JP2003081986A - Rare earth complex, optically functional material using the same and emission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a rare earth complex and a transparent solid carrier containing the same having high phototransformation efficiency, useful as a novel emission device by being combined with an LED (light-emitting diode) or a semiconductor laser and applicable to general lighting systems, signaling devices, or displays. SOLUTION: This rare earth complex for optically functional materials is expressed by general formula (I) [wherein Ln expresses a rare earth atom; n1 expresses 2 or 3; n2 expresses 1 or 2; n3 expresses 1, 2, 3 or 4; X expresses H, D, a halogen (F, Cl, Br or I), a 1-20C group, OH, nitro, amino, sulfonyl, cyano, silyl, a phosphonic acid group, diazo or mercapto; Y expresses a 1-20C group, OH, nitro, amino, sulfonyl, cyano, silyl, a phosphonic acid group, diazo or mercapto; D expresses deuterium]. This optically functional material is obtained by bringing the rare earth complex to be included in the transparent solid carrier. This emission device is provided by combining the optically functional material with the LED or the semiconductor laser.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a rare earth complex having useful optical characteristics, and an optical functional material and a light emitting device to which the rare earth complex is applied.

[0002]

2. Description of the Related Art The development of electronic materials has been remarkable, and many optical functional materials have been developed in the field of optoelectronics. For example, as an electronic device for laser light,
Glass containing neodymium has been put to practical use. However, it is difficult to manufacture and process, and the manufacturing cost is high, so that its use is limited.

Japanese Patent Application Laid-Open No. 64-26583 discloses a resin composition containing a thiophene and an ammonium salt of a β-diketone / Eu complex having CF ₃ as a substituent as a polymer composition having a light emitting property. There is. Furthermore, Japanese Patent Application 10
-238973, as a polymer composition having a luminescent property, C
A resin composition containing a deuterated β-diketone / Eu complex or a sulfonate / Eu complex having F ₃ as a substituent is disclosed.

[0004]

However, these resin compositions have not yet reached a satisfactory level of light emission characteristics.

On the other hand, some of the inventors of the present invention began to reexamine the energy gap theory to design a group of complexes of rare earth metals such as neodymium capable of emitting light in an organic medium for the first time in 1995. Succeeded (Yasuya Hasegawa, "How to make non-luminous neodymium glow in an organic medium?", Kagaku to Kogyo, Vol. 53 (2000) No. 2, pp.126.
-130). We also filed patent applications for some of these (PC
T / JP98 / 00970 = WO98 / 40388 publication, Japanese Patent Application No. 10-238973 = JP2
000-63682, Japanese Patent Application No. 11-62298 = Japanese Patent Laid-Open No. 2000-256251).

These complexes are stable even at a high temperature of 350 ° C. and are less susceptible to photodegradation, which overturns the conventional wisdom that organic compounds are susceptible to degradation by heat or light irradiation. In addition, it has high affinity with resin-based host materials such as plastics and polymers, and is expected to become the next-generation optical device in combination with easy processability.

Therefore, the inventors of the present invention have applied for a patent for a composition having these excellent light emitting properties, and a light emitting device in which they are combined with an LED or a semiconductor laser (Japanese Patent Application No. 2001-135116).

While further researching the complex, the present inventors came to find a composition having further excellent absorption and emission characteristics, and now, the composition itself and an optical functional material using the composition, and further Provides a light emitting device by combining it with an LED or a semiconductor laser.

[0009]

The composition according to the present invention comprises:
It is a rare earth complex represented by the general formula (II) in FIG.

In the general formula (II) of FIG. 1, Ln represents a rare earth atom, and n1 represents 2 or 3. n2 represents 1 or 2. n3 represents 1, 2, 3 or 4. X is the same or different hydrogen atom, deuterium atom, halogen atom (F, Cl, Br,
I), a C _{1 to} C ₂₀ group, a hydroxyl group, a nitro group, an amino group, a sulfonyl group, a cyano group, a silyl group, a phosphonic acid group, a diazo group and a mercapto group. Y is the same or different C _{1 to} C ₂₀
Group, hydroxyl group, nitro group, amino group, sulfonyl group, cyano group, silyl group, phosphonic acid group, diazo group and mercapto group. Z represents a hydrogen atom or a deuterium atom.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Each constituent element will be described in more detail.

