JP2005247934A - Optically active polyaniline derivative and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optically active polyaniline having high stability and enabling the change of color and the circular dichroism to be controlled. <P>SOLUTION: The optically active polyaniline derivative is represented by formula (I) (wherein, R is an optically active substituent; and n is an integer of ≥2 showing a polymerization degree). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The invention of this application relates to an optically active polyaniline derivative and a method for producing the same. More specifically, the invention of this application relates to a stable optically active polyaniline derivative having an optically active substituent in the side chain and a method for producing the same.

  Various types of conjugated polymers are known as conductive polymers, but many of these are insoluble and infusible in most solvents, so in the electropolymerization method in such a solution system, the solid state There was a problem that the structure and morphology were determined during polymerization. In other words, there are known methods for controlling the higher order structure of a conjugated polymer, providing a helical structure while maintaining conductivity, and obtaining an optically active substance without undergoing separation and purification using a column or the like. There was no actual situation.

  Polyaniline, which is one of conductive polymers, is excellent in stability and is widely used as a capacitor, battery electrode material, solar battery, electrochromic material, and the like. Polyaniline, like other conductive polymers, exhibits conductivity through a conjugated π-electron oxidation-reduction reaction. In addition, it is known that proton addition to a nitrogen atom is also involved in conductivity. Yes. Further, it has been studied to hydrogen bond an optically active camphorsulfonic acid to the nitrogen moiety of such polyaniline, and it has been reported that this optically active polyaniline complex exhibits circular dichroism (for example, Non-patent documents 1 to 6). However, the hydrogen bond in such a polyaniline complex is fragile, and there is a problem that the optically active site is easily dissociated due to a change in the external environment such as pH and the optical activity is lost. Therefore, the prospect of practical application up to now is not standing.

  By the way, an enzyme-modified electrode that selectively detects optically active sugars electrochemically is known. Such an enzyme-modified electrode can detect saccharide D-form and L-form with high sensitivity from potential changes, and is applied in the fields of biochemistry and medicine. However, the enzyme-modified electrode has low stability, and no electrode using an artificial optically active compound has been prepared.

If a highly stable optically active polyaniline can be realized, it is expected that an “optically active solid electrode” having excellent mechanical stability and high convenience can be realized instead of the enzyme-modified electrode.
Norris, Ian D .; Kane-Maguire, Leon AP; Wallace, Gordon G., Macromolecules (1998), 31 (19), 6529-6533. Su, Shi-Jian; Kuramoto, Noriyuki., Macromolecules (2001), 34 (21), 7249-7256. Su, Shi-Jian; Kuramoto, Noriyuki., Chemistry Letters (2001), (6), 504-505. Thiyagarajan, Muthiah; Samuelson, Lynne A .; Kumar, Jayant; Cholli, Ashok L., Polymer Preprints (2003), 44 (2), 234-235. Havinga, EE; Bouman, MM; Meijer, EW; Pomp, A .; Simenon, MMJ, Synthetic Metals (1994), 66 (1), 93-7. Majidi, Mir Reza; Kane-Maguire, Leon AP; Wallace, Gordon G., Polymer (1995), 36 (18), 3597-9.

  Therefore, the invention of this application has been made in view of the circumstances as described above, solves the problems of the prior art, has high stability, and can control color change and circular dichroism. It is an object to provide an optically active polyaniline.

  In order to solve the above problems, the invention of this application includes, firstly, the following formula (I):

(However, R represents an optically active substituent, and n is an integer of 2 to 100 indicating the degree of polymerization.)
An optically active polyaniline derivative is provided.

  In the invention of this application, secondly, R is represented by the following formula (II):

(However, R ¹ , R ² , and R ³ are each independently a hydrogen atom or an alkyl group)
And thirdly, an optically active polyaniline derivative in which R is a 1-methylheptyl group.

  The invention of this application is, fourthly, a method for producing an optically active polyaniline derivative, wherein 2-hydroxynitrobenzene is reacted with the following formula (III) in the presence of diethyl azodicarboxylate and triphenylphosphine:

(However, R ¹ , R ² , and R ³ are each independently a hydrogen atom or an alkyl group)
After reacting with an optically active secondary alcohol represented by the formula, the nitro group is converted to an amino group, and the resulting formula (IV)

(However, R ¹ , R ² , and R ³ are as described above.)
There is also provided a method for producing an optically active polyaniline derivative, wherein the optically active aniline monomer is polymerized using ammonium peroxodisulfate.

  The optically active polyaniline derivatives according to the first to third inventions are very stable, forming a helical structure on either the right or left side depending on the absolute configuration of the optically active substituent, and circularly polarized light. Shows color. In addition, in such optically active polyaniline derivatives, reversible color tone changes based on doping / dedoping are observed in solution and under acid-alkali conditions, and color and circular dichroism can be controlled by doping. is there.

  In the method for producing an optically active polyaniline derivative of the fourth invention, optically active polyaniline can be obtained in a high yield by a relatively simple operation.

  The optically active polyaniline derivative of the invention of this application has the following formula (I)

It is represented by

  At this time, R represents an optically active substituent, and its structure is not particularly limited. Examples thereof include optically active monoterpenes and (+) or (−)-menthol. Furthermore, the following formula (II)

Among them, those in which R ^{1 to} R ³ are all different substituents are exemplified. Specifically, R ^{1 to} R ³ are selected from the group consisting of a hydrogen atom and an alkyl group. Examples thereof include linear or branched alkyl groups such as methyl, ethyl, propyl, butyl, pentyl and hexyl, and cyclic alkyl groups such as cyclohexyl and cycloheptyl. Among them, it is preferable that R ¹ is a methyl (CH ₃ ) group, R ² is a hexyl (C ₆ H ₁₃ ) group, and R ³ is a hydrogen atom.

  On the other hand, n is an integer of 2 to 100 indicating the degree of polymerization, and preferably an integer of 10 to 100.

  Such an optically active polyaniline derivative may be produced by any method. For example, 2-hydroxynitrobenzene in the presence of diethyl azodicarboxylate and triphenylphosphine has the formula (III)

(However, R ¹ , R ² and R ³ are as described above.)
After reacting with the optically active secondary alcohol represented by the formula (IV), the nitro group is converted to an amino group.

(However, R ¹ , R ² , and R ³ are as described above.)
The optically active aniline monomer of the formula (I) can be obtained by polymerizing the optically active aniline monomer with ammonium peroxodisulfate.

  The optically active polyaniline derivative of the invention of this application as described above has optical activity, as will be apparent from the examples described later, and a π → π * transition of the polymer main chain to the circular dichroism spectrum by doping. The cotton effect in the absorption band derived from is shown. Thus, no optically active conductive polymer that can modulate the Cotton effect by doping has been known so far.

  Therefore, the optically active polyaniline derivative of the invention of this application is useful as a biosensor element that can recognize various optically active compounds including biomolecules such as enzymes with high sensitivity.

  Hereinafter, examples will be shown, and the embodiments of the present invention will be described in more detail. Of course, the present invention is not limited to the following examples, and it goes without saying that various aspects are possible in detail.

<Example 1> Synthesis (1) Synthesis of nitrobenzene having a chiral substituent at o-position (Compound 1) Diethyl azodicarboxylate (hereinafter referred to as DEAD) 10.03 dissolved in 50 ml of THF in an argon-substituted three-necked flask g (23 mmol) and 3.2 g (23 mmol) of nitrophenol are stirred at room temperature for 10 minutes, and then 6.03 g (23 mmol) of triphenylphosphine and 3.0 g (23 mmol) of (R)-(-)-2-octanol Was dissolved in 20 mL of THF and added dropwise. After 24 h, the solvent was removed under reduced pressure.

  This was extracted with dichloromethane and purified by silica gel column chromatography (dichloromethane). Furthermore, it vacuum-dried and obtained 2.8 g (yield 48%) of the target object.

  In addition, the same synthesis was performed for the S form to obtain 3.9 g (yield 74%) of the target product.

  Table 1 shows the identification results of R-form and S-form.

