JP6513898B2 - Iron amino complex and method for producing the same - Google Patents

Description

  The present invention relates to an iron amino complex and a method for producing the same.

  As a complex in which nitrogen is coordinated to iron, an iron phthalocyanine complex, an iron porphyrin complex, etc. are known. Although these have long been used for pigments, etc., it is known that these complexes, or their fired products, have oxygen reduction activity, and according to Patent Document 1, oxygen reduction of fuel cell electrodes has recently been carried out. Research as a catalyst material is actively conducted.

JP 2012-101155 A JP, 2011-162575, A

  However, phthalocyanine complexes and porphyrin complexes in which nitrogen is coordinated to iron have a problem that there is no appropriate solvent that can be sufficiently dissolved. Therefore, even if it is going to be complexed with other materials, they are separated, so there is a problem that the compounding can not be performed sufficiently or a problem that film thinning is difficult.

  In order to solve this problem, it has also been studied to produce a soluble complex in which nitrogen is coordinated to iron by introducing a t-butyl group into phthalocyanine (see Patent Document 2). However, the complex obtained by such a production method also has problems of insufficient solubility and complicated production method.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a novel iron amino complex and a method for producing the same.

  As a result of repeated studies to solve the above-mentioned problems, the present inventor surprisingly found that an iron compound and a compound having two amino groups and two nitrile groups are dissolved in a solvent and mixed, It has been found that amino complexes can be synthesized, and the present invention has been achieved.

That is, the present invention is as follows.
[1]
An organic electronic material comprising an iron amino complex in which diiminosuccinonitrile is coordinated to anhydrous iron (II) chloride, wherein the solubility of the iron amino complex in methanol is 0.05 to 1.0. Electronic material.
[2]
The organic electronic material according to [1], which is used for a fuel cell electrode.

  According to the present invention, a novel iron amino complex and a method for producing the same can be provided.

5 is a graph showing an ultraviolet-visible absorption spectrum of Example 1; It is a figure which shows the presumed structure which consists of 2 molecules of diaminomaleonitrile and 1 molecule of iron (II) chloride used for simulation of the structure based on first-principles calculation, and an ultraviolet visible absorption spectrum.

  Hereinafter, modes for carrying out the present invention (hereinafter, simply referred to as "the present embodiment") will be described in detail. The present embodiment is an example for explaining the present invention, and the present invention is not limited to only the embodiment. That is, the present invention can be variously modified without departing from the scope of the invention.

[Iron amino complex]
The iron amino complex of the present embodiment is obtained by mixing an iron compound and a compound having two amino groups and two nitrile groups in a solvent. The iron amino complex of the present embodiment may be soluble. The term "soluble" means that the solubility in methanol is preferably 0.005 to 1.0, more preferably 0.01 to 1.0, and still more preferably 0.05 to 1.0. Say By having such solubility, separation at the time of complexing with other materials can be suppressed. It can be suitably used for forming a thin film, etc. The solubility in methanol can be measured by the method described in the examples.

[Fe compounds]
The iron compound is not particularly limited. For example, cyano complex, hydroxy complex, chloro complex, acetylacetonato complex, nitrate, sulfate, acetate, carbonate, oxalate, nitrite, chloride, bromide And iodides or various organic metal compounds. Among these, preferred are cyano complexes, chloro complexes, acetylacetonato complexes, nitrates, chlorides and bromides, and particularly preferred are chlorides, bromides and nitrates.

