JP2022017658A - Compound - Google Patents

Abstract

To provide a novel compound with a specific structure which has low ligand planarity, low aggregability and high sublimability, and exhibits near-infrared absorption or emission.SOLUTION: The compound is represented by formula (1) in the figure. [In formula (1), A and B each independently represent an optionally substituted aromatic hydrocarbon ring or aromatic heterocycle; X represents an acceptor-type substituent; M represents Ir, Os or Pt; L represents an n-valent ligand; and m and n each independently represent an integer from 1 to 3.]SELECTED DRAWING: Figure 1

Description

The present invention relates to novel compounds. The compound of the present invention has absorption / emission characteristics higher than those in the near-infrared region, and is, for example, a near-infrared emission marker, indicator, bioimaging, sensor, wavelength conversion film, emission transistor, OLED, electrochemical emission cell, photo. It can be suitably used as a member for dynamic therapy, optical beauty, night vision display, security, anti-counterfeiting, and the like.

Until now, visual selection and recognition have been the mainstream, but with the development of science and technology, the labor force is decreasing due to the aging population and declining birthrate, and there is a shift to robot-based selection and recognition. .. Visible light can only be used for visual sorting and recognition, but near-infrared light emission that cannot be visually captured can also be used when using a robot, and improvement in sorting and identification accuracy can be expected. Furthermore, since near-infrared light passes through cells, it can be expected to be applied to bioimaging, biosensors, medical diagnostic agents, PDT, and the like. Among them, Ir and Pt
, Os and the like exhibit phosphorescence, and are therefore attracting particular attention.
For example, Patent Document 1 reports that an iridium complex having a quinazoline skeleton as a ligand emits light in the near infrared and can be used for OLED applications. Further, Non-Patent Document 1 shows that a cationic iridium complex having a ligand of a quinosoline skeleton can be used as an electrochemical cell.
However, further performance improvement is required for practical use.

Published in the United States 2019/0062357

Chem. Eur. J. 2019, 25, 5489 --5497 (Cationic IrIII Emitters with Near-Infrared Emission Beyond 800 nmand Their Use in Light-Emitting Electrochemical Cells)

In the compounds disclosed in Patent Document 1 and Non-Patent Document 1, it is considered that the flatness of the ligand is high, the ligand is easily aggregated, and the sublimation property is low.

As a result of repeated studies to solve the above problems, the present inventor has found that the above problems can be solved by introducing an electron-withdrawing group into the quinazoline skeleton. The present invention has been achieved based on such findings, and the gist thereof is as follows.
[1] A compound represented by the formula (1).

[In equation (1)
A and B each independently represent an aromatic hydrocarbon ring or an aromatic heterocycle which may have a substituent.
Z represents an acceptor substituent
M represents Ir, Os or Pt and represents
L represents an n-valent ligand
m and n each independently represent an integer of 1 to 3. ]
[2] The compound according to claim 1, wherein L is represented by the following formula (2).

[In equation (2)
X and Y independently represent C, N or O atoms, respectively. ]

The present invention provides a novel compound having a specific structure having near-infrared absorption or light emission.

The absorption spectrum of the compound obtained in Example 1 is represented. The emission spectrum of the compound obtained in Example 1 is represented. The absorption spectrum of the compound obtained in Example 2 is represented. The emission spectrum of the compound obtained in Example 2 is represented. The absorption spectrum of the compound obtained in Example 3 is represented. The emission spectrum of the compound obtained in Example 3 is represented. The absorption spectrum of the compound obtained in Comparative Example 1 is represented. The emission spectrum of the compound obtained in Comparative Example 1 is represented.

Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments, and can be variously modified and implemented within the scope of the gist thereof.

The novel compound of the present invention is represented by the following formula (1).

[In equation (1)
A and B each independently represent an aromatic hydrocarbon ring or an aromatic heterocycle which may have a substituent.
Z represents an acceptor substituent
M represents Ir, Os or Pt and represents
L represents an n-valent ligand
m and n each independently represent an integer of 1 to 3. ]

The reason why the compound represented by the formula (1) exerts the effect of the present invention is not clear, but the following can be considered. X in formula (1) induces an electronic effect on the N atoms coordinated to A and M via the bond, stabilizing the coordinate bond. Therefore, MLCT (Charge Transfer Metal to Ligand Charge)
The energy of Transfer) becomes small and induces long wavelength emission. Further, it is conceivable that Z interacts with A via space to stabilize the compound represented by the formula (1).

(A and B)
A and B each independently represent an aromatic hydrocarbon ring or an aromatic heterocycle which may have a substituent. These rings may have a single or multiple substituents.
Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthrene ring.
Examples of the aromatic heterocycle include benzothiophene ring, dibenzothiophene ring, dibenzofuran ring, benzofuran ring, carbazole ring, thiophene ring, pyridine ring, pyrimidine ring, pyrazine ring, pyridazine ring, thiazole ring, thiadiazole ring, oxazole ring, and oxadi. Examples include the azole ring.
Among these, A is preferably an electron-donating ring, and among them, a benzene ring, a naphthalene ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a dibenzofuran ring, and a carbazole ring are preferable. Further, B is preferably a benzene ring, a naphthalene ring, a pyridine ring, a pyrimidine ring, a pyrazine ring, a pyridazine ring, a thiazole ring, a thiadiazole ring, an oxazole ring, an oxadiazole ring and the like. With these rings, the bandgap of the ligand becomes small, and near-infrared emission tends to be obtained.

The substituents that A and B may have are independent of each other and are not particularly limited. Specifically, a hydrogen atom, a heavy hydrogen atom, an alkyl group which may have a substituent, an alkoxyl group which may have a substituent, an amino group which may have a substituent, a halogen, and the like. It may have a cyano group, an aryl group which may have a substituent, a heteroaryl group which may have a substituent, a cycloalkyl group which may have a substituent, and a substituent. Examples thereof include an alkenyl group and an alkynyl group which may have a substituent. Among these, a hydrogen atom, a heavy hydrogen atom, an alkyl group which may have a substituent, an alkoxyl group which may have a substituent, an amino group which may have a substituent, a halogen and a cyano group. However, it is preferable because the steric obstacle is reduced.
The number and position of the substituents are not particularly limited, but substitution in the direction opposite to M (central metal) is preferable because the stability of the compound represented by the formula (1) tends to be improved.

(Z)
Z represents an acceptor substituent. In the present invention, the acceptable substituent means that the contribution of the resonance effect is small and the substituent constant (σ value) according to Hammett's rule is larger than 0. Among these, from the viewpoint of lengthening the wavelength, the σ value is preferably 0.1 or more, and more preferably 0.3 or more. The upper limit is not particularly limited, but is preferably 2.0 or less, and more preferably 1.5 or less.
Specific examples of the accepting substituent include a halogen, a cyano group, a trifluoromethyl group, a carbonyl group, an alkylcarbonyl group, an alkyloxycarbonyl group, an imino group and the like.
Further, the A and Z may be combined to form a ring.

[L]
L represents an n-valent ligand, and is not particularly limited as long as the characteristics of the present invention are not impaired. When there are a plurality of Ls in the same molecule, they may be the same or different.
As L, those represented by the following formula (2) are preferable.

In formula (2), X and Y independently represent C, N or O atoms, respectively.
The C atom, N atom and O atom are a part of a ring or a group, and the ring or the group containing X and Y, respectively, is bonded. The ring or group containing a C atom, an N atom and an O atom is not particularly limited, but from the viewpoint of stability, the ring containing M, X and Y is preferably a 5-membered ring or a 6-membered ring. Specifically, the following structure can be mentioned.

The preferable structure of L is exemplified in the following formulas (2A) to (2F), but the present invention is not limited to this. As long as the structure can be maintained, the carbon atom of the skeleton may be replaced with another atom such as a nitrogen atom, or the carbon atom may further have a substituent.
When L has a substituent, the substituents include -F, -CN, -CF ₃ , a linear, branched or cyclic alkyl group having 1 or more and 30 or less carbon atoms, and an aryloxy having 5 or more and 40 or less carbon atoms. Group, arylthio group with 5 or more and 40 or less carbon atoms, diarylamino group with 10 or more and 40 or less carbon atoms, aralkyl group with 5 or more and 60 or less carbon atoms, aromatic group with 5 or more and 60 or less carbon atoms, and 5 or more and 60 or less carbon atoms. Examples include the complex aromatic group of. Preferably -F, -CN, -C
Examples include F ₃ , alkyl group, aralkyl group, aromatic group or complex aromatic group, -F, -CN.
, -CF ₃ , alkyl groups, aromatic groups, complex aromatic groups are more preferred.

