JPH06271539A - Calixarene derivative/carboxylic acid complex - Google Patents

Abstract

PURPOSE:To obtain a new calixarene-based substance capable of assuming physical properties such as reduction in melting point, noncrystallization or manifestation of flow birefringence as opposed to those of a conventional system based on a calixarene. CONSTITUTION:This complex of a calixarene derivative expressed by the formula [(n) is 4, 6 or 8] with an aliphatic or an aromatic carboxylic acid having at least one carboxyl group in the molecule. The complex is simply obtained by dissolving the calixarene derivative and carboxylic acid in a solvent capable of dissolving both (e.g. chloroform) in an optional ratio, then decompressing or heating the solvent and distilling away the solvent. The ratio of the carboxyl groups to pyridine residue in the calixarene derivative is preferably regulated to 0.25-1.5, preferably 0.5-1.25. This complex is used as a display or a pressure sensor causing the molecular orientation with a stress as an external field based on the flow birefringence within a low-temperature region including ordinary temperature or a temperature sensor, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a complex composed of a calixarene derivative and a carboxylic acid, and particularly, unlike a conventional system based on calixarene, it has a low melting point, is non-crystalline, and has a fluid birefringence. The present invention relates to a novel calixarene-based substance exhibiting physical properties such as expression.

[0002]

[Prior Art and Problems] Calixarene is a cyclic oligomer formed by the condensation reaction of phenol and formaldehyde. Its molecular structure is
This name was given because it is an aromatic compound (Arene) similar to x). Calix Arene is 195
Around 0 years, it was found by Zinke et al. In phenol-formaldehyde resins (A.Zinke, E.Zegler, Chem.Be.
r., 77, 264, (1944)), and later in the late 1970s, Kaemmerer et al.
A monomer was synthesized and identified for the first time (H. Kaemmerer, GH
appel, V.Bohmer, D.Rathay, Monatsh.Chem., 109,767 (1
978)). Furthermore, Gutsche et al. Made it possible to synthesize 4,6,8-mer from p-tert-butylphenol and formaldehyde in a single step in good yield (CD Gutsche,
Acc. Chem. Res., 16, 161, (1985)). This facilitated the supply of calixarene, and the detailed study on the manufacturing method, structure and physical properties of various calixarene derivatives came to be carried out.

The calixarene has the following characteristics. By changing the number of phenol ring members,
It is possible to synthesize compounds having different pore diameters, various functional groups can be introduced by utilizing a phenolic hydroxyl group, various functional groups can be introduced by an aromatic substitution reaction, and conformations can be controlled. By successfully applying these characteristics, the interaction with various ions and molecules can be controlled, so the calixarene derivative is a “third clathrate compound” next to the crown ether and cyclodextrin host compounds, It attracts attention as an important research material in host-guest chemistry and is expected as various functional materials in practical use.

The conventionally known calixarene derivatives are generally sparingly soluble and have a high melting point. Therefore, in many systems using a calixarene derivative, the function of the calixarene derivative is exerted by dissolving the calixarene derivative in an appropriate solvent or plasticizer while taking advantage of the above-mentioned characteristics of the calixarene derivative. If a system with good solubility and a low melting point can be obtained using a calixarene derivative, it will be easy to handle, and a new functional material based on the bulk properties of the calixarene derivative will not be affected by solvents and plasticizers. Can be expected. However, there is no specific means for doing so.

[0005]

[Means for Solving the Problems and Effects of the Invention] While the present inventor conducted research on calixarene,
We have found a new system that exhibits physical properties different from those of the conventional high melting point calixarene derivatives. That is,
The present invention provides a calixarene derivative represented by the following general formula (Formula 1) (wherein n is 4, 6 or 8) and an aliphatic or aromatic compound having at least one carboxyl group in the molecule. A complex with a group carboxylic acid is provided.

[0006]

[Chemical 1]

Surprisingly, it was found that the complex composed of the calixarene derivative represented by the general formula [Chemical Formula 1] and the carboxylic acid has a significantly lowered melting point and exhibits flow birefringence. That is, the calixarene derivative / carboxylic acid complex of the present invention has a significantly lower melting point than the calixarene derivative, and exhibits flow birefringence near the melting point. here,
Flow birefringence means that molecular orientation occurs along the flow generated by the application of external stress and a birefringence phenomenon is observed.

The reason why such properties are expressed in the calixarene derivative / carboxylic acid complex of the present invention is not fully clear, but the upper edge side of the calixarene structure (the side where phenolic OH does not exist).
It is presumed that an interaction occurs between the pyridine unit introduced in and the carboxyl group of the carboxylic acid, and the structure has a low melting point and fluidity.

