SYNTHESIS OF GREEN ELECTROCHROMIC MATERIALS

• US 20090067030A1
• Filed: 10/22/2007
• Published: 03/12/2009
• Est. Priority Date: 06/25/2002
• Status: Active Grant

• Current Assignee: University of Washington
• Original Assignee: University of Washington
• Inventors: Taya, Minoru, Xu, Chunye, Liu, Lu
• Granted Patent: US 7,808,691 B2
• Time in Patent Office: Days
• US Class Current: 359/265
• CPC Class Codes: C07D 493/04 Ortho-condensed systems
• CPC Class Codes: C08G 2261/1424 containing ether groups, including alkoxy
• CPC Class Codes: C08G 2261/3221 containing one or more nitrogen atoms as the only heteroatom, e.g. pyrrole, pyridine or triazole
• CPC Class Codes: C08G 2261/3223 containing one or more sulfur atoms as the only heteroatom, e.g. thiophene
• CPC Class Codes: C08G 2261/3241 containing one or more nitrogen atoms as the only heteroatom, e.g. carbazole
• CPC Class Codes: C08G 2261/3243 containing one or more sulfur atoms as the only heteroatom, e.g. benzothiophene
• CPC Class Codes: C08G 2261/44 Electrochemical polymerisation, i.e. oxidative or reductive coupling
• CPC Class Codes: C08G 2261/54 electrochromatic
• CPC Class Codes: C08G 61/122 derived from five- or six-membered heterocyclic compounds, other than imides
• CPC Class Codes: C08G 61/124 with a five-membered ring containing one nitrogen atom in the ring
• CPC Class Codes: C08G 61/126 with a five-membered ring containing one sulfur atom in the ring
• CPC Class Codes: C09K 2211/1044 containing two nitrogen atoms as heteroatoms
• CPC Class Codes: C09K 2211/1051 with sulfur
• CPC Class Codes: C09K 2211/1088 containing oxygen as the only heteroatom
• CPC Class Codes: C09K 2211/1092 containing sulfur as the only heteroatom
• CPC Class Codes: C09K 2211/1408 Carbocyclic compounds
• CPC Class Codes: C09K 9/02 Organic tenebrescent materials
• CPC Class Codes: G02F 1/15165 Polymers
• CPC Class Codes: G02F 1/153 Constructional details
• CPC Class Codes: G02F 1/1533 structural features not otherwise provided for
• CPC Class Codes: G02F 1/163 : Operation of electrochromic cells, e.g. electrodeposition cells; Circuit arrangements therefor
• CPC Class Codes: G02F 2001/15145 : the electrochromic layer comprises a mixture of anodic and cathodic compounds

Abstract

Green electrochromic (EC) materials based on thiophene, and a green EC material based on pyrazine are disclosed. A first thiophene derivative (2,3-Di-thiophen-2-yl-thieno[3,4-b]pyrazine), which was previously investigated as a nonlinear optical material, is here disclosed for its use as an EC material and for its incorporation into an EC device. Synthesis of two new thiophene derivatives (2,5-di(thien-2-yl)-3,4-di(2,2,2-trifluoro-ethoxy)-thiophene and 2,5-(2,3-dihydro-thieno[3,4-b][1,4]dioxin-5-yl)-3,4-di(2,2,2-trifluoro-ethoxy)-thiophene), and a new pyrazine derivative (2,3-dibenzyl-5,7-di(thien-2-yl)thieno[3,4-b]pyrazine) are also disclosed, since these materials are all able to selectively change state to appear a green color and can be polymerized to achieve a green EC polymer.

Claims

1. An electrochromic device comprising:

(a) a transparent electrode;

(b) an electrochromic organic material that in a first state is not green and in a second state exhibits a green color, the electrochromic organic material exhibiting a single absorbance band; and

(c) an electrolyte.

