WO2019177042A1 - Compound, dispersant, complex, dispersion, and method for producing complex - Google Patents

Abstract

A compound represented by general formula (1). (In formula (1), R1-R3 each are a C1-12 alkyl group or a phenyl group, and X1 - is any anion selected from Cl-, Br-, I-, PF6 -, Tf2N-, BETI-, and TSAC-.)

Description

Compound, dispersant, complex, dispersion, and method for producing complex

The present invention relates to a compound, a dispersant, a composite, a dispersion, and a method for producing the composite.
This application claims priority based on Japanese Patent Application No. 2018-47036 filed in Japan on March 14, 2018, the contents of which are incorporated herein by reference.

Conventionally, oleic acid, oleylamine, citric acid, dopamine, and the like are used as a dispersant for dispersing metal nanoparticles in a solvent. Further, as a dispersant for dispersing metal nanoparticles in a solvent, for example, a particle dispersant described in Patent Document 1 has been proposed. The particle dispersant described in Patent Document 1 has a catechol skeleton that is a structure capable of coordinate bonding with magnetic particles. Patent Document 1 describes water-dispersible magnetic particles in which magnetic particles are coated with a dispersant, and describes metal oxides as the magnetic particles.

CoFe ₂ O ₄ nanoparticles, which are metal nanoparticles, have properties as a supermagnetic material or a ferromagnetic material. CoFe ₂ O ₄ nanoparticles can impart magnetic properties to the medium by mixing with the medium that does not have magnetic properties.
CoFe ₂ O ₄ nanoparticles are used in magnetic tapes, hard disks, magnetic switches, and the like.

JP 2008-69092 A

However, conventional dispersants cannot be used in a wide range of solvents.
Further, CoFe ₂ O ₄ nanoparticles have a strong absorption in the visible light region and are brown. Therefore, conventionally, a material in which CoFe ₂ O ₄ nanoparticles are mixed with a medium is brown, and its usage is limited.

This invention is made | formed in view of the said situation, and makes it a subject to provide the compound which can be used suitably as a dispersing agent which disperse | distributes a metal nanoparticle to a wide range solvent, and a dispersing agent containing this.
The present invention also relates to a composite of the above compound and CoFe ₂ O ₄ nanoparticles, which can be dispersed in a wide range of solvents, a method for producing the composite, and a composite that is dispersed in a solvent. It is an object to provide a dispersion liquid.

[1] A compound represented by the following general formula (1).

（式（１）中のＲ^１～Ｒ^３は、それぞれ炭素数１～１２のアルキル基またはフェニル基である。Ｘ_１ ^－は、Ｃｌ^－、Ｂｒ^－、Ｉ^－、ＰＦ_６ ^－、Ｔｆ_２Ｎ^－、ＢＥＴＩ^－、ＴＳＡＣ^－から選ばれるいずれかの陰イオンである。）

(In the formula (1), R ¹ to R ³ are each an alkyl group or phenyl group having 1 to 12 carbon atoms. X ₁ ^- represents Cl ⁻ , Br ⁻ , I ⁻ , PF ₆ ⁻ , Tf ₂ N ^-, BETI ^-, TSAC ^- is any anion selected from).

[2] the above formula (1) in _{X 1} ^- is Cl ^- A compound according to a [1].
[3] The compound according to [1] or [2], wherein R ¹ to R ³ in the formula (1) are all n-butyl groups.

[4] A dispersant for dispersing metal nanoparticles in a solvent,
[1] A dispersant containing the compound according to any one of [3].

[5] A complex of metal oxide nanoparticles and a compound, represented by the following general formula (2).

（式（２）中、Ａは金属酸化物である。Ｒ^５～Ｒ^７は、それぞれ炭素数１～１２のアルキル基またはフェニル基である。Ｘ_２ ^－は、Ｃｌ^－、Ｂｒ^－、Ｉ^－、ＰＦ_６ ^－、Ｔｆ_２Ｎ^－、ＢＥＴＩ^－、ＴＳＡＣ^－から選ばれるいずれかの陰イオンである。）

(In the formula (2), A is a metal oxide. R ⁵ to R ⁷ are each an alkyl group having 1 to 12 carbon atoms or a phenyl group. X ₂ ⁻ is Cl ⁻ , Br ⁻ , I ^−. , PF ₆ ⁻ , Tf ₂ N ⁻ , BETI ⁻ , TSAC ⁻ .

[6] The composite according to [5], wherein the metal oxide is any one selected from CoFe ₂ O ₄ , Fe ₂ O ₃ , TiO ₂ , and ZnO.
[7] The composite according to [5], wherein the metal oxide is CoFe ₂ O ₄ .

A composite according to any one of a ^{[5] ~ [7] -} [8] X 2 in the formula (2) ^- is Cl.
[9] The composite according to any one of [5] to [8], wherein R ⁵ to R ⁷ in the formula (2) are all n-butyl groups.

[10] A dispersion, wherein the complex according to any one of [5] to [9] is dispersed in a solvent.
[11] The dispersion according to [10], wherein the solvent has a relative dielectric constant at 25 ° C. of 4.8 to 80.

[12] A washing step of washing the CoFe ₂ O ₄ nanoparticles with alcohol;
And a reaction step of reacting the washed CoFe ₂ O ₄ nanoparticles with the compound according to any one of [1] to [3] in the presence of oleylamine to form a complex. A method for producing a composite.

