JP3141221B2 - Linear poly (phenylene-ethynylene-xylylene-ethynylene) polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear poly (phenylene-ethynylene-xylylene-ethynylene) polymer used as a light- and electric-responsive heat-resistant functional material, a method for producing the same, and a light-emitting material using the polymer. About.

[0002]

2. Description of the Related Art Generally, examples of polymers having a π-conjugated bond in the main chain include polyacetylene and poly (p-
Polyarylene such as phenylene), poly (2,5-phenylene) or poly (1,4-naphthalenediyl), or polyarylenevinylene such as poly (p-phenylenevinylene) or poly (2,5-phenylenevinylene) And the like, all of which have a single skeleton-double bond repetition as a basic skeleton.
The above-mentioned polyarylene having an aromatic ring continuously bonded and having a π-conjugated bond is chemically stable and has excellent heat resistance.

[0003] With respect to these electric responsiveness, it is known that polyacetylene having the simplest structure exhibits conductivity comparable to that of metal by doping under special conditions.

Further, π-conjugated polymers having a triple bond in the main chain have high crystallinity, and although various polydiacetylenes have been studied as nonlinear optical materials, research reports on other compounds have been extremely limited. Few. Examples of the synthesis of a π-conjugated polymer having an arylene-acetylene bond in the main chain include poly (1,4-phenylene-ethynylene) and poly (1,4-phenylene-ethynylene-).
2,5-Chenylene-ethynylene) and the like.

[0005]

However, the above-mentioned conventional conductive polyacetylene has a problem that it has poor moldability and is chemically unstable. In addition, most compounds of other polyarylenes, which are also expected to have conductivity, have low solubility in organic solvents and are infusible, so that they can be sufficiently used as functional materials utilizing their respective characteristics. I couldn't. In particular, polyarylene vinylene, which has an intermediate structure between polyacetylene and polyarylene, is considered to be useful as the intended material because it passes through a solvent-soluble precursor in its synthesis method, but it is considered that the conversion from the precursor Is difficult to do completely,
The conjugated chain had a defect that a defect occurred.

[0006] Even π-conjugated polymers having an arylene-acetylene bond in the main chain are hardly soluble in organic solvents (Bull. Chem. Soc. Jpn.,
57, p. 752, (1984)), it was difficult to form a thin film or a thread into a shape that could make use of functions such as conductivity.

Therefore, the present invention solves the above-mentioned problems and maintains the excellent heat resistance and chemical stability of the polymer by devising the structure of a polymer having a π-conjugated bond in the main chain. At the same time, it shall show conductivity and photo-responsivity, and further enhance the solubility in as many organic solvents as possible to sufficiently enhance the usability such as molding as a functional material. It is an issue.

[0008]

In order to solve the above-mentioned problems, the present invention provides a linear poly (phenylene-ethynylene-xylylene-ethynylene) polymer represented by the following formula (4).

[0009]

Embedded image

This polymer comprises a compound represented by the following formula (5) and a compound represented by the following formula (6) (provided that
One of Ar and Ar ′ in both formulas is a 2,5-xylenediyl group and the other is p-phenylene), palladium-
It can be produced by a dehydrohalogenation coupling reaction in the presence of a copper catalyst and an amine.

[0011]

Embedded image

[0012]

Embedded image

Further, a light-emitting material comprising the above-mentioned linear poly (phenylene-ethynylene-xylylene-ethynylene) polymer can be used. The details are described below.

The principle of the method for producing the linear poly (phenylene-ethynylene-xylylene-ethynylene) polymer shown in Chemical formula 4 will be described below.

First, as shown in the following reaction formula 7, an aryl halide (Ar-X) and a terminal acetylene are reacted in the presence of a palladium phosphine complex catalyst (Pd (PPh ₃ ) ₄ ) and an amine (NR ₃ ). The acetylene hydrogen is replaced by an aryl group (see, for example, J. Organ
omet. Chem. 93, p. 253, (197
5)). In this case, the palladium catalyst Pd (PP
Instead of _{h 3) 4, PdCl 2 (} PPh 3) 2, PdC
A catalyst comprising a palladium compound such as l ₂ (DPPE) ₂ (where DPPE represents difephosphinoethane), Pd (0Ac) ₂ + 2PPh ₃ can also be used. In addition, the amine may be a highly basic alkylamine such as diethylamine or piperidine in addition to triethylamine. The amount of the amine is not particularly limited, and may be a slight excess with respect to the reaction substrate.

[0016]

Embedded image

In particular, when copper iodide is added, the reaction proceeds smoothly. This is because copper acetylide is generated, and the reaction proceeds by transmetallation with palladium (Pd) and reductive elimination, as shown by the reaction formula of Chemical Formula 8 below.
(Tetrahedron Lett., P. 4407, 1
975). In this case, the copper iodide is particularly preferable in terms of easy handling, but it is a matter of course that the same effect can be expected with copper chloride or copper bromide instead.

[0018]

Embedded image

Accordingly, as shown in the following reaction formula, a dihalogenated aryl compound having two halogens (X) in a molecule and an aromatic compound having two ethynyl groups in the same molecule are used. When a certain diethynylaryl is reacted with a solvent in the presence of a palladium-copper catalyst and an amine, a polymer is obtained by dehydrohalogenation coupling.

