KR20090099198A - Electrochromic viologens and device therefrom - Google Patents

Abstract

An electrochromic viologen derivative, and an electrochromic device containing the viologen derivative are provided to have a very rapid coloring response and to show an excellent memory characteristics in a liquid electrolyte. An electrochromic viologen derivative is represented by the formula 1, wherein R^1 is a C2-C20 alkyl group, an aryl group, an alkylene group, or an alkyl halide group; and R^2 is a C2-C20 alkyl group, an aryl group, or an alkyl halide group. The viologen derivative contains a counter ion, and the counter ion is Br^-, I^-, Cl^-, SO2CF3^-, or N(SO2CF3)2^-.

Description

Novel electrochromic viologen derivatives and electrochromic devices comprising the same {Electrochromic viologens and device therefrom}

The present invention relates to a novel viologen derivative having electrochromic properties and an electrochromic device to which the viologen derivative is applied. The electrochromic viologen derivatives of the present invention are easy and simple to synthesize, and when electrochromic devices are used, they show an improved response speed and higher color contrast than conventional viologen derivatives when voltage is applied.

Electrochromic reversibly adjusts the color of a material in response to the potential of an applied electric field, which can lead to a change in energy absorption due to electron transfer accompanying oxidation or reduction. Electrochromic materials include oxides of metals such as tungsten, iridium, nickel and vanadium, organic materials such as viologen and quinone, and conductive polymers such as polythiophene and polyaniline. Among them, viologen has been studied a lot since the 1970s because it can be easily and inexpensively synthesized, but it is difficult to realize multicolored color compared to conductive polymer, and it is difficult to develop a new electrochromic viologen derivative due to the weakness of stability and memory effect. Is in a state.

Early electrochromic devices made by dissolving viologens with short alkyl chains such as methyl viologen in liquid electrolyte are very soluble in both 2+ (dication) and 1+ (radicalcation) forms of viologen. When the contrast of the coloration / discoloration or the applied voltage after removal is removed, the memory effect of maintaining color is inferior. In order to solve this phenomenon, methyl viologen is immobilized using metal oxide nanoparticles or the like on the surface of the electrode [US Patent 5441827, Graetzel et al] or methyl viologen is introduced by introducing a gel or a solid electrolyte instead of a liquid electrolyte. Cationic radicals were used to slow the diffusion phenomenon from the electrode toward the bulk electrolyte as much as possible. Chem . Soc . Rev. , 1997, 26 147]

However, it is easy to manufacture the electrochromic device having the memory effect, high color contrast, fast response and high stability only by the characteristics of the electrochromic material itself. Thus, studies have been made to develop 4,4'-bipyridine derivatives having long alkyl chains or complex aromatics to maintain colored cationic radicals (Japanese Patent No. 11142893 (Izuru Sugiura et al.), The viologen derivatives are not easily obtainable by simple synthesis.

The present invention aims to provide a viologen derivative which is very simple in synthesis and stable for a long time even in a colored state in a liquid electrolyte and has a high color contrast. Another object of the present invention to provide an electrochromic device comprising the viologen derivative.

While the present inventors have studied electrochromic viologen derivatives, in the case of novel viologen derivatives having an alkyl group, an aryl group, an alkylene group or an alkyl halide in a 4,4'-bipyridyl unit, the synthesis is simple and the applied voltage According to the present invention, the color intensity (intensity) can be finely adjusted, and the fast discoloration and discoloration and the memory effect persist on the liquid electrolyte.

The present invention provides a viologen derivative having an alkyl group, an aryl group, an alkylene group or an alkyl halide as a functional group at both ends of 4,4'-bipyridyl and an electrochromic material including the same.

Furthermore, an electrochromic device including the electrochromic material is provided.

The viologen derivatives of the present invention are represented by the following formula (1).

Wherein R ¹ is an alkyl group or aryl group, alkylene group or alkyl halide having 2 to 20 carbon atoms, R ² is an alkyl group or aryl group, alkylene group or alkyl halide having 2 to 20 carbon atoms, and Y ⁻ is a counterion of a viologen a (counterion) Br ^- or _{^{I -, Cl -, SO 2}} CF 3 -, N (SO ₂ CF ₃ ) ₂ ⁻ is possible.

Examples of the formula (1) include the following compounds 1-1 to 1-11.

