JP2003109758A - Organic electroluminescent element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electroluminescent element of high brightness using phosphorescent compound having light color at blue region for use in organic electroluminescence. SOLUTION: Metal complex having biaryl ligand of a specific structure expressed in formula (I) with the torsion angle (dihedron) of the plane of its two aryl rings at not less than 9 deg. and less than 90 deg. is contained in a light emitting layer. In the formula, X denotes C<1> , N, O atoms, M denotes C, N atoms, Y denotes C, N atoms, Z denotes C, N atoms, A and B denote carbon cycles or heterocyles of 5 to 6 members, and Me denotes iridium, platinum, and osmium.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescence (hereinafter abbreviated as organic EL) device. More specifically, the present invention relates to an organic electroluminescence device having an excellent color tone in the blue to blue-green range and high emission brightness.

[0002]

2. Description of the Related Art An electroluminescent display (ELD) is used as a light emitting type electronic display device.
There is. Examples of the ELD constituent elements include an inorganic electroluminescent element and an organic electroluminescent element. Inorganic electroluminescent elements have been used as a flat light source, but a high alternating voltage is required to drive the light emitting element. An organic electroluminescence device has a structure in which a light emitting layer containing a compound that emits light is sandwiched between a cathode and an anode, and electrons and holes are injected into the light emitting layer to recombine to generate excitons (excitons). It is an element that emits light by utilizing the emission of light (fluorescence / phosphorescence) when the excitons are generated and deactivated, and can emit light at a voltage of several V to several tens of V. Further, it is a self-luminous type. Therefore, it has a wide viewing angle and high visibility, and since it is a thin-film type complete solid-state element, it is attracting attention from the viewpoints of space saving, portability, and the like.

However, in the organic EL element for practical use in the future, it is desired to develop an organic EL element which emits light with high efficiency and low power consumption.

The full color system of the organic EL device of the present invention is characterized by using a fluorescent light emitting material as a host compound and a phosphorescent compound as a dopant.

In Japanese Patent No. 3093796, a stilbene derivative, a distyrylarylene derivative or a trisstyrylarylene derivative is doped with a small amount of a phosphor to improve the emission brightness and prolong the life of the device.

Further, a device having an organic light-emitting layer in which an 8-hydroxyquinoline aluminum complex is used as a host compound and a slight amount of phosphor is doped therein (Japanese Patent Laid-Open No. 63-264).
No. 692), an element having an organic light-emitting layer obtained by doping an 8-hydroxyquinoline aluminum complex as a host compound with a quinacridone dye (JP-A-3-25).
No. 5190) is known.

As described above, when light emission from excited singlet is used, the production ratio of singlet excitons and triplet excitons is 1 :.
Therefore, the limit of the external extraction quantum efficiency (η _ext ) is set to 5% because the generation probability of the luminescent excited species is 25% and the light extraction efficiency is about 20%.
However, Princeton et al. Reported on an organic EL device using phosphorescence emission from excited triplet (MA Baldo.
et al. , Nature, Volume 395, 151-1
Since page 54 (1998)), research on materials that exhibit phosphorescence at room temperature has become active. For example, M.
A. Baldo et al. , Nature, 403
Vol. 17, No. 17, pp. 750-753 (2000), and US Pat. No. 6,097,147.

When the excited triplet is used, the upper limit of the internal quantum efficiency is 100%, so that the luminous efficiency is four times as high as that of the excited singlet in principle, and the performance almost equal to that of the cold cathode tube is obtained. It can be applied to lighting and is attracting attention.

For example, S. Lamansky et a
l. J. Am. Chem. Soc. , Volume 123, 43
On page 04 (2001) and the like, many compounds have been studied for synthesis centering on heavy metal complexes such as iridium complex.

In addition, the above-mentioned M. A. Baldo et a
l. , Nature, 403, No. 17, 750-75.
In page 3 (2000), studies using tris (2-phenylpyridine) iridium as a dopant are conducted.