The compound of the present invention is bonded to metal nanoparticles by two hydroxyl groups (—OH) of the catechol skeleton and has an organic phosphonium ion. For this reason, the compound of this invention can be conveniently used as a dispersing agent which disperse | distributes a metal nanoparticle to a wide range solvent.
The complex of the present invention is a complex in which two hydroxyl groups (—OH) of a catechol skeleton are bonded to CoFe ₂ O ₄ nanoparticles and have an organic phosphonium ion. For this reason, the composite of the present invention can be dispersed in a wide range of solvents.

3 is a graph showing the results of ¹ H-NMR measurement of Compound A. 2 is a photograph showing the results of agarose gel electrophoresis of the nanoparticles of Example 1. FIG. Compound is a transmission electron micrograph of a complex between A and CoFe ₂ O ₄ nanoparticles. It is a transmission electron micrograph of CoFe ₂ O ₄ nanoparticles coated with oleic acid and oleylamine. It is a spectrum which shows the result of having measured the light absorbency of the dispersion liquid which disperse | distributed the nanoparticle of Example 1 in the solvent. It is a spectrum which shows the result of having measured the light absorbency of the dispersion liquid which disperse | distributed the nanoparticle of Example 1 in the solvent. It is a spectrum which shows the result of having measured the light absorbency of the dispersion liquid which disperse | distributed the nanoparticle of Example 1 in the solvent. It is a spectrum which shows the result of having measured the light absorbency of the dispersion liquid which disperse | distributed the nanoparticle of Example 1 in the solvent. 4 is a photograph of a dispersion liquid in which the composite of Example 2 is dispersed in solvents 1 to 7. 4 is a photograph of a dispersion liquid in which the composite of Example 3 was dispersed in solvents 1 to 7. 4 is a photograph of a dispersion liquid in which the composite of Example 4 is dispersed in solvents 1 to 7. 2 is a transmission electron micrograph of the composite of Example 2. 4 is a transmission electron micrograph of the composite of Example 3. 4 is a transmission electron micrograph of the composite of Example 4. The dispersion of the composite of Example 5 is a photograph of a dispersion of CoFe ₂ O ₄ nanoparticles coated with oleic acid. The dispersion of the composite of Example 5, a spectrum showing a result of measuring the absorbance of the dispersion of CoFe ₂ O ₄ nanoparticles coated with oleic acid. 6 is a photograph of a dispersion in which the composite of Example 5 is dispersed in solvents 11 to 20.

Hereinafter, the compound of the present invention, the dispersant, the composite, the dispersion, and the method for producing the composite will be described in detail.
<Compound>
In order to solve the above-mentioned problems, the present inventor has made extensive studies.
As a result, it has been found that a compound having an organic phosphonium ion bonded to metal nanoparticles by two hydroxyl groups (—OH) having a catechol skeleton can be used as a dispersant for dispersing the metal nanoparticles in a wide range of solvents. Completed the invention.

The compound of this embodiment is represented by the following general formula (1).

（式（１）中のＲ^１～Ｒ^３は、それぞれ炭素数１～１２のアルキル基またはフェニル基である。Ｘ_１ ^－は、Ｃｌ^－、Ｂｒ^－、Ｉ^－、ＰＦ_６ ^－、Ｔｆ_２Ｎ^－、ＢＥＴＩ^－、ＴＳＡＣ^－から選ばれるいずれかの陰イオンである。）

(In the formula (1), R ¹ to R ³ are each an alkyl group or phenyl group having 1 to 12 carbon atoms. X ₁ ^- represents Cl ⁻ , Br ⁻ , I ⁻ , PF ₆ ⁻ , Tf ₂ N ^-, BETI ^-, TSAC ^- is any anion selected from).

R ¹ to R ³ in the formula (1) are each an alkyl group having 1 to 12 carbon atoms or a phenyl group. The alkyl group having 1 to 12 carbon atoms used as R ¹ to R ³ may be linear, branched or cyclic. In the formula (1), R ¹ to R ³ are all preferably n-butyl groups in order to enhance the amphiphilicity of the compound represented by the general formula (1).

X ₁ ⁻ in the formula (1) is Cl ⁻ , Br ⁻ , I ⁻ , hexafluorophosphate (PF ₆ ⁻ ), bis (trifluoromethanesulfonyl) imide (Tf ₂ N ⁻ ), bis (perfluoroethylsulfonyl). And an anion selected from imide (BETI ⁻ ) and (2,2,2-trifluoro-N- (trifluoromethanesulfonyl) acetamide (TSAC ⁻ ), wherein X ₁ ⁻ in formula (1) is Cl ⁻ is preferred because it is a standard anion.
In the compound represented by the formula (1), depending on the type of solvent for dispersing metal nanoparticles, X ₁ ^- is preferable to appropriately select.

The method for producing the compound represented by the formula (1) can be appropriately determined according to R ¹ to R ³ and X ₁ in the formula (1), and is not particularly limited.
Examples of the method for producing the compound represented by the formula (1) include a method in which an organic phosphonium ion is covalently bonded to acrylic dopamine.

