JP4392499B2 - Process for producing chiral polymer and optical activity control of chiral polymer and chiral polymer by dynamic electrochemical method - Google Patents

Description

  The present invention relates to a method for producing a chiral polymer, a chiral polymer, and a method for controlling the optical activity of a chiral polymer.

Much work has been done on optically active polymers related to the synthesis of polypeptides, vinyl polymers and helical conjugated polymers. The optically active polymer has been obtained by various methods including polymerization of an optically active monomer, asymmetric selective polymerization, and introduction of a chiral group into the optically inactive polymer by a polymer reaction (for example, Non-Patent Documents 1 to 3). . Polymers prepared by such methods contain a side chain or main chain asymmetric carbon. It is also possible to synthesize conjugated polymers with right or left screw orientation by using optically active catalysts, but the optical activity of such polymers without bulky substituents is lost upon melting and decomposition. Will be.
Spiral polyacetylene having chiroptical properties was synthesized in a chiral nematic liquid crystal as a reaction field (Non-patent Documents 4 and 5). The helical polyacetylene prepared by such a method exhibits relatively stable optical activity as a result of its poor solubility and insolubility.

In contrast, electrochemical synthesis is simple, safe and effective for the production of conjugated polymers. Electrochemical polymerization prepares many types of conjugated polymers such as polypyrrole, polythiophene, poly (3,4-ethylenedioxythiophene) (PEDOT) and poly (3,4-ethylenedioxypyrrole) (PEDOP). Can be used for. These polymers are being investigated for potential applications in electrochromic devices as buffer layers for electrochromic devices and in sensors.
A polymer film synthesized by such electrochemical polymerization usually does not exhibit either linear dichroism or circular dichroism, but optical activity is improved by using a chiral nematic liquid crystal (N ^* -LC) field. It has been reported that an unsubstituted optically active PEDOT (PEDOT ^* ) can be produced (Patent Document 1).

By the way, it is known that such a chiral conjugated polymer is effective as a substance having an optical switch function and a photochromic function because of its conductivity and optical activity. For this reason, there is a demand not only to obtain a stable chiral polymer but also to control optical activity.
As a method for controlling optical activity, a method for producing optical activity by doping metal ions (Patent Document 2) and a method for changing optical activity by adding a poor solvent to convert to an aggregated structure have been developed. (Patent Document 3).
Macromolecules, 2002, Vol.35, pp.6439 J. Polym. Sci., 1959, Vol.34, pp.157. Nature, 1999, Vol.399, pp.449. Science 1998, Vol.282, pp.1683. Curr. Appl. Phys. 2001, Vol.1, pp.88. JP 2003-306531 A JP 2004-168992 A JP 2001-115033 A

However, if the optical activity can be easily controlled, a chiral polymer having a specific optical activity can be obtained efficiently.
Accordingly, an object of the present invention is to provide a production method for easily producing a chiral polymer having a selected optical activity and a chiral polymer capable of easily changing the optical activity. Moreover, it is providing the control method which controls easily the optical activity of a chiral polymer.

In the method for producing a chiral polymer of the present invention, a chiral monomer or a chiral dopant is used for electropolymerization to obtain a chiral polymer, and an oxidation potential or a reduction potential is applied to the charge of the chiral polymer. Controlling the optical activity.
The method for controlling the optical activity of the chiral polymer of the present invention is a method comprising applying an oxidation potential or a reduction potential to the chiral polymer obtained by electrolytic polymerization.
The present inventors have found that the optical activity of a chiral polymer can be easily controlled electrochemically by applying a voltage within a predetermined range to the chiral polymer, thereby completing the present invention.

  According to the present invention, since the optical activity can be controlled electrochemically by applying a voltage of a predetermined condition to the chiral polymer, a chiral polymer having a specific optical activity can be easily obtained. The optical activity of the chiral polymer can be easily controlled.

The method for producing a chiral polymer according to the present invention comprises the steps of electropolymerization using a chiral monomer or a chiral dopant to obtain a chiral polymer, and applying an oxidation potential or a reduction potential to the charge of the chiral polymer to obtain the optical properties of the chiral polymer. Modulating the activity.
The method for controlling the optical activity of the chiral polymer of the present invention includes applying an oxidation potential or a reduction potential to the chiral polymer obtained by electrolytic polymerization.

  The chiral polymer in the present invention may be any polymer obtained by electrolytic polymerization and having optical activity, and can be produced using a chiral monomer or a chiral dopant. Conditions can be selected as appropriate.

Electropolymerization using chiral monomers is well known to those skilled in the art, for example J. Polym. Sci., Part A: Polym. Chem., 2001, Vol. 39, p2164-p.2178, Chem. Mater., 2000, Vol.12, p.1563-p.1571, etc. can be used.
As the chiral monomer used here, various known ones can be exemplified, but from the viewpoint of affinity with liquid crystal, an aromatic compound having 4 to 6 carbon atoms containing a hetero atom is preferable, and thiophene, Examples include pyrrole, isothianaphthene, bithiophene, terthiophene, and 3,4-ethylenedioxythiophene derivatives.

  Examples of the supporting salt used for the electropolymerization include tetrabutylammonium perchlorate, lithium perchlorate, and sodium chloride. Such a supporting salt is dissolved in an appropriate organic solvent or water to prepare an electrolytic solution. Examples of the electropolymerization using a chiral monomer include a method in which a chiral monomer is added to a prepared electrolyte and a voltage is applied between two electrodes or between three electrodes including a reference electrode to perform the electropolymerization. .

A chiral polymer obtained from such a chiral monomer is an optically active conjugated polymer, and examples of such a conjugated polymer include polythiophene, polypyrrole, polyisothianaphthene, polybithiophene, polyterthiophene, poly ( Examples include various derivatives such as 3,4-ethylenedioxythiophene) derivatives. Examples of the mixed conjugated polymer obtained by electrolytic polymerization of two or more types of monomers include polythiophene phenylene derivatives. These conjugated polymers have optical activity reflecting the optical activity of the monomer. For chiral monomers composed of two different units, preferably (R)-or (S) -1,4-bis [2- (3,4-ethylenedioxy) thienyl] -2,5-benzoic acid -1-methylheptyl ester [BEDOT-B (OCT ^* )] and the like.