2. A method for synthesizing a desired product, the desired product comprising 2,5-di(thien-2-yl)-3,4-di(2,2,2-trifluoroethoxy)-thiopene, a monomer suitable for polymerization to achieve a fluorinated electrochromic polymer exhibiting a green color in a first state and a red color in a second state, the method comprising the steps of:

(a) producing a first intermediate reagent, the first intermediate reagent comprising 2,5-dibromo-3,4-bis-(2,2,2-trifluoroethoxy)-thiopene, by;

(i) providing a first solution comprising a first precursor, the first precursor comprising 3,4-bis-(2,2,2-trifluoroethoxy)-thiopene; and

(ii) heating the first solution to facilitate a reaction that produces the first intermediate reagent; and

(b) producing the desired product by heating a second solution comprising the first intermediate reagent and a substituted thiophene, to facilitate a reaction that produces the desired product.

3. The method of claim 2, wherein:

(a) the first solution further comprises N-bromosuccinimide, chloroform and acetic acid;

(b) the substituted thiopene comprises 2-tributyltin thiopene, and the second solution further comprises a palladium catalyst and tetrahydrofuran; and

(c) the second solution is heated for substantially longer than the first solution.

4. The method of claim 2, wherein:

(a) the first solution is heated for a period of time ranging from about 15 minutes to about 45 minutes; and

(b) the second solution is heated for about 15 hours.

5. The method of claim 2, wherein:

(a) the step of heating the first solution comprises the step of refluxing the first solution under an inert atmosphere; and

(b) the step of heating the second solution comprises the step of refluxing the second solution under an inert atmosphere.

6. The method of claim 2, further comprising the steps of:

(a) purifying the first intermediate reagent using chromatography; and

(b) purifying the desired product using chromatography.

7. The method of claim 2, further comprising the step of dissolving the first precursor into the first solution by stirring the first solution for an extended period of time.

8. The method of claim 2, further comprising the step of producing the first precursor by:

(a) providing a third solution comprising a second precursor, the second precursor comprising 3,4-bis-(2,2,2-trifluoroethoxy)-thiophene-2,5-dicarboxylic acid; and

(b) heating the third solution to facilitate a reaction that will produce the first precursor.

9. The method of claim 8, wherein:

(a) the third solution further comprises quinoline and a barium promoted copper chromite catalyst;

(b) the third solution is heated for substantially longer than the first solution;

(c) the third solution is heated for a period of time ranging from about 12-18 hours;

(d) the third solution is heated to about 170-190°

C.;

(e) the first precursor is purified before being used to produce the first intermediate reagent; and

(f) the third solution is heated under an inert atmosphere.

10. The method of claim 8, further comprising the step of producing the second precursor by:

(a) providing a fourth solution comprising a third precursor, the third precursor comprising 3,4-bis-(2,2,2-trifluoro-ethoxy)-thiophene-2,5-dicarboxylic acid dimethyl ester; and

(b) heating the fourth solution to facilitate a reaction that will produce the second precursor.

11. The method of claim 10, wherein:

(a) the fourth solution further comprises sodium hydroxide and ethanol;

(b) the fourth solution is heated for substantially longer than the first solution;

(c) the fourth solution is heated for a period of time ranging from about 12-20 hours;

(d) the fourth solution is heated to about 50-70°

C.;

(e) the second precursor is purified before being used to produce the first precursor;

(f) the step of heating the fourth solution comprises the step of stirring while heating; and

(g) the step of heating the fourth solution comprises the step of heating the fourth solution under an inert atmosphere.

12. The method of claim 10, further comprising the step of neutralizing any sodium hydroxide in the fourth solution using an acid after the solution has been heated.

13. The method of claim 10, further comprising the step of producing the third precursor by:

(a) providing a fifth solution comprising a fourth precursor and 2,2,2-trifluoroethanol, the fourth precursor comprising 3,4-dihydroxy-thiophene-2,5-dicarboxylic acid dimethyl ester; and

(b) heating the fifth solution to facilitate a reaction that will produce the third precursor.