(2) Synthesis of aniline monomer having chiral substituent at o-position Compound 1 (R) (3.5 g, 14 mmol) and copper (II) acetylacetonate (0.35 g, 14 mmol) were placed in an argon-substituted three-necked flask. was dissolved in ethanol 60 mL, was added NaBH ₄ a (1.575 g, 42 mmol) portionwise. After 24 hours, the mixture was poured into a large excess of water, extracted with dichloromethane, and the solvent was removed by evaporation to obtain the desired product.

  Table 2 shows the identification results of mono (R) and mono (S) obtained.

(3) Polymerization
At 0 ° C., mono (R) (0.5 g, 2.25 mmol) was dissolved in 2 mL of CH ₃ Cl. To this was added a solution of (NH ₄ ) ₂ S ₂ O ₈ (0.26 g, 1.13 mmol) dissolved in 1 mL of water and 1 mL of perchloric acid and stirred. After 2 h, the reaction solution was dissolved in a minimum amount of THF, added to a large excess of methanol, washed for 72 h, and then suction filtered to obtain poly1 (oxidized form).

  Next, poly1 (oxidized form) (0.09 g) was dissolved in a small amount of THF, and this was added to 50 mL of methanol containing ammonia and stirred for 24 h. This was filtered off and vacuum dried to obtain poly2 (reduced form). Along with the spectroscopic measurement, a small amount of hydrochloric acid was added to poly2 (reduced form) dissolved in chloroform solution to obtain poly2 (oxidized form).

  In consideration of the poor solubility of poly1 (oxidized form) in the solution, an operation to make an oxidized polymer was performed again. In other words, once it was made into poly2 (reduced form) and dissolved in a solution, it was possible to measure oxidized form by adding a small amount of hydrochloric acid. For both R and S forms, synthesis was performed in the same manner.

  Table 3 shows the identification results of poly1 and poly2.

Table 4 summarizes the polymerization results.

<Example 2> Evaluation of optically active polyaniline (1) Comparison of compound 1 and mono The UV-Vis spectrum, CD spectrum, and ORD spectrum of compound 1 and mono (R) in chloroform solution were respectively shown in Figs. And shown in FIGS.

  Compound 1 showed an absorption peak at 330 nm in the UV-Vis spectrum, and negative and positive Cotton effects in (R) and (S) around 315 nm in the CD spectrum, respectively. In the ORD spectrum, compound 1 (R) showed a negative to positive cotton effect, and compound 1 (S) showed the opposite.

On the other hand, Mono showed an absorption peak at 292 nm in the UV-Vis spectrum. In the CD spectrum, as in the case of Compound 1, positive and negative cotton effects were shown in (R) and (S), respectively, at around 288 nm. In the ORD spectrum, as in the CD spectrum, positive and negative cotton effects were shown in (R) and (S), respectively. The fact that the UV-Vis spectrum of Compound 1 shifted slightly from mono to a longer wavelength is considered to be due to the π → π * transition of the main chain of Compound 1 due to the electron donating property of NO ₂ .
(2) Comparison of poly2 (reduced form) and poly2 (oxidized form) The UV-Vis spectrum of poly2 (reduced form) and poly2 (oxidized form) in chloroform solution is shown in Fig. 3, the CD spectrum is shown in Fig. 4, and ORD The spectrum is shown in FIG.

  In the UV-Vis spectrum of the polymer after doping, a large absorption peak derived from the doping band (polaron band) was observed on the long wavelength side.

  Poly2 (R) (reduced form) showed a positive to negative cotton effect in both the CD spectrum and the ORD spectrum.

On the other hand, poly2 (oxidized form) after doping showed a cotton effect of positive → negative → positive → negative from the long wavelength side in CD in (R). In ORD, (R) showed a negative cotton effect.
(3) Electrochemical measurement
The modified (R) and (S) isomers of poly2 (reduced form) were dissolved in THF and cast on the working electrode surface to prepare modified electrodes.

  FIG. 6 shows the results of cyclic voltammetry (hereinafter referred to as CV) in 0.1 M TBAP of the modified electrode in acetonitrile.