  In addition, examples of the chiral polymer obtained by using a chiral dopant include a chiral polymer obtained by performing an asymmetric polymerization using a nematic liquid crystal as a reaction field and adding at least a chiral dopant and a monomer to a supporting electrolyte. be able to. The nematic liquid crystal used as the reaction field does not inhibit the electropolymerization reaction, and it is necessary to be a nematic liquid crystal in order to obtain an organic chiral nematic phase as the reaction field. Among them, a thermotropic liquid crystal that realizes a liquid crystal form without including a solvent is preferable. In addition, the main chain type and the side chain type are classified into the main chain type liquid crystal having a mesogen in the main chain, even if the liquid crystal forming group (mesogen) is introduced to the flexible main chain to some extent. There may be. The structure of such a liquid crystal is not particularly limited. For example, two benzene rings are connected by a linking group containing a double bond such as trans-stilbene, azoxybenzene, or nitrone, or a linking group such as biphenyl or cyclohexane. Is exemplified. Further, it is preferable that a flexible substituent such as an alkyl group or an alkoxy group is introduced at the end of the mesogenic compound, and further, a substituent having an aliphatic chain, a rigid straight chain, or an asymmetric structure is introduced. Also good. Since the length of these substituents affects the transition temperature of the liquid crystal, it may be appropriately selected in consideration of the temperature of electrolytic asymmetric polymerization.

Among the various liquid crystals as described above, those having a wide temperature range capable of maintaining the liquid crystal state at room temperature or higher and exhibiting a liquid crystal phase can be given. In addition, from the viewpoint of easily transporting monomers and ions to increase the polymerization rate, liquid crystal molecules having a large polarity, such as those containing a nitrile group, an ester group, and a nitro group, are preferable. 6CB, or a PCH _n OR having a phenylcyclohexyl group, an n-alkyl group, and a hexamethylene chain.

  The chiral dopant is not particularly limited as long as it is a compound that does not inhibit the electrolytic asymmetric polymerization reaction and is highly compatible with the nematic liquid crystal. Examples thereof include those selected from the group consisting of various axial chiral compounds and central chirality compounds. Among them, chiral liquid crystal systems can be applied, and phenylcyclohexyl compounds having a binol derivative or an asymmetric carbon are preferable. It is illustrated as a thing. Specific examples include a binol derivative of the following chemical formula (I) or (II) and a phenylcyclohexyl compound of the chemical formula (III) or (IV). Of these, those having strong axial chirality such as PCH506-binol are preferred in order to have a sufficient helical twisting force and to maintain a high transition temperature of the liquid crystal as a reaction field.

  Such an electrolytic asymmetric polymerization method is applied to various conjugated polymer monomers. One or more monomers may be selected from various compounds that give various polymers such as aliphatic conjugated systems, aromatic conjugated systems, heterocyclic conjugated systems, and heteroatom-containing conjugated systems. If one type is selected, a homopolymer is obtained, and if two types or more are selected, a mixed conjugated polymer is obtained. The monomer used in the electrolytic asymmetric polymerization has no optical activity, and as the monomer, a compound having a particularly low ionization potential is preferable. Specifically, 3,4-ethylenedioxythiophene represented by the following formula (V): Examples thereof include (EDOT), isothianaphthene (ITN) of the formula (VI), pyrrole of the formula (VII), thiophene of the formula (VIII), and bithiophene. Among these, in order to obtain a stable polymer, bithiophene (BT), terthiophene (3T), and thiophenephenylenethiophene (TPT) having a linear molecular shape and good affinity for liquid crystals are preferable.

  In the electrolytic asymmetric polymerization, the supporting electrolyte is used to impart conductivity in addition to the chiral dopant and the monomer. The supporting electrolyte is not particularly limited as long as it does not inhibit the electropolymerization reaction and gives sufficient conductivity to the liquid crystal. Generally, the supporting electrolyte is appropriately selected from various ionic salts used for electrochemical reactions according to the applied voltage. You can choose. Specifically, tetrabutylammonium perchlorate (TBAP) and lithium perchlorate are preferable. Moreover, salt can also be mentioned.

  The chiral polymer obtained by such an electrolytic asymmetric polymerization is an optically active conjugated polymer, and examples of such a conjugated polymer include aliphatic conjugated polymers such as polyacetylene and poly (1,6-heptadiyne). Molecules, aromatic conjugated polymers such as poly (paraphenylene), polynaphthalene and polyanthracene, heterocyclic conjugated polymers such as polypyrrole, polyfuran and polythiophene, and poly (paraphenylene sulfide) and poly (paraphenylene oxide) ), And various types such as heteroatom-containing conjugated polymers such as polyaniline. Examples of the mixed conjugated polymer obtained by electrolytic polymerization of two or more types of monomers include poly (paraphenylene vinylene), poly (thiophene vinylene), poly (2,2′-thienyl pyrrole) and the like. . These conjugated polymers reflect the helical structure of chiral nematic liquid crystal, which is a reaction field, by the above-described electrolytic asymmetric polymerization, and have optical activity.

  The voltage applied in the electropolymerization in the present invention is appropriately selected according to the kind of the monomer to be polymerized (that is, the target conjugated polymer), the liquid crystal reaction field used in the electrolytic asymmetric polymerization, the electrode material, etc. There is no particular limitation. For example, as shown in Examples described later, the electropolymerization of pyrrole in (R) -PCH5O6-binol / 6CB can be performed under a voltage of about 1.1V. Of course, the applied voltage is not limited to such an example.

  Furthermore, any electrode may be used for the electrolytic polymerization, and it is not particularly limited. For example, metal electrodes such as gold, silver and platinum, carbon electrodes, and transparent glass electrodes such as indium tin oxide (ITO) are exemplified. These are appropriately selected according to the type of monomer (that is, the target conjugated polymer), the type of liquid crystal, etc., or the amount of the target polymer.

In the present invention, in order to control or change the optical activity of the chiral polymer, a predetermined oxidation or reduction potential is applied to the chiral polymer obtained by electrolytic polymerization.
The oxidation / reduction potential applied here is set based on the charge of the reference electrode (standard electrode), and is appropriately set by the reference electrode selected according to the monomer. For example, in the present invention, when the chiral polymer obtained by electrolytic polymerization is (R) -polybithiophene and an Ag / Ag ⁺ reference electrode is selected, an oxidation potential of 100 mV to 1300 mV is applied. The optical activity of the chiral polymer is reversed. The optical activity of the chiral polymer can be reversibly changed by applying an oxidation potential or a reduction potential at room temperature. If it is out of this range, the optical activity may not be effectively reversed.

  The oxidation / reduction potential necessary for controlling the optical activity varies depending on the polymer, but the oxidation / reduction is usually performed by sweeping the potential within the range of −1 to + 1.3V. The sweep speed is 10 mV / s to 500 mV / s. When sweeping at high speed, the durability may be inferior, and therefore sweeping at a speed of about 30 mV / s is preferable.