Specific examples include a method of reacting a reaction product obtained by reacting acrylic dopamine and organic phosphonium under acidic conditions with a compound that produces a desired anion.
As the organic phosphonium to be reacted with acrylic dopamine, an organic phosphonium having an organic group corresponding to R ¹ to R ³ in the formula (1) is used. For example, when producing a compound in which R ¹ to R ³ in formula (1) are all n-butyl groups, tributylphosphine is used.
Hydrochloric acid is mentioned as a compound which produces | generates a desired anion. When producing a compound in which X ₁ in formula (1) is Cl 2 ^— , it is preferable to use hydrochloric acid.

When producing the compound other than, for example, X ₁ is Cl ^{- -} X ₁ is Cl with a compound in which can be prepared a compound represented by the formula (1) by the following method. That, X ₁ is Cl ^- in which the compound was dissolved in chloroform and the chloroform solution. This chloroform solution, the lithium salt containing the desired anion, X ₁ is Cl ^-, compound and was added in equal amounts to the reaction solution. Thereafter, the reaction solution can be produced, for example, by heating at 60 ° C. for 2 hours and removing by-product lithium chloride using an equal amount of water to the reaction solution.

The compound represented by the formula (1) is a dispersant that binds to metal nanoparticles by two hydroxyl groups (—OH) having a catechol skeleton and disperses the metal nanoparticles in a wide range of solvents by having organic phosphonium ions. Can be used as Specifically, the compound represented by the formula (1) can be used as a dispersant for dispersing metal nanoparticles in a wide range of solvents (relative permittivity of 4.8 to 80 at 25 ° C.).

<Dispersant>
The dispersing agent of this embodiment is a dispersing agent which disperse | distributes a metal nanoparticle to a solvent, and contains the compound represented by Formula (1).
The metal nanoparticles in the present embodiment preferably have a particle size in the range of 10 to 50 nm, and more preferably in the range of 15 to 30 nm. When the particle size of the metal nanoparticles is in the range of 10 to 50 nm, by dispersing in a solvent, the magnetic material can be preferably used in various products such as magnetic tapes, hard disks, and magnetic switches.
The particle size of the metal nanoparticles in the present embodiment means an average particle size measured by a dynamic light scattering method using an ultraviolet / visible absorption spectrum method (UV-VIS spectrum method) in a state of being dispersed in a solvent. .

In the dispersant of this embodiment, examples of the metal nanoparticles dispersed in the solvent include transition metal oxides such as CoFe ₂ O ₄ , CuO, Fe ₃ O ₄ , Fe ₂ O ₃ , TiO ₂ , and ZnO, titanium, Examples thereof include nanoparticles made of metals such as gold and silver. Said metal nanoparticles may be disperse | distributed individually by 1 type, and may be used in mixture of 2 or more types.

In the dispersant of the present embodiment, as the solvent for dispersing the metal nanoparticles, a solvent having a relative dielectric constant of 4.8 to 80 at 25 ° C. is preferably used, and a solvent having a relative dielectric constant of 4.8 to 70 is used. It is more preferable.
Specifically, dimethyl sulfoxide (DMSO) (relative permittivity at 25 ° C .; 48.9), ethylene glycol (EG) (relative permittivity at 25 ° C .; 38.7), N, N— Dimethylformamide (DMF) (relative permittivity at 25 ° C .; 38), acetonitrile (ACN) (relative permittivity at 25 ° C .; 37), acetone (ACE) (relative permittivity at 25 ° C .; 21), tetrahydrofuran (THF) (relative permittivity at 25 ° C .; 7.5), chloroform (CHL) (relative permittivity at 25 ° C .; 4.8), isopropanol (ISO) (relative permittivity at 25 ° C .; 18) Ethanol (eta) (dielectric constant at 25 ° C .; 24), methanol (met) (dielectric constant at 25 ° C .; 33), water (H ₂ O) (dielectric constant at 25 ° C .; 80) Etc. can be used. Said solvent may be used individually by 1 type, and may be used in mixture of 2 or more types.

<Composite>
The composite of this embodiment is a composite of a metal oxide nanoparticle and a compound represented by formula (1), and is represented by the following general formula (2).

（式（２）中、Ａは金属酸化物である。Ｒ^５～Ｒ^７は、それぞれ炭素数１～１２のアルキル基またはフェニル基である。Ｘ_２ ^－は、Ｃｌ^－、Ｂｒ^－、Ｉ^－、ＰＦ_６ ^－、Ｔｆ_２Ｎ^－、ＢＥＴＩ^－、ＴＳＡＣ^－から選ばれるいずれかの陰イオンである。）

(In the formula (2), A is a metal oxide. R ⁵ to R ⁷ are each an alkyl group having 1 to 12 carbon atoms or a phenyl group. X ₂ ⁻ is Cl ⁻ , Br ⁻ , I ^−. , PF ₆ ⁻ , Tf ₂ N ⁻ , BETI ⁻ , TSAC ⁻ .

In the formula (2), the metal oxide represented by A is preferably any one selected from CoFe ₂ O ₄ , Fe ₂ O ₃ , TiO ₂ , and ZnO, and particularly CoFe ₂ O _4. preferable.
A complex of any one kind of metal oxide selected from CoFe ₂ O ₄ , Fe ₂ O ₃ , TiO ₂ and ZnO and the compound represented by the formula (1) can be dispersed in a wide range of solvents.

The composite of this embodiment is preferably a composite of CoFe ₂ O ₄ nanoparticles and a compound represented by formula (1).

