JP4994000B2 - Fluorine-containing Nile red derivative and method for producing the same - Google Patents

Description

  The present invention relates to a novel fluorine-containing Nile red derivative that is effective as a red fluorescent dye for display materials.

  In recent years, fluorescent materials are expected to be used as light emitting elements in various fields including various display materials. However, at present, no satisfactory low-molecular fluorescent material capable of emitting red light has been developed.

  Among them, various Nile red derivatives are provided for analytical use and fluorescent dye use.

  However, conventionally known Nile red derivatives have strong intermolecular interactions, and thus have problems such as a decrease in fluorescence intensity due to concentration quenching, a decrease in solubility in various media, and difficulty in vacuum deposition.

  In order to solve these problems, for example, a Nile red derivative is provided in which an aromatic ring containing a fluorinated alkyl group having 1 to 5 carbon atoms is introduced at the 6-position of the Nile red skeleton (Patent Document 1).

However, it is desired to develop a novel compound exhibiting red fluorescence that still has high fluorescence intensity and solubility and is relatively easy to vacuum deposit.
JP 2003-277369 A

  It is an object of the present invention to provide a novel fluorine-containing nile red exhibiting red fluorescence, which has high fluorescence intensity and solubility and is relatively easy to vacuum deposit.

  The present inventor has intensively studied to develop a new fluorine-containing compound exhibiting red fluorescence. As a result, it has been found that by introducing a fluorine-containing functional group capable of expressing sufficient steric hindrance to the Nile Red derivative, it is possible to suppress a decrease in fluorescence intensity, a decrease in solubility, difficulty in vacuum deposition, and the like. It was. The present invention has been completed based on such findings.

The present invention provides the following fluorine-containing Nile red derivative, a method for producing the derivative, a fluorescent material in the red to near infrared region containing the derivative, and a light-emitting element:
Item 1. Fluorine-containing Nile Red Derivatives Represented by General Formula (I):

[Wherein, R ₁ and R ₂ are the same or different and each represents a linear or branched alkyl group having 1 to 10 carbon atoms, a phenyl group, a benzyl group, or a phenethyl group. Rf represents a perfluoroalkenyl group having 6 to 10 carbon atoms. ].

Item 2. R ₁ and R ₂ are the same or different and each represents a linear or branched alkyl group having 4 to 10 carbon atoms, a phenyl group, a benzyl group or a phenethyl group, and Rf is

Or

Item 2. The fluorine-containing Nile red derivative according to Item 1.

  Item 3. Nile red derivatives represented by general formula (II):

[Wherein, R ₁ and R ₂ are the same or different and each represents a linear or branched alkyl group having 1 to 10 carbon atoms, a phenyl group, a benzyl group, or a phenethyl group. ]
And a method of producing a fluorine-containing Nile red derivative, wherein a perfluoroalkene having 6 to 10 carbon atoms is reacted.

  Item 4. Item 3. A red fluorescent material comprising the fluorine-containing Nile red derivative according to Item 1 or 2.

  Item 5. Item 3. A solid red fluorescent material comprising the fluorine-containing Nile red derivative according to Item 2.

  Item 6. Item 6. A light emitting device comprising the solid red fluorescent material according to Item 5 between a pair of electrodes.

  In the fluorine-containing Nile red derivative of the present invention, a perfluoroalkenyloxy group having 6 to 10 carbon atoms is bonded to the 6-position of the Nile red skeleton, not an aromatic ring, and the structure is completely different from the conventional Nile red derivative. It is a new compound.

  According to the present invention, there is provided a fluorine-containing Nile red derivative exhibiting red fluorescence, which has better fluorescence efficiency and is easier to handle as various display material applications. The fluorine-containing nile red derivative of the present invention emits fluorescence from red to the near infrared region. Since such long-wavelength light is highly transmissive, the fluorine-containing Nile red derivative of the present invention is useful not only for illumination purposes but also as a label for various analyses.