  Specifically, the iron compound is not particularly limited. For example, ammonium hexacyanoferrate (II) trihydrate, potassium hexacyanoferrate (III) trihydrate, ammonium hexacyanoferrate (III), hexacyano Iron (III) potassium, sodium hexacyanoferrate (II) decahydrate, sodium hexacyanoferrate (III) monohydrate, iron (II) nitrate hexahydrate, iron (III) nitrate nonhydrate, Iron (II) chloride, iron (II) chloride tetrahydrate, iron (III) chloride, iron (III) chloride hexahydrate, iron (II) bromide, iron (II) bromide hexahydrate, Iron (III) bromide, iron (III) bromide hexahydrate, iron (III) thiocyanate, iron (II) carbonate, iron (II) carbonate monohydrate, methyl ammonium hexachloroferrate (III), Tetrachloroferrate (II) acid Lamethylammonium, potassium pentacyanonitrosylferrate (III) dihydrate, potassium hexacyanoferrate (II) iron (III) hydrate, sodium pentacyanonitrosylferrate (III) dihydrate, amminepentacyano Sodium iron (II) trihydrate, sodium aquapentacyanoferrate (II) heptahydrate, iron (II) thiocyanate trihydrate, iron acetate, iron oxalate (III) pentahydrate, Iron (II) oxalate dihydrate, iron (III) citrate citrate trihydrate, iron (II) iodide, iron (II) iodide tetrahydrate, iron (III) sulfate, iron (III) sulfate ) Nitrate hydrate, ammonium tetrachloroferrate (II), iron perchlorate (II) hexahydrate, iron perchlorate (III) hexahydrate, potassium aquapentafluoroferrate (III), sulfuric acid Potassium iron (III Dodecahydrate, bis (sulfato) iron (II) diammonium hexahydrate, tris (sulfate) ferrate (III) sodium trihydrate, iron (III) phosphate dihydrate, iron phosphate (II) octahydrate, iron (II) sulfate heptahydrate and the like. Among these, iron chloride (II), iron chloride (III), iron bromide (II), iron bromide (III) and iron nitrate (III) nonahydrate are preferable.

[Compound Having Two Amino Groups and Two Nitrile Groups]
The compound has two amino groups and two nitrile groups. The amino group is not particularly limited, and examples thereof include -NH ₂ or -NR ¹ R ² and = NR. Here, N is nitrogen, and R ¹ , R ² and R are hydrogen atoms or organic functional groups such as methyl and ethyl. By including at least one member selected from the group consisting of —NH ₂ or —NR ¹ R ² and NRNR as an amino group, the stability of the complex and the solubility of the complex tend to be further improved.

  Although it does not specifically limit as said compound, For example, a diaminomaleonitrile and / or diimino succinonitrile can be illustrated. When the compound contains diaminomaleonitrile and / or diiminosuccinonitrile, the stability of the complex and the solubility of the complex tend to be further improved.

Diaminomaleonitrile, the carbon in the structure - carbon double bonds, two amino (-NH 2), having _two nitrile groups. A commercially available diaminomaleonitrile may be used, or it may be manufactured and used based on a well-known method (For example, refer Unexamined-Japanese-Patent No. 49-126619, Unexamined-Japanese-Patent No. 60-651158 grade | etc.,). Diaminomaleonitrile may be purified by a method such as recrystallization to increase its purity, or may be unpurified.

  Diiminosuccinonitrile has a carbon-carbon single bond, two amino groups (= NH), and two nitrile groups in the structure. Diiminosuccinonitrile can be obtained by oxidizing diaminomaleonitrile. Although the oxidation method is not particularly limited, for example, an oxidizing agent such as 2,3-dichloro-5,6-dicyano-p-benzoquinone can be used.

〔solvent〕
The solvent is not particularly limited, and, for example, water, alcohols (methanol, ethanol, propanol, butanol etc.), ketones (acetone, diethyl ketone etc.), ethers (diethyl ether, tetrahydrofuran etc.), chlorinated hydrocarbons (Dichloromethane, chloroform, dichloroethylene, trichloroethylene, carbon tetrachloride etc.), glycols (ethylene glycol, propylene glycol etc.), nitriles (acetonitrile, propionitrile, benzonitrile etc.), amides (N, N-dimethylformamide , Dimethylacetamide etc.), lactams (N-methyl-2-pyrrolidone etc.), dimethylsulfoxide, aliphatic hydrocarbons (n-pentane, n-hexane, cyclohexane, n-heptane, n-octane etc.), aroma Hydrocarbons (benzene, toluene, xylene, ethylbenzene, etc.) and the like. Among these, methanol, ethanol, acetonitrile, N, N-dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, dimethylsulfoxide and the like are particularly preferable. The solvents may be used alone or in combination of two or more.