The C ₁ -C ₂₀ group is: * a linear or branched alkyl group (C _n H _{2n + 1} ; n = 1)
To 20), and a perfluoroalkyl group (C _n F _{2n + 1} ; n
= 1-20), per chloroalkyl group _{(C n Cl 2n +1; n} =
1-20) and other straight-chain or branched perhalogenated alkyl groups;

* Linear or branched alkenyl groups (vinyl group, allyl group, butenyl group), perfluoroalkenyl groups (perfluorovinyl group, perfluoroallyl group, perfluorobutenyl group), perchloroalkenyl A straight-chain or branched perhalogenated alkenyl group such as a group; a cycloalkyl group (C _n H _2n-1 ; n = 3 to 2)
0), and a perfluorocycloalkyl group (C
_n F _2n-1 ; n = 3 to 20), perchloroalkyl group (C _n Cl
_2n-1 ; a linear or branched perhalogenated alkyl group such as n = 3 to 20); cycloalkenyl groups (cyclopentyl group, cyclohexyl group, etc.), and perfluorocycloalkenyl groups, perchloroalkenyl groups, etc. Perhalogenated alkyl group;

* Aromatic groups such as phenyl group, naphthyl group, biphenyl group, and perfluorophenyl group, perfluoronaphthyl group, perfluorobiphenyl group, perchlorophenyl group, perchloronaphthyl group, perchlorobiphenyl group, etc. Halogenated aromatic groups;

* Heteroaromatic groups such as pyridyl groups, and perhalogenated heteroaromatic groups such as perfluoropyridyl groups;

* Aralkyl groups such as benzyl group and phenethyl group, and perhalogenated aralkyl groups such as perfluorobenzyl group;

And the like.

The C _{1 to} C ₂₀ group represented by X and Y includes a deuterium atom, a halogen atom (F, Cl, Br, I), if necessary,
It may be substituted with a substituent such as a hydroxyl group, a nitro group, an amino group, a sulfonyl group, a cyano group, a silyl group, a phosphonic acid group, a diazo group or a mercapto group.

Further, one or more --O--, --COO--, and --CO-- are interposed between CC single bonds at arbitrary positions of the C _{1 to} C ₂₀ group to form an ether, ester or ketone structure. Good.

General formula (II) in which X and Y are alkenyl groups
If desired, the rare earth complex may be polymerized with an olefin such as ethylene or propylene and a halogenated olefin to obtain a polymer rare earth complex.

In the compound represented by the general formula (II), Y
As the above, the above-mentioned ones can be used. Particularly, considering the stability and the emission intensity of the rare earth complex or the transparent solid support containing the rare earth complex, an alkyl group having 1 to 4 carbon atoms, a perhalogenated alkyl group. A group, an aromatic group, a perhalogenated aromatic group, a heteroaromatic group, and a perhalogenated heteroaromatic group are preferable, and a perfluoroalkyl group, an aromatic group, and a heteroaromatic group are most preferable.

The rare earth elements represented by Ln include La, Ce,
Examples thereof include lanthanum series elements such as Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, and Nd, Eu, Tb and Yb are preferable.

N1 is 2 or 3, but is preferably 3. n2 is 1 or 2, but preferably 2 is shown.
n3 is any of 1 to 4, but preferably 3 is shown.

A complex of the general formula (I) as defined in claim 1 (wherein Z is a deuterium atom D) by subjecting the complex of the general formula (II) and a deuterating agent to a deuterium substitution reaction. ) Is obtained. Examples of the deuterating agent used include deuterium-containing protic compounds, specifically, deuterated water, deuterated alcohols such as deuterated methanol and deuterated ethanol, deuterium chloride and deuterated alkali. To be A basic agent or additive such as trimethylamine or triethylamine may be added to accelerate the reaction. The deuterium substitution reaction can be obtained by mixing the complex represented by the general formula (II) with a deuterating agent, but an aprotic solvent may be added during the reaction. Examples of the aprotic solvent include ketone solvents such as acetone and methyl ethyl ketone, ether solvents such as diethyl ether and tetrahydrofuran, halogen solvents such as chloroform and methylene chloride, DMSO and DMF. Among them, a solvent in which the general formula (II) is soluble and soluble is preferable.

The amount of deuterating agent used is, for example, about 1 to 100 parts by weight, preferably 1 part by weight, relative to the total amount of the complex represented by the general formula (II) (1 part by weight). It is about 20 parts by weight.

The method of mixing is not particularly limited, and the temperature is from room temperature to 150 ° C., preferably from 30 ° C. to 100 ° C., if necessary with stirring for 0.1 to 100 hours, preferably 0.1.
Mix for 1 to 20 hours.