  Next, a solution obtained by adding a small amount of (R) and (S) isomers of 3,3-Dimethyl-2-butylamine (hereinafter referred to as DBA) to 0.1 M TBAP, 10 ml acetonitrile solution, respectively, CV was measured using the electrode, and the result is shown in FIG.

There was no change in potential due to the (R) and (S) isomers of DBA, but a strong reduction wave when a compound with the same electrode and absolute configuration, such as poly2 (R) (reduced form) and DBA (R), was mixed. A peak (6.36 × 10 ⁻⁵ A) was shown. When DBA (S) with different absolute configuration was measured with a modified electrode using poly 3-2 (R) (reduced form), the reduction wave (1.93 × 10 ^-7 ) decreased.

  When CV was performed using poly2 (S) (reduced form) as an electrode, the same results as poly2 (R) were obtained. This is thought to be due to the difference in the adsorptivity to the polymer-modified electrode having the same absolute configuration due to the difference in the steric shapes of the DBA (R) and (S) isomers.

  Also, the oxidation wave was not clearly observed because the conductivity increased as a result of the P-type doping, and a large peak separate from the oxidation wave was observed near the peak of the oxidation wave. it is conceivable that. In addition, N-type doping is unlikely to occur in this polymer, so a signal derived from DBA appears clearly on the reduction wave side.

  From the above, it was confirmed that a solid asymmetric electrode capable of recognizing a chiral compound can be obtained by the optically active polyaniline of the invention of this application.

FIG. 5 is a diagram showing the evaluation results of Compound 1 synthesized in the examples of the invention of this application. (A: UV-Vis spectrum, b: CD spectrum, c: ORD spectrum) It is the figure which showed the evaluation result of mono (R) synthesize | combined in the Example of invention of this application. (A: UV-Vis spectrum, b: CD spectrum, c: ORD spectrum) It is the figure which showed the UV-Vis spectrum in the chloroform solution of poly2 (reduced form) and poly2 (oxidized form) synthesize | combined in the Example of invention of this application. (A: poly2 (reduced form), b: poly2 (oxidized form)) It is the figure which showed CD spectrum in the chloroform solution of poly2 (reduced form) and poly2 (oxidized form) synthesize | combined in the Example of invention of this application. (A: poly2 (reduced form), b: poly2 (oxidized form)) It is the figure which showed the ORD spectrum in the chloroform solution of poly2 (reduced form) and poly2 (oxidized form) synthesize | combined in the Example of invention of this application. (A: poly2 (reduced form), b: poly2 (oxidized form)) It is the figure which showed the cyclic voltammogram of the electrode modified by the (R) and (S) body of poly2 (reduced form) synthesize | combined in the Example of invention of this application. (A: poly2 (reduced form) (R), b: poly2 (reduced form) (S)) The figure which shows the cyclic voltammogram of (R) and (S) body of DBA using the electrode modified by the (R) and (S) body of poly2 (reduced form) synthesize | combined in the Example of invention of this application. It is. (A: poly2 (reduced form) (R) electrode, b: poly2 (reduced form) (S) electrode)

Claims (4)

Formula (I)
(However, R represents an optically active substituent, and n is an integer of 2 to 100 indicating the degree of polymerization)
An optically active polyaniline derivative represented by the formula: R is the following formula (II)
(However, R ¹ , R ² , and R ³ are each independently a hydrogen atom or an alkyl group)
The optically active polyaniline derivative of Claim 1 represented by these. The optically active polyaniline according to claim 1, wherein R is a 1-methylheptyl group. A process for producing an optically active polyaniline derivative according to claims 1 to 3, wherein 2-hydroxynitrobenzene is converted to the following formula (III) in the presence of diethyl azodicarboxylate and triphenylphosphine:
(However, R ¹ , R ² , and R ³ are each independently a hydrogen atom or an alkyl group)
After reacting with the optically active secondary alcohol represented by the formula (IV), the nitro group is converted to an amino group.
(However, R ¹ , R ² , and R ³ are as described above.)
A method for producing an optically active polyaniline derivative, wherein the optically active aniline monomer is polymerized using ammonium peroxodisulfate.