ratio Number of structural units of the formula (II) / Number of structural units of formula (I) a value <0.5. But also polycondensation products, at which this ratio ranges from 0.35 to 0.5 lies, have such a solubility that of them at least 1% solutions in at least produce some of the above solvents to let.

The solutions of the polycondensation products according to the invention can be processed into foils by using them uniformly thick layers and the solvent from these, e.g. B. removed by evaporation (Cast films). The solutions can be made in an analogous manner  of the polycondensation products also for the production of Use coatings from these products on third party materials. The solutions are preferably dipped, Painting or spraying on such third party materials upset.

To convert the polycondensation products into the Polyheteroarylenvinylenes become the polycondensation products or those made from them or with them coated moldings only at elevated temperature warmed or heated.

The duration of the heating depends on the chosen one Temperature; the choice of temperature depends on whether the polycondensation product is on a temperature sensitive or temperature-insensitive third-party material located. The higher the heating temperature, the shorter the heating time can be. For example can be the transition temperature for a coating of glass with the polycondensation products according to the invention 300 ° C and the reaction time is 10 minutes.

The conductivity of the polyheteroarylene vinylenes thus obtained can then be treated with dopants such as halogens, fluorides of antimony and Arsenic, chlorides of iron, aluminum and copper and Nitrosonium salts can be significantly improved.

Another method for converting the invention  Condensation products in electrically conductive polyheteroarylene vinylenes consists of the invention Polycondensation products with common dopants to treat. This procedure represents one represents a particularly simple method, the inventive Polycondensation products directly in electrical to transfer conductive polyheteroarylene vinylenes.

The polycondensation products according to the invention or polyheteroarylene vinylenes available from them are versatile. You can use them electrically conductive or semiconducting components, e.g. B. surface heating conductor, electronic devices, battery elements, Capacitors, photovoltaic converters, intercalation materials and sensors and materials for manufacture the nonlinear optics.

Example 1

5 g of 5-methyl-furan-2-carbaldehyde are mixed with the solution of 20 g of potassium hydroxide in 50 ml of water. The Mixture is stirred for 70 hours at room temperature, then neutralized and extracted with carbon tetrachloride. The organic phase is separated off Dried sodium sulfate and then in a vacuum freed of solvent at low temperature. It will 3.95 g polycondensation product in the form of a red-brown, highly viscous, in water and organic solvents, such as ethanol, acetonitrile and methylene chloride, soluble oil.

According to the NMR spectrum, the ratio is the number of Structural units of the formula (II) / number of structural units of formula (I) 0.5.

Example 2

The solution of 20 g of potassium hydroxide in 5 ml of water heated to 150 ° C and within this temperature 15 minutes with 5 g of 5-methyl-furan-2-carbaldehyde added dropwise. It immediately creates a dark, granular mass. The reaction mixture is a further 2 hours stirred at 150 ° C. After cooling to room temperature the mixture is mixed with 20 ml of water and neutralized with aqueous hydrochloric acid while stirring in an ice bath. The neutralization mixture is with carbon tetrachloride extracted. The organic phase becomes after  evaporated to dryness in a rotary evaporator and dried in vacuo over phosphorus pentoxide. It 3.33 g of polycondensation product in the form of a dark powder.

According to the NMR spectrum, the ratio is the number of Structural units of the formula (II) / number of structural units of formula (I) 1.19.

Example 3

32 g (0.29 mol) of 5-methyl-furan-2-carbaldehyde and 16.16 g (0.29 mol) of KOH in 100 ml of dimethylformamide for 5 hours stirred at 80 ° C. The reaction mixture is then evaporated to dryness in vacuo. The residue one week in the Soxleth extractor with water extracted. The extraction residue is vacuum P₄O₁₀ dried. There are 26.24 g of polycondensation product in the form of a brown powder (melting range around 150 ° C).

Ratio of number of structural units of the formula (II) / Number of structural units of the formula (I): 0.35.

By quickly heating the polycondensation product to 300 ° C and hold at this temperature for 10 minutes this is in the corresponding poly-2,5-furandiylvinylene transferred. This polyfuranediyl vinylene is not more soluble in organic solvents and melts not even at temperatures below 350 ° C.  

Before heating to 300 ° C., the polycondensation product has an electrical conductivity of 3 × 10 ^-8 S / cm and the polyfuranediyl vinylene has an electrical conductivity of 2 × 10 ^-10 S / cm (powder compact, two-electrode method).

By treatment with dopants, the polycondensation product in electrically conductive poly (2.5- furandiylvinylene) transferred. That was the endowment Polycondensation product in anhydrous acetonitrile recorded and with those in the table below specified dopants treated. The composition and the electrical conductivity of the Treatment with the different dopants obtained conductive poly (2,5-furandiylvinylenes) also given in the table below.

table

Example 4

The solution of 2 g (15.9 mmol) of 5-methyl-thiophene-2-carbaldehyde in 100 ml of dimethylformamide with 3.56 g (31.7 mmol) potassium tert-butoxide and 5 hours stirred at 75 ° C. The reaction mixture is then divided into two portions.

Portion (a) is mixed with 50 ml of water; subsequently be tert-butanol, water and dimethylformamide on a rotary evaporator distilled off. The backlog is in Carbon tetrachloride added; the organic phase will washed with water. After drying over sodium sulfate the solvent is distilled off in vacuo. It 820 mg of polycondensation product in the form of a Obtained dark red viscous oil. Ratio number of the structural units of the formula (II) / number of structural units of formula (I): 1.