The present invention includes a solution type electrochromic device including the electrochromic material. The electrochromic device of the present invention is disposed on a transparent or reflective substrate and includes a working electrode, a counter electrode, and an electrolyte, and at least one of the working electrode, counter electrode, and electrolyte includes the electrochromic material of the present invention. . The ion conductive electrolyte solution may be a solution in which an electrolytic nitrile is dissolved and used to manufacture the electrochromic device by dissolving the electrochromic material and injecting the same or injecting it into a vacuum.

At this time, the electrochromic electrolyte mixed solution is 1) 0.0005 ~ 10 M electrochromic compound represented by Formula 1; 2) 0.001 to 10 M of electrolyte salt, preferably 0.1 to 0.5 M; And 3) 1 M of solvent.

If the amount of the viologen derivative is less than 0.0005 M, the electrochromic property is not observed. If the amount of the viologen derivative is greater than 10 M, the compound may be eluted from the solution.

In this case, the electrolyte salt is a general one used in the art, but is not particularly limited, and specifically n-Bu ₄ NClO ₄ , n-Bu ₄ NPF ₆ , NaBF ₄ , LiClO ₄ , LiPF ₆ , LiBF ₄ , LiN (SO ₂ C ₂ F ₅ ) ₂ , LiCF ₃ SO ₃ , C ₂ F ₆ LiNO ₄ S _2, K ₄ Fe (CN) ₆ and the like can be used. These electrolyte salts can use 1 type of single compound or 2 or more types of mixtures. Since the electrolyte salt is used in the range of 0.001 to 10 M, it is preferable to maintain the above range because the amount of the electrolyte salt is less than 0.001 M, the electrochromic property is not observed, and when the amount exceeds 10 M, the compound is eluted from the solution. .

At this time, when manufacturing as the electrochromic device, a compound having additional electrochromic properties, specifically Methyl viologen, Dimethyl viologen, Diisobutyl viologen, Benzyl viologen, 1-benzyl viologen, 1,1'-dibenzyl viologen and derivatives thereof As the compound or a mixture of two or more kinds may be used, it may be contained in an amount of 0.001 to 700 parts by weight based on 100 parts by weight of the novel viologen derivative. The solvent is a non-aqueous solvent used in the art, specifically one selected from dichloromethane, chloroform, acetonitrile, ethylene carbonate (EC), propylene carbonate (PC), tetrahydrofuran (THF), butylene carbonate, and the like. The above solvent can be used.

In addition, antioxidants such as AO-30, AO-60, IRGANOX 1010, DH-43, or Ferrocyanide trihydrate, which are commonly used in the art, may be contained. Such additives may be used by those skilled in the art. Can be used by

The electrochromic device may be used for a large-area information display device, a small-area portable information display device, a car window for blocking sunlight, a building window, and the like.

The novel viologen derivatives synthesized according to the present invention are easy and simple to synthesize, exhibit very fast coloring response when applied to electrochromic devices, and can realize different colors when coloring according to electrolyte salts, and are excellent in liquid electrolytes. There is a memory characteristic, it is possible to save electricity, but also has excellent electrochromic characteristics.

Such electrochromic materials are easily used in the construction of electrochromic devices, and the electrochromic devices manufactured therefrom are widely used in various fields such as displays, e-books, electronic papers, rearview mirrors, portable computers, solar control windows, and decorative products. It is possible.

Hereinafter, the present invention will be described in detail with reference to the following examples. The following examples are only for explaining the present invention in detail, and the present invention is not limited to these examples.

Starting materials for the compounds 1-1 to 11 are known from Synth . Commun . , 1998, 28 3121; Nanotechnology , 2006, 17 403; Polym . Adv . Tech . 1999, 10 60; Helvetica Chim . Act . 2000, 83, 181; Tetrahedron Lett . 1994, 35 4835; Polymer 2001, 42 807) was applied.