  As described above, the chiral polymer of the present invention is a chiral polymer obtained by electrolytic polymerization and capable of changing optical activity by applying an oxidation potential or a reduction potential. Further, this chiral polymer has excellent film forming properties, and can easily form a film by a simple process such as coating. Thereby, further, functionalization using the chiral polymer obtained by the present invention can be performed easily and at low cost.

  In the present invention, by applying the conditions for changing the optical activity as they are, the absorption wavelength of the chiral polymer can be controlled and the electrochromic phenomenon can be induced. Thereby, the electrochromic phenomenon of the chiral polymer can be easily induced. This can be defined as an “optically active electrochromic phenomenon”, an effect that has not been found so far. In addition, an “optical rotation phenomenon” and an “optically active electrochromic hysteresis phenomenon” by applying a potential are also shown.

  In the present invention, the optical activity of the chiral polymer can be reversibly changed and easily controlled, so that a chiral polymer having a specific optical activity can be easily obtained. Applications of the polymer can be expanded. Such applications include optical switches, optical isolators, optical modulators, etc. used for optical switches and optical fiber cables. In addition, since it has an optically active electrochromic hysteresis phenomenon, the switching of the physical properties of the chiral polymer can be adjusted according to various purposes, and is not limited to the above applications, but for various applications using optical activity switching. Can be used widely.

  Examples of the present invention will be described below, but the present invention is not limited thereto. Further,% in the examples is based on weight (mass) unless otherwise specified.

[Example 1]
Synthesis of chiral polymers using chiral dopants in liquid crystal reaction fields (1) Chiral nematic electrolytes Chiral nematic liquid crystals with a mesoscopic helical structure by adding a small amount of optically active molecules as chiral dopants to nematic liquid crystals (N-LC) It is known that the formation of N-LC (N ^* -LC) can be induced. N ^* -LC directors rotate gradually in one screw direction to form a spiral structure. It was confirmed that the liquid crystallinity of 4-cyano-4′-hexylbiphenyl (6CB) was maintained after addition of tetrabutylammonium perchlorate (TBAP) as the supporting salt and bithiophene as the monomer, It has been found that the addition of a chiral dopant induces a chiral nematic liquid crystal in a mixed system. Chiral dopants themselves do not exhibit liquid crystallinity, but this causes a chiral nematic phase. The substance 6CB having thermotropic liquid crystallinity can be regarded as a fluid solvent, and the addition of a supporting salt to 6CB brings about ionic conductivity. Thus, the LC and support salt mixture can be used as an electrolyte for electrochemical polymerization instead of conventional systems such as TBAP or lithium perchlorate in acetonitrile.
In this synthesis, 6CB was employed as a solvent for asymmetric electrochemical polymerization. The molecular structure of this substance is shown in Scheme 1 below.

An N ^* -LC mixture consisting of 3 mM TBAP (supporting electrolyte) in 42 mM (R)-or (S) -PCH506-binol (chiral dopant), 0.48 M bithiophene (monomer) and 6CB (LC solvent). And prepared as an electrolyte (Scheme 1).
Chiral dopants, ie (R)-or (S) -1,1-binaphthyl-2,2-bis [para- (trans-4-pentylcyclohexyl) phenoxy-1-hexyl] -ether [abbreviation (R)- Or (S) -PCH506-binol] is a Williamson's of (R)-(+)-and (S)-(−)-1,1′-2-binaphthol and phenylcyclohexyl derivatives, respectively. Prepared by the etherification reaction as described in the literature (Science, 1998, Vol.282, p.1683-p.1686) except at 156 ° C. to prevent partial racemization during the etherification reaction. Instead of using potassium iodide for cyclohexanone, synthesis was performed using 18-crown-6-ether as a catalyst for acetone at 60 ° C.

1- [para- (trans-4-n-pentylcyclohexyl) phenoxy] -6-bromohexane is synthesized by the method described in the literature (Macromolecules, 2001, Vol..34, p.7989-p.7988). It was done. The chemical structure of the chiral dopant was confirmed by NMR. 4-n-hexyl-4′-cyanobiphenyl (6CB) was purchased from Merck Ltd. Bithiophene (BTh) was obtained from Sigma Aldrich and purified by recrystallization from ethanol before use. Tin-indium oxide (ITO) glass is composed of an ITO layer having a thickness of 0.2 to 0.3 μm on glass (9Ω / cm ² ).

The optical measurement was performed as follows.
Infrared spectroscopy measurements were performed using a Jasco 550 Fourier infrared (FT-IR) spectrometer. Differential scanning calorimetry (DSC) was performed using a TA instrument Q100 DSC instrument at a rate of 10 ° C./min under a nitrogen stream. Optical tissue was observed by polarized light microscopy (POM) using a Nikon ECLIPS E 400 POL polarizing microscope equipped with a Linkam ™ 600PM heating and cooling stage. Temperature control during polymerization was achieved using a custom cooling stage based on Peltier elements. Observation of the polymer by optical phase contrast microscopy (PCM) was performed using a WRAYMER BX-3500T microscope equipped with an optical phase contrast unit. Scanning electron microscopy (SEM) observations were performed using a JEOL ED electron microscope. Polymer electrochemical measurements were obtained using an ALS660A electrochemical analyzer (BAS).

(2) of (R)-(+)-1,1-binaphthyl-2,2-bis [para- (trans-4-pentylcyclohexyl) phenoxy-1-hexyl] ether [(R) -PCH506-binol] Synthesis (R)-(+)-1,1′-bi-2-naphthol (1 g, 3.5 mmol), 1- [p- (trans-4-n-pentylcyclohexyl) phenoxy] -6-bromohexane ( 3.1 g, 7.3 mmol), K ₂ CO ₃ (1.4 g, 10 mmol) and acetone (100 mL) in 18-crown-6-ether (46 mg, 0.2 mmol) were refluxed at 60 ° C. After 24 hours, the solution was evaporated, washed thoroughly with water and extracted with ether. The organic layer was evaporated. The crude product is purified by column chromatography (silica gel, CHCl ₃ / n-hexane = 1) to give 2.7 g of a white solid (yield: 82%). Anal. Calcd for C ₆₈ H ₉₂ O ₄ : C, 83.90, H; 9.53. Found: C; 84.02, H; 9.22.IR (KBr, cm ^-1 ): 2937, 2884, 1515, 1235 (COC st.) ¹ H NMR (500 MHz, CDCl ₃ , ppm): 0.87-1.87 (m, 33H, CH, CH ₂ , CH ₃ ), 2.35 2.45 (m, 1H, ph), 3.71 (t, J = 6.8 Hz, 2H, CH ₂ O), 3.9-4.0 (m, 2H, CH ₂ O), 6.8-7.9 (m, 8H, ph). ¹³ C NMR (125 MHz, CDCl ₃ , ppm): 14.1, 22.7, 25.4, 25.5, 26.6, 29.0, 29.3, 32.2, 33.6, 34.6, 37.3, 37.4, 43.7, 67.6, 69.6, 114.0, 115.7, 120.6, 123.2, 125.2, 125.8, 127.3, 127.5, 128.8, 129.0, 133.9, 139.6, 154.2, 156.9. [Α] _D ²³ = + 22.5 ° (THF).