In addition, M. E. Tompson et al.
he 10th International Wor
kshop on Inorganic and Or
ganic Electroluminescence
(EL'00, Hamamatsu), as a dopant, L ₂
Ir (acac) For example (ppy) ₂ Ir (acac)
See also Moon-Jae Young, Tetsuo
After all, Tsutsui et al. Are The 10th I
international Workshop I
norganic and Organic Elec
troluminence (EL'00, Hamamatsu)
In, as a dopant, tris (2- (p-tolyl) pyridine) iridium (Ir (ptpy) ₃ ), tris (benzo [h] quinoline) iridium (Ir (bz
q) ₃ ), Ir (bzq) ₂ ClP (Bu) _{3 and the} like are being studied.

Further, the above-mentioned S. Lamansky et
al. J. Am. Chem. Soc. , Volume 123, 4
Even on page 304 (2001) and the like, attempts have been made to form devices using various iridium complexes.

In addition, tris (2-phenylpyridine)
Improvements using iridium have also been reported in several documents.

These phosphorescent compounds, especially the complexes centering on iridium, are compounds having phosphorescence in the green to blue-green region, but in order to realize full color, in the three primary color regions of red, green and blue. A device material that emits light is required. For red and green, a phosphorescent compound having high emission efficiency as a dopant and excellent chromaticity has been found as a dopant, but in the complex centered on iridium, light emission from green to blue-green region is shown, and Among them, even a compound which emits light in a short-wave region has a drawback of having too long wavelength, and when a system using these phosphorescent compounds as a dopant is made into a full color, a problem in color reproduction occurs. A phosphorescent compound having a wider bandgap and emitting light in the short wavelength region such as 420 to 460 nm at the emission maximum wavelength was required as a dopant.

In order to obtain high luminous efficiency, The
10th International Works
op on Inorganic and Organ
icElectroluminescence (EL
(00, Hamamatsu), Ikai et al. Use a hole-transporting compound as a host for a phosphorescent compound. Also,
M. E. Tampson et al. Use various electron-transporting materials as a host of a phosphorescent compound by doping them with a novel iridium complex. Furthermore, Tsutsui
Et al. Obtained high luminous efficiency by introducing a hole blocking layer.

The host compound when the phosphorescent compound is used as a dopant is required to have an emission maximum wavelength in a region shorter than the emission maximum wavelength of the phosphorescent compound. Regarding the host compound of the phosphorescent compound, For example,
C. Adachi et al. , Appl. Phy
s. Lett. , 77, 904 (2000)
Etc., the use of a phosphorescent compound that emits light in the blue region as a dopant requires a host compound having a wider band gap than conventionally known host compounds. In conventional host compounds, the band gap is narrow, so the efficiency of energy transfer is low, and the emission intensity is weak.
As the host compound, a fluorescent compound that emits short-wave light with a wider band gap is required.

[0017]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a phosphorescent compound having a luminescent color in the blue region used for organic electroluminescence, and an organic electroluminescent device using the same having a high emission brightness. Is to provide.

[0018]

The above objects of the present invention can be achieved by the following means.

1. Represented by the general formula (1), NM-
An organic electroluminescence device comprising a light emitting layer containing a metal complex having a dihedral angle of YZ (that is, a twist angle of two rings) of 9 degrees or more and less than 90 degrees.

2. An organic electroluminescence device comprising a light emitting layer containing the metal complex represented by the general formula (2).

3. An organic electroluminescence device comprising a light emitting layer containing the metal complex represented by the general formula (3).

4. An organic electroluminescence device comprising a light emitting layer containing the metal complex represented by the general formula (4).

5. In the general formula (4), NM-
5. The organic electroluminescent device as described in 4 above, wherein the YZ dihedral angle (that is, the twist angle of the two rings) is 9 degrees or more and less than 90 degrees.

6. An organic electroluminescent device comprising a light emitting layer containing the metal complex represented by the general formula (5).

7. An organic electroluminescence device comprising a light emitting layer containing the metal complex represented by the general formula (6).

8. An organic electroluminescence device comprising a light emitting layer containing the metal complex represented by the general formula (7).

9. An organic electroluminescence device comprising a light emitting layer containing the metal complex represented by the general formula (8).