R ⁵ to R ⁷ in the formula (2) are each an alkyl group having 1 to 12 carbon atoms or a phenyl group. The alkyl group having 1 to 12 carbon atoms used as R ⁵ to R ⁷ may be linear, branched or cyclic. In formula (2), R ⁵ to R ⁷ are all preferably n-butyl groups in order to increase the amphipathic properties of the complex represented by the general formula (2).
X ₂ ⁻ in the formula (2) is any anion selected from Cl ⁻ , Br ⁻ , I ⁻ , PF ₆ ⁻ , Tf ₂ N ⁻ , BETI ⁻ , TSAC ⁻ and in the formula (1) and similarly, Cl ^{- -} _{X 1} are preferred.

<Method for producing composite>
Examples of the method for producing the composite represented by the formula (2) include a dispersion in which metal oxide nanoparticles are dispersed in a solvent, and a dispersant in which the compound represented by the formula (1) is dissolved in the solvent. And metal nanoparticles are bonded to the two hydroxyl groups (—OH) of the catechol skeleton of the compound represented by the formula (1).

The complex of this embodiment is a complex in which two hydroxyl groups (—OH) of a catechol skeleton are bonded to metal oxide nanoparticles and have an organic phosphonium ion. For this reason, the composite of this embodiment can be dispersed in a wide range of solvents.

As the metal oxide nanoparticles, in the case of producing a composite comprising a CoFe ₂ O ₄ nanoparticles, it is preferable to use a manufacturing method described below.
First, CoFe ₂ O ₄ nanoparticles coated with an acetic acid compound are prepared. As the acetic acid compound, for example, oleic acid, nonadecanoic acid, butyric acid, hexanoic acid and the like can be used, and oleic acid is preferably used from the viewpoint of the affinity of the solvent.
CoFe ₂ O ₄ nanoparticles coated with an acetic acid compound can be produced by a conventionally known method.

Next, the CoFe ₂ O ₄ nanoparticles coated with the acetic acid compound are washed with alcohol (cleaning step). Examples of the alcohol used in the washing step include methanol and / or ethanol.
Next, the CoFe ₂ O ₄ nanoparticles coated with the acetic acid compound after washing and the compound represented by the formula (1) are reacted in the presence of oleylamine to form a complex (reaction process).
By performing the above steps, a composite of CoFe ₂ O ₄ nanoparticles and the compound represented by formula (1) is obtained.

The composite of the CoFe ₂ O ₄ nanoparticles thus obtained and the compound represented by the formula (1) can be dispersed in a wide range of solvents. Moreover, this composite is preferable because it does not color the dispersion in which it is dispersed in a solvent.

<Dispersion>
The dispersion of this embodiment is a dispersion of the composite of this embodiment in a solvent.
In the dispersion liquid of the present embodiment, it is preferable to use a solvent having a relative dielectric constant of 4.8 to 80 at 25 ° C. as the solvent for dispersing the composite. Specifically, the metal nanoparticles in the above-described dispersant are used. The thing similar to what was mentioned as a solvent to disperse can be used.

The color of the dispersion liquid of the present embodiment varies depending on the relative dielectric constant of the solvent. Specifically, the higher the relative dielectric constant of the solvent of the dispersion liquid, the larger the maximum absorption wavelength of the spectrum measured using the ultraviolet / visible absorption spectrum method (UV-VIS spectrum method).

The dispersion liquid of the present embodiment may be any dispersion liquid of the complex of the present embodiment in a solvent. For example, tetrabutylphosphonium chloride (TC) may be used in addition to the complex of the present embodiment and the solvent. It may be included.
By containing tetrabutylphosphonium chloride (TC) in the dispersion, the color of the dispersion can be changed.

As mentioned above, although embodiment of this invention was described, this invention is not limited to this, It can change suitably in the range which does not deviate from the technical idea of the invention.

"Synthesis of compounds"
3-Hydroxytyramine hydrochloride (10.0 g, 52.8 mmol) and triethylamine (7.31 mL, 52.7 mmol) were dissolved in methanol (100 mL) to obtain a raw material solution.
Next, while the raw material solution was cooled on an ice bath and maintained at pH 9, a mixed solution of triethylamine (11.0 mL, 79.1 mmol), acryloyl chloride (5.11 mL, 63.2 mmol) and methanol (11 mL) , Tetrahydrofuran (5 mL) were added dropwise alternately, and the mixture was stirred at room temperature for 1 hour to be reacted.

The solvent was removed from the solution after the reaction under vacuum, and the residue was dissolved in ethyl acetate and washed with 1 mol / L hydrochloric acid and brine (saturated sodium chloride aqueous solution). Sodium sulfate was added to the washed solution to dry the organic layer, followed by filtration to remove sodium sulfate. The dried solution (filtrate) was evaporated and concentrated to obtain acrylic dopamine.

The acrylic dopamine (3 g, 14.4 mmol) thus obtained was dissolved in dioxane (20 mL), acetic acid (1.73 g, 28.8 mmol (density 1.05 g / cm ³ , 1.64 mL)), Tributylphosphine (2.91 g, 14.4 mmol, 3.64 mL) was added and reacted at room temperature for 1 hour.
1 mol / L hydrochloric acid (30 mL) was added to the solution after the reaction, washed twice with hexane (30 mL), extracted twice with chloroform (30 mL), and the solvent was removed under reduced pressure using an evaporator. The residue is dissolved in a mixed solution of methanol (20 mL) and 1 mol / L hydrochloric acid (20 mL), kept at 80 ° C. for 3 hours, the solvent is removed under reduced pressure using an evaporator, and the target compound is a white solid compound A was obtained (70% yield).

