KR20090099662A - Magenta electrochromic element during applying a voltage including electrochromic viologens derivatives - Google Patents

Abstract

An electrochromic viologen compound, and an electrochromic device containing the compound are provided to obtain a rapid response velocity in case of the application of voltage and to obtain a magenta color. An electrochromic viologen compound is represented by the formula 1, wherein R1 is hydrogen, or methyl group, C1-C20 alkyl group or alkylene group containing a halogen atom; and X is an counter ion of viologen and is F^-, Br^-, Cl^-, ClO4^-, BF4^-, I^-, PF6^-, SO2CF3^- or (CF3SO3^-)2N.

Description

Magenta electrochromic element during applying a voltage including electrochromic viologens derivatives}

The present invention relates to a novel viologen derivative and an electrochromic device comprising the same. More specifically, the present invention relates to a viologen derivative that exhibits magenta when electrochromic and an electrochromic device including the same.

The electrochromic viologen derivatives of the present invention have an advantage of easy synthesis and fast response time when voltage is applied when electrochromic devices are formed, and magenta color, not blue or violet color, which is seen in general viologen compounds.

Electrochromism is a phenomenon in which the optical properties of a material are changed by an electrochemical reaction, and the intrinsic color or light transmittance of the material may be changed by changing the electronic state or structure of the material electrochemically. Materials exhibiting such electrochromic phenomena include organic materials such as viologen, ferrocene and phenothiazine, and inorganic metal oxides such as WO ₃ , NiOxHy, LiNiO ₂ , Nb ₂ O ₅ , V ₂ O ₅ , TiO ₂ , and MoO ₃ . And conductive polymers such as PODOT, polypyrrole, polyaniline, polyazulene, polythiophene, polypyridine, polyindole, polycarbazole, polyazine and polyquinone.

Among them, viologen has been studied a lot since the 1970s because it can be easily and inexpensively synthesized. However, new electrochromic viologen is difficult due to the disadvantages of multi-color implementation, inferior stability and memory effect, and slow response. Derivative development is stale.

The electrochromic phenomenon was known in 1961, but due to the disadvantages that it is difficult to implement multiple colors, the speed of color development and discoloration is slow, complete discoloration is poor, and stability is poor, it is easily broken by repeated color-bleaching. There are few commercially available electrochromic devices.

The electrochromic device is generally composed of a cathode, an anode, an electrolyte, and an electrochromic material. The electrochromic material is formed in a film form on one or both electrodes, or may be included in an electrolyte. When the electric field is applied to the electrochromic device, the color of the electrochromic material is changed by the electric redox reaction, thereby changing the light transmission characteristics of the device.

The most successful products using the electrochromic device include a rear view mirror for automobiles and a smart window, or development for application to a display such as an electronic board or an electronic book. For example, when applied to a rearview mirror for automobiles, the strong light entering through the rearview mirror may interfere with the driver's vision and cause an accident, and in order to prevent the driver's glare by optimizing the reflectance of the rearview mirror The ability to secure the field of view can be realized through electrochromic devices.

It is an object of the present invention to provide a viologen derivative which expresses a crimson color when electrochromic and an electrochromic device comprising the same. Another object of the present invention is to provide a viologen derivative that is simple in synthesis and shows fast response speed according to an applied voltage when the electrochromic device is formed, and finely adjusts the color intensity.

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

And wherein R ₁ is hydrogen, a methyl group having 1 to 20 carbon atoms, Al kilgi or alkylene group comprising a halogen element, X is a counter ion of Gen to rain ^{F -, Br -, Cl -} , ClO 4 -, BF 4 ^{_{-, I -, PF 6 -}} , SO 2 CF 3 - or (CF ₃ SO ₃ ^-) ₂ N is possible.

Examples of the formula (1) include compounds represented by the following formula (1-1)

It includes a solution type electrochromic device comprising the electrochromic material of the present invention. 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. . As the ion conductive electrolyte solution, a solution in which an electrolyte salt is dissolved may be used, and the electrochromic material is dissolved and used for the preparation of the electrochromic device by injection or vacuum injection.

At this time, the electrochromic electrolyte mixed solution may be used by containing the electrochromic compound 0.0005 ~ 10M, the electrolyte salt 0.001 ~ 10M represented by the formula (1).

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

At this time, the electrolyte salt is a general one used in the art, but is not particularly limited, 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 ~ 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 seen, and when the amount exceeds 10 M, the compound is eluted from the solution. .

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

The viologen derivatives of the present invention are easy and simple to synthesize, and have electrochromic properties that can be implemented in magenta colors when applied to electrochromic devices.

Such electrochromic materials are easily used for 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.

Example 1

* Preparation of Compound 1-1 (1-methyl-4,4'-bipyridinium iodide)

As shown in Formula 2, a solution containing 4,4'bipyridyl (7.1 g, 45.2 mmol) and methyl iodode (6.4 g, 45.2 mmol) in 125 ml of Acetone was stirred with a stirrer at room temperature for 24 hours. The resulting yellow precipitate was filtered, washed with acetone, and dissolved in acetonitrile and filtered. The filtrate was dried to give a light yellow solid.

¹ H- NMR (300 MHz, DMSO-d ₆ ): δ 9.15 (d, 2H), 8.86 (dd, 2H), 8.63 (d, 2H), 8.04 (dd, 2H), 4.39 (s, 3H).

[ Example  2]

* Electrochromic device fabrication using compound 1-1

The viologen compound 1-1 (0.1 g) obtained in Example 1 was mixed with an organic solvent Propylene Carbonate (10 ml) and an electrolyte N-Lithiotrifluoromethane sulfonamide (0.5 g) to obtain a thickness of 100 μm between two sheets of ITO glass. The spacer was placed, injected, and sealed to prepare a liquid electrochromic device. The manufactured electrochromic device was discolored in magenta color when applied with a minimum voltage of 1.8V.

Figure 1a) is a graph showing the measurement of the drive voltage of the electrochromic device manufactured in Example 2,

Figure 1 b) is a graph showing the measurement of the absorbance change according to the driving voltage of the electrochromic device manufactured in Example 2.

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

Claims (3)

The electrochromic viologen compound represented by the following Chemical Formula 1: [Formula 1]

Wherein R ₁ is hydrogen containing a halogen element, a methyl group having 1 to 20 carbon atoms, an alkyl group or an alkylene group, and X is a counter ion of a viologen as F ⁻ , Br ⁻ , Cl ⁻ , ClO ₄ ⁻ , BF ₄ ^-, I ^-, PF ₆ ^- and a _{2 N), SO 2 CF 3} - - or (CF ₃ SO _3). An electrochromic device comprising the viologen derivative according to claim 1. The electrochromic device according to claim 2, wherein the color to be expressed is crimson-based.

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