(3) of (S)-(−)-1,1-binaphthyl-2,2-bis [para- (trans-4-pentylcyclohexyl) phenoxy-1-hexyl] ether [(S) -PCH506-binol] Synthesis This compound was prepared using methods similar to those described for (R) -PCH506-binol. The amounts used are as follows: PCH506Br (4.4 g, 10.5 mmol), K ₂ CO ₃ (1,4 g, 10.5 mmol), 18-crown-6-ether (46 mg, 0.2 mmol) and acetone ( 100 mL). Yield: 57%, 9 g (white crystals). _{Anal Calcd for C 68 H 92 O} 4:. C; 83.90, H; 9.53, O; 6.57. Found: C; 83.92, H; 9.19. IR (KBr, cm ^-1 ): 2940, 2843, 1514, 1247 (COC st.). ¹ H NMR (500 MHz, CDCl ₃ , ppm): 0.87-1.87 (m , 33H, CH, CH ₂ , CH ₃ ), 2.35-2.45 (m, 1H, ph), 3.72 (t, J = 6.8 Hz, 2H, CH ₂ O), 3.86-3.98 (m, 2H, CH ₂ O ), 6.76-7.90 (m, 8H, ph).
¹³ C NMR (125 MHz, CDCl ₃ , ppm): 14.1 (CH, CH ₂ , CH ₃ ), 22.7, 25.4, 25.4, 26.6, 29.0, 29.3, 32.2, 33.6, 34.6, 37.3, 37.4, 43.7, 67.6, 69.6, 114.0, 115.7, 120.6, 123.2, 125.2, 125.8, 127.3, 127.5, 128.8, 129.0, 133.9, 139.6, 154.2, 156.9. [Α] _D ²³ = -23.3 ° (THF).

(4) Polymerization In the absence of monomer (R) -N ^* -LC electrolyte in a sandwich system with indium titanium oxide (ITO) glass plates, when examining ionic conductivity as a function of frequency at 25 ° C., the corresponding impedance spectrum is It was found to show a Cole-Cole plot with a semi-circular part at a higher frequency and a linear part at a lower frequency (not shown). This indicates that the monomer-free N ^* -LC electrolyte can be explained by an equivalent electrical circuit as a model of impedance. Since the low ionic dc conductivity (<10 ⁶ S / cm) of the LC electrolyte can lead to ir drop (decrease in E), to correct for this drop, electrochemical polymerization is shown in FIG. This was carried out using a two-electrode method with a narrow gap with such a polymerization cell 10.
The polymerization cell 10 is configured by integrating a pair of ITO electrodes 16 having a spacer 14 made of Teflon (registered trademark) having a thickness of 0.19 mm with a clip 18. A part of the spacer 14 is provided with an inlet 20 for the N ^* -LC mixture 12.
The polymerization cell 10 is placed on a temperature control stage 22 having a Peltier element for temperature adjustment.

When the N ^* -LC mixture (N ^* -LC, electrolyte, monomer) 12 is injected into the polymerization cell 10 from the injection port 20, the polymerization cell 10 is heated to 30 ° C. and then gradually cooled to 10 ° C. A good fingerprint organization was obtained. A voltage of 4 V was then applied to the polymerization cell 10. The optical texture of the N ^* -LC mixture remained unchanged when voltage was applied. However, repeated voltage scans by cyclic voltammetry during the polymerization process destroyed the helical structure of N ^* -LC, resulting in a clear mixture. This can be due to helical unwinding under alternating current, where LC molecules are aligned perpendicular to the substrate (homeotropic alignment).
The polymerization temperature was kept constant at 10 ° C. in order to maintain the N ^* -LC phase, and after 30 minutes, an insoluble, infusible indigo polymer film up to 6 μm thick was formed on the anode side of the ITO electrode 16. Covered. After washing in order of methanol, water, acetonitrile, methanol, water and acetone, the polymer film on ITO 16 was dried under reduced pressure.

The transition temperature of the N ^* -LC electrolyte containing the monomer was measured by DSC. For the (R) -N ^* -LC electrolyte, K · 10 (3) · N ^* · 16 (14) · I before polymerization, K · 11 (3) · N ^* · 16 (15) · I after polymerization. For the (S) -N ^* -LC electrolyte, K · 10 (4) · N ^* · 16 (15) · I before polymerization, and K · 11 (5) · N ^* · 17 (16 ) · I (K, crystal; N ^* , chiral nematic; I, isotropic).

The transition temperature of the N ^* -LC solution after electrochemical polymerization was slightly higher than that before polymerization. This generally suggests that the monomers in N ^* -LC were consumed during the polymerization because impurities in the LC mixture lowered the transition temperature. Polymerization of thiophene as a monomer using this method did not give a stable film, probably because thiophene has lower polymerization activity than bithiophene in N ^* -LC media. Be careful.

Electrochemical polymerization of bithiophene can be carried out by using (R)-or (S) -4-cyano-4 ′-(1-methylheptyloxy) -biphenyl (CB60 ^* ) or (CHI) as a chiral dopant instead of PCH506-Binol. Run in N ^* -LC using (R)-or (S) -1,1'-bi-2,2'-naphthol (binol ^* ).
In these cases, a greater amount was required to effect the formation of a chiral nematic phase compared to PCH506-binol. This, PCH506- Bainoru (β _M = 22.5) compared to be due to the CB60 ^* and Bainoru ^* of helical twisting power is low (β _M <2) it. The helical twisting force of the chiral dopant was evaluated from the helical pitch of the chiral dopant-containing N ^* -LC by the Kano-Wedge method.
Electrochemical polymerization was also performed using a chiral smectic LC composed of the following system.