"Identification of compounds"
The compound A thus obtained was subjected to ¹ H-NMR measurement, and the structure was identified from the results shown in FIG. As a result, the compound A is a compound represented by the formula (1) (wherein R ¹ to R ³ in the formula (1) are all n-butyl groups and X ₁ ^— is Cl 2 ^— ). I was able to confirm.

"Manufacture of composites"
Example 1
CoFe ₂ O ₄ nanoparticles (500 mg) coated with oleylamine were dissolved in chloroform (200 mL), and a dispersant (20 mL) was added using a syringe. As the dispersant, a compound in which Compound A was dissolved in chloroform at a concentration of 100 mg / mL was used. The solution to which the dispersant was added was stirred at 50 ° C. for 24 hours at a rotation speed of 500 rpm using a stirrer. Thereafter, chloroform was removed under reduced pressure using an evaporator until the amount of the solution reached 10 mL.

When this solution was put in a 50 mL conical tube (manufactured by Falcon) together with 30 mL of hexane, a red-purple precipitate was formed. This operation was repeated three times. Thereafter, the precipitate is put into a mixed solution of chloroform (50 mL) and water (100 mL), liquid-liquid separated, water is removed from the aqueous layer under reduced pressure using an evaporator, and the target nanoparticle of Example 1 is obtained. Obtained.

The nanoparticles of Example 1 thus obtained were subjected to agarose gel electrophoresis by the method shown below.
An agarose gel is prepared by adding 1% by weight of agarose to tris, acetic acid, and ethylenediaminetetraacetic acid buffer (TAE buffer). Next, nanoparticles dispersed in a 20% aqueous glycerol solution are added to the prepared agarose gel and a voltage is applied. As a result, the nanoparticles move to the negative electrode side. The result is shown in FIG.

As shown in FIG. 2, the nanoparticles of Example 1 were electrophoresed by agarose gel electrophoresis. Therefore, in the nanoparticle of Example 1, for example, agarose gel electrophoresis can be used as a method for separating the particle size of the nanoparticle.
Moreover, the surface of the composite in which the surface of CoFe ₂ O ₄ nanoparticles is coated with compound A is positively charged. The nanoparticles of Example 1 migrated in the positive to negative direction. From this, it can be said that the nanoparticles of Example 1 are a composite in which the surface of CoFe ₂ O ₄ nanoparticles is coated with Compound A.

(Comparative Example 1)
In an eggplant flask, diphenyl ether (30 mL), tris (2,4-pentandionato) iron (III) (0.353 g), and bis (2,4-pentandionato) cobalt (II) (0.129 g) And oleic acid (3.808 mL) were added to obtain a metal particle solution. The metal particle solution was heated at 180 ° C. for 24 hours using an oil bath and cooled to room temperature. The cooled metal particle solution (10 mL) was placed in a recovery flask together with a stirrer chip, and dehydrated by heating at 180 ° C. for 30 minutes with stirring.

Diphenyl ether (30 mL) was heated at 180 ° C. for 30 minutes using an oil bath to remove water in diphenyl ether. Into the eggplant flask, diphenyl ether (30 mL) from which water has been removed, oleic acid (0.5 mL), and oleylamine (3.0 mL) are placed together with a stirrer chip. It was heated at 180 ° C for 1.5 hours using a bath and cooled to room temperature.

To the cooled solution, 3 times the amount of methanol was added and centrifuged at a rotational speed of 5000 rpm for 5 minutes to obtain a precipitate. The supernatant was discarded, and the precipitate was washed with methanol, dispersed in chloroform, and centrifuged at a rotational speed of 7000 rpm for 5 minutes. The supernatant was removed from the solution after centrifugation to obtain nanoparticles (precipitates) of Comparative Example 1 as the target product.

"Dispersibility of complex"
The nanoparticles of Example 1 (complex of Compound A and CoFe ₂ O ₄ nanoparticles) thus obtained and the nanoparticles of Comparative Example 1 (CoFe ₂ O ₄ nanoparticles coated with oleic acid and oleylamine) were obtained. ) Were observed with a transmission electron microscope (TEM) by the following methods. The results are shown in FIGS. The TEM grit was prepared by drop-casting nanoparticles dispersed in methanol onto elastic carbon.

FIG. 3 is a transmission electron micrograph of a complex of Compound A and CoFe ₂ O ₄ nanoparticles. FIG. 4 is a transmission electron micrograph of CoFe ₂ O ₄ nanoparticles coated with oleic acid and oleylamine.
The composite of Compound A and CoFe ₂ O ₄ nanoparticles shown in FIG. 3 has less aggregation and good dispersibility than the CoFe ₂ O ₄ nanoparticles coated with oleic acid and oleylamine shown in FIG. It was confirmed that there was.

"Composite dispersion"
The nanoparticles of Example 1 (complex of compound A and CoFe ₂ O ₄ nanoparticles) were each dispersed in the following solvent so as to have a concentration of 80 mg / ml. As a result, the nanoparticles of Example 1 could be dispersed in any solvent, and a dispersion was obtained.