After stirring, the deuterating agent and the solvent are distilled off to obtain the complex represented by the general formula (I). Further, if necessary, it can be further purified by a method such as recrystallization, column chromatography, sublimation or the like.

By the above method, the general formula (I) and the general formula
The rare earth complex represented by (II) can be prepared.

The light absorption and emission characteristics of the rare earth complex according to the present invention will be described in detail later.

By incorporating a rare earth complex having the above-mentioned useful light absorption and emission characteristics into a transparent solid support, it can be used for various optical functional materials such as a light emission auxiliary and an optical lens. The crystal itself of the rare earth complex can be used as an optical functional material, of course.

Further, a crystal of the rare earth complex or a transparent solid support containing the rare earth complex is combined with a light emitting diode or a semiconductor laser which emits excitation light corresponding to the ff transition of the central ion of the rare earth complex or the absorption of the ligand. Further, the light emitting device can be used as a light emitting device having high luminous efficiency.

As the above-mentioned transparent solid carrier, a transparent polymer matrix, transparent glass or the like can be used.

As the transparent polymer matrix, polymethylmethacrylate, fluorine-containing polymethacrylate, polyacrylate, fluorine-containing polyacrylate, polystyrene, polyethylene, polypropylene, polyolefin such as polybutene, fluorine-containing polyolefin, polyvinyl ether, fluorine-containing polyvinyl ether, poly Vinyl acetate, polyvinyl chloride, and their copolymers, cellulose, polyacetal, polyester, polycarbonate, epoxy resin, polyamide resin, polyimide resin,
Examples include polyurethane, Nafion, petroleum resin, rosin, and silicon resin, and preferably polymethyl methacrylate, fluorine-containing polymethacrylate, polyacrylate, fluorine-containing polyacrylate, polystyrene, polyolefin, polyvinyl ether, and copolymers thereof, epoxy. Resin or the like can be used. Of course, a combination of two or more of these may be used.

When the rare-earth complex is contained in the transparent polymer matrix or transparent glass, a polar solvent may be contained at the same time in order to enhance its transparency.

As the polar solvent, for example, DMSO-d ₆ (dimethyl sulfoxide) can be used.

[0036]

INDUSTRIAL APPLICABILITY The rare earth complex and the transparent solid support containing the same of the present invention have high light conversion efficiency and are useful as a novel light emitting device in combination with an LED or a semiconductor laser. It can be applied to devices.

In the rare earth complex of the present invention, the emission wavelength can be changed by changing the structure of the ligand and / or the kind of the rare earth atom, and the color of any wavelength can be obtained.

[0038]

The present invention will be described in more detail based on the following examples, but it goes without saying that the present invention itself is not limited to these examples.

Synthesis of Eu (hfa-H) ₃ (H ₂ O) ₂ Complex Europium acetate (Eu (CH ₃ COO) ₃ : 5 g, 12.5 mmol) 50 m
Dissolve in 1 liter of distilled water and add hexafluoroacetylacetone.
_{(hfa) (CF 3 COCH 2} COCF 3: 7g, 33.6mmol) was added, at room temperature
Stir for 3 hours. The precipitated solid was filtered, washed with water, and recrystallized with methanol and distilled water to obtain the target complex (Eu (hfa-H) ₃
(H ₂ O) ₂ : pale yellow) was obtained. The obtained complex has a differential thermal analysis (D
SC) confirmed that it was a dihydrate. IR (c
m ^-1 ): 3450 (OH st.), 1650 (CO st.), 1250 ~ 1150 (C-
F) 19F-NMR (acetone-d ₆ , standard substance C ₆ F ₆ ; ppm): -78.3
(CF ₃ )

Synthesis of Eu (hfa-H) ₃ (TPPO) ₂ Complex The complex (Eu (hfa-H) ₃ (H ₂ O) ₂ 5.77 g) obtained in Example 1 and triphenylphosphine oxide (TPPO: 2.97 g) 10
It was dissolved in 0 ml of methanol and heated under reflux for 12 hours. 1
After 2 hours, methanol was removed by distillation under reduced pressure to obtain a white product. This powder was washed with toluene and unreacted
After removing the Eu (hfa-H) ₃ (H ₂ O) ₂ complex by suction filtration,
Toluene was distilled off under reduced pressure. The obtained product was washed with hexane to obtain a powder. The yield was 5.28 g, and the yield was 74%. The target complex (Eu (hfa-H) ₃ (TPPO) ₂ ) was obtained by recrystallization from a mixed solvent of toluene and hexane. IR (cm ^-1 ): 1650 (C = O), 1250 ~ 1150 (CF), 1125 (P = O) 19F-NMR (acetone-d ₆ , standard substance C ₆ F ₆ ; ppm): δ-76.7
(s, CF) ¹ H-NMR (acetone-d ₆ , standard substance TMS; ppm): δ 7.6 (m, a
romatic CH), 5.4 (s, CH) Elemental analysis (EuC ₅₁ H ₃₃ O ₈ F ₁₈
P ₂ ) Measured value C, 45.94; H, 2.57% Calculated value C, 45.96; H, 2.50%

Synthesis of Eu (hfa-D) ₃ (TPPO) ₂ The deuteration reaction of the complex obtained in Example 2 was carried out according to known literature (Hasegawa, Y .; Murakoshi, K .; Wada, Y .; Yanagida,
S .; Kim, J .; Nakashima, N .; Yamanaka, TJ Phys.
Chem. 1996, 100, 10201.). The obtained powder is thoroughly dried and the target complex (Eu (hfa-D) ₃ (TPPO) ₂ ) is obtained.
Got

Preparation of Polymer Containing Eu (hfa-D) ₃ (TPPO) _{2 The} polymer containing the complex obtained in Example 3 was prepared according to known literature (Hasegawa, Y .; Sogabe, K .; Wada, Y. ; Kitamura,
T .; Nakashima, N .; Yanagida, S. Chem. Lett. 1999, 3
Preparation was performed according to 5.).

Luminescent Properties Luminescent properties of PMMA polymer (A, B) containing Eu (hfa-D) ₃ (TPPO) ₂ are shown in FIG. For comparison, PMMA polymers containing rare earth complexes described in the literature (Hasegawa, Y .; Sogabe, K .; Wada, Y .;
Kitamura, T .; Nakashima, N .; Yanagida, S. Chem. L
ett. 1999, 35.) The emission characteristics of (C, D) are shown in the same graph. As shown in FIG. 2, a transparent solid support (A,
B) is a PMM containing the one described in the literature (Eu (hfa-D) ₃ (D ₂ O) ₂
It can be seen that the emission quantum yield is dramatically improved compared to A) (C, D).

FIG. 3 shows a graph of the emission spectrum of each sample. The spectrum intensity on the vertical axis was normalized with the emission intensity at 590 nm being 1. The excitation wavelength is 465 nm, which corresponds to the ff transition of Eu ³⁺ , the central ion of the complex. PM containing sample A (Eu (hfa-D) ₃ (TPPO) ₂ ), which is an example of the present invention.
MA) shows that the emission intensity at 615 nm (red) is relatively strong. Moreover, what is noticed in FIG. 3 is that the peak intensity ratios of the respective samples are different. This shows that the color rendering of light emission can be adjusted within a certain range by appropriately designing the selection of the ligand and the presence / absence (the amount) of the additive.

FIG. 4 shows a sample A (E which is an embodiment of the present invention.
7 shows the excitation spectrum of PMMA) containing u (hfa-D) ₃ (TPPO) ₂ . In addition to the sharp peak at 465 nm, it has a broad absorption band at 370 to 450 nm. 465 nm is the central ion Eu as described above
It is due to the ³⁺ ff transition, and the broad absorption band at 370-450 nm is thought to be due to many overlapping ff transitions or due to the ligand.

FIG. 5 shows a sample A (E
u (hfa-D)₃(TPPO)₂Of the transmitted light.
This is a spectrum measurement. InGaN-LED
Adjust the component variable x so that the center of the emission wavelength is 465 nm.
It has been prepared and has an emission peak in the range of 450 to 500 nm.
However, the rare earth complex Eu (hfa-D) at 465 nm
₃(TPPO)₂The central ion of Eu³⁺Absorption due to f-f transition of
There is a peak. Also, a large emission peak at 615 nm
Appears and is small even near 591 nm and 700 nm.
The luminescence peak appears. As shown in Figure 2, these
Has a high luminous efficiency of about 70%.

FIG. 6 shows that the component variable x of the InGaN-LED is adjusted so that it falls within the broad excitation light range of 370 to 450 nm of sample A (PMMA containing Eu (hfa-D) ₃ (TPPO) ₂ ). Emission wavelength is 405n
It is the result of performing the same measurement as m. In this case as well, a large peak appears in the vicinity of 615 nm, which is 591 nm and 700 nm.
A small peak appears in the vicinity.