LC electrolyte containing TBAP and monomer (LC matrix, 5 mg; CB60 ^* , 5 mg; TBAP, 0.03 mg; bithiophene, 0.1 mg) showed SmC ^* phase, but the polymer film was chiral smectic phase at 7 ° C Could not be formed due to the high viscosity. Precipitation was also suppressed by the low conductivity and low mobility of the monomers in the chiral smectic matrix. These results show that the electrochemical polymerization in thermotropic LC has a sufficiently low viscosity for easily transporting chiral dopants with sufficient helical twisting force to form N ^* -LC and ions and monomers. It shows that both N ^* -LC matrix is required.

(5) Characterization A) Optical texture The N ^* -LC mixture before polymerization clearly displayed the chiral nematic LC texture. This solution was heated once to 80 ° C. to completely dissolve TBAP, bithiophene and chiral dopant in N ^* -LC solvent. Differential scanning calorimetry (DSC) measurements and polarized light microscopy (POM) observations show that both (R)-and (S) -N ^* -LC systems show a thermotropic N ^* -LC phase. I confirmed that. General N ^* -LC fingerprint tissue was observed by POM (FIG. 2A). The distance between stripes in the tissue coincides with the half pitch of the helix.

On the other hand, phase contrast optical microscopy (PCM) (FIG. 2B and FIG. 2C) of polybithiophene [(R) -PBTh ^* ] made in (R) —N ^* -LC shows the helical structure of the polymer. , Similar to that of the original N ^* -LC system. FIG. 2D shows another part of the same (R) -PBTh ^* membrane. This image shows that the sample is composed of multiple layers, and some overlap between the spiral texture (upper layer) and the polygonal network (lower layer) due to changes in the LC anchoring conditions Indicates the part. This unique pattern mimics the N ^* -LC texture during electrochemical polymerization. Thus, this electrochemical polymerization method also provides detailed information regarding the classification of LC structures.

The PBTh ^* film did not show birefringence under POM, suggesting that this texture is not due to LC but to the polymer itself. Thus synthesized PBTh ^* appeared to have repeated the structure of N ^* -LC, demonstrating that N ^* -LC is effective as an asymmetric reaction field.

B) Cyclic voltammetry FIG. 3 shows cyclic voltammetry of (R) or (S) -PBTh ^* membranes (vs. Ag / Ag ⁺ ) at various sweep rates in a TBAP / acetonitrile solution. The redox switching in the monomer-free electrolyte solution shows a clear quasi-reversible redox process. Polymers prepared with both (R)-and (S) -chiral electrolytes show the same redox behavior, suggesting that the polymers have essentially the same structure. Both polymers were electroactive and adhered well to the ITO electrode.

C) Optical properties The circular dichroism (CD) spectrum of the polymer is shown in FIG. Here, the oxidation potential with respect to Ag / Ag ⁺ is +1.3 V, and the reduction potential is 0.1 V (0.1 M TBAP / acetonitrile solution).
As shown in FIG. 4, both the (R)-and (S) -PBTh ^* films strongly showed a mirror image effect in the π-π ^* transition region of the polymer main chain in the reduced state. This means that (R)-and (S) -PBTh ^* have the same degree of chirality but in opposite directions. In the oxidized state, the CD spectrum of the polymer showed a decrease in strength and a reversal of the sign of the Cotton effect. As shown in FIG. 5, since the cotton effect of the chiral dopant is only observed from 240 nm to 340 nm, the mirror image relationship between (R)-and (S) -PBTh ^* is related to the chiral dopant used in the polymerization. It is not caused by. Through a change in the electronic state of the polymer, the phenomenon of reversible reversal of the coincidence of the Cotton effect at 592 nm in the redox process indicates that the polymer has an essentially chiral structure.

Also, as shown in FIG. 6, in the oxidation step (a → d), the peak at 492 nm in the absorption spectrum related to the π-π * transition of the polymer main chain becomes weak, while the radicals on the polymer main chain The peak at 680 nm (1.8 eV, mid gap) attributed to cation formation is stronger.
The color of the polymer also changes from red to indigo during oxidation (not shown), accompanied by the generation of a broad absorption band in the NIR region (FIG. 7). This transition is also evident by weakening the 592 nm positive extrema and 410 nm negative extrema in the CD spectrum and also by the appearance of an isosbestic point at 461 nm.
On the other hand, in the reduction step (d → f), application of 0.6V or 0.1V will restore these peaks to the original intensity of the reduced state in both UV-Vis-NIR and CD spectra. (FIG. 6).

This result indicates that the polythiophene main chain itself has a chiral structure, and the cotton effect of the polymer can be changed by adjusting the conditions for electrochemical polymerization. However, the redox process did not cause any change in the optical texture or surface structure of PBTH ^* s. The large change in the cotton effect of the polymer due to the redox reaction in the TBAP / acetonitrile solution is due to the weaker cotton effect in the oxidized state. This electrochemical process makes it possible to control the CD intensity.

The CD spectrum of a polymer in a poor solvent or the CD spectrum of a polythiophene film into which an optically active substituent has been injected is usually interpreted as being due to exciton coupling due to electronic vibrational splitting and isotopic Davidoff splitting. Exciton binding requires the presence of a chromophore that is not conjugated in a chiral configuration, which can occur through interchain and intrachain interactions in the condensed state. While the CD spectrum of reduced PBTh ^* shows a bisignate cotton effect, it does not show it when it is in the oxidized state.

The observation of such a bisignate band for PBTh ^* can also indicate the presence of intermolecular processes during aggregate formation. In this case, the aggregate induction band is a charge transfer π-π * stacking of the polymer backbone, which is caused by electronic communication. Alternatively, the conjugated polymer backbone can be helically twisted, thereby producing a chiral chromophore. With helically aggregated polymers, several hierarchical levels of helical structure are possible from the molecule to the visible state. This redox-induced change in CD for PBTh ^* can therefore be reasonably explained as being due to intercalation of perchlorate ions and solvent between polymer backbones at the molecular level, and this result , Which will extend the distance between the polymer backbone in the oxidized state. In this case, the exciton-coupled bisignate couplet of the CD spectrum represents a one-handed helical assembly with a positive couplet for (R) -PTBh ^* and a negative couplet for (S) -PTBh ^* . In the oxidized state, the polymer does not exhibit such bisignate properties, and the sign of the cotton effect on the order of 600 nm is opposite to that in the reduced state. This result indicates that the helical aggregate is released upon doping and disappears from the chiral aggregate structure. However, the polymer still exhibits a cotton effect resulting from the chiral structure of the polymer backbone.