(solvent)
Dimethyl sulfoxide (DMSO), dielectric constant at 25 ° C .; 48.9
Ethylene glycol (EG), dielectric constant at 25 ° C .; 38.7
N, N-dimethylformamide (DMF), relative permittivity at 25 ° C .; 38
Acetonitrile (ACN), relative permittivity at 25 ° C .; 37
Acetone (ACE), relative permittivity at 25 ° C .; 21
Tetrahydrofuran (THF), dielectric constant at 25 ° C .; 7.5
Chloroform (CHL), relative dielectric constant at 25 ° C .; 4.8
Isopropanol (ISO), dielectric constant at 25 ° C .; 18
Ethanol (eta), dielectric constant at 25 ° C .; 24
Methanol, relative dielectric constant at 25 ° C .; 33
Water (H ₂ O), relative dielectric constant at 25 ° C .; 80

"Dispersion color"
The nanoparticles of Example 1 are placed in dimethyl sulfoxide (DMSO), N, N-dimethylformamide (DMF), acetonitrile (ACN), acetone (ACE), isopropanol (ISO), ethanol (eta), methanol (met). The dispersion was dispersed to give a concentration of 80 mg / ml. The absorbance of each dispersion was measured using an ultraviolet / visible absorption spectrum method (UV-VIS spectrum method). The results are shown in FIG. 5 and FIG.

As shown in FIG. 5 and FIG. 6, the dispersions in which the nanoparticles of Example 1 (complex of compound A and CoFe ₂ O ₄ nanoparticles) were dispersed in the above-described solvents respectively had different spectral shapes. It has a peak (maximum absorption wavelength) at different wavelengths of 350 to 570 nm. From this, it was confirmed that the nanoparticles of Example 1 can be dispersed in a wide range of solvents, and various colors from magenta to green (350 to 570 nm) can be added to the medium.
In addition, it can be seen that in the dispersion liquid in which the nanoparticles of Example 1 are dispersed in the solvent, the maximum absorption wavelength of the spectrum tends to increase as the relative dielectric constant of the solvent increases.

"Relationship between additive and dispersion color"
Tetrabutylphosphonium chloride (TC) as an additive was added to a dispersion obtained by dispersing the nanoparticles of Example 1 in chloroform (CHL) as a solvent so as to have a concentration of 80 mg / ml. Then, liquids added with 5 mg, 10 mg, 20 mg, 40 mg, and 80 mg were prepared, and the absorbance of each liquid was measured using the absorbance measurement method described above. The results are shown in FIG. 7 together with the absorbance of the dispersion (0 mg) to which no additive was added.
As shown in FIG. 7, it can be understood that the maximum absorption wavelength of the spectrum becomes smaller and the color of the liquid tends to become transparent as the content of the additive increases.

Moreover, the dispersion liquid of Comparative Example 1 was prepared by dispersing the nanoparticles of Comparative Example 1 (CoFe ₂ O ₄ nanoparticles coated with oleic acid and oleylamine) at a concentration of 80 mg / ml in chloroform. And the light absorbency of the dispersion liquid of the comparative example 1 was measured using the light absorbency measuring method mentioned above. The results are shown in FIG. 8 together with the absorbance of the dispersion (0 mg) to which the additive shown in FIG. 7 was not added and the absorbance of the liquid in which 80 mg of tetrabutylphosphonium chloride (TC) was added to 1 mL of the dispersion.
As shown in FIG. 8, the absorbance of the dispersion of Comparative Example 1, the absorbance of the dispersion without addition of the additive (0 mg), and the absorbance of the liquid added with 80 mg of TC showed different spectral shapes. .

"Manufacture of composites"
(Example 2)
0.1 g of iron oxide (Fe ₂ O ₃ ) as metal oxide nanoparticles and 10 g of sodium chloride were weighed into a 100 mL glass vial, and 10 mL of water was added to obtain a mixed solution. The obtained mixed solution was irradiated with ultrasonic waves of 45 Hz for 100 minutes, transferred to a 50 mL conical tube (manufactured by Falcon), added with 40 mL of water, centrifuged at 16000 g of relative centrifugal force (RCF), and the supernatant was obtained. Removed. Thereafter, 40 mL of water was added to the precipitate separated by centrifugation, and centrifugation was performed at 16000 g of relative centrifugal force (RCF), and the supernatant was removed three times.

Next, the precipitate separated by centrifugation and 1 g of the compound A dissolved in 50 mL of water were mixed, put into a 100 ml eggplant flask, and reacted by heating at 80 ° C. for 3 hours.
The reaction solution after the reaction was transferred again to a 50 mL conical tube, centrifuged at 16000 g of relative centrifugal force (RCF), and the supernatant was removed. Thereafter, 40 mL of water was added to the precipitate separated by centrifugation, and centrifugation was performed at 16000 g of relative centrifugal force (RCF), and the supernatant was removed three times.
Thereafter, a complex of iron oxide (Fe ₂ O ₃ ) nanoparticles and Compound A was obtained as a precipitate separated by centrifugation.