  The maximum absorption wavelength in the UV-visible absorption spectrum of the 0.1% by mass methanol solution of the iron amino complex of the present embodiment is preferably 400 to 700 nm, more preferably 450 to 650 nm, and still more preferably 500 to 600 nm. is there. When the maximum absorption wavelength is in the above range, the formation of a complex can be confirmed. The maximum absorption wavelength can be measured by the method described in the examples. Here, the "maximum absorption wavelength" refers to a point at which the absorption intensity in the UV-visible absorption spectrum changes from an increase to a decrease, and in the range of 400 to 700 nm, a wavelength corresponding to the absorption coefficient of the maximum peak.

  In the UV-visible absorption spectrum of a 0.1% by mass methanol solution of the iron amino complex of the present embodiment, the absorption intensity at a maximum absorption wavelength in the range of 400 to 700 nm is preferably 0.10 or more, more preferably 0.1. It is 20 or more, more preferably 0.30 or more. The upper limit of the absorption intensity at the maximum absorption wavelength in the range of 400 to 700 nm is not particularly limited, but is preferably 5.0 or less, more preferably 3.0 or less, and still more preferably 1.0 or less. When the absorption intensity at the maximum absorption wavelength in the range of 400 to 700 nm is within the above range, formation of a complex can be confirmed. The absorption intensity at the maximum absorption wavelength in the range of 400 to 700 nm can be measured by the method described in the examples.

[Method of producing iron amino complex]
The method for producing an iron amino complex of the present embodiment has a mixing step of mixing an iron compound and a compound having two amino groups and two nitrile groups in a solvent to obtain an iron amino complex.

[Mixing process]
When mixing an iron compound and a compound having two amino groups and two nitrile groups in a solvent, a compound having two amino groups and two nitrile groups may be added to a solvent in which the iron compound is dissolved. Alternatively, the iron compound may be added to a solvent in which a compound having two amino groups and two nitrile groups is dissolved, and a compound having two amino groups and two nitrile groups and an iron compound may be simultaneously added to the solvent. Alternatively, a solvent in which the iron compound is dissolved may be mixed with a solvent in which the compound having two amino groups and two nitrile groups is dissolved.

  The mass ratio of the compound having two amino groups and two nitrile groups to the solvent (compound / solvent) is preferably 0.0001 to 0.99, more preferably 0.001 to 0.90, and further It is preferably 0.005 to 0.5, and particularly preferably 0.01 to 0.25. When the mass ratio of the compound having two amino groups and two nitrile groups to the solvent is 0.0001 or more, the complex formation rate tends to be faster. In addition, when the mass ratio of the compound having two amino groups and two nitrile groups and the solvent is 0.99 or less, the generation of rapid heat of reaction tends to be further suppressed.

  The molar ratio of the compound having two amino groups and two nitrile groups to the iron compound (compound / iron compound) is preferably 0.1 to 10000, and more preferably 1: 1.0 to 100.0. , More preferably 1: 1.0 to 6.0, particularly preferably 1: 2.0 to 3.0. When the molar ratio of the compound having two amino groups and two nitrile groups to the iron compound is 0.1 or more, the stability of the complex tends to be further improved. In addition, when the molar ratio of the compound having two amino groups and two nitrile groups to the iron compound is 10000 or less, the solubility of the complex tends to be further improved.

  The temperature at which the iron compound and the compound having two amino groups and two nitrile groups are mixed in a solvent is preferably 0 to 200 ° C., more preferably 10 to 100 ° C., particularly preferably 20 to 20 ° C. It is 50 ° C. When the temperature is 0 ° C. or more, the reaction rate tends to be further improved. In addition, when the temperature is 200 ° C. or less, the safety tends to be further improved.

  The pressure at which the iron compound and the compound having two amino groups and two nitrile groups are mixed in a solvent is preferably 0.05 to 2.0 MPa, more preferably 0.08 to 1.5 MPa. More preferably, it is 0.1 to 1.0 MPa. When the pressure is 0.05 MPa or more, the reaction rate of complex formation tends to be further improved. In addition, when the pressure is 2.0 MPa or less, the runaway reaction can be further suppressed, and the safety at the time of complex formation tends to be further improved.

  The time for mixing the iron compound and the compound having two amino groups and two nitrile groups in a solvent is preferably 1 minute to 240 hours, more preferably 10 minutes to 120 hours, and still more preferably 30 minutes to 60 hours. When the time is 1 minute or more, the stability of the complex tends to be further improved. In addition, when the time is 240 hours or less, the solubility of the complex tends to be further improved.