There are other explanations for this phenomenon. Solid films of polythiophene derivatives have been reported to exhibit conformation-induced chromism via a doping-dedoping redox method. This optical effect appears to be reversible and is not due to any degradation of the polymer. Such an optical effect is considered to be related to a reversible transition between a coplanar shape of a high conjugated state and a non-planar shape of a low conjugated structure of a polymer main chain. Thus, the electrochromism of PBTh ^* s in CD during the redox process may result from a small change in dihedral angle between adjacent thiophene unit cells.

In the case of helical polyacetylene, the dihedral angle is in the range of 0.02 ° to 0.23 °, and the polymer shows a strong cotton effect in the CD spectrum. Small continuous changes in the twist angle in the one hand twist direction between adjacent units of polyacetylene will result in a consistent cotton effect. Changes in the cotton effect of the film state PBTh ^* can be caused by small dihedral angle changes as a result of the alternating potential during the iterative redox doping / undoping process. This process results in the polaron and bipolaron states of the polymer. In monomer units, the dihedral angle must be very small, but a small change in twist angle in one direction is thought to produce strong chirality for PBTh ^* , and the “polymer effect” of chiral chemistry. Is shown. This is closely related to the elastic behavior of the polymer during the redox process, which will allow structural recovery between doped and undoped states in the film. Thus, the phenomenon of reversible changes in the Cotton effect may be considered a form of “electrochemical isomerization”.
The PBTh ^* structure must be reflected in both the molecular form and the N ^* -LC aggregation state. CD bands thus arise from intermolecular aggregation of chromophores and helical twisting of the polymer backbone.

Electrochemical polymerization of bithiophene in an LC mixture using an isotropic phase (30 ° C.) resulted in a polymer without a helical structure. As can be seen in the SEM photograph, the obtained PBTh had a random spherical structure, but had no cotton effect. Similarly, polymers synthesized by electrochemical polymerization using nematic liquid crystals (N-LC) without chiral dopants under the same polymerization conditions for N ^* -LC showed no Cotton effect. . These results suggest that the chiral nematic LC environment is important for the synthesis of chiral bithiophene. Thus, electrochemical polymerization of the N ^* -LC field allows for the preparation of electrically and optically active solid state conjugated polymers with controllable Cotton effect.

(6) Polymerization model of N ^* -LC field The PBTh ^* film exhibited chiroptical properties and formed a chiral structure similar to that of N ^* -LC. The structure formed during the polymerization was preserved after washing. None of the chiral molecules chemically reacted with the monomer during the polymerization, but it is known that the electrolyte acts only as a matrix. The poor solubility and insolubility of PBTh ^* is important for retention of metastable chiral structures.
FIG. 8 shows a reasonable polymerization mechanism for PBTh ^{* in} the N ^* -LC field. In this model, the polymer grows from the anode to the cathode via an N ^* -LC three-dimensional helical structure. The polymer backbone grows twisted in only one direction during the polymerization process and forms a bundle structure by agglomeration of twisted polymer backbones by van der Waals forces. This bundle forms a macroscopic cholesteric liquid crystal finger-like structure. It should be emphasized that the polymerization mechanism in the N ^* -LC field is different from that of achiral monomers using chiral catalysts.

(7) Repeated redox properties and CD
The large change in both color and cotton effect through the electrochemical doping / undoping process suggests that PBTh ^* can be used as an electrochromic material. The electrochromic switching behavior of PBTh ^* was investigated through observation of changes in absorption and CD spectra upon repeated changes in applied voltage between the reduced and oxidized states. A platinum plate was used as the counter electrode, and samples of (R)-or (S) -PBTh * films were prepared by depositing on ITO-coated glass by electrochemical polymerization of N ^* -LC.

FIG. 9 shows the change in absorption at (R) -PBTh ^{* from} 0.1 to 1.3 V repetitive voltage scan (100 mV / s) to Ag / Ag ⁺ in 0.1 M TBAP / acetonitrile electrolyte. Absorption intensity was monitored at 492 nm and 680 nm at 12 second intervals. In the oxidation process (1.3 V versus Ag / Ag ⁺ ), the absorption intensity at 492 nm was weakened, while the absorption intensity at 680 nm was increased. This change in absorption intensity was confirmed to be repetitive during the next reduction (0.1 V vs. Ag / Ag ⁺ ).

As shown in FIG. 10, the CD intensity of (R)-and (S) -PBTh ^* during voltage scanning is also subject to a reversible symmetrical change. The CD intensity at 592 nm is lowest at 1.3 V (oxidation state) against Ag / Ag ⁺ , both polymers show a cotton effect, negative values for (R) -PBTh *, negative values for (S) -PBTh ^* A positive value was shown. Application of 0.1 V to Ag / Ag ⁺ imparts a reduced state, causing a subsequent increase in CD intensity at 592 nm, with a sign opposite to that of the Cotton effect for the oxidized state. Thus, control of the redox process allows a reversible change in CD intensity.

Thus, PBTh has been shown to repeat the helical form of N ^* -LC used as a solvent for electrochemical polymerization, yielding an optically active conjugated polymer (PBTh ^* ) exhibiting optically active electrochromism. it is obvious. The method of this example gives new possibilities for chiral engineering, allows the synthesis of a range of conjugated polymers with chiroptical properties, and expands the use of such polymers in biological science and engineering. This study also highlights the importance and flexibility of chiral reaction fields for chemical synthesis.

[Example 2]
Next, the chiral polymer according to the present invention was polymerized using the chiral monomer.
(1) Monomer synthesis (R)-and (S) -1,4-bis [2- (3,4-ethylenedioxy) thienyl] -2,5-benzoic acid-1-methylheptyl ester [BEDOT- The chiral compound of B (OCT ^* )] was prepared as a chiral monomer for electrochemical polymerization. The synthetic route to BEDOT-B (OCT ^* ) is described in Scheme 1.

Organotin compounds were easily obtained by direct lithiation in the same molar ratio as EDOT and subsequent reaction with tin chloride (J. Mater. Chem., 2004, Vol. 14, p1679-1681. Dibromo compounds ( R) -1 and (S) -1 are (R) or (S) -octanol and 2,5 dipromobenzoic acid using diethyl azodicarboxylate (DEAD) and triphenylphosphine (TPP) in tetrahydrofuran solution. Was produced via the Mitsunobu reaction, which was characterized by S _N 2 type Walden inversion at the chiral center without racemization, resulting in the formation of the desired compound. (Synthesis, 1981, p.1).

