JPH01230554A - Viologen derivative - Google Patents

Abstract

NEW MATERIAL:A compound expressed by the formula (R<1> is substituent group having vinyl group part; R<2> is substituent group without containing the vinyl group part, X is counter ion). USE:An electrochromic display element substance, useful also as a reduction indicator and capable of assuming a color in reduction and binding to other polymers. PREPARATION:4,4'-Bipyridyl is reacted with a halogen-containing vinylic compound (e.g., vinyl halide) at 1:2 molar ratio in a solvent, such as ethanol, as necessary, while being heated and stirred to afford the aimed compound expressed by the formula. The above-mentioned compound contains 1 or 2 or more vinyl groups parts.

Description

[Detailed description of the invention] [Industrial application field] This invention relates to novel viologen derivatives.

[Prior Art] Viologen compounds change color (mainly from colorless to blue) upon reduction, and their application to electrochromic display elements (hereinafter referred to as EC elements) is being developed by utilizing this property. . Viologen compounds are also used as indicators for various reductions based on the above properties.

From the viewpoint of application to EC devices, various viologen compounds that exhibit different colors upon reduction have been synthesized and are attracting attention as display materials that can be multicolored. In addition, in order to suppress deterioration,
Viologen polymers, such as viologen dimers and trimers, have also been synthesized in which the substituents on the two nitrogen atoms of viologen are made extremely asymmetric, and in order to widen the redox potential range.

[Problems to be Solved by the Invention] However, when conventional viologen compounds are used as display materials for EC elements, they are all dissolved in an electrolytic solution. Therefore, the reduced viologen deposited on the display layer easily diffuses into the electrolytic solution and disappears, resulting in insufficient color development.

Therefore, an object of the present invention is to provide a viologen derivative that can be easily combined with other functional polymers to obtain an electrochromic material with excellent color development upon reduction.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides viologen derivatives containing one or more vinyl group moieties.

The viologen derivative of the present invention can be represented by the symbol -mono (where R is a substituent having a vinyl group moiety, R2 is a substituent containing or not containing a vinyl group moiety, and X is a counter ion).

In the above formula (I), R1 and R2 are usually
Each has a vinyl group moiety. Also, R1 and R
2- can each be a carboxylic acid vinyl ester group.

The viologen derivative of the present invention can be produced by reacting 4,4°-bipyridyl with a halogen-containing vinyl compound.

Examples of the halogen-containing vinyl compound include:

Vinyl halides, acrylic halides, acrylic halides, and other halogenated vinyl compounds: vinyl monooctoacetate, vinyl monohalopropionate, vinyl monohaloacetate, vinyl monohalocaproate, vinyl monohalocaprylate, monohalolauric acid Vinyl, monohalocarboxylic acid vinyl esters such as vinyl monohalomyristate, vinyl monohalopalmitate, and vinyl monohalostearate can be mentioned.

In producing the viologen derivative of this invention, 4,4
'-Bipyridyl and a halogen-containing vinyl compound are reacted in a good solvent for both (e.g. ethanol) at a molar ratio of 1:2 with thorough stirring.
The reaction temperature may be room temperature, but heating may be used. of a solvent (eg dimethyl ether) to obtain the product.

Since the viologen derivative of the present invention has a vinyl group moiety, it can be polymerized or crosslinked with itself or with other polymers to form a polymer gel. Examples of such other polymers include polyacrylic acid, polymethacrylic acid,
Sodium polystyrene sulfonate, poly-4-vinylpyridine and its quaternized product, poly-2-acrylamido-2-methylpropanesulfonic acid, polyacrylamide, poly 2-hydroxyethyl methacrylate, polymethyl methacrylate, polyacrylonitrile, poly Acrylonitrile, polyvinyl alcohol, agar, alginic acid,
These include collagen, gelatin, gum arabic, and starch. When the monomers constituting these polymers are polymerized in water in the presence of the viologen derivative of the present invention,
A desired polymer gel can be produced.

To illustrate the method for producing the polymer gel, the monomer, viologen derivative, and initiator (for example,
potassium persulfate, etc.) and polymerization is carried out at a temperature of 30°C to 80°C, preferably 40°C to 70°C.

In this case, ferrous chloride may be present as an initiator, and the polymerization may be carried out at a low temperature such as 0° C. by a so-called redox polymerization method. Furthermore, instead of using an initiator, polymerization can also be initiated by irradiation with radiation, electron beams, etc. Other crosslinkers (e.g. N,N-methylenebisacrylamide,
The ratio of the viologen derivative units of the present invention in the polymer constituting the obtained polymer gel, to which ethylene glycol dimethacrylate, etc.) may be added, is usually 0.0.
01 mol% or more.