[ Example  One]

* Preparation of Compound 1-1

As described in Formula 2, (1-bromo-2-propen-1-yl) -Benzene (0.34 g, 1.73 mmol) and 4,4 synthesized from known techniques (Synthetic Communications, 28 (1998) 3121) '-bipyridinium bromide (0.2 g, 0.85 mmol) was added to N, N-dimethylformamide (DMF, 5 ml) / CH ₃ CN (25 ml) solution, and the mixture was refluxed at 120 ° C. for 48 hours. After the reaction, the precipitate was washed several times with CH ₃ CN and dried under reduced pressure to obtain a compound in an orange solid state. (Yield 70%)

¹ H NMR (300 MHz, D ₂ O; δ), δ = 5.35 (2H), 5.9 (6H), 6.7 (2H), 7.4 (8H), 8.7 (4H), 9.5 (4H)

MS (70 eV, EI): 390.5 m / z

[ Example  2]

* Preparation of Compound 1-2

As described in Chemical Formula 3, 4,4'-bipyridinium bromide (0.1 g, 0.42 mmol) was added to 20 ml of ethanol in which 1,4-dibromobutane (0.2 g, 0.93 mmol) was dissolved, and the mixture was then heated for 120 hours. It was refluxed at < RTI ID = 0.0 > After the reaction, the precipitate was washed several times with CH ₃ CN and dried under reduced pressure to obtain a compound as an orange solid. (Yield 75%)

¹ H NMR (300 MHz, D ₂ O; δ), δ = 1.3 (4H), 1.3 (4H), 1.79 (4H), 4.3 (4H), 8.72 (4H), 9.3 (4H)

MS (70 eV, EI): 428.3 m / z

[ Example  3 ~ 5]

Preparation of Compounds 1-3 to 1-5

The same procedure as in Example 1 was carried out, but the conditions of the reactants and the solvent were changed as described in Table 1 to obtain compounds 1-3 to 1-5.

[ Example  6]

Preparation of Compound 1-6

Dichlorobenzyl) octadecyldimethylammonium chloride was synthesized by applying a known method (Nanotechnology, 2006, 17 403), and compound 1-6 was synthesized using 4,4'-bipyridinium chloride and the method of Example 2 (yield 52%). )

¹ H NMR (300 MHz, D ₂ O; δ), δ = 8.65 (4H), 7.6 (4H), 4.99 (2H), 6.94 (8H), 3.62 (2H), 3.38 (2H), 2.27 (4H) , 2.36 (2H), 1.39 (2H), 1.57 (2H), 1.29 (26H)

MS (70 eV, EI): 907.2 m / z

[ Example  7]

Preparation of Compound 1-7

In the same manner as in Example 6, except that Compound 1-7 was obtained by changing the conditions as shown in Table 1.

[ Example  8]

Preparation of Compound 1-8

4,4'-bipyridinium bromide (1.2 g, 5.09 mmol) and 1,4-bis (chloromethyl) -Benzene (2.8 g, 16 mmol) were reacted by the method of Example 2 to generate 1,1'-bis [ [4- (chloromethyl) phenyl] methyl] -4,4'-Bipyridinium and 2,2,3,3,4,4,5,5-octafluoro-1,6-hexanediol (38.9 g, 10.2 mmol) ₂ CO ₃ (12 g) was dissolved in dissolved DMF (20 ml) solution and refluxed for 24 hours. After evaporating the DMF solvent, MC and H ₂ O were added to the remaining reactant in a ratio of 1: 1, and the compound dissolved in the MC layer was extracted through layer separation. (62% yield)

¹ H NMR (300 MHz, D ₂ O; δ), δ = 2.0 (2H), 3.85 (2H), 3.69 (2H), 4.63 (2H) 7.07 (4H), 6.99 (4H), 2.6 (2H), 8.66 (4H), 9.3 (4H)

MS (70 eV, EI): 1064.5 m / z

[ Example  9]

Preparation of Compound 1-9

In the same manner as in Example 8, except that Compound 1-9 was obtained by changing the conditions as shown in Table 1.

[ Example  10]

Preparation of Compound 1-10

By introducing the method of Examples 1 and 2, 4,4'-bipyridinium bromide (1.2 g, 5.09 mmol) and 1,2-Bis (2-bromoethoxy) ethane (1.4 g, 5.35 mmol) were reacted. After synthesizing the intermediate with bromoethoxyethene on only one side of the dill, the precipitate was obtained by refluxing for 24 hours at the same molar ratio as 6-Bromohexanoyl bromide (1.3 g, 5.04 mmol), in the same manner as in Example 1 Compound 1-10 was purified. (Yield 53%)

¹ H NMR (300 MHz, D ₂ O; δ), δ = 9.3 (4H), 8.7 (4H), 3.47 (1H), 3.87 (1H), 3.54 (1H), 3.41 (1H), 3.3 (1H) , 2.4 (1H), 1.79 (1H), 1.61 (1H), 1.29 (1H)

MS (70 eV, EI): 587.18 m / z

[ Example  11]

Preparation of Compound 1-11

In the same manner as in Example 10, but changing the conditions as shown in Table 1 to obtain compound 1-11.