Fluorine-containing Nile red derivative In the fluorine-containing Nile red derivative of the present invention, Rf bonded to the Nile red skeleton in the general formula (I) is a C 6-10 perfluoroalkenyl group.

  Examples of the perfluoroalkenyl group having 6 to 10 carbon atoms include linear or branched perfluoroalkenyl groups having 6 to 10 carbon atoms, and include both trans and cis isomers. More specifically, for example, perfluoro-2-hexen-2-yl group, perfluoro-2-hepten-2-yl group, perfluoro- (2-, 3- or 4-) octen-2-yl group, perfluoro -(2-, 3- or 4-) nonen-2-yl group, perfluoro- (2-, 3- or 4-) decen-2-yl group, perfluoro-2-ethyl-1-buten-1-yl Group, perfluoro-4-methyl-3-isopropyl-2-penten-2-yl group, perfluoro (2-isopropyl-1,3-dimethyl-1-butenyl) group, perfluoro (1-ethyl-2-methyl-1) -Propenyl) group, perfluoro-2-methyl-2-penten-3-yl group and the like.

  Preferably a perfluoro-2-hexen-2-yl group, a perfluoro-4-methyl-3-isopropyl-2-penten-2-yl group, a perfluoro (2-isopropyl-1,3-dimethyl-1-butenyl) group, A perfluoro (1-ethyl-2-methyl-1-propenyl) group and a perfluoro-2-methyl-2-penten-3-yl group.

R ₁ and R ₂ represent a linear or branched alkyl group having 1 to 10 carbon atoms, a phenyl group, a benzyl group, or a phenethyl group.

  Examples of the linear or branched alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, and a sec-butyl group. Group, n-pentyl group, 1-ethylpropyl group, isopentyl group, neopentyl group, n-hexyl group, 1,2,2-trimethylpropyl group, 3,3-dimethylbutyl group, 2-ethylbutyl group, isohexyl group, A 3-methylpentyl group, n-heptyl group, n-octyl group, n-nonyl group and n-decyl group can be mentioned.

  Examples of the phenethyl group include a 1-phenylethyl group and a 2-phenylethyl group.

  Preferred linear or branched alkyl groups having 1 to 10 carbon atoms are n-ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n- Octyl group.

Moreover, as R < ₁ > and R < ₂ >, a phenyl group and a benzyl group are also preferable. R ₁ and ₂ may be the same or different.

  The fluorine-containing Nile red derivative of the present invention emits fluorescence in the red to near-infrared region when dissolved in a solvent such as dichloromethane. Therefore, the fluorine-containing Nile red derivative of the present invention can be used as a red fluorescent material.

In the general formula (I), R ₁ and R ₂ are the same or different and each represents a linear or branched alkyl group having 4 to 10 carbon atoms, a phenyl group, a benzyl group, or a phenethyl group, and Rf is

Or

Fluorine-containing Nile Red derivatives exhibiting fluoresce in the red to near infrared region not only in solution but also in a solid state. Therefore, the fluorine-containing Nile red derivative can also be used as a solid red fluorescent material.

The fluorine-containing Nile red derivative of the present invention is, for example,
Nile red derivatives represented by general formula (II):

[Wherein, R ₁ and R ₂ are the same or different and each represents a linear or branched alkyl group having 1 to 10 carbon atoms, a phenyl group, a benzyl group, or a phenethyl group. ]
And a perfluoroalkene having 6 to 10 carbon atoms.

  The above reaction can be performed, for example, according to perfluorofluorinated alkenyl etherification by reaction of perfluoroalkene described in JP-A-7-101916 and a hydroxyl group in a Nile red derivative.

  Examples of the perfluoroalkene having 6 to 10 carbon atoms include perfluoro- (2- or 3-) hexene, perfluoro- (2-, 3- or 4-) heptene, perfluoro- (2-, 3- or 4-). Examples include octene, perfluoro- (2-, 3- or 4-) nonene, perfluoro-4-methyl-3-isopropyl-2-pentene, and perfluoro-2-methyl-2-pentene.