The carboxylic acid used in the present invention is an aliphatic or aromatic carboxylic acid having at least one carboxyl group in its molecule. Preferred carboxylic acids include, for example, propionic acid, butanoic acid, pentanoic acid,
Caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, eicoic acid,
Behenic acid and other monocarboxylic acids, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid and other dicarboxylic acids, p-hexylbenzoic acid And the like, alkylphenylacetic acid such as p-octylphenylacetic acid, p-alkoxybenzoic acid, and polymeric carboxylic acids such as alginic acid and carboxyvinyl polymer.

To obtain the complex of the present invention,
Generally, a calixarene derivative and a carboxylic acid are
The pyridine residue of the calixarene derivative has 0.25 to 1.5 carboxyl groups, preferably 0.5.
It is desirable to set the ratio to about 1.25. The carboxylic acid contained in the complex is not limited to a single kind, and may be plural kinds.

The calixarene derivative / carboxylic acid complex of the present invention can be used for various applications by utilizing its unique property, and in particular, there are various applications based on flow birefringence in a low temperature range including normal temperature. Hereinafter, such applications will be described, but the uses of the present invention are not limited to the following.

When the calixarene derivative / carboxylic acid complex of the present invention is sandwiched between polarizing plates orthogonal to each other at a temperature exhibiting a liquid (isotropic) state, light does not pass therethrough, but when external stress is applied, birefringence occurs. Appears and light comes to pass between the polarizing plates. Therefore, the calixarene derivative / carboxylic acid complex of the present invention can be used, for example, as a display, a pressure sensor, or the like in which stress causes molecular orientation as an external field. At this time, when the calixarene derivative / carboxylic acid complex of the present invention is used, the response is based on the change from the isotropic phase (liquid) to the birefringent phase, and therefore based on the change from the birefringent phase to the birefringent phase. Compared to liquid crystal display,
There is a large difference in the amount of transmitted light when off, and a display with clear contrast can be obtained. Further, the liquid crystal display requires a pretreatment for causing the molecular orientation from the beginning, but the display of the present invention also has an advantage that such an orientation treatment need not be performed.

As another application example, stress is applied to the compound of the present invention sandwiched between polarizing plates which are orthogonal to each other under the isotropic phase temperature, and the temperature is lowered to the melting point or lower while the orientation due to the flow is generated. Then, the molecules of the compound are fixed in the aligned state, exhibiting permanent birefringence, and light can pass through the orthogonal polarizing plates. If this is placed in an environment above the melting point, the birefringence disappears immediately and light cannot pass through. By using this, various temperature sensors corresponding to the melting point of the compound can be manufactured. By combining several compounds having different melting points, a device which loses light transmittance at an arbitrary temperature can be produced. These can be used as a maximum thermometer and the like.

Further, since the conventional calixarene derivative has low solubility, it is difficult to obtain a uniform coating film. On the other hand, since the calixarene derivative / carboxylic acid complex of the present invention has good solubility, it is possible to form a uniform coating film by means such as dissolving in a suitable volatile solvent and coating. At this time, when the initial coating is carried out under the temperature condition below the melting point to form an emulsion-colored coating film, the coating film becomes transparent by raising the temperature. Since such a phenomenon can be reversibly reproduced with the melting point as a boundary, it seems that it can be applied to a display element that does not use a temperature sensor or a polarizing plate.

Furthermore, the present invention retains the structural features of the calixarene itself, thus
Provided is a calixarene derivative / carboxylic acid complex which is excellent in solubility and has a low melting point and is easy to handle without impairing the function originally possessed by the calixarene structure. For example, by substituting the phenolic hydroxyl group on the lower rim with a functional group as conventionally known, the carboxylic acid according to the present invention can be retained while maintaining the ability to selectively bind a specific metal ion. By forming a complex with, the melting point can be extremely lowered.

The calixarene derivative [Chemical formula 1] for preparing the complex of the present invention can be produced by devising a known synthesis method.

That is, calixarene [n] arene is reacted with methyl halide, and then the obtained compound is formylated. Γ-lithiated to this compound
By reacting picoline, a calixarene derivative [Chemical formula 1] is produced.

Further, the complexing of the calixarene derivative and the carboxylic acid is carried out by using a solvent capable of dissolving the both,
For example, it can be easily obtained by dissolving an arbitrary ratio of the calixarene derivative and the carboxylic acid in chloroform or the like, and then distilling off the solvent by reducing the pressure or heating.

In order to further clarify the features of the present invention, the present invention will be described below with reference to examples.

[0020]

EXAMPLE A calixarene derivative [Chemical formula 1] of the present invention was produced according to the flow chart shown in FIG.