[ Example  12-25]

* Preparation of Electrochromic Device Using Compound 1-1 ~ 1-11

The viologen compounds obtained in Examples 1 to 11 were mixed with an electrolyte salt and an organic solvent or H ₂ 0 as shown in Table 2, with a spacer having a thickness of 20 μm between two sheets of ITO glass as electrodes, and then sealed. A liquid electrochromic device was prepared. The manufactured electrochromic device was discolored blue or red after at least 40 msec when a minimum 1.25 V voltage was applied.

In this case, a compound having an additional electrochromic property, specifically Methyl viologen, Benzyl viologen, and the novel viologen derivative compound 1-1 to 11, or a mixture of two or more thereof may be mixed and used as the electrochromic device. have.

In the case of Example 12, Compound 1-1 (0.5 M) was applied to the electrochromic device, C ₂ F ₆ LiNO ₄ S ₂ (0.5 M) as the electrolyte salt, and PC (10 mL) as the solvent. Used. It was blue when discolored and showed a long duration of coloring for 10 hours in the liquid phase compared to the simple chemical structure. Through Equations 1 and 2, the discoloration efficiency was 198 cm ² / C.

In Examples 15 and 16, unlike Example 15, in which only Compound 1-2 was introduced as an electrochromic material, in Example 16, Compound 1-2 and Methyl viologen were introduced 1: 1, and KN was used as an electrolyte salt. (SO ₂ CF ₃ ) ₂ (0.5 M) and H ₂ O (10 mL) as a solvent were applied to the liquid electrochromic device. At this time, since the discolored reduced state of methyl viologen is unstable, it has a significantly lower memory performance compared to compound 1-2, so it was confirmed that discoloration persistence of Example 16 was lower than that of Example 15.

[ Example  26]

* Fabrication of electrochromic device using two kinds of compounds 1-1 ~ 1-11

In Example 26, Compound 1-8 and Compound 1-11 were mixed.The electrolyte salt and the organic solvent were mixed as shown in Table 2, and a spacer having a thickness of 20 μm was placed between two sheets of ITO glass as electrodes, followed by sealing. A liquid electrochromic device was prepared. The manufactured electrochromic device discolored blue after at least 103 msec when a minimum 1.25 V voltage was applied. The low color duration of Example 25 containing only compound 1-11 was mixed with compound 1-8 having a long duration to maintain the colored state more stably at 24 hours.

[ Example  27]

* Fabrication of electrochromic device using two kinds of compounds 1-1 ~ 1-11

In Example 27, Compound 1-1 and Compound 1-2 were mixed The electrolyte salt and the organic solvent were mixed as shown in Table 2, and a spacer having a thickness of 20 μm was placed between two sheets of ITO glass as electrodes, followed by sealing. A liquid electrochromic device was prepared. The manufactured electrochromic device discolored blue after at least 47 msec when a minimum 1.25 V voltage was applied. The response time of 60 msec of Example 14 containing only Compound 1-2 could be reduced by mixing with Compound 1-1, and the coloring duration was not different to 10 hours.

[ Comparative example ]

_{^{Benzyl viologen (Y -; BF 4}} -) as in Example 12, the method of observation of a color change characteristics by making the electrochromic device, when the -2 V was applied on the blue color change response time is 30 msec, the colored duration Was measured in 1 minute. In addition, the discoloration efficiency was measured at 91 cm ² / C.

[ Experimental Example : Electrochromic Experiment of Electrochromic Device]

When the applied voltage is changed from 0 V to -2.0 V or 2.0 V in the fabricated electrochromic device, the color changes from colorless transparent to dark blue. The response time was measured by changing the applied voltage from -2.0 V to 0 V every 15 seconds to change 70% of the total absorbance change from 400 to 410 nm. At this time, the color contrast (ΔOD, optical density) is calculated by Equation 1.

Color Contrast (ΔOD) = log [Transmittance (%) / Coloration (%)]

The coloring duration is defined as the time taken for 90% of the absorbance to decrease after removing the applied voltage after coloring.