Portion (b) is mixed with 6.3 g (33 mol) of p-toluenesulfochloride added and stirred for 20 hours at room temperature. The tosylation mixture is worked up in the usual way; there will be 1.1 g of polycondensation product tosylated OH group in the form of an almost black oil receive. Ratio number of structural units of the Formula (II) / number of structural units of the formula (I): 1.  

Example 5

5 g of 5-methyl-furan-2-carbaldehyde are 3 days at room temperature with 50 ml of 25% aqueous ammonia solution stirred. The resulting yellow solid is filtered off, washed with water and in vacuo over P₄O₁₀ dried.

There are 1.82 g of polycondensation product with structural units of the formula (II) in which Y represents an NH₂ group stands, received.

Ratio of number of structural units of formula (II) / Number of structural units of the formula (I): 3.3.

Example 6

The solution of 0.55 g of 5-methyl-furan-2-carbaldehyde in 7.5 g of 25% aqueous hydrochloric acid is 4 days at room temperature touched. The precipitate is filtered off, and washed several times with water and then in Vacuum dried over potassium hydroxide. It becomes 0.26 g Polycondensation product in the form of a light brown powder receive.

Ratio of number of structural units of formula (II) / Number of structural units of the formula (I): 0.63.

Example 7

20 ml of a solution of 1.1 g of 5-methyl-furan-2-carbaldehyde and 1.65 g tetraethylammonium chloride in 50 ml  Dimethylformamide is electrolyzed for 24 hours (electrode material: Platinum; Clamping voltage 3 V). Subsequently the electrolyte is freed from the solvent in vacuo. The residue is mixed with water and not reacted Furan carbaldehyde azeotropic with water distilled off in vacuo. The distillation residue is washed several times with water and then in Vacuum dried over P₄O₁₀.

There are 0.32 g of polycondensation product in the form of a preserved dark red oil.

Ratio of number of structural units of formula (II) / Number of structural units of the formula (I): 1.

Example 8

Was the solution described in Example 7 at a Voltage of 2.5 V was electrolyzed, so 0.34 g Polycondensation product in the form of an orange-red oil receive.

Ratio of number of structural units of formula (II) / Number of structural units of the formula (I): <3.

Example 9

The solution of 5 g of 5-methyl-furan-2-carbaldehyde in 50 ml Acetonitrile is mixed with 1 g of tetraethylammonium chloride  and then electrolyzed for 48 hours (electrode material: Platinum; Voltage 3.5 V). Subsequently the electrolyzed solution is stirred in with vigorous stirring Water entered. The precipitate is filtered off, washed with water and in vacuo over potassium hydroxide dried.

1.43 g of polycondensation product in the form of a preserved light brown powder.

The polycondensation product consists exclusively of Structural units of the formula (II).

Example 10

The polycondensation product obtained according to Example 1 is dissolved in chloroform and the solution in thinner Layer applied to a slide. After this Evaporation of the solvent leaves a thin, transparent, light brown film. After a three hour Heat treatment at 220 ° C and 20 hours of treatment The surface resistance is (doping) with iodine vapor the poly (2,5-furandiyl-vinylene) layer 1 × 10⁵ Ω. The layer is dark brown and transparent.

Example 11

The polycondensation product obtained according to Example 9 was dissolved in chloroform and the chloroform solution was dissolved applied a slide in a thin layer. To  evaporation of the solvent leaves a thin, transparent, light brown film on the slide back. After three hours of heat treatment at 220 ° C and 20 hours of treatment (doping) with iodine vapor the surface resistance of the poly (2,5-furandiylvinylene) - Film 1 × 10⁶ Ω. By heat treatment and Doping takes the conductive layer a gray-brown Color on, but keeps its transparency.

Claims (4)

1. Polycondensation products of 5-membered 5-methyl-hetaryl-2-carbaldehydes or their Schiff bases, which consist of structural units of the formula (II) and optionally of the formula (I) are built in which
X represents an oxygen or sulfur atom or a with R = H, alkyl or aryl,
Y represents an -NR₁R₂- or an -OR₃ group in which R₁ and R₂ independently of one another are hydrogen, C₁- C₈-alkyl, an acyl radical or an alkali or alkaline earth metal ion and R₂ can additionally represent optionally substituted aryl and R₃ is hydrogen, represents an acyl radical or an alkali or alkaline earth metal ion,
with the proviso that the ratio of the number of structural units of the formula (II) / the number of structural units of the formula (I) has a value <0.3, preferably <0.35, 2. A process for the preparation of the polycondensation products according to claim 1, characterized in that aldehydes or aldehyde derivatives of the formula in the
X has the meaning given under formulas (I) and (II) and
Z represents oxygen or a = NR₂ group in which R² has the meaning given under formula (II),
optionally condensed in diluents, the course of the reaction being followed analytically in the alkaline and acidic condensation and the reaction being terminated when the ratio of the number of structural units of the formula (II) / number of structural units of the formula (I) has the desired value <0 , 3 has reached, and optionally subsequently acylated the polycondensation products. 3. Use of the polycondensation products according to Claim 1 for the production of polyheteroarylene vinylenes, which consist of structural units of the formula (I) are set up. 4. Use according to claim 3, characterized in that according to the polycondensation products Claim 1 by treatment with dopants converted into doped polyheteroarylene vinylenes.