The monomer is then steel coupled using Pd (PPh ₃ ) ₄ as a catalyst to produce (R)-and (S) -BEDOT-B (OCT ^* ) in 61% and 65% yields, respectively. Generated by the method. These monomers were characterized by proton nuclear magnetic resonance ( ¹ H NMR) and infrared (IR) absorption spectroscopy to confirm the structure (CD in chloroform: (R) -1, λ _max = 350 nm, Δε = + 1.6, (S) −1, λ _max = 348 nm, Δε = 2.1).

(2) Electrochemical polymerization The electrochemical polymerization of monomers was carried out by established methods for producing PEDOT or PBEDOT derivatives (J. Polym. Sci., Part A: Polym. Chem., 2001, Vol. 39, p. .2164). The polymer is 0.01M monomer and 0.1M tetrabutylammonium perchlorate (TBAP) in anhydrous acetonitrile for poly [(R)-or (S) -BEDOT-B (OCT ^* )]). It was generated electrochemically from the containing solution. Both monomers were electrooxidatively polymerized on platinum disks by repeated scanning for Ag / Ag ⁺ at 10 mV / s.

As shown in FIG. 11, the results for electrochemical polymerization of (R)-and (S) -BEDOT-B (OCT ^* ) are similar. During the oxidative scan, the monomer oxidation peak was -0.123 V and +0.579 V for poly [(R) -BEDOT-B (OCT ^* )] in the first scan and poly [(S)- BEDOT-B (OCT ^* )] is -0.113V and + 0.579V. In the return scan, polymer reduction was observed. The growing polymer redox process can be seen in the next scan. All peaks showed an increase in current response, indicating the formation of an electroactive film. After polymerization, the polymer membrane was washed with electrolyte solution and acetonitrile. Switching the membrane redox in the monomer-free electrolyte solution showed a clear redox process.

FIG. 12 also shows the cyclic of poly [(S) -BEDOT-B (OCT ^* )] film at scan rates of 10, 20, 30, 60, 80 and 100 mV / s in 0.1 M TBAP / acetonitrile. A voltammogram is shown. The half-peak oxidation potential (E _1/2 ) of the polymer is −0.339 V with respect to Ag / Ag ⁺ (E _{ox / p} = −0.098 V and E _{red / p} = −0.540 V at 100 mV / s). And the value for poly [l, 4-bis (2- (3 ′, 4′-ethylenedioxy) thienyl) -2-methoxy-5-2-ethylheptylbenzene] poly (BEDOT-MEHB)]) It is the same. The polymer showed a very clear quasi-reversible redox process. It is noted that (R)-and (S) -BEDOT-B (OCT ^* ) exhibit very similar electrochemical behavior, presumably because the chirality of the polymer does not affect the redox behavior. Deserves.

(3) Optical properties The poly [BEDOT-B (OCT ^* )] film was coated with indium titanium oxide (ITO) by electrochemical deposition from a 0.1M TBAP and acetonitrile 0.01M monomer solution. Deposited on the glass substrate.
FIG. 13 shows the UV of poly [(S) -BEDOT-B (OCT ^* )] when −0.85 V (reduced state) or +0.80 V (oxidized state) is applied to Ag / Ag ⁺ . / Vis absorption spectrum (the upper diagram in FIG. 13), CD spectrum (the lower diagram in FIG. 13), and cyclic voltammetry (the lower diagram in FIG. 13) are shown.

As shown in FIG. 13, during oxidation (+0.80 V applied to Ag / Ag ⁺ ), the peak of the absorption spectrum at 533 nm corresponding to the π-π ^* transition of the polymer main chain has a longer wavelength. The generation of low energy charge carriers weakens with a change in polymer color from purple to emerald green and the appearance of a broad absorption band. The 452 nm positive signal and 556 nm negative peak in the CD spectrum are also weakened. Application of -0.85 V as the reduction process restored these peaks in the UV / Vis and CD spectra to their original intensity in the reduced state.

As shown in FIG. 14, the cotton effect of the monomer and the corresponding polymer basically has the same sign at a single wavelength. Furthermore, the reduced polymer film shows a cotton effect that shows the expected mirror image in the region of the π-π ^* transition of the polymer backbone, suggesting that the polymer is chiral in the film state.

  Polymers can be formed with head-to-head (HH) or regular head-to-tail (HT) position regularity, but it is assumed that such structural changes affect the optical properties of the polymer. However, control of the polymer site regularity is difficult to achieve with the present electrochemical polymerization process which tends to form polymers with random HH and HT regularity. Therefore, synthesis of chiral monomers with asymmetric structures and subsequent polymerization should result in a strong cotton effect.

  Thus, the electrochemical polymerization of the chiral monomer of this example gave a stable chiral polymer film in the oxidative polymerization process. It has also been shown that the optical activity of these films deposited on ITO can be adjusted electrochemically by changing the electronic state of the polymer. This procedure is likely to result in the manufacture of new electrochromic devices and improved fabrication of durable electrochromic devices based on the good film-forming properties of chiral polymers.

[Example 3]
It was confirmed whether the chiral polymer [(R)-or (S) -PBTh ^* ] of Example 1 shows an optical activity history (hysteresis) phenomenon.
FIG. 15 shows a change in the absorption spectrum at 498 nm when the potential is swept based on the Ag / Ag ⁺ reference electrode. As shown in FIG. 15 (absorption spectrum of (R) -PBTh ^* (similar graph is also obtained in the case of (S) form), it shows an absorption of 4 × 10 ⁵ / cm during reduction and during oxidation. Decreases to about 2 × 10 ⁵ / cm. As a result, it was shown that the absorption intensity of the polymer can be electrochemically controlled with the redox. It was also shown that the absorption intensity when the potential was changed from the reduced state to the oxidation direction and from the oxidation to the reduction direction was different, and a hysteresis curve was drawn as a whole. Thereby, the redox history phenomenon of this chiral polymer, ie, a conductive polymer, was found.

FIG. 16 is based on Ag / Ag ⁺ reference electrode, and cyclic voltammetry based on Ag / Ag ⁺ reference electrode accompanying redox of the circular dichroism spectrum at 480 nm when the potential is swept (upper part of FIG. 16). ) And the intensity change of the circular dichroism spectrum at 592 nm (lower part of FIG. 16).
As shown in FIG. 16, when the potential is changed from the reduced state to the oxidized state, (R) -PBTh ^* changes from the left circularly polarized state to the right polarized state. On the other hand, (S) -PBTh ^* changes in the opposite direction. This relationship is a mirror image relationship, indicating that the (R) and (S) isomers have inverted optical activity. These chiral polymers also exhibited hysteresis. Thus, it was confirmed that the chiral polymer according to the present invention exhibits an “optical activity history phenomenon” by an electrochemical method.