The bonding mode between M and L of the compound represented by the formula (1) of the present invention is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a mode of bonding with a nitrogen atom and a carbon atom of L,
Examples include a mode in which L is bonded with two nitrogen atoms, a mode in which L is bonded with two carbon atoms, a mode in which L is bonded with a carbon atom and an oxygen atom, and a mode in which L is bonded with two oxygen atoms.
Among the above, (2A) or (2F) is preferable because the stability of the compound represented by the formula (1) is improved.

(M and n)
m and n each independently represent an integer of 1 to 3. When M is Ir or Os, n + m = 3
When M is Pt, n + m = 2.

[Method for producing a compound represented by the formula (1)]
The method for producing the compound represented by the above-mentioned formula (1) is not particularly limited, and examples thereof include the following schemes.

Examples of the above M ^* include IrCl ₃ / xH ₂ O, Ir (acac) ₃ , [Ir (COD) ₂ ] ₂ Cl, PtCl ₂ , and the like.

[Physical characteristics of the compound represented by the formula (1)]
Weight reduction of the compound The maximum temperature is not particularly limited, but since the compound is easily thermally decomposed, 4
It is preferably 45 ° C. or lower, and more preferably 440 ° C. or lower. When the maximum weight reduction temperature is in the above range, the sublimation property is high, the purity tends to be high by sublimation purification, and the compatibility with devices such as vacuum vapor deposition is improved.

[Specific example of the compound represented by the formula (1)]
Specific examples of the compound represented by the formula (1) are shown below, but the present invention is not limited thereto.

[Element]
The compound represented by the formula (1) of the present invention has absorption / emission characteristics in the near infrared region or higher, and is, for example, a near infrared emission marker, an indicator, a bioimage, a sensor, a wavelength conversion film, a light emitting transistor, and the like. It can be suitably used as a member for OLED, light-emitting cell, photodynamic therapy, photobeauty, night vision display, security, anti-counterfeiting application and the like.

[Synthesis Example 1]

Synthesis was performed based on the formulation of Chemistry of Heterocyclic Compounds 2015, 51 (3), 259-268 to obtain the desired product.
[Synthesis of compound 1]

O-phenylenediamine (4.99 g, 1.0 equiv.) Was added to a solution of Ethyl trifluoropyruvate (7.85 g, 46.14 mmol) in ethanol (80 mL) under a nitrogen atmosphere, and the mixture was stirred under reflux for 4 hours.
The solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography (ethyl acetate / hexane = 1/4) to obtain Compound 1 (yellow powder, 7.62 g, yield 77.1%). ..

[Synthesis of compound 2]

In a nitrogen atmosphere, compound 1 (7.50 g, 35.02 mmol) was added to phosphorus oxychloride (75 mL).
Was added at room temperature and refluxed for 8 hours to dissolve and the reaction proceeded.
After cooling to room temperature, the solvent was distilled off under reduced pressure, and the residue was added dropwise to the stirred ice water (200 mL) and stirred for a while.
The obtained precipitate was collected by filtration, washed successively with purified water (100 mL) and diethyl ether (100 mL), air-dried, and dried under vacuum under reduced pressure. Compound 2 (light brown powder, 7,27 g, yield 89.2%). )
Got

[Synthesis of compound 3]

Compound 2 (3.70 g, 15.48 mmol), phenylboronic acid (2.
45g, 1.3equiv.), DME (40mL), 2M tripotassium phosphate aqueous solution (19.3m)
L, 2.5 equiv.) Was charged, nitrogen bubbling was performed at room temperature for 20 minutes, and then Pd (pph ₃ ) ₄ (89).
4 mg, 5 mol%) was added, and the mixture was stirred under reflux for 9 hours.
After cooling to room temperature, toluene (50 mL x 2 times) was extracted. Combine the organic layers and purified water (5)
After washing once with 0 mL), anhydrous sodium sulfate was dried, filtered, and the filtrate was concentrated.
The obtained residue is subjected to silica gel column chromatography (ethyl acetate / hexane = 1/4).
The compound 3 (yellow powder, 3.88 g, yield 91.4%) was obtained.