  The amount of perfluoroalkene added is 1 to 5 mol, preferably 1 to 3 mol, per mol of hydroxyl group.

  An aprotic polar solvent can be used as the reaction solvent. The reaction solvent is preferably a ketone solvent such as acetone, methyl ethyl ketone, or methyl isopropyl ketone, or an amide such as N, N-dimethylformamide, N, N-dimethylacetamide, N, N′-dimethylimidazolidinone, or N-methylpyrrolidone. Solvent, ether solvents such as dioxane, tetrahydrofuran and diethyl ether, and more preferably acetone, methyl ethyl ketone, N, N-dimethylformamide, N, N-dimethylacetamide and N-methylpyrrolidone.

Alkalis used in the reaction include amines such as trimethylamine, triethylamine and tributylamine, alkali metal salts such as sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate, alkali metal alkoxides such as sodium ethoxide and potassium butoxide, hydrogen Alkali metal hydrides such as sodium hydride can be used. Triethylamine, potassium carbonate, sodium hydride and sodium ethoxide are preferred, and triethylamine, potassium carbonate and sodium hydride are more preferred.
The amount of alkali added is 1 to 6 mol per mol of hydroxyl group. Preferably it is 2-4.

  The reaction temperature is −10 to 80 ° C., preferably 0 to 60 ° C.

  The reaction time is 1 to 48 hours, preferably 2 to 24 hours.

Light-Emitting Element The present invention provides a light-emitting element comprising a solid red fluorescent material containing the fluorine-containing Nile red derivative of the present invention between a pair of electrodes.

  This light emitting device is obtained by 1) sandwiching a fluorine-containing solid red fluorescent material between two electrodes, a cathode for electron injection and an anode for hole injection (single layer structure). 2) A hole transport layer sandwiched between the anode and the fluorine-containing solid red fluorescent material (two-layer structure), or an electron transport layer sandwiched between the cathode and the fluorine-containing solid red fluorescent material (2 (Layer structure) 3) A three-layer structure in which an anode, a hole transport layer, a fluorine-containing solid red fluorescent material, an electron transport layer, and a cathode are sandwiched in this order can be employed.

  As the light emitting element, a transparent substrate such as glass, sapphire, or a plastic film can be used. Here, aluminum, magnesium, an aluminum alloy, a magnesium alloy, or the like is suitable for the cathode. The anode is preferably an inorganic transparent conductive material typified by ITO.

  The fluorine-containing solid red fluorescent material is desirably formed on the anode by vacuum deposition. Alternatively, it can be formed by dipping or coating a fluorine-containing solid red fluorescent material dissolved in a fluorine-based solvent, a chlorine-based solvent, a hydrocarbon, an ether-based solvent, or an ester-based solvent, followed by drying. .

  Hole transport layers include amine-based, hydrazine-based, and stilbene-based layers. Amine-based N, N'-diphenyl-N, N '-(3-methylphenyl) -1,1'-biphenyl-4,4'-diamine and the like are preferable.

  As the electron transport material, zinc benzothiazole complex, silole derivative, oxazole-based material can be used, but 2- (4-biphenyl) -5- (4-tert-butylphenyl) -1,3,4-oxadi An azole or the like is preferred.

Synthesis Example 1: 9-diethylamino-1- [perfluoro-4-methyl-3- (1-methylethyl) -2-penten-2-oxy] benzo [a] phenoxazin-5-one (Compound 1)
334 mg of 9-diethylamino-6-hydroxybenzo [a] phenoxazin-5-one and 30 mL of N, N-dimethylformamide were placed in a reaction vessel, then 480 mg of sodium hydride and perfluoro-4-methyl-3-isopropyl- 900 mg of 2-pentene was added. The mixture was stirred at room temperature for 2 hours, and then the reaction solution was poured into 50 mL of a saturated aqueous ammonium chloride solution. After extracting the product with ethyl acetate, the product was isolated by silica gel column chromatography to obtain 122 mg of the title compound (yield 16%). The physical properties of Compound 1 are shown in Table 1.