FIG. 17 shows the optical rotation of the chiral polymer accompanying redox. It was revealed that the (R) and (S) isomers showed a mirror image relationship with each other and exhibited optical rotation comparable to that of inorganic compounds in a reduced state (520 nm,> 2 × 10 ⁴ deg / cm). (Example of Faraday rotation (magneto-optical rotation): Fe 3.825 × 10 ⁵ deg / cm, YFeO ₃ 4.9 × 10 ³ deg / cm, NdFeO ₃ 4.72 × 10 ⁴ deg / cm). As shown in FIG. 17, it was demonstrated that the chiral polymer of this example can control the optical rotation electrochemically. From this, the “electrochemical optical rotation phenomenon” in the conductive polymer was shown for the first time.

  Thus, according to the present invention, the optical activity of the chiral polymer can be easily changed and adjusted, whereby a chiral polymer having the desired optical activity can be obtained efficiently. Thus, the chiral polymer whose optical activity can be changed electrochemically can be used in various applications utilizing the change in optical activity.

It is the schematic of the polymerization cell used in the present Example. Polarization microscope image of (R) -PCH506-binol electrolyte at 10 ° C. The bar is 10 μm. Phase contrast optical microscope image (no polarizer) showing the fingerprint structure of (R) -PBTh ^* film at 25 ° C. The bar is 10 μm. A phase-contrast optical microscope image (no polarizer) showing the two-helical texture of the (R) -PBTh ^* film at 25 ° C. The bar is 10 μm. Phase contrast optical microscope image (no polarizer) showing the polygonal fingerprint texture of the (R) -PBTh ^* film at 25 ° C. The bar is 10 μm. FIG ^{. 6} is a graph showing cyclic voltammetry of (R) -PBTh ^* membranes (vs. Ag / Ag ⁺ ) at various scan rates with a 0.1 M TBAP / acetonitrile solution, where the scan rate is (a) 10 mV / Second, (b) 20 mV / second, (c) 40 mV / second, (d) 60 mV / second, (e) 80 mV / second, and (f) 100 mV / second. It is a graph which shows the circular dichroism spectrum of the (R)-and (S) -PBTh ^* film | membrane of a redox state. It is a graph which shows the CD spectrum of (R)-and (S) -PCH506-binol in THF. Various voltages for Ag / Ag ⁺ [(a) 0.2 V, (b) 1 V, (c) 1.2 V, (d) 1.25 V, (e ) 0.6V, (f) 0.1V] in situ UV-Vis-NIR absorption spectrum (top) and CD spectrum (bottom) of (R) -PBTh ^* on the ITO electrode. ). It is a graph which shows the UV-vis-NIR spectrum of (R) -PBTh ^* at the time of 0.7V application. It is a conceptual diagram of the polymerization mechanism of PBTh ^* in a N ^* LC reaction field. UV- at 492 nm (top) and 680 nm (bottom) for electrochromic cells based on (R) -PBTh ^* during repetitive voltage scans (scan rate 100 mV / s) to Ag / Ag ⁺ It is a graph which shows switching of vis absorption intensity. Electrochromic cells based on (R) -PBTh ^* (top) and (S) -PBTh ^* (bottom) during repetitive voltage scans of 0.1 to 1.3 V against Ag / Ag ⁺ (scan rate 100 mV / s) It is a graph which shows switching of CD intensity in 592 nm. Electrochemistry of (R) or (S) BEDOP-B (OCT ^* ) (0.01 M) by repeated potential scanning in 0.1 M TBAP / acetonitrile at a rate of 10 mV / s in another embodiment of the invention It is a graph which shows the voltammogram regarding superposition | polymerization. FIG. 6 is a graph showing cyclic voltammograms of poly [(S) -BEDOT-B (OCT ^* )] film at various scan rates in 0.1 M TBAP / acetonitrile, where the scan rate is (a) 10 mV / Second, (b) 20 mV / second, (c) 30 mV / second, (d) 60 mV / second, (e) 80 mV / second, and (f) 100 mV / second. UV / Vis (UV / Vis) absorption spectrum of poly [(S) -BEDOT-B (OCT ^* )] in the oxidized and reduced state (top) and in a 0.1 M TBAP / acetonitrile solution in the absence of monomer. It is a graph which shows the UV / Vis and CD spectrum (bottom) of poly [(R) -BEDOT-B (OCT ^* )] after applying a voltage with respect to Ag / Ag ⁺ , respectively. It is a graph which shows the CD spectrum (insert part) of a monomer, and the CD spectrum of a poly [(R)-and (S) -BEDOT-B (OCT ^* )] film, respectively. A change in the absorption spectrum at 498 nm when the potential is swept based on the Ag / Ag ⁺ reference electrode is shown. With respect to the Ag / Ag ⁺ reference electrode, caused by the oxidation-reduction of the circular dichroism spectrum of 480nm at the time of sweeping the potential, and cyclic voltammetry relative to the Ag / Ag ⁺ reference electrode (above), cyclic It is a graph which respectively shows the hysteresis phenomenon (bottom) of the cotton effect of (R)-and (S) -PBTh ^* film | membrane (vs. Ag / Ag ⁺ ) in 592 nm by the application of the continuous electric field by a voltammogram. The optical rotation phenomenon by application of the electric field of (R)-and (S) -PBTh ^* film (vs. Ag / Ag ⁺ ) is shown. The oxidation state is 1.3 V and the reduction state is 0.1 V (vs. Ag / Ag ⁺ ).

Explanation of symbols

10 Polymerization cell

Claims (4)

A production method for producing a chiral polymer, comprising:
Obtaining a chiral polymer by performing electropolymerization using a chiral monomer or chiral dopant;
A production method comprising controlling an optical activity of a chiral polymer by applying an oxidation or reduction potential to the chiral polymer.   The production method according to claim 1, wherein the chiral monomer is selected from the group consisting of aromatics having 4 to 6 carbon atoms containing a hetero atom.   The method for producing a chiral polymer according to claim 1, wherein the chiral dopant is selected from the group consisting of a central chirality compound and an axial chiral compound. A method for controlling the optical activity of a chiral polymer comprising:
An optical activity control method comprising applying an oxidation potential or a reduction potential to a chiral polymer obtained by electrolytic polymerization.