Iridium chloride-3.64 hydrate (127 mg, 0.3473 mmol) under nitrogen atmosphere
Was dissolved in purified water (1 mL), diglyme (4 mL) and compound 3 (200 mg, 2.1equiv.) Were added, the oil bath was set at 50 ° C., and nitrogen bubbling was performed for 30 minutes. Then N, N-diisopropyleth
ylamine (94 mg, 2.1equiv.) Was added, and the mixture was stirred while raising the temperature to 120 ° C. for 3 hours, then the temperature was raised, and the mixture was reflux-stirred for 19 hours.
After allowing to cool to room temperature, dichloromethane (40 mL) and purified water (10 mL) are added for extraction, anhydrous syrup is dried, filtered, and the filtrate is concentrated. Compound 4 (159 mg) was obtained.

Compound 4 (150 mg, 0.1938 mmol), acetylacetone (2) under a nitrogen atmosphere.
Stir 5 mg, 1.3 equiv.), 2-ethoxyethanol (3 mL) at room temperature and t-BuOK (28 mg, 1
.. 3 equiv.) Was introduced. The resulting mixture was stirred at 40 ° C. for 2 hours.
After cooling with ice, it was quenched with purified water (4 mL) and extracted with dichloromethane (20 mL × 2 times).
The organic layers were combined, washed once with purified water (5 mL), dried over anhydrous Glauber's salt and filtered, and the filtrate was concentrated. The obtained residue was purified by silica gel column chromatography (ethyl acetate / dichloromethane: 1/19) to obtain NIR-1 (blackish brown powder, 115 mg, yield 70.9%, LC purity 99.4%). ..
Moreover, the absorption spectrum and the emission spectrum of the obtained NIR-1 were measured. The absorption spectrum was measured by preparing a degassed methylene chloride solution of 10-5 mol / L using a U3900 spectrophotometer manufactured by Hitachi, Ltd. The emission spectrum was measured by preparing a degassed methylene chloride solution of 10-5 mol / L using an ultraviolet-visible near-infrared spectrophotometer V-7200 manufactured by JASCO Corporation. The measurement results are shown in FIGS. 1 and 2.

Ethyl trifluoropyruvate (5.00 g, 29.40 mmol) and 2,3-diaminonaphthalen
By performing the same synthesis as that of compound 1 using e (4.65 g, 1eq.), Compound 5 (6)
.. 46 g, yield 83.2%) was obtained.

Compound 6 (6.66 g, yield 97.0%) was obtained by performing the same synthesis as compound 2 using compound 5 (6.42 g, 24.30 mmol).

Compound 7 (5.61 g, yield 74.8%) was obtained by performing the same synthesis as compound 4 using compound 6 (6.61 g, 23.39 mmol).

Under a nitrogen atmosphere, iridium chloride-3.64 hydrate (535 mg, 1.468 mmol) was dissolved in purified water (2 mL), diglyme (20 mL) and compound 7 (1.000 g, 2.1equiv.).
Was added, the oil bath was set at 50 ° C., and nitrogen bubbling was performed for 30 minutes. Then triethylamine (4
30 μL, 2.1equiv.) Was added, and the mixture was stirred for 1 hour while raising the temperature to 120 ° C., then raised, and reflux-stirred for 15 hours.
After allowing to cool to room temperature, dichloromethane (100 mL) and purified water (20 mL) were added for extraction, anhydrous Glauber's salt was dried and filtered, and the filtrate was concentrated. The obtained residue was washed with methanol and collected by filtration to obtain compound 8 (286 mg, yield 22.3%) as a black powder.

Compound 8 (250 mg, 0.2860 mmol), acetylacetone (3) under a nitrogen atmosphere.
Stir 7 mg, 1.3 equiv.), 2-ethoxyethanol (3 mL) at room temperature and t-BuOK (42 mg, 1
.. 3 equiv.) Was introduced. The resulting mixture was stirred at 40 ° C. for 2 hours.

After cooling with ice, it was quenched with purified water (4 mL) and extracted with dichloromethane (20 mL × 2 times). The organic layers were combined, washed once with purified water (5 mL), dried over anhydrous Glauber's salt, filtered, and the filtrate was concentrated.
The obtained residue was subjected to silica gel column chromatography (Kanto Chemical Co., Inc., silica gel 60N,
Ethyl acetate / dichloromethane = (1/40) using spherical neutral, 40-50 μm, 10 g)
Purification was carried out in 1/19) to obtain NIR-2 (black powder, 239 mg, yield 89.1%, LC purity 98.2%).

The absorption spectrum and emission spectrum of the obtained NIR-2 were measured by the same method as in Example 1. The measurement results are shown in FIGS. 3 and 5.