[0020]

Embedded image

The mixing ratio of the palladium catalyst used in the above production method is 0.1 to 10 mol% based on the reaction substrate.
Is preferable, and 1 to 4 mol% is particularly preferable. The proportion of copper iodide is suitably about 0.1 to 10 mol%. As the reaction solvent, toluene is used as a representative example, and benzene, dimethylformamide (hereinafter abbreviated as DHF), tetrahydrofuran (hereinafter abbreviated as THF), pyridine and the like can be employed without particular limitation. The concentration of the reaction substrate in the reaction solvent is not particularly limited, and is preferably 0.01 to 1 mol.
/ Liter, particularly preferably 0.05 to 0.2 mol /
May be liters. Further, the reaction temperature may be from room temperature to the solvent reflux temperature (for example, 40 to 100 ° C.), and the reaction time is about 5 minutes to 100 hours, and particularly 1 to 100 hours.
A period of about 24 hours is preferable in terms of production efficiency.

[0022]

EXAMPLE 1 mmo of 2,5-dibromo-p-xylene
1, 2 mmol of piperidine to 1 mmol of p-diethynylbenzene, 0.01 mmol of tetrakistriphenylphosphinepalladium: Pd (PPh ₃ ) ₄ as a zero-valent palladium compound, and 0.02 mmol of copper iodide, and 100 ° C. in 8 ml of toluene. The mixture was stirred and reacted for 1 hour. When a powdery polymer was obtained in this reaction system, it was sufficiently washed with a large amount of methanol, filtered, and dried using a vacuum line. The yield of the obtained polymer was 76%.

The obtained polymer was analyzed for its constituent elements by thermal decomposition according to a conventional method. As a result, the percentage of carbon and hydrogen as constituent elements was 92.32% for carbon and 92.32% for carbon.
7.68% hydrogen.

On the other hand, the calculated value of the elemental composition C ₁₈ H ₁₂ of the polymer containing the compound represented by the above formula as a repeating unit is 94.70% of carbon and 5.30% of hydrogen. It almost matched the percentage. Incidentally, the obtained polymer,
Since it has high thermal stability and it is not easy to completely burn it during elemental analysis, it was presumed that a slight error occurred between the observed value and the calculated value.

[Experimental Example 1] The infrared absorption spectra of the examples showed the following absorptions (cm ^-1 ).

3026, 2930, 2852, 220
0, 1578, 1505, 1447, 1385, 125
2,1205,1114,1017,958,883,
836 Thus, the infrared absorption spectrum of the working example
At around 200 cm ^-1 , an absorption characteristic of stretching vibration is shown in the acetylene bond, and the absorption at 840 cm ^-1 is due to C-
The absorption characteristic of the out-of-plane bending vibration was exhibited.

[Experimental Example 2] The absorption spectrum (H'-NMR) by nuclear magnetic resonance method of the example was examined using tetramethylsilane as a standard substance. , 2.35, 2.46, 7.41;
It was at 7.50.

In this case, the σ values of 2.35 and 2.46 are C
The proton of the H ₃ group, 7.41 is assigned to the proton of the benzene ring of xylylene, and 7.50 is assigned to the proton of the phenyl group, and the integral ratio is also 1: 1. Therefore, the compounds of the examples were identified as the compounds represented by the above formulas.

Experimental Example 3 The polymer of the example was subjected to thermogravimetric analysis. As a result, the thermal decomposition temperature was about 300 ° C., indicating high thermal stability.

[Experimental Example 4] The UV-visible spectrum of the chloroform solution in Example was measured.
At 360 nm, an absorption maximum showing a relatively sharp and clear mountain shape was shown.

[Experimental example 5]
G. FIG. P. The number average molecular weight (Mn) was determined according to Method C (using tetrahydrofuran).
^{Was 3} . The weight average molecular weight (Mw) is 3.9
It was 5 × 10 ⁴ .

[Experimental Example 6] For the polymer of Example, at a concentration of 1 mg / milliliter at about 25 ° C., formic acid or chloroform, N-methylpyrrolidone (NMP), tetrahydrofuran (THF), toluene, benzene, dimethylsulfoxide (DMSO) ) Was prepared, spread on a petri dish, and then the solvent was removed by an evaporation method to obtain a film-like substance. Inspection of the infrared absorption spectrum of this substance showed that it was consistent with the infrared absorption spectrum of the polymer before the solvent was added, and the polymer of Example was easily formed into a film or a thread by a well-known injection method. It turned out that it can be molded into.

The polymer of Example was dissolved in chloroform (99% concentration) at 25 ° C. under stirring conditions.
It showed a solubility of 1 mg / ml.

[Experimental Example 7] In the polymer of the present example, a thin film formed on a metal substrate by vacuum evaporation was observed to emit light while being weakly semiconducting due to the applied voltage. A material that can be used as an optical material was obtained.

[0035]

As described above, according to the present invention, since the linear poly (phenylene-ethynylene-xylylene-ethynylene) polymer represented by the predetermined formula is used, the 2,5-xylenediyl group has a polymer main chain. Forms a continuous π-conjugated system along with and becomes a compound whose orientation is highly controlled, while maintaining excellent heat resistance and chemical stability,
It has photo-responsiveness, and is highly soluble in many organic solvents, so that it is easy to form and process, and has the advantage of providing a highly usable general-purpose functional material.

────────────────────────────────────────────────── (5) References JP-A-57-143321 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 61/00-61/10 CA (STN ) REGISTRY (STN)

Claims (3)

(57) [Claims] 1. A linear poly (phenylene-ethynylene-xylylene-ethynylene) polymer represented by the following formula: Embedded image 2. A compound represented by the following formula (2) and a compound represented by the following formula (3):
Or one of Ar 'is a 2,5-xylenediyl group and the other is p-phenylene), a palladium-copper catalyst, and a dehydrohalogenation coupling reaction in the presence of an amine. A method for producing a poly (phenylene-ethynylene-xylylene-ethynylene) polymer. Embedded image Embedded image 3. The linear poly (phenylene) according to claim 1,
A light-emitting material comprising an (ethynylene-xylylene-ethynylene) polymer.