Synthesis Example 2: 9-dibutylamino-1- [perfluoro-4-methyl-3- (1-methylethyl) -2-penten-2-oxy] benzo [a] phenoxazin-5-one (Compound 2)
390 mg 9-dibutylamino-6-hydroxybenzo [a] phenoxazin-5-one and 10 mL N, N-dimethylformamide were placed in a reaction vessel, then 120 mg sodium hydride and perfluoro-4-methyl-3-isopropyl. 900 mg of 2-pentene was added. The mixture was stirred at room temperature for 2.5 hours, and then the reaction solution was poured into 100 mL of saturated aqueous ammonium chloride solution. After extracting the product with ethyl acetate, the product was isolated by silica gel column chromatography to obtain 146 mg of the title compound (yield 18%). The physical properties of Compound 2 are shown in Table 1.

Synthesis Example 3 9-Dibenzylamino-1- [perfluoro-4-methyl-3- (1-methylethyl) -2-penten-2-oxy] benzo [a] phenoxazin-5-one (Compound 3)
458 mg of 9-dibenzylamino-6-hydroxybenzo [a] phenoxazin-5-one and 5 mL of N, N-dimethylformamide were placed in a reaction vessel, then 405 mg of triethylamine and perfluoro-4-methyl-3-isopropyl- 900 mg of 2-pentene was added. The mixture was stirred at room temperature for 18 hours, and then the reaction solution was poured into 100 mL of a saturated aqueous ammonium chloride solution. After extracting the product with ethyl acetate, the product was isolated by silica gel column chromatography to obtain 88 mg of the title compound (yield 10%). The physical properties of Compound 3 are shown in Table 1.

Synthesis Example 4: 9-dibutylamino-1- [perfluoro-2-methyl-2-pentene-3-oxy] benzo [a] phenoxazin-5-one (Compound 4)
390 mg of 9-dibutylamino-6-hydroxybenzo [a] phenoxazin-5-one and 10 mL of acetone are placed in a reaction vessel, then 276 mg of potassium carbonate, 52 mg of 18 crown 6 ether and perfluoro-2-methyl-2-pentene. 3000 mg was added. After stirring this mixture at room temperature for 18 hours, water was poured into the reaction solution and extracted with ethyl acetate (100 mL × 3 times), and then the organic layer was dried over anhydrous sodium sulfate. After filtration, the solvent was distilled off. The product was isolated by column chromatography (SiO ₂ , hexane / ethyl acetate (v / v = 5: 1)) to obtain 248 mg of the title compound (yield 37%). The physical properties of Compound 4 are shown in Table 1.

Example 1 Visible / ultraviolet absorption spectrum and fluorescence spectrum of a fluorine-containing Nile red derivative in dichloromethane Visible / ultraviolet absorption spectrum and fluorescence spectrum of a dichloromethane solution (concentration: 1 × 10 ⁻⁵ mol · dm ⁻³ ) of compounds 1 to 3 Was measured.

  The measurement results are shown in FIG. In the figure, UV-vis indicates a visible / ultraviolet absorption spectrum. FL indicates a fluorescence spectrum.

  Compounds 1 to 3 had a maximum absorption wavelength of 543 to 574 nm, a molar extinction coefficient of 52900 to 59600, and a maximum fluorescence wavelength of 608 to 632 nm in dichloromethane. There was no significant difference in fluorescence intensity between compounds 1 to 3.