14. The method of claim 13, wherein:

(a) the fifth solution further comprises triphenylphosphine (PPh₃), tetrahydrofuran and diethyl azodicarboxylate (DEAD);

(b) the fifth solution is heated for substantially longer than the first solution;

(c) the fifth solution is heated for a period of time ranging from about 15-24 hours;

(d) the third precursor is purified before being used to produce the second precursor; and

(e) the step of heating the fifth solution comprises the step of refluxing the fifth solution under an inert atmosphere.

15. The method of claim 14, wherein the third precursor is purified by evaporating the fifth solution to dryness to generate a solid reaction product, and eluding the third precursor from the solid reaction product using hexane and dichloromethane.

16. A method for synthesizing a fluorinated electrochromic monomer suitable for polymerization to achieve a fluorinated electrochromic polymer, the fluorinated electrochromic monomer being a fluorinated derivative of 2,5-di(thien-2-yl)-3,4-dihydroxy-thiophene, the fluorinated derivative corresponding to 2,5-di(thien-2-yl)-3,4-di(R-oxy)-thiophene, with R comprising a fluorinated functional group, the method comprising the steps of:

(a) producing a first intermediate reagent comprising a fluorinated derivative of 3,4-dihydroxy-thiophene-2,5-dicarboxylic acid dimethyl ester, the fluorinated derivative corresponding to 3,4-bis-(R-oxy)-thiophene-2,5-dicarboxylic acid dimethyl ester, by performing the steps of;

(i) providing a first solution comprising 3,4-dihydroxy-thiophene-2,5-dicarboxylic acid dimethyl ester and a fluorinated alcohol comprising R, the fluorinated functional group; and

(ii) heating the first solution to facilitate a reaction that will produce the first intermediate reagent;

(b) producing a second intermediate reagent comprising a fluorinated derivative of 3,4-dihydroxy-thiophene-2,5-dicarboxylic acid, the fluorinated derivative corresponding to 3,4-bis-(R-oxy)-thiophene-2,5-dicarboxylic acid, by performing the steps of;

(i) adding the first intermediate reagent to a second solution; and

(ii) heating the second solution to facilitate a reaction that will produce the second intermediate reagent;

(c) producing a third intermediate reagent comprising a fluorinated derivative of 3,4-dihydroxy-thiophene, the fluorinated derivative corresponding to 3,4-bis-(R-oxy)-thiophene, by performing the steps of;

(i) adding the second intermediate reagent to a third solution; and

(ii) heating the third solution to facilitate a reaction that will produce the third intermediate reagent;

(d) producing a fourth intermediate reagent comprising a fluorinated derivative of 2,5-dibromo-3,4-dihydroxy-thiophene, the fluorinated derivative corresponding to 2,5-dibromo-3,4-bis-(R-oxy)-thiophene, by performing the steps of;

(i) adding the third intermediate reagent to a fourth solution; and

(ii) heating the fourth solution to facilitate a reaction that will produce the fourth intermediate reagent; and

(e) using the fourth intermediate reagent to produce the fluorinated derivative of 2,5-di(thien-2-yl)-3,4-dihydroxy-thiophene by;

(i) adding the fourth intermediate reagent to a fifth solution comprising a substituted thiophene; and

(ii) heating the fifth solution to facilitate a reaction that will produce the fluorinated derivative of 2,5-di(thien-2-yl)-3,4-dihydroxy-thiophene.

17. The method of claim 16, wherein the fluorinated alcohol is selected from a group consisting of 2,2,2-trifluoroethanol, 2-fluoroethanol, 2,3,4,5,6-pentfluorobenzyl alcohol, and 2,2-difluoro-1,3-propanediol.

18. The method of claim 16, wherein the first, fourth and fifth solutions are refluxed during heating.

19. The method of claim 16, wherein:

(a) the first solution further comprises triphenylphosphine (PPh₃), tetrahydrofuran and diethyl azodicarboxylate (DEAD);

(b) the second solution comprises sodium hydroxide and ethanol;

(c) the third solution comprises quinoline and a barium promoted copper chromite catalyst;

(d) the fourth solution comprises N-bromosuccinimide, chloroform and acetic acid; and

(e) the substituted thiopene comprises 2-tributyltin thiopene, and the fifth solution further comprises a palladium catalyst and tetrahydrofuran.