Under a nitrogen atmosphere, compound 9 (3.500 g, 15.05 mmol), naphthalene-2-ylboronic acid (3.36 g, 1.3equiv.), DME (40 mL), 2M tripotassium phosphate aqueous solution.
After charging (18.8 mL, 2.5 equiv.) And nitrogen bubbling at room temperature for 20 minutes, Pd (p)
ph ₃ ) ₄ (894 mg, 5 mol%) was added, and the mixture was stirred under reflux for 16 hours.
After cooling to room temperature, toluene (50 mL × 2 times) was extracted. Combine the organic layers and purified water (5)
After washing once with 0 mL), anhydrous sodium sulfate was dried, filtered, and the filtrate was concentrated. The obtained residue was subjected to silica gel column chromatography (developing solution dichloromethane / hexane = 1/4) to compound 10.
(White powder, 3.931 g) was obtained in a yield of 80.6%.

Under a nitrogen atmosphere, iridium chloride-3.64 hydrate (534 mg, 1.468 mmol) was dissolved in purified water (5 mL), and diglyme (20 mL) and compound 10 (1.000 g, 3.084 m) were dissolved.
Mol, 2.1equiv.) Was added, the oil bath was set at 50 ° C., and nitrogen bubbling was performed for 30 minutes.
Then, N, N-diisopropylethylamine (399 mg, 2.1equiv.) Was added, and the mixture was stirred while raising the temperature to 120 ° C. for 2 hours, then the temperature was raised, and the mixture was reflux-stirred for 21 hours. After allowing to cool to room temperature, dichloromethane (40 mL) and purified water (10 mL) are added for extraction, anhydrous syrup is dried, filtered, and the filtrate is concentrated. Compound 11 (424 mg)
Was obtained in a yield of 33.0%.
Subsequently, compound 11 (401 mg, 0.4587 mmol), acetylacetone (60 mg, 1.3equiv.), And 2-ethoxyethanol (7 mL) were stirred at room temperature under a nitrogen atmosphere, and t-BuOK (6).
76 mg, 1.3 equiv.) Was added. The resulting mixture was stirred at 40 ° C. for 2 hours and 20 minutes. After cooling with ice, it was quenched with purified water (10 mL) and extracted with dichloromethane (30 mL × 2 times). Combine the organic layers, wash once with purified water (10 mL), dry with anhydrous Glauber's salt, and filter.
The filtrate was concentrated.
The obtained residue is subjected to silica gel column chromatography (developing solution toluene / hexane = 1 /).
Purify with (4), wash the concentrated residue with methanol, and remove by filtration, NIR-3 (blackish brown powder, 296 m).
g, yield 68.8%, LC purity 96.2%) were obtained.
Moreover, the absorption spectrum and the emission spectrum of the obtained NIR-3 were measured in the same manner as in Example 1. The measurement results are shown in FIGS. 5 and 6.

[Comparative Example 1]
Based on the literature (J. Mater. Chem. C, 2013, 1, 6446-6454), the following compound A was synthesized. The absorption spectrum and emission spectrum of compound A were measured in the same manner as in Example 1. The measurement results are shown in FIGS. 7 and 8.

For each of the compounds obtained in Examples 1 to 3 and Comparative Example 1, the weight phenomenon maximum temperature and the emission maximum wavelength were measured by TG-DTA. The results are shown in Table 1. The maximum temperature of the weight phenomenon and the maximum emission were measured using SII EXSTAR 6000. Using an Al container at N ₂ 200 mL / min, the temperature was raised to 40-600 ° C. at 10 ° C./min for measurement.

Since the compounds of Examples 1 to 3 have a lower weight loss maximum temperature than the compounds of Comparative Example 1, they have high sublimation properties and can be expected to be highly purified by sublimation purification. It is also presumed to be more suitable for device fabrication such as vacuum vapor deposition.

Claims (2)

A compound represented by the formula (1).

[In equation (1)
A and B each independently represent an aromatic hydrocarbon ring or an aromatic heterocycle which may have a substituent.
Z represents an acceptor substituent
M represents Ir, Os or Pt and represents
L represents an n-valent ligand
m and n each independently represent an integer of 1 to 3. ] The compound according to claim 1, wherein L is represented by the following formula (2).

[In equation (2)
X and Y independently represent C, N or O atoms, respectively. ]

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