The complex of Example 2 obtained in this way was dispersed in the following solvents 1 to 7 so that the concentration would be 1 mg / ml. The result is shown in FIG.
FIG. 9 is a photograph of a dispersion obtained by dispersing the composite of Example 2 in solvents 1-7. As shown in FIG. 9, the composite of Example 2 could be dispersed in any solvent, and a transparent dispersion was obtained. Further, as shown in FIG. 9, since iron oxide (Fe ₂ O ₃ ) nanoparticles did not precipitate and a transparent dispersion liquid was obtained, in Example 2, iron oxide (Fe ₂ O ₃ ) nanoparticles were obtained. Can be said to form a complex with Compound A.

(solvent)
Solvent 1. 1. Aqueous solvent 2. Dimethyl sulfoxide solvent NN dimethylformamide solvent 4. 4. Methanol solvent Ethanol solvent6. 6. chloroform solvent Isopropanol

(Example 3)
A composite of titanium oxide (TiO ₂ ) nanoparticles and Compound A was obtained in the same manner as in Example 2 except that titanium oxide (TiO ₂ ) was used as the metal oxide nanoparticles.

The composite of Example 3 thus obtained was dispersed in each of the above solvents 1 to 7 in the same manner as the composite of Example 2. The result is shown in FIG.
FIG. 10 is a photograph of a dispersion obtained by dispersing the composite of Example 3 in solvents 1-7. As shown in FIG. 10, the composite of Example 3 could be dispersed in any solvent, and a transparent dispersion was obtained. Further, as shown in FIG. 10, since titanium oxide (TiO ₂ ) nanoparticles did not precipitate and a transparent dispersion liquid was obtained, in Example 3, titanium oxide (TiO ₂ ) nanoparticles were combined with Compound A. It can be said that a complex is formed.

Example 4
A composite of zinc oxide (ZnO) nanoparticles and compound A was obtained in the same manner as in Example 2 except that zinc oxide (ZnO) was used as the metal oxide nanoparticles.

The composite of Example 4 thus obtained was dispersed in the above solvents 1 to 7 in the same manner as the composite of Example 2. The result is shown in FIG.
FIG. 11 is a photograph of a dispersion obtained by dispersing the composite of Example 4 in solvents 1-7. As shown in FIG. 11, the composite of Example 4 could be dispersed in any solvent, and a transparent dispersion was obtained. Further, as shown in FIG. 11, since zinc oxide (ZnO) nanoparticles did not precipitate and a transparent dispersion liquid was obtained, in Example 4, zinc oxide (ZnO) nanoparticles were combined with compound A. It can be said that it forms.

Further, the composites of Examples 2 to 4 were observed with a transmission electron microscope (TEM). The results are shown in FIGS.
FIG. 12 is a transmission electron micrograph of the composite of Example 2. FIG. 13 is a transmission electron micrograph of the composite of Example 3. FIG. 14 is a transmission electron micrograph of the composite of Example 4.
As shown in FIGS. 12 to 14, it was confirmed that the composites of Examples 2 to 4 had good dispersibility.

(Example 5)
CoFe ₂ O ₄ nanoparticles coated with oleic acid were placed in a 50 mL conical tube (manufactured by Falcon), 40 mL of methanol was added, and the supernatant was removed by centrifugation at 5000 g of relative centrifugal force (RCF). Thereafter, 40 mL of ethanol was added to the precipitate separated by centrifugation, centrifugation was performed at a relative centrifugal force (RCF) of 5000 g, and the supernatant was removed five times (washing step).

Next, the precipitate separated by centrifugation is dispersed in 50 mL of chloroform and placed in a 100 mL eggplant flask. Further, 0.17 g of the above compound A and 0.408 g of oleylamine are added, and 3 ° C. is added at 60 ° C. The reaction was conducted by heating for a period of time (reaction process).
After the reaction, 25 mL of the reaction solution was transferred to a 50 mL conical tube, 25 mL of hexane was added, and centrifugation was performed at 7000 g of relative centrifugal force (RCF), and the supernatant was removed. Thereafter, an operation of adding 40 mL of acetonitrile to the precipitate separated by centrifugation, centrifuging with a relative centrifugal force (RCF) of 10,000 g, and removing the supernatant was repeated twice.
Thereafter, a composite of cobalt ferrite (CoFe ₂ O ₄ ) nanoparticles and compound A was obtained as a precipitate separated by centrifugation.

The composite of Example 5 was dispersed in a solvent consisting of chloroform so that the concentration would be 10 mg / ml to obtain a dispersion. Further, CoFe ₂ O ₄ nanoparticles coated with oleic acid used as a raw material for the composite of Example 5 were dispersed in a solvent composed of chloroform so as to have a concentration of 10 mg / ml to obtain a dispersion.
FIG. 15 is a photograph of the composite dispersion of Example 5 and a dispersion of CoFe ₂ O ₄ nanoparticles coated with oleic acid. As shown in FIG. 15, the dispersion of CoFe ₂ O ₄ nanoparticles coated with oleic acid was dark brown. Further, the dispersion liquid of the composite of Example 5 was transparent.

Further, the absorbances of the dispersion of the composite of Example 5 and the dispersion of CoFe ₂ O ₄ nanoparticles coated with oleic acid were measured using an ultraviolet / visible absorption spectrum method (UV-VIS spectrum method). The result is shown in FIG. As shown in FIG. 16, the dispersion of CoFe ₂ O ₄ nanoparticles coated with oleic acid had high absorbance in a short wavelength region. On the other hand, the dispersion of the composite of Example 5 had low absorbance in any wavelength region.