  When mixing an iron compound and a compound having two amino groups and two nitrile groups in a solvent, a batch reactor may be used or a flow reactor may be used. The flow type reactor may be a complete mixing tank, a tubular reactor, or a combination of a complete mixing tank and a tubular reactor.

  The atmosphere in the reactor may be air, but may be an inert gas such as nitrogen, helium or argon.

  After the above mixing, the iron amino complex can be isolated by a method of distilling off the solvent by distillation or a method of precipitating an iron amino complex as crystals. The isolated iron amino complex can be washed and purified using methanol, ethanol, acetonitrile, N, N-dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, dimethylsulfoxide and the like. The purified iron amino complex can be powdered by removing the washing solution by a method such as vacuum drying.

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples and the like, but these are illustrative, and the present invention is not limited thereto. Therefore, those skilled in the art can implement the present invention by adding various modifications to the examples shown below.
First, the measurement method performed in the present embodiment will be described.

(Solubility of iron amino complex in methanol)
10 g (mass of iron amino complex charged) and 10 g (solvent) of methanol are weighed and mixed, stirred at 25 ° C. for 10 minutes, then made by ADVANTEC, type: No. Suction filtration is carried out using a filter paper of 5 C (retention particle diameter 1 μm (value described in the catalog)), and the iron amino complex remaining on the filter paper is recovered as a filtrate. The filtrate obtained is dried under reduced pressure at 120 ° C. for 10 hours to measure the iron amino complex residual mass (g). Based on the obtained iron amino complex residual mass, the solubility (x) of the iron amino complex in methanol was calculated by formula (I).
Solubility of iron amino complex in methanol (x)
= (Iron amino complex preparation mass-iron amino complex residual mass) / methanol mass = (10-iron amino complex residual mass) / 10
... (I)

(Measurement method of UV-visible absorption spectrum)
The ultraviolet and visible absorption spectrum is prepared by dissolving 0.1 g of a sample in methanol (manufactured by Wako Pure Chemical Industries, Ltd., 98%, reagent special grade) to make the whole 10.0 g, collecting 1.0 g of the solution and further diluting with methanol The total amount is 10.0 g, and the final sample concentration is 0.1 wt. Adjusted to be%. The solution is filled in a 2 mm thick quartz cell and the UV-visible absorption spectrum is measured. From the obtained UV-visible spectrum, the UV-visible absorption spectrum of a 2 mm thick quartz cell filled with methanol (blank) is shown UV-visible absorption spectra were obtained by subtraction as background.
Device: UV-visible absorption spectrophotometer V-670, manufactured by JASCO Corporation
Light source: Deuterium lamp, halogen lamp Measurement wavelength range: 1100 to 250 nm
Detector: Photomultiplier, cooled PbS photoconductive device Bandwidth: 1.0 nm
Scanning speed: 400 nm / min

(Simulation of structure and UV-visible absorption spectrum)
In order to deduce the structure of the iron amino complex in the present embodiment, several structures of one or two molecules of diaminomaleonitrile and one molecule of iron (II) chloride anhydride are assumed, as an example. Energy calculation based on one-principle calculation was performed. In addition, for compounds presumed to have the most stable structure, the UV-visible absorption spectrum shown in a methanol solvent was simulated using the same calculation software, method, and basis functions. The structure estimated based on first-principles calculations and the simulation of UV-visible absorption spectra is shown in FIG.
First principles calculation software: Gaussian 09
Calculation method: B3LYP
Basis function: 6-311 + G (d. P)

[ Reference Example 1]
4 g of diaminomaleonitrile, 2.345 g of anhydrous iron (II) chloride, and 200 g of methanol as a solvent were prepared and mixed in a beaker. After stirring for 5 hours at room temperature, the solution was transferred to a 500 mL eggplant flask, immersed in a water bath at 50 ° C., and methanol was removed by an evaporator. After removing the solvent, deep blue-purple crystals were taken out and crushed in an agate mortar. Thereafter, drying under reduced pressure was performed at 80 ° C. for 12 hours to recover 6.0 g of iron amino complex.

  It was 0.40 when the solubility to methanol of the obtained iron amino complex was measured. In addition, 0.1 wt. The ultraviolet-visible absorption spectrum of the 100% methanol solution was measured to find that it had an absorption maximum at 570 nm and the intensity was 1.1. The obtained UV-visible absorption spectrum is shown in FIG.

  An energy calculation was carried out in the first principle calculation, and it is shown in FIG. 2 that the structure in which the NH 2 group of two diaminomaleonitrile molecules is coordinated to iron (II) chloride at the trans position is the most stable. I got the result. Furthermore, when the ultraviolet visible absorption spectrum which the compound of this structure shows in a methanol solvent is simulated by the same calculation software, method and basis function, the result has an absorption maximum at 570 nm. Thereby, it can be estimated that the iron amino complex of Example 1 has this structure.

[ Reference Example 2]
6.2 g of the iron amino complex of Reference Example 2 was obtained in the same manner as in Reference Example 1, except that the stirring for 5 hours in Reference Example 1 was changed to stirring for 0.5 hours.
It was 0.10 when the solubility to methanol of the obtained iron amino complex was measured. In addition, 0.1 wt. The ultraviolet-visible absorption spectrum of the 100% methanol solution was measured to have an absorption maximum at 580 nm, and the intensity was 0.3.

[ Reference Example 3]
Iron (II) chloride anhydride 2.345g of Reference Example 1, except for changing the iron (II) chloride anhydride 4.69 g, iron amino complexes 7.9g of Reference Example 1 Reference Example in the same manner as 3 I got

  It was 0.30 when the solubility to methanol of the obtained iron amino complex was measured. In addition, 0.1 wt. The ultraviolet-visible absorption spectrum of the 100% methanol solution was measured to find that it had an absorption maximum at 600 nm and the intensity was 1.0.

[ Reference Example 4]
6.1 g of the iron amino complex of Reference Example 4 was obtained in the same manner as in Reference Example 1 except that 200 g of the solvent methanol in Reference Example 1 was changed to 200 g of acetonitrile.

  It was 0.45 when the solubility to methanol of the obtained iron amino complex was measured. In addition, 0.1 wt. The ultraviolet-visible absorption spectrum of the 100% methanol solution was measured to find that it had an absorption maximum at 570 nm and the intensity was 1.2.

[ Reference Example 5]
Iron amino complex 7 of Reference Example 5 in the same manner as Reference Example 1 except that 2.345 g of iron (II) chloride anhydride of Reference Example 1 was changed to 3.90 g of iron (II) bromide anhydride. I got 5g.

  It was 0.28 when the solubility to methanol of the obtained iron amino complex was measured. In addition, 0.1 wt. The ultraviolet-visible absorption spectrum of the 100% methanol solution was measured to find that it had an absorption maximum at 590 nm and the intensity was 1.0.

[Example 6]
8 g of diaminomaleonitrile, 8.4 g of 2,3-dichloro-5,6-dicyano-p-benzoquinone and 200 g of methanol were mixed in a beaker. The mixture was stirred at 40 ° C. for 5 hours, cooled, and 4.2 g of diiminosuccinonitrile was recovered by a recrystallization method.

5.8 g of the iron amino complex of Example 6 was obtained in the same manner as in Reference Example 1 except that 4 g of diaminomaleonitrile in Reference Example 1 was changed to 3.9 g of diiminosuccinonitrile synthesized above.

  It was 0.28 when the solubility to methanol of the obtained iron amino complex was measured. In addition, 0.1 wt. The UV-visible absorption spectrum of the 100% methanol solution was measured to find that it had an absorption maximum at 570 nm and the intensity was 1.0.

Comparative Example 1
When the solubility in methanol was measured using a commercially available iron phthalocyanine complex (manufactured by Tokyo Chemical Industry Co., Ltd.), the solubility was 0.001 or less.

  The iron amino complex according to the present invention can be used as an organic electronic material such as a fuel cell electrode, an electric double layer capacitor, an organic thin film transistor, a solar cell material, and the like.

Claims (2)

An organic electronic material containing iron amino complexes diisopropyl Minos comb Bruno nitrile iron (II) chloride anhydride is coordinated, solubility in methanol of the iron amino complex is 0.05 to 1.0 organic Electronic material.   The organic electronic material according to claim 1, which is used for a fuel cell electrode.