10. An organic electroluminescence device comprising a light emitting layer containing the metal complex represented by the general formula (9).

11. The aromatic group represented by Ar in the general formula (7) is an aromatic hydrocarbon ring group substituted with an electron-withdrawing group having a Hammett's substituent constant σp value of 0.02 or more and 2 or less. 9. The organic electroluminescence device according to the above item 8, which is characterized.

12. The aromatic group represented by Ar in the general formula (7) is an aromatic hydrocarbon ring group substituted with an electron-withdrawing group having a Hammett's substituent constant σp value of 0.02 or more and 2 or less, and 9. The organic electroluminescent device as described in 8 above, wherein the substituent represented by R ₈₂ is an electron-withdrawing group having a Hammett's specified number of substitutions σp value of 0.02 or more and 2 or less.

13. At least one of the substituents represented by R _{101 to} R ₁₀₆ in the general formula (9) is an electron-withdrawing group having a Hammett's specified substitution number σp value of 0.02 or more and 2 or less. 10. The organic electroluminescent element according to 10.

The present invention will be described in detail below. As a result of earnest studies, the inventors of the present invention have made the above general formulas (1) to (9).
It was found that the metal complex compound represented by the formula (3) is a phosphorescent compound that emits light in the blue region of a shorter wavelength than the conventional one at the maximum emission wavelength, and is used as a dopant together with a host fluorescent compound to form an organic light emitting layer. It was found that an organic electroluminescence element (EL element) having an excellent emission color in the blue region can be obtained by configuring the above.

That is, when the metal complex compound of the present invention is used as a dopant, the emission color is a spectral radiance meter CS-1.
000 (manufactured by Minolta), and measure the coordinates with CI
E chromaticity coordinates (Fig. 4.16 on page 108 of "New Color Science Handbook" (edited by the Japan Color Association, The University of Tokyo Press, 19
85)) when applied to Blue, Greenis
h Blue (green-blue), Blue Green (blue-green)
Alternatively, it has an emission color in the area of Blue Green.

As a result, the emission color required for full color display can be obtained. As described above, a heavy metal complex such as an iridium complex system having a 2-phenylpyridine derivative as a ligand has been typical, and it is known to emit light in the green to blue-green region. However, in order to obtain a shorter-wavelength blue light emission as a primary color, as a result of earnest studies on a phosphorescent compound having a further shorter-wavelength light emission, these 2-phenylpyridine derivatives, or two Phosphorescence emission of a heavy metal complex having a ligand having a structure in which an aryl or heteroaryl ring is directly bonded is shortened, and Blue to Blues
It has been found that light can be emitted in a shorter wave region called h Green than before. 1) Increase the twist angle (dihedral angle) of the ring plane of two aryl or heteroaryl rings such as a 2-phenylpyridine ligand. 2) A bulky group is introduced into at least one of the ortho positions of the direct bonding sites of the two rings to increase the twist angle (dihedral angle) of the two ring planes. 3) Furthermore, the substituents on the two aryl or heteroaryl rings, or the groups substituting the substituents on the rings are electron-withdrawing groups.

By the above method, the wavelength of phosphorescence emission of the heavy metal complex coordinated by the ligand having two rings such as 2-phenylpyridine can be shifted to a shorter wavelength in the blue region.

The heavy metal complex used in the present invention is represented by the general formulas (1) to (9). First, the compound represented by formula (1) will be described.

That is, in the general formula (1), the ring planes of the ring formed by A together with X-M-N and the ring formed by B by C-Y-Z are connected to each other with a twist angle. is necessary. That is, NM- in the general formula (1)
A metal complex having a YZ dihedral angle (that is, a twist angle of two rings) of 9 degrees or more and less than 90 degrees exhibits phosphorescence in the blue chromaticity region, which is slightly shorter than the conventional one as described above. It is a material, and when it is used as a dopant, it becomes an organic electroluminescence device that exhibits highly efficient light emission in the blue region.