FIG. 7 shows a conventional white LED (InGaN blue LED is Y
Sample A (Eu (hfa-D)) on top of AG phosphor)
PMMA) containing ₃ (TPPO) ₂ was covered and the same measurement was performed. An absorption peak due to the ff transition of Eu ³⁺ is clearly observed at 465 nm. And as a result, 615n
A large emission peak appears near m. As is clear from this figure, the light-emitting device manufactured in this way is
It becomes close to an ideal white color that supplements the red component that was lacking in conventional white LEDs, and the light source using it becomes a white light source with extremely high color rendering. This can be used as a useful light source in fields in which color identification or color rendering is particularly required, such as surgery and product displays.

Since the rare earth complex according to the present invention has such an absorption characteristic, it can be effectively used as a highly efficient wavelength conversion light functional material by combining an LED or a semiconductor laser as its excitation light source. In particular, a broad absorption band of 370 to 450 nm as shown in FIG. 4 is considered to bring about a great effect in combination with a broadband light emitter such as EL.

Regarding the usefulness of such a wavelength-converting optical functional material and a light emitting device in which it is combined with an LED or a semiconductor laser, the above-mentioned application (Japanese Patent Application No. 2001-1)
35116). The rare earth complex according to the present invention and an optical functional material which is a transparent solid support containing the same,
Furthermore, the light emitting device by combining it with LEDs, semiconductor lasers and other light emitters provides the same industrial utility to society.

[Brief description of drawings]

FIG. 1 is a general formula of a rare earth complex according to the present invention.

FIG. 2 is a comparison table of emission characteristics of a rare earth complex which is an example of the present invention and a rare earth complex of a comparative compound.

FIG. 3 is a graph of emission spectra of a rare earth complex which is an example of the present invention and a rare earth complex of a comparative compound.

FIG. 4 is a graph of an excitation spectrum of a rare earth complex which is an example of the present invention.

FIG. 5 is a graph showing a result of measuring a spectrum of transmitted light by covering sample A on an InGaN blue LED having a central emission wavelength of 465 nm.

FIG. 6 is a graph showing a result of measuring a spectrum of transmitted light by covering sample A on an InGaN purple LED having a central emission wavelength of 405 nm.

FIG. 7 is a graph showing a result of measuring a spectrum of transmitted light by covering the white LED in which the InGaN blue LED is covered with the YAG phosphor with the sample A.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05B 33/14 H05B 33/14 B (72) Inventor Junichi Shimada 31 Kawanakamachi, Yamanashi-ku, Kyoto-shi, Kyoto Prefecture -3 (72) Inventor Yoichi Kawakami 665-6 Shimogasa-cho, Kusatsu City, Shiga Prefecture (72) Inventor Shigeo Fujita 47-35 Shimazu, Momoyama-cho, Fushimi-ku, Kyoto City, Kyoto Prefecture 3K007 AB04 AB14 DA01 DB03 EB00 4H048 AA01 AB92 VA45 VA70 VB10 4H050 AB92 5F041 AA11 CA34 EE25 FF11

Claims (4)

[Claims] 1. A compound represented by the general formula (I): [In the formula, Ln represents a rare earth atom, and n1 represents 2 or 3. n2 represents 1 or 2. n3 represents 1, 2, 3 or 4. X represents the same or different hydrogen atom, deuterium atom, halogen atom, C _{1 to} C ₂₀ group, hydroxyl group, nitro group, amino group, sulfonyl group, cyano group, silyl group, phosphonic acid group, diazo group, mercapto group. Show. Y represents the same or different C _{1 to} C ₂₀ group, hydroxyl group, nitro group, amino group, sulfonyl group, cyano group, silyl group, phosphonic acid group, diazo group and mercapto group. D represents a deuterium atom. ] The rare earth complex for optical functional materials represented by. 2. A transparent fixed carrier for an optical functional material, which comprises the rare earth complex according to claim 1. 3. A compound represented by the general formula (II): [Wherein Ln, n1, n2, n3, X and Y are the same as above, and Z
Represents a hydrogen atom or a deuterium atom. ] A crystal of a rare earth complex represented by or a transparent fixed support containing the rare earth complex, and a light emitting diode or semiconductor emitting excitation light corresponding to the ff transition of the central ion Ln ^{n1 +} of the complex or the absorption of the ligand of the complex A light-emitting device characterized by being combined with a laser. 4. The light emitting device according to claim 3, wherein the central ion Ln ^{n1 +} is Eu ³⁺ .