(Confirmation of magnetic material)
The complex of Example 5 was dispersed in a solvent consisting of chloroform so as to have a concentration of 10 mg / ml to obtain a dispersion, which was placed in a 10 ml test tube. Then, the neodymium magnet was brought close to the test tube until the distance between the test tube and the neodymium magnet became 50 mm and held for 1 minute. As a result, it was confirmed that the test tube was attracted to the neodymium magnet, and it was confirmed that the composite of Example 5 was a magnetic material.

Further, the complex of Example 5 was dispersed in each of the solvents 11 to 20 shown below so that the concentration was 10 mg / ml. The result is shown in FIG.
FIG. 17 is a photograph of a dispersion obtained by dispersing the composite of Example 5 in solvents 11-20. As shown in FIG. 17, the composite of Example 5 could be dispersed in any solvent, and a transparent dispersion was obtained. Further, as shown in FIG. 17, CoFe ₂ O ₄ nanoparticles did not precipitate and a transparent dispersion was obtained. In Example 5, CoFe ₂ O ₄ nanoparticles formed a complex with Compound A. It can be said that.

(solvent)
Solvent 11. 11. Dimethyl sulfoxide solvent Ethylene glycol solvent 13. NN dimethylformamide solvent14. Acetonitrile solvent15. Acetone solvent16. Chloroform solvent 17. Aqueous solvent 18. Ethanol solvent 19. Methanol solvent 20. Isopropanol

Next, the result of dispersing the composite of Compound A and CoFe ₂ O ₄ nanoparticles produced in Example 1 (hereinafter referred to as “complex of Example 1”) in the solvent, The result of examining the difference from the result of dispersing the composite in the solvent will be described.

As described above, the dispersion liquid in which the composite of Example 1 was dispersed in the above solvent had various colors from magenta to green (350 to 570 nm). Further, as shown in FIG. 7, the liquid color tends to become transparent by adding tetrabutylphosphonium chloride (TC) to the dispersion obtained by dispersing the complex of Example 1 in chloroform (CHL). Was seen.

On the other hand, all of the dispersions obtained by dispersing the composite of Example 5 in the above solvent were colorless and transparent as shown in FIG.
This is because the complex of Example 5 was obtained by the production method having the above washing step and the above reaction step, so that the content of impurities produced with the complex was slight. It is estimated that

That is, it is presumed that the composite of Example 1 has a larger content of impurities generated together with the composite at the time of manufacture than the composite of Example 5.
From this, it is presumed that the color added by dispersing the composite of Example 1 in the above-mentioned solvent is due to the impurities generated together with the composite of Example 1. In addition, the liquid color tends to become transparent by adding tetrabutylphosphonium chloride to the dispersion liquid in which the composite of Example 1 was dispersed in chloroform. The reason is as follows. It is estimated that. That is, it is presumed that the impurities generated together with the composite of Example 1 disappeared by the reaction of tetrabutylphosphonium chloride, and the color of the liquid became close to transparent.
From these facts, it is presumed that a dispersion obtained by dispersing impurities in the composite of Example 1 in the above solvent becomes colorless and transparent.

Claims (12)

A compound represented by the following general formula (1).

(In the formula (1), R ¹ to R ³ are each an alkyl group or phenyl group having 1 to 12 carbon atoms. X ₁ ^- represents Cl ⁻ , Br ⁻ , I ⁻ , PF ₆ ⁻ , Tf ₂ N ^-, BETI ^-, TSAC ^- is any anion selected from). Is Cl ^{- -} compound of Claim 1 which is _{X 1} in the formula (1). The compound according to claim 1 or 2, wherein R ¹ to R ³ in the formula (1) are all n-butyl groups. It is a dispersant for dispersing metal nanoparticles in a solvent,
A dispersant comprising the compound according to any one of claims 1 to 3. A complex of metal oxide nanoparticles and a compound, represented by the following general formula (2).

(In the formula (2), A is a metal oxide. R ⁵ to R ⁷ are each an alkyl group having 1 to 12 carbon atoms or a phenyl group. X ₂ ⁻ is Cl ⁻ , Br ⁻ , I ^−. , PF ₆ ⁻ , Tf ₂ N ⁻ , BETI ⁻ , TSAC ⁻ . The composite according to claim 5, wherein the metal oxide is any one selected from CoFe ₂ O ₄ , Fe ₂ O ₃ , TiO ₂ , and ZnO. The composite according to claim 5, wherein the metal oxide is CoFe ₂ O ₄ . Formula (2) X in ₂ ^- is Cl ^- in which composite according to any one of claims 5 to claim 7. The composite according to any one of claims 5 to 8, wherein R ⁵ to R ⁷ in the formula (2) are all n-butyl groups. A dispersion, wherein the complex according to any one of claims 5 to 9 is dispersed in a solvent. The dispersion according to claim 10, wherein the solvent has a relative dielectric constant of 4.8 to 80 at 25 ° C. A cleaning step of cleaning the CoFe ₂ O ₄ nanoparticles with alcohol;
A reaction step of reacting the washed CoFe ₂ O ₄ nanoparticles with the compound according to any one of claims 1 to 3 in the presence of oleylamine to form a complex. A method for producing a complex.

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