Example 2 Solid of 9-dibutylamino-1- [perfluoro-4-methyl-3- (1-methylethyl) -2-penten-2-oxy] benzo [a] phenoxazin-5-one (Compound 2) Fluorescence Spectrum Measurement in State The fluorescence spectrum in the powder state of Compound 2 was measured using a solid fluorescence measurement cell. As a result of the measurement, it was found that Compound 2 emits strong red fluorescence (FIG. 2).
λem = 719nm.

Example 3 9-Dibenzylamino-1- [perfluoro-4-methyl-3- (1-methylethyl) -2-penten-2-oxy] benzo [a] phenoxazin-5-one (compound 3) Fluorescence spectrum measurement in solid state The fluorescence spectrum in the powder state of Compound 3 was measured using a solid fluorescence measurement cell. As a result of the measurement, it was found that Compound 3 emits strong red fluorescence (FIG. 3).
λem = 682nm.

Example 4 Measurement of fluorescence spectrum of 9-dibutylamino-1- [perfluoro-2-methyl-2-penten-3-oxy] benzo [a] phenoxazin-5-one (compound 4) in the solid state The fluorescence spectrum in the powder state was measured using a solid fluorescence measurement cell. As a result of the measurement, it was found that Compound 4 emits strong red fluorescence (FIG. 4).
λem = 720 nm.

Comparative Example 1 Fluorescence spectrum measurement of 9-dibutylamino-6-hydroxybenzo [a] phenoxazin-5-one (Compound 5) in the solid state And measured. As a result of the measurement, Compound 5 did not emit red fluorescence. (FIG. 5).

Comparative Example 2 Measurement of fluorescence spectrum of 9-dibutylamino-benzo [a] phenoxazin-5-one (Compound 6) in the solid state The fluorescence spectrum of Compound 6 in the powder state was measured using a cell for measuring solid fluorescence. did. As a result of the measurement, Compound 6 did not emit red fluorescence. (FIG. 6).

  The fluorine-containing Nile red derivative according to the present invention is useful, for example, as various red fluorescent dyes and various analytical reagents.

FIG. 1 shows a visible / ultraviolet absorption spectrum and a fluorescence spectrum of a dichloromethane solution (concentration: 1 × 10 ⁻⁵ mol · dm ⁻³ ) of compounds 1 to 3 in Examples of the present application. FIG. 2 is a fluorescence spectrum in a powder state of Compound 2 in Examples of the present application. FIG. 3 is a fluorescence spectrum in a powder state of Compound 3 in Examples of the present application. FIG. 4 is a fluorescence spectrum in a powder state of Compound 4 in Examples of the present application. FIG. 5 is a fluorescence spectrum in a powder state of Compound 5 in Comparative Example of the present application. FIG. 6 is a fluorescence spectrum of Compound 6 in a powder state in Comparative Example of the present application.

Claims (6)

Fluorine-containing Nile red derivative represented by the general formula (I):

[Wherein, R ₁ and R ₂ are the same or different and each represents a linear or branched alkyl group having 1 to 10 carbon atoms, a phenyl group, a benzyl group, or a phenethyl group. Rf represents a perfluoroalkenyl group having 6 to 10 carbon atoms. ]. R ₁ and R ₂ are the same or different and each represents a linear or branched alkyl group having 4 to 10 carbon atoms, a phenyl group, a benzyl group or a phenethyl group, and Rf is

Or

The fluorine-containing Nile red derivative according to claim 1, wherein Nile red derivatives represented by general formula (II):

[Wherein, R ₁ and R ₂ are the same or different and each represents a linear or branched alkyl group having 1 to 10 carbon atoms, a phenyl group, a benzyl group, or a phenethyl group. ]
A method for producing a fluorine-containing Nile red derivative represented by the general formula (I) according to claim 1, wherein the perfluoroalkene having 6 to 10 carbon atoms is reacted. A red fluorescent material comprising the fluorine-containing Nile red derivative according to claim 1. A solid red fluorescent material comprising the fluorine-containing nile red derivative according to claim 2. A light emitting device comprising the solid red fluorescent material according to claim 5 between a pair of electrodes.

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