In the above general formula (1), N represents a nitrogen atom, C represents a carbon atom, X represents a carbon atom, a nitrogen atom or an oxygen atom, M represents a carbon atom or a nitrogen atom, and Y represents a carbon atom. Or a nitrogen atom, Z represents a carbon atom or a nitrogen atom, A represents an atomic group necessary for forming a 5- or 6-membered heterocycle together with X-M-N, and B represents C-.
It represents a group of atoms necessary for forming a 5- or 6-membered hydrocarbon ring or heterocycle with YZ. Further, the two rings may each independently have a substituent, and adjacent substituents may further form a condensed ring. Me represents iridium, platinum or osmium, and W ₁ represents an oxygen atom, a nitrogen atom or a sulfur atom. n represents 1, 2, 3 or 4, m is 3-n when Me is iridium, 4-n or 2-n when platinum, and 2-n when osmium.
Represents W ₂ represents an oxygen atom, a nitrogen atom or a sulfur atom, L ₁ represents a nitrogen atom or a carbon atom, L ₂ represents a nitrogen atom or an oxygen atom, and l represents 1 or 2.
In addition, W ₁ and L ₁ , L ₁ and L ₂ , L ₂ and L ₂ (when 1 is 2),
The bond between L ₂ and W ₂ may be a single bond or a double bond.

The 5- or 6-membered heterocyclic ring formed by A together with X-M-N represents a heteroaryl ring such as pyridine, pyrazine, pyrimidine, quinoline, isoquinoline, oxazole, pyrazole and benzoxazole.

The 5- or 6-membered hydrocarbon ring or heterocycle formed by B together with C--Y--Z is a benzene ring, a naphthalene ring or the like as the hydrocarbon ring, and the heterocycle is as described above. A mentioned above as the 5- to 6-membered heterocycle formed with X-M-N are included. However, the ortho position of the heterocyclic ring, which is a position directly bonded to the 5- or 6-membered heterocyclic ring formed together with X-M-N, is a carbon atom, and in the carbon atom, B is C-Y- 5-6 formed with Z
The member heterocycle is bonded to a heavy metal atom.

Of these, iridium is particularly preferable as Me. In the present invention, the twist angle θ of the two rings in the general formula (1) is the dihedral angle N-M-Y-Z, and means the value obtained by molecular mechanics calculation. Specifically, the structure of the complex is drawn by molecular mechanics calculation (using module is OFF Minimizer) of Cerius2, which is a molecular design support software manufactured by Accelrys in the United States.
It is obtained by performing structural optimization. At this time, the charge of the complex is Charge-Equilibra.
The force field is calculated using the universal force field.

For example, in the case of the above structure, the twist angle θ (dihedral angle) of two rings is as shown below for the complexes A and B of phenylpyridine and iridium, for example, θ ₁ , Indicates θ ₂ .

[0043]

[Chemical 10]

When there are a plurality of dihedral angles as in this example, it is not always possible to obtain the same value for θ ₁ and θ ₂ depending on the symmetry of the complex, but in that case, the average of θ ₁ and θ ₂ The value θ
Value of.

In the present invention, θ is 9 degrees or more and less than 90 degrees, and preferably 9 degrees or more and less than 45 degrees.

For example, by selecting an iridium complex having such a phenylpyridine derivative as a ligand, the ring planes of the phenyl ring bound to iridium and the pyridine ring also coordinated to iridium at the 2-position of the ring are obtained. Twist angles θ ₁ and θ ₂ (that is, dihedral angles) are generated between the two, which widens the band gap and shifts the wavelength of phosphorescence emission to the short-wave side.

The twist angles θ ₁ , θ obtained by the above-mentioned molecular calculation for the above-mentioned two types of iridium complexes (A, B) in which several phenylpyridine derivatives are coordinated.
₂ is shown in Table 1.

[0048]

[Table 1]

In order to obtain a biaryl derivative having such a twist angle, taking the case of the above phenylpyridine derivative as an example, a substitution with a bulky steric hindrance at the ortho position in view of the bonding position of the phenyl ring and the pyridine ring. It is better to introduce a group.

Therefore, from another point of view of the present invention, it is necessary to select such that the sum of the steric parameters Es of the substituