Aromatic monomers deriving from glycerol units, process for their preparation and use thereof for the preparation of water-soluble conjugated polymers

Abstract

Monomers having formula (I) and process for their synthesis which comprises the etherification reaction of a halogen-derivative (ZCl, Br, I) having formula (III) with the hydroxyl group of the glycerol derivative (IV), according to the following scheme: ##STR00001##

Claims

1. A monomer of formula (II): ##STR00020## wherein: Ar represents a C.sub.6-C.sub.12 aromatic radical, a C.sub.12-C.sub.18 polycyclic aromatic radical, or a heteroaromatic radical comprising a heteroatom, optionally polycondensed; X represents a functional group which can be polymerized by Suzuki, Stille, Heck or Yamamoto reaction, said functional group selected from the group consisting of Br, Cl, I, O(SO.sub.2)CF.sub.3, B(OH).sub.2, B(OR).sub.2, SnR.sub.3, B(ORO) and vinyl, such that R represents a C.sub.1-C.sub.6 alkyl radical and R represents an ethylene radical, optionally substituted with C.sub.1-C.sub.1 alkyl groups; R.sub.1 and R.sub.2 independently represent a hydrogen atom or a C.sub.1-C.sub.6 alkyl radical; R represents a divalent C.sub.1-C.sub.12 alkylene radical; n ranges from 1 to 4; Ar represents a heteroaromatic radical comprising a heteroatom; and m=1 or 2.

2. The monomers according to claim 1, wherein Ar is a radical deriving from benzene, fluorene, thiophene, carbazole, dithienocyclopentadiene or from phenothiazine.

3. The monomers according to claim 1, wherein Ar is a radical deriving from thiophene, thieno-thiophene, thiazole, carbazole, dithienocyclopentadiene or from phenothiazine.

4. A process for synthesizing the monomer of claim 1, the process comprising condensing a monomer of formula (I) with a compound of formula (IX) to form an intermediate of formula (X) ##STR00021## followed by halogenation of the intermediate of formula (X) to form the monomer of formula (II), wherein W represents SnR.sub.3, B(OH).sub.2, or B(OR).sub.2.

5. The process according to claim 4, wherein a molar ratio of the monomer of formula (I): to the compound of formula (IX) is between 1:2 and 1:4.

6. The process according to claim 4, wherein the condensing occurs at temperatures ranging from 10 to 200 C.

7. A process for preparing a conjugated polymer or copolymer, the process comprising reacting at least one monomer of claim 2 with at least one co-monomer selected from the group consisting of: ##STR00022## ##STR00023## ##STR00024## followed by acid hydrolysis of an initially-obtained polymer or copolymer, to yield a conjugated polymer or copolymer, wherein: R.sub.3-R.sub.10 independently represents a hydrogen atom, an optionally branched C.sub.1-C.sub.37 alkyl group, and an OC.sub.1-OC.sub.16 alkoxyl group; and Y is a group which can be polymerized by Suzuki, Stille, Heck or Yamamoto reaction.

8. The process according to claim 7, wherein the reacting occurs by a condensation reaction, which is catalyzed by a derivative of: palladium, in the case of a Suzuki, Stille or Heck reaction; or nickel, in the case of a Yamamoto reaction.

9. The process according to claim 6, wherein the reaction is carried out at temperatures ranging from 30 to 150 C.

10. The process of claim 7, wherein the polymer or copolymer is soluble in water.

11. The process according to claim 1, wherein Ar is a heteroatom selected from the group consisting of S, N and Se.

Description

Example 1

Synthesis of 2,7-dibromo-9,9-bis(3-bromopropyl)fluorene

Intermediate

(1) ##STR00013##

(2) The following products are added, in an inert atmosphere, to a solution of 2,7-dibromofluorene (10.0 g, 31.06 mmoles) in 40 ml of 1,3-dibromopropane: first sodium hydroxide (30.0 g, 750.0 mmoles) dissolved in 60 ml of water and finally 0.2 g of tetrabutylammonium bromide. The temperature is brought to 100 C. After 6 hours, after the addition of water, extraction is effected with dichloromethane. After washing the organic phase with water until neutrality, said organic phase is anhydrified on sodium sulfate. The dichloromethane and 1,3-dibromopropane in excess are removed by distillation at reduced pressure. After purification by elution on a chromatographic silica gel column (eluent: heptane/ethyl acetate=99/1), 5.2 g of 2,7-dibromo-9,9-bis(3-bromopropyl)fluorene are obtained (yield=30%).

Synthesis of 2,7-dibromo-9,9-bis{3-[(2,2-dimethyl-1,3-dioxolan-4-yl)methoxy]propyl}fluorene

(3) ##STR00014##

(4) Potassium terbutylate (3.0 g, 26.7 mmoles) are added, in an inert atmosphere, to a solution of solketal (3.5 g, 26.7 mmoles) in 50.0 ml of 1,2-dimethoxyethane. After 20 minutes, 5.0 g of 2,7-dibromo-9,9-bis(3-bromopropyl)fluorene (5.0 g, 8.9 mmoles) dissolved in 15.0 ml of 1,2-dimethoxyethane are added.

(5) After 8 hours, after removing 1,2-dimethoxyethane by distillation at reduced pressure, the residue is recovered with ethyl acetate and is washed with water until neutrality. After anhydrifying the organic phase on sodium sulfate, the solvent is removed by distillation at reduced pressure. After purification by elution on a chromatographic alumina column (heptane/ethyl acetate=95/5), 4.0 g of 2,7-dibromo-9,9-bis{3-[(2,2-dimethyl-1,3-dioxolan-4-yl)methoxy]propyl}fluorene are obtained (yield=74%).

Example 2

Synthesis of 2,5-dibromo-3-methylthiophene

First Intermediate

(6) ##STR00015##

(7) N-bromosuccinimide (20.0 g, 113.0 mmoles) is added, in an inert atmosphere to 3-methylthiophene (5.0 g, 51.0 mmoles) dissolved in 40 ml of tetrahydrofuran and 40 ml of acetic acid. After 1 hour, water is added and extraction is effected with ethyl ether.

(8) After washing the organic phase to neutrality, first with water and then with a saturated aqueous solution of sodium bicarbonate, said organic phase is anhydrified on sodium sulfate. The solvent is distilled at reduced pressure. 9.7 g of 2,5-dibromo-3-methylthiophene are obtained (yield=75%)

Synthesis of 2,5-dibromo-3-bromomethylthiophene

Second Intermediate

(9) ##STR00016##

(10) The following products are added, in an inert atmosphere to a solution of 2,5-dibromo-3-bromomethylthiophene (5.6 g, 22.0 mmoles) in 50 ml of carbon tetrachloride: N-bromosuccinimide (4.4 g, 24.9 mmoles) and finally 50 mg of dibenzoylperoxide. After 7 hours, water is added and extraction is effected with ethyl acetate. After washing the organic phase to neutrality with water, said organic phase is anhydrified on sodium sulfate. After removing the solvent by distillation at reduced pressure, 5.0 g of 2,5-dimethyl-3-bromomethylthiophene are obtained (yield=70%).

Synthesis of 4-{[(2,5-dibromo-3-thienyl)methoxy]methyl}-2,2-dimethyl-1,3-dioxolane

(11) ##STR00017##

(12) Potassium terbutylate (2.6 g, 23.2 mmoles) are added, in an inert atmosphere, to a solution of solketal (3.1 g, 23.5 mmoles) in 35.5 ml of 1,2-dimethoxyethane. After 15 minutes, 2,5-dimethyl-3-bromomethylthiophene (5.0 g, 15.0 mmoles) dissolved in 15 ml of 1,2-dimethoxyethane, are added dropwise.

(13) After 3 hours, the 1,2-dimethoxyethane is removed by distillation at reduced pressure, the residue is recovered with water and extracted with ethyl acetate. After washing the organic phase with water until neutrality, said organic phase is anhydrified on sodium sulfate. The solvent is removed by distillation at reduced pressure. After purification by elution on an alumina column (heptane/ethyl acetate=95/5), 4.0 g of 4-{[(2,5-dibromo-3-thienyl)methoxy]methyl}-2,2-dimethyl-1,3-dioxolane are obtained (yield=70%).

Example 3

Synthesis of 3,6-dibromo-9-(3-bromopropyl)carbazole

Intermediate

(14) ##STR00018##

(15) The following products are added, in an inert atmosphere, to a solution of 3,6-dibromocarbazole (2.5 g, 7.74 mmoles) in 13 ml of toluene: potassium hydroxide (6.5 g, 98 mmoles) dissolved in 13 ml of water, tetrabutylammonium bromide and finally 1,3-dibromopropane (9.9 g, 49.2 mmoles).

(16) The temperature is brought to 70 C. After 3 hours, water is added and extraction is effected with ethyl acetate. After washing the organic phase with water to neutrality, said organic phase is anhydrified on sodium sulfate. After removing the solvent by distillation at reduced pressure 2.5 g of 3,6-dibromo-9-(3-bromopropyl) carbazole are obtained (yield=75%).

Synthesis of 3,6-dibromo-9-{3-[(2,2-dimethyl-1,3-di-oxolan-4-yl)methoxy]propyl}-9H-carbazole

(17) ##STR00019##

(18) Potassium terbutylate (0.8 g, 7.1 mmoles) are added, in an inert atmosphere, to a solution of solketal (0.9 g, 7.1 mmoles) in 10 ml of 1,2-dimethoxyethane. After 15 minutes, 3,6-dibromo-9-(3-bromopropyl)carbazole (2.1 g, 4.7 mmoles) dissolved in 10 ml of 1,2-dimethoxyethane, are added dropwise. After hours, the 1,2-dimethoxyethane is removed by distillation at reduced pressure, the residue is recovered with water and extracted with ethyl acetate. After washing the organic phase with water until neutrality, said organic phase is anhydrified on sodium sulfate. The solvent is removed by distillation at reduced pressure. After purification by elution on an alumina column (heptane/ethyl acetate=9/1), 1.6 g of 3,6-dibromo-9-{3-[(2,2-dimethyl-1,3-di-oxolan-4-yl)methoxy]propyl}-9H-carbazole are obtained (yield=70%).

Example 4

Synthesis of the random copolymer poly{(2,1,3-benzothiadiazole)-alt-[(3-(4-sodiumsulfobutoxy)methyl-thiophene)-co-(9,9-bis-(3-((2,2-dimethyl-1,3-dioxolan-4-yl)methoxy)propyl)fluorene)]}

(19) The following products are introduced in an inert atmosphere into a 50 ml two-necked flask equipped with a magnetic stirrer and reflux cooler: 324.3 mg (0.485 mmoles) of 2,7-dibromo-9,9-bis{3-[(2,2-dimethyl-1,3-dioxolan-4-yl)methoxy]propyl}fluorene; 373.80 mg (0.963 mmoles) of 4,7-bis(pinacolboronic-2,1,3-benzothiadiazole) ester; 200.6 mg (0.482 mmoles) of [(2,5-dibromo-3-thienyl)methoxy]sodium butanesulfonate; 10 ml of distilled THF (tetrahydrofuran); 1 ml of an aqueous solution 4 M of K.sub.2CO.sub.3; a few drops of Aliquat 334.

(20) The reaction mixture is heated to 70 C. for 15 minutes and the following product is then added: 12 mg (0.01 mmoles) of Pd (0) tetrakis(triphenylphosphine);

(21) The reaction mixture is left at this temperature for 40 hours. After 5 hours the reaction is almost dry and a further 5 ml of THF are added. After 40 hours the mixture is cooled and the solvent removed by distillation.

Hydrolysis of poly{(2,1,3-benzothiadiazole)-alt-[(3-(4-sodiumsulfobutoxy)methylthiophene)-co-(9,9-bis-(3-((2,2-dimethyl-1,3-dioxolan-4-yl)methoxy)propyl)fluorene)]}

(22) The following products are introduced into a 250 ml two-necked flask: 600 mg of random copolymer between 2,7-dibromo-9,9-bis{3-[(2,2-dimethyl-1,3-dioxolan-4-yl)methoxy]propyl}-fluorene, 4,7-bis pinacolboronic-2,1,3-benzothiadiazole ester and [(2,5-dibromo-3-thienyl)methoxy]sodium butanesulfonate, previously prepared, 45 ml of acetone; 35 ml of water; 5 ml of HCl at 37%.

(23) After 18 hours, the mixture is cooled to room temperature. The solution is at neutral pH, as resulting from a litmus paper test. The solvent is then removed by distillation. The polymer is re-dissolved in a solution consisting of 45 ml of acetone and 5 ml of distilled water.

(24) The solution containing the polymer is transferred to a dialysis membrane with a cut-off at 1,200 Da and dialyzed for 2 days in a 1 l cylinder also containing an acetone/water solution in a weight ratio of 9:1.

(25) The solvent is removed from the solution containing the polymer by distillation. 375 mg of a dark red polymer are obtained.

(26) The NMR spectrum shows the disappearance of the signals due to the methyl groups of the dioxolane groups and their transformation into glycol groups.