In addition, in order to increase the conductivity in the polymer gel, a supporting electrolyte may be added. Preferred supporting electrolytes include:
Potassium chloride, potassium bromide, sodium sulfate, sodium hydroxide, sulfuric acid, etc.

[Example] Example 1 4.4'-Dipyridyl and monochlorovinyl acetate were mixed in a molar ratio of 1:2 to 0% of the volume of monochlorovinyl acetate.
．． The mixture was added to 5 times the amount of ethanol and reacted at room temperature for 72 hours while stirring well. The reaction product was washed with excess dimethyl ether, filtered through filter paper, and then dried. This was subjected to liquid chromatography, and the desired fractions were collected to obtain the desired viologen derivative shown in the symbol below. This viologen derivative was highly water-absorbing.

0H2=OH The infrared absorption spectrum of this viologen derivative is shown in FIG. 1, and the results of its elemental analysis were as follows.

C: 54.35 (calculated value 54.44) N: 7
．． 12 (calculated value 7.05) This viologen derivative showed an electrochromic effect and turned blue upon reduction. When the solvent was water, the ultraviolet absorption spectrum during coloring was as shown in FIG.

Reference Example 1 Mix purified acrylamide and water at a weight ratio of 228, and add 0.02M of the viologen derivative obtained in Example 1 to this.
Furthermore, potassium persulfate was added as an initiator at a ratio of t,ia mol% of acrylamide. This mixture was thoroughly stirred, frozen and degassed, and then polymerized to obtain a polymer gel.

This gel was filled between a pair of tin oxide transparent electrodes to a thickness of 1
．． A 2 mm cell was fabricated. When a DC voltage of 3.5 V was applied to this cell, it colored blue. Even when this cell was subjected to vibration, uneven coloring did not occur. The coloring characteristics at this time are shown in Figure 3 (curve b).The coloring characteristics when using the 0.02M aqueous solution of the viologen derivative obtained in Example 1 are as shown in curve a in Figure 3. Ta.

Reference Example 2 ゛Purified acrylamide and water were mixed at a weight ratio of 228, and 0.02M of the viologen derivative obtained in Example 1 was added to the mixture.
Furthermore, potassium persulfate was added as an initiator in a proportion of 1.18 mol % of acrylamide, and potassium chloride was added as a supporting electrolyte in a proportion of 0.03 M.

This mixture was thoroughly stirred, frozen and degassed, and then polymerized to obtain a polymer gel. This gel was filled between a pair of tin oxide transparent electrodes to produce a cell with a thickness of 1.2 mm. When a DC voltage of 3.5 .mu. was applied to this cell, it was colored blue. The coloring rate at that time was increased by about 4% compared to the one to which no supporting electrolyte was added.

Even when this cell was subjected to vibration, color unevenness did not occur.

Reference Example 3 Mix purified acrylamide and water at a weight ratio of 1:9, and add 0.02M of the viologen derivative obtained in Example 1 to this.
Furthermore, N,N-methylenebisacrylamide was added as a crosslinking agent in a proportion of 1 mol% of the acrylamide, and potassium persulfate was added as an initiator in a proportion of 1 mol% of the acrylamide. This mixture was thoroughly stirred, frozen and degassed, and then subjected to one polymerization to obtain a polymer gel. This gel became harder and had increased strength against pressure compared to when no crosslinker was added. This gel was filled between a pair of tin oxide transparent electrodes to produce a cell with a thickness of 1.2 mm. When a DC voltage of 3.5 V was applied to this cell, it colored blue. Note that even when this cell was subjected to vibration, color unevenness did not occur.

[Effects of the Invention] As explained above, according to the present invention, a viologen derivative that exhibits color upon reduction and is capable of bonding with other polymers is provided.

4. Brief explanation of the drawings - Figure 1 is an infrared absorption spectrum diagram of a viologen derivative;
FIG. 2 is a graph showing the ultraviolet absorption spectrum of the reduced viologen, and FIG. 3 is a graph showing the coloring characteristics of the polymer gel.

X pieces (cm”) Liquid length (nm) Figure 2

Claims (4)

[Claims] (1) Viologen derivatives containing one or more vinyl group moieties. (2) General formula▲There are mathematical formulas, chemical formulas, tables, etc.▼ (Here, R^1 is a substituent having a vinyl group moiety, R^
2 is a viologen derivative represented by a substituent containing or not containing a vinyl group moiety, and X is a counter ion). (3) The viologen derivative according to claim 2, wherein R^1 and R^2 each have a vinyl group moiety. (4) The viologen derivative according to claim 2, wherein R^1 and R^2 are each a carboxylic acid vinyl ester group.