In addition, the coloration efficiency (CE) of the electrochromic device can be obtained, and it is calculated by Equation 2.

Discoloration efficiency (CE, cm ² / C) = color contrast (ΔOD) / charge consumption per unit area (C / cm ² )

Example Reactant (g) Product (Yield,%) Solvent (mL) Catalyst (g) Temperature (℃) / hour ¹ H NMR (300 MHz, D ₂ O), δ One 4,4’-bipyridinium bromide (0.2), (1-bromo-2-propen-1-yl) -Benzene (0.34) Compound 1-1 (70) DMF (5) + CH ₃ CN (25) Reflux / 48 Example 1 δ = 5.35 (2H), 5.9 (6H), 6.7 (2H), 7.4 (8H), 8.7 (4H), 9.5 (4H) 2 4,4’-bipyridine (0.1), 1,4-dibromobutane (0.2) Compound 1-2 (75) ethanol (20) Reflux / 48 Example 2 δ = 1.3 (4H), 1.3 (4H), 1.79 (4H), 4.3 (4H), 8.72 (4H), 9.3 (4H) 3 4,4’-bipyridinium hexafluorophosphate (0.2), 9-bromoanthracene (0.5) Compound 1-3 (52) DMF (10) + CH ₃ CN (50) Reflux / 48 Example 1 δ = 7.3 (4H), 7.32 (4H), 7.6 (2H), 7.7 (6H), 7.67 (4H), 8.68 (4H), 9.3 (4H) 4 4,4’-bipyridinium bromide (1.2), 1,2-Diiodoethane (3.0) Compound 1-4 (82) ethanol (20) Reflux / 48 Example 2 δ = 1.9 (2H), 3.2 (2H), 8.69 (4H), 9.3 (4H) 5 4,4’-bipyridinium chloride (1.6), 6-Bromohexanoyl chloride (4.5) Compound 1-5 (45) DMF (5) + CH ₃ CN (25) Reflux / 4 + reaction (at room temperature) / 24 Example 1 δ = 9.29 (4H), 8.7 (4H), 3.3 (2H), 1.79 (2H), 2.4 (2H), 1.62 (2H), 1.29 (2H) 6 4,4’-bipyridinium chloride (1.6), (Dichlorobenzyl) octadecyldimethylammonium chloride (8.4) Compound 1-6 (52) ethanol (20) Reflux / 2 + Reaction (at room temperature) / 24 + Reflux / 48 Example 6 δ = 8.65 (4H), 7.6 (4H), 4.99 (2H), 6.94 (8H), 3.62 (2H), 3.38 (2H), 2.27 (4H), 2.36 (2H), 1.39 (2H), 1.57 (2H ), 1.29 (26H) 7 4,4’-bipyridinium bromide (1.2), 1-Bromo-5-methylhexane (3.2) Compound 1-7 (59) ethanol (20) Reflux / 48 Example 1 δ = 1.01 (4H), 1.25 (2H), 1.29 (2H), 1.3 (4H), 1.83 (2H), 3.3 (4H), 8.71 (4H), 9.3 (4H) 8 4,4'-bipyridinium bromide (1.2), 1,4-bis (chloromethyl) -Benzene (2.8), 2,2,3,3,4,4,5,5-octafluoro-1,6-hexanediol (38.9 ) Compound 1-8 (62) DMF (20) K ₂ CO ₃ (12) Reflux / 24 + Reflux / 48 Example 8 δ = 2.0 (2H), 3.85 (2H), 3.69 (2H), 4.63 (2H) 7.07 (4H), 6.99 (4H), 2.6 (2H), 8.66 (4H), 9.3 (4H) 9 4,4’-bipyridinium bromide (1.0), 1-bromo-4- (heptadecafluorooctyl) benzene (4.5) Compound 1-9 (80) MeCN (40) Reflux / 48 Example 1 delta = 7.1 (4H), 7.2 (4H), 8.7 (4H), 9.29 (4H) 10 4,4′-bipyridinium bromide (1.2), 1,2-Bis (2-bromoethoxy) ethane (1.4), 6-Bromohexanoyl bromide (1.3) Compound 1-10 (53) ethanol (20) Reflux / 48 + Reflux / 24 Example 10 δ = 9.3 (4H), 8.7 (4H), 3.47 (1H), 3.87 (1H), 3.54 (1H), 3.41 (1H), 3.3 (1H), 2.4 (1H), 1.79 (1H), 1.61 (1H ), 1.29 (1 H) 11 4,4′-bipyridinium bromide (1.2), (1-bromo-2-propen-1-yl) -Benzene (1.0), 1,4-dibromobutane (1.4) Compound 1-11 (51) DMF (5) + CH ₃ CN (25) Reflux / 48 + Reflux / 24 Example 10 δ = 9.3 (4H), 8.7 (4H), 7.07 (3H), 7.14 (2H), 4.93 (2H), 6.30 (1H), 3.5 (1H), 1.4 (2H), 1.79 (1H), 3.3 (1H )

Example Electrochromic material (m) Electrolyte (M), Solvent (mL) Color (-2 V applied) Response time (msec) Coloring duration 12 Compound 1-1 (0.5) C ₂ F ₆ LiNO ₄ S ₂ (0.5), PC (10) blue 40 10 hours 13 Compound 1-1 (0.5) KN (SO ₂ CF ₃ ) ₂ (0.5) , PC (10) dark green 43 10 hours 14 Compound 1-2 (0.5) C ₂ F ₆ LiNO ₄ S ₂ (0.5), PC (5) + ACN (5) Dark blue 60 10 hours 15 Compound 1-2 (0.5) KN (SO ₂ CF ₃ ) ₂ (0.5), H ₂ O (10) blue 85 9 hours 16 Compound 1-2 (0.2) + Methyl viologen (0.2) KN (SO ₂ CF ₃ ) ₂ (0.5), H ₂ O (10) purple 45 1 hours 17 Compound 1-3 (0.2) + Benzyl viologen (0.2) C ₂ F ₆ LiNO ₄ S ₂ (0.5), PC (10) blue 48 40 minutes 18 Compound 1-4 (0.5) C ₂ F ₆ LiNO ₄ S ₂ (0.5), PC (10) Red 58 2 hours 19 Compound 1-5 (0.5) KN (SO ₂ CF ₃ ) ₂ (0.5), H ₂ O (10) blue 77 6 hours 20 Compound 1-6 (1) LiClO ₄ (0.5), PC (5) + ACN (5) blue 125 24 hours 21 Compound 1-7 (1) C ₂ F ₆ LiNO ₄ S ₂ (0.5) PC (10) blue 90 3 hours 22 Compound 1-8 (0.5) KCl (0.5), H2O (10) blue 110 30 hours 23 Compound 1-9 (0.5) KN (SO ₂ CF ₃ ) ₂ (0.5), H ₂ O (10) purple 100 20 hours 24 Compound 1-10 (0.5) LiClO ₄ (0.5), PC (10) Indigo 140 22 hours 25 Compound 1-11 (0.4) LiClO ₄ (0.5), PC (10) purple 104 5 hours 26 Compound 1-8 (0.3) + Compound 1-11 (0.2) LiClO ₄ (0.5), PC (10) blue 103 24 hours 27 Compound 1-1 (0.4) + Compound 1-2 (0.1) C ₂ F ₆ LiNO ₄ S ₂ (0.5), PC (10) blue 47 10 hours PC: Propylene Carbonate ACN: Acetonitrile

1 is a photograph of a discolored / colored state of a thirteenth electrochromic device.

Fig. 2 is a photograph of a discolored / colored state of the electrochromic device of Example 15.

Claims (5)

The electrochromic viologen derivative represented by Formula 1

(In Formula 1, R ¹ is an alkyl group or aryl group, an alkylene group, or an alkyl halide having 2 to 20 carbon atoms, and R ² is an alkyl group, an aryl group, an alkylene group, or an alkyl halide having 2 to 20 carbon atoms.) The compound of claim 1, wherein R ¹ and R ² May be the same or different, and may include aromatic cyclic compounds or fluorine-based, electrochromic viologen derivatives having alkyl chains of various lengths. 9. The method of claim 1, in the rain Gen derivative comprises a counter ion (counterion), the counter ion is Br ^- or _{^{I -, Cl -, SO 2}} CF 3 -, An electrochromic viologen derivative characterized by being N (SO ₂ CF ₃ ) ₂ ⁻ . The electrochromic viologen derivative according to claim 1, wherein the viologen derivative comprises a derivative having the structure of Formulas 1-1 to 1-11.

Electrochromic device characterized in that it comprises a novel viologen derivative according to claim 1.

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