Example 1 Preparation of Intermediate [Chemical Formula 3] 6.0 g (14.15 mmol) of calix [4] arene, 9.0 g (380 mmol) of sodium hydride,
And 68.0 g (470 mmol) of methyl iodide were added to a mixed solvent of 270 ml of dried tetrahydrofuran and 30 ml of N, N-dimethylformamide, which was also dried, and the solution was added under a nitrogen stream at 6
Heated to reflux for hours. The solvent was distilled off from the reaction mixture under reduced pressure, 500 ml of water was poured into the residue, and the mixture was extracted with 500 ml of chloroform. The organic layer was separated, washed 4 times with 500 ml of water and then dried over magnesium sulfate. The solution was concentrated and then treated with methanol to give a white solid. This was further recrystallized from a mixed solvent of chloroform and methanol to obtain a pure intermediate [Chemical Formula 3] (Compound (3) in FIG. 1) (white crystals, 6.3 g, yield 92%).

<Production Example 2> Production of Intermediate [Chemical Formula 4] Tetramethoxycalix [4] arene 4.0 g
(8.3 mmol), hexamethylenetetramine 42 g
(300 mmol) was added to 200 ml of trifluoroacetic acid, and this solution was added at 90 to 100 ° C. under a nitrogen stream for 24 hours.
Heated to reflux for hours. The reaction mixture was poured into 500 ml of ice water and the stirring was continued for 1 hour.
Extracted twice. The organic layer was washed 4 times with 500 ml of water and then dried over magnesium sulfate. The solvent was distilled off under reduced pressure to obtain about 4.6 g of a pale yellow solid. This was recrystallized from a mixed solvent of chloroform and n-hexane to give a pure intermediate [Chemical Formula 4] (compound (4) in FIG. 1) (white crystals, 3.
5 g, yield 70%) was obtained.

<Preparation Example 3> Preparation of Intermediate [Chemical Formula 5] Under ice temperature, 10 ml of dry tetrahydrofuran containing 1.52 g (15 mmol) of diisopropylamine was added to
It was added dropwise to a 6.25 ml hexane solution containing 0 mmol butyllithium. Also under ice temperature, 1.4 g (15 mmol) of γ-picoline was added to the above-mentioned mixed solution.
ml of dry tetrahydrofuran solution was added slowly. The stirring was continued for another hour under ice temperature. Similarly, under ice temperature, 10 ml of tetrahydrofuran containing 1.0 g (7 mmol) of tetraformyltetramethoxycalix [4] arene [Chemical Formula 4] was slowly added dropwise to the above pale yellow transparent solution. After 10 hours, the reaction mixture was poured into 100 ml of water and stirring was continued for 30 minutes. It was extracted with 400 ml of chloroform, washed 5 times with 700 ml of water, and dried over magnesium sulfate. After filtration, the solvent was distilled off under reduced pressure,
About 1.3 g of the crude compound [Chemical Formula 5] was obtained.

Production Example 4 Production of Calixarene Derivative [Chemical Formula 1] 1.0 g of the compound [Chemical Formula 5] was dissolved in 100 ml of trifluoroacetic acid and refluxed for about 2 hours. The reaction solution was poured into 800 ml of ice water, and sodium carbonate was added to adjust the pH to 8. The suspension was extracted with 400 ml of chloroform and washed 4 times with 500 ml of water. After drying over magnesium sulfate and filtering, the solvent was distilled off to obtain a crude product. This was reprecipitated from a mixed solvent of chloroform-n-hexane to obtain about 600 mg of a calixarene derivative [Chemical formula 1].

Preparation Example 5 Preparation of Comparative Compound [Chemical Formula 6] At -78 ° C, 25 ml of dry tetrahydrofuran containing 930 mg (10 mmol) of γ-picoline and 9.5 ml of hexane containing 15 mmol of butyllithium. Dropped into the solution. After about 2 hours, under the same condition of -78 ° C, 1.
25 containing 36 g (10 mmol) of anisaldehyde
A ml of a tetrahydrofuran solution was slowly added to the above reaction solution. After about 3 hours, the reaction mixture was poured into 300 ml of ice water and stirred for 30 minutes. It was extracted with 250 ml of chloroform, washed 4 times with 300 ml of water, and dried over magnesium sulfate. The solvent was distilled off under reduced pressure to obtain about 2.2 g of a crude alcohol. The total amount of this alcohol was refluxed with 25 ml of trifluoroacetic acid for about 2 hours. The reaction solution was poured into 250 ml of ice water and adjusted to pH 8.0 with sodium carbonate. This suspension was extracted with 250 ml of chloroform and washed 4 times with 300 ml of water. After drying over magnesium sulfate, the solvent was distilled off to obtain a crude comparative compound [Chemical Formula 6]. Chloroform-n
By reprecipitation from a hexane mixed solution, 1.5 g of the following pure comparative compound [Chemical Formula 6] was obtained.

[0026]

[Chemical 6]

<Example 6> Calixarene derivative /
Preparation of carboxylic acid complex 223 mg (0.2
5 mmol) and 1 mmol of various carboxylic acids were dissolved in 2 ml of chloroform, and the mixture was heated under reduced pressure to completely distill off chloroform to obtain a complex as shown in Table 1.

[0028]

[Table 1]

Preparation Example 7 Preparation of Comparative Compound [Chemical Formula 6] / Decanoic Acid Complex [Compound 14] 211 mg (1 mmol) of the comparative compound [Chemical Formula 6] and 172 mg (1 mmol) of decanoic acid were dissolved in 2 ml of chloroform. After that, the chloroform was distilled off completely by heating under reduced pressure.

<Physical Property Measurement Example 1> Complex [Complex 1]
[Compound 14] and thermal analysis of decanoic acid Complex [Compound 1] obtained in Production Examples 6 and 7,
[Compound 14] and decanoic acid were weighed in a quantity of several mg each in a 15 μl sealed cell made of Ag, and the temperature rising rate was 1.0 ° C./mi.
n. DSC measurement was performed in the range of -30 ° C to 130 ° C (Seiko, DSC120). In [Complex 1], which is a complex of the calixarene derivative and decanoic acid, the endothermic peaks due to the decanoic acid and the calixarene derivative disappear, and heat is not input or output over the entire temperature range. On the other hand, two large endothermic peaks were observed in the [Compound 14] which is a complex of the comparative compound [Chemical Formula 6] and decanoic acid, and the low temperature side peak was the melting of decanoic acid containing [Chemical Formula 6] The peak on the side is probably due to the melting of [Chemical Formula 6] containing decanoic acid, and it is presumed that the system undergoes phase separation. This indicates that [Complex 1] is a complex showing a completely new thermophysical property as in the present invention, and that it is still a mixture in Comparative Example [Complex 14] ( (Fig. 2). Furthermore, in microscopic observation using a thermo stage, [Complex 1] maintained fluidity up to around -30 ° C and exhibited fluid birefringence in the range of -30 ° C to room temperature.
This indicates that the present invention [Compound 1] functions as a device such as a pressure sensor in a very wide range.

<Physical Property Measurement Example 2> Complex [Complex 2]
~ Thermal analysis of [compound 13] Complex [compound 2] obtained in Production Example 6 ~ [compound 13]
DSC measurement and microscopic observation were performed. [Duplicate 3],
[Complex 4] and [Complex 5] showed endothermic peaks at low temperature in DSC measurement, but no clear peaks were observed in other complexes, and in all complexes, the original carboxylic acid and calix The endothermic peak of the arene derivative has disappeared, clearly showing the complexing effect. The fluidization temperature of the complex by microscopic observation using a thermo stage is shown in Table 2 below. The flow birefringence phenomenon was observed in all the complexes.

[0032]

[Table 2]

<Physical property measurement example 3> In order to clarify the characteristics of the calixarene derivative / carboxylic acid complex of the present invention, an observation experiment of flow birefringence was conducted. This observation can be easily performed with an optical microscope under direct polarized light. This flow birefringence phenomenon is considered to be because the calixarene derivative / carboxylic acid complex of the present invention has an elongated molecular structure, and therefore molecular orientation occurs along the flow generated by the load of external stress. Further, the birefringence due to the flow disappears with the lapse of time when the application of the external stress is stopped, but this is temperature dependence because of the molecular motion of the calixarene derivative / carboxylic acid complex. Therefore, the appearance and elimination behavior of flow birefringence at several temperatures were observed as follows.

The flow birefringence can be observed by sandwiching the sample between two glass plates and shifting the glass plates with a constant force. At this time, when the vibrating surfaces of the two polarizing plates of the microscope are directly illuminated, the dark field is obtained when the sample is isotropic, and the field becomes brighter when anisotropy occurs in the sample. The change in brightness of this visual field was measured by an exposure meter. The time required to return to the dark field was defined as the birefringence elimination time, with the stress being 60 times as bright as the dark field. The results are shown in Table 3.

[0035]

[Table 3] ・ Sample: Complex [Complex 1]

From the above observation, the complex of the present invention is a pressure sensor capable of operating even at an extremely low temperature,
It is shown that it can be applied as a display, a storage element, and the like.

[Brief description of drawings]

FIG. 1 is a production flowchart of a calixarene derivative used in the complex of the present invention.

FIG. 2 DSC of a complex of the present invention and a comparative example
The temperature rising curve is shown.

Claims (1)

[Claims] 1. The following general formula [Chemical formula 1] A complex of a calixarene derivative represented by the formula (wherein n is 4, 6 or 8) and an aliphatic or aromatic carboxylic acid having at least one or more carboxyl groups in the molecule.