20. A method for synthesizing a desired product, the desired product comprising 2,5-(2,3-dihydro-thieno[3,4][1,4]dioxin-5-yl)-3,4-di(2,2,2-trifluoroethoxy)-thiopene, a monomer suitable for polymerization to achieve a fluorinated electrochromic polymer exhibiting a green color in a first state and a purple color in a second state, the method comprising the steps of:

(a) providing a first solution comprising a first intermediate reagent and a second intermediate reagent, the first intermediate reagent comprising 2,5-dibromo-3,4-bis-(2,2,2-trifluoroethoxy)-thiopene, and the second intermediate reagent comprising a substituted ethylenedioxyl thiophene; and

(b) heating the first solution to facilitate a reaction that will produce the desired product.

21. A method for synthesizing a fluorinated electrochromic monomer suitable for polymerization to achieve a fluorinated electrochromic polymer, the fluorinated electrochromic monomer being a fluorinated derivative of 2,5-(2,3-dihydro-thieno[3,4][1,4]-dioxin-5-yl)-3,4-dihydroxy-thiopene, the fluorinated derivative corresponding to 2,5-(2,3-dihydro-thieno[3,4][1,4]-dioxin-5-yl)-3,4-di(R-oxy)-thiopene, with R corresponding to a fluorinated functional group, the method comprising the steps of:

(a) producing a first intermediate reagent comprising a fluorinated derivative of 3,4-dihydroxy-thiophene-2,5-dicarboxylic acid dimethyl ester, the fluorinated derivative corresponding to 3,4-bis-(R-oxy)-thiophene-2,5-dicarboxylic acid dimethyl ester, by performing the steps of;

(i) providing a first solution comprising 3,4-dihydroxy-thiophene-2,5-dicarboxylic acid dimethyl ester and a fluorinated alcohol comprising R, the fluorinated functional group; and

(ii) heating the first solution to facilitate a reaction that will produce the first intermediate reagent;

(b) producing a second intermediate reagent comprising a fluorinated derivative of 3,4-dihydroxy-thiophene-2,5-dicarboxylic acid, the fluorinated derivative corresponding to 3,4-bis-(R-oxy)-thiophene-2,5-dicarboxylic acid, by performing the steps of;

(i) adding the first intermediate reagent to a second solution; and

(ii) heating the second solution to facilitate a reaction that will produce the second intermediate reagent;

(c) producing a third intermediate reagent comprising a fluorinated derivative of 3,4-dihydroxy-thiophene, the fluorinated derivative corresponding to 3,4-bis-(R-oxy)-thiophene, by performing the steps of;

(i) adding the second intermediate reagent to a third solution; and

(ii) heating the third solution to facilitate a reaction that will produce the third intermediate reagent;

(d) producing a fourth intermediate reagent comprising a fluorinated derivative of 2,5-dibromo-3,4-dihydroxy-thiophene, the fluorinated derivative corresponding to 2,5-dibromo-3,4-bis-(R-oxy)-thiophene, by performing the steps of;

(i) adding the third intermediate reagent to a fourth solution; and

(ii) heating the fourth solution to facilitate a reaction that will produce the fourth intermediate reagent; and

(e) using the fourth intermediate reagent to produce the fluorinated derivative of 2,5-(2,3-dihydro-thieno[3,4][1,4]-dioxin-5-yl)-3,4-dihydroxy-thiopene by;

(i) adding the fourth intermediate reagent to a fifth solution comprising a substituted ethylenedioxyl thiophene; and

(ii) heating the fifth solution to facilitate a reaction that will produce the fluorinated derivative of 2,5-(2,3-dihydro-thieno[3,4][1,4]-dioxin-5-yl)-3,4-dihydroxy-thiopene.

22. A method for synthesizing a desired product, the desired product comprising 2,3-dibenzyl-5,7-di(thien-2-yl)-thieno-[3,4]-pyrazine, a monomer suitable for polymerization to achieve a fluorinated electrochromic polymer exhibiting a green color in a first state and being substantially transparent in a second state, the method comprising the steps of:

(a) providing a first solution comprising a first intermediate reagent and a second intermediate reagent, the first intermediate reagent comprising 2,5-di(thien-2-yl)-3,4-diamino-thiophene, and the second intermediate reagent comprising benzil; and

(b) heating the first solution to facilitate a reaction that will produce the desired product.

23. A method for polymerizing an electrochromic monomer to achieve a stable electrochromic polymer, where the monomer comprises at least one monomer selected from a group consisting of a fluorinated derivative of 2,5-di(thien-2-yl)-3,4-dihydroxy-thiopene and a fluorinated derivative of 2,5-(2,3-dihydro-thieno[3,4][1,4]-dioxin-5-yl)-3,4-dihydroxy-thiopene, the method comprising the steps of:

(a) preparing a solution comprising the monomer, an ionic source, and a solvent;

(b) purging the solution with an inert gas; and

(c) performing an electropolymerization of the solution using at least one step selected from the group of steps consisting of;

(i) electro-polymerizing using cyclic voltammetry; and

(ii) electro-polymerizing using chronoamperometry followed by cyclic voltammetry.

24. A method for polymerizing an electrochromic monomer to achieve a stable electrochromic polymer, where the monomer comprises 2,3-dibenzyl-5,7-di(thien-2-yl)-thieno-[3,4]-pyrazine, comprising the steps of:

(a) preparing a solution comprising the monomer, an ionic source, and a solvent;

(b) purging the solution with an inert gas; and

(c) performing an electropolymerization of the solution using cyclic voltammetry.

25. A monomer suitable for polymerization to achieve a fluorinated electrochromic polymer, the monomer comprising a fluorinated derivative of 2,5-di(thien-2-yl)-3,4-dihydroxy-thiophene, the fluorinated derivative corresponding to 2,5-di(thien-2-yl)-3,4-di(R)-thiophene, with R comprising a deprotonated fluorinated alcohol.

26. The monomer of claim 25, wherein the fluorinated alcohol is selected from a group consisting of 2,2,2-trifluoroethanol, 2-fluoroethanol, 2,3,4,5,6-pentfluorobenzyl alcohol, and 2,2-difluoro-1,3-propanediol.

27. The monomer of claim 25, wherein the fluorinated derivative of 2,5-di(thien-2-yl)-3,4-dihydroxy-thiophene comprises 2,5-di(thien-2-yl)-3,4-di(2,2,2-trifluoroethoxy)-thiopene.

28. A monomer suitable for polymerization to achieve a fluorinated electrochromic polymer, the monomer comprising a fluorinated derivative of 2,5-(2,3-dihydro-thieno[3,4][1,4]-dioxin-5-yl)-3,4-dihydroxy-thiopene, the fluorinated derivative corresponding to 2,5-(2,3-dihydro-thieno[3,4][1,4]-dioxin-5-yl)-3,4-di(R)-thiopene, with R comprising a deprotonated fluorinated alcohol.

29. The monomer of claim 28, wherein the fluorinated alcohol is selected from a group consisting of 2,2,2-trifluoroethanol, 2-fluoroethanol, 2,3,4,5,6-pentfluorobenzyl alcohol, and 2,2-difluoro-1,3-propanediol.

30. The monomer of claim 28, wherein the fluorinated derivative 2,5-(2,3-dihydro-thieno[3,4][1,4]-dioxin-5-yl)-3,4-dihydroxy-thiopene comprises 2,5-(2,3-dihydro-thieno[3,4][1,4]dioxin-5-yl)-3,4-di(2,2,2-trifluoroethoxy)-thiopene.

31. A monomer suitable for polymerization to achieve an electrochromic polymer, the monomer comprising at least one monomer selected from the group consisting of:

(a) 2,3-dibenzyl-5,7-di(thien-2-yl)-thieno-[3,4]-pyrazine; and

(b) a fluorinated derivative of 2,3-dibenzyl-5,7-di(thien-2-yl)-thieno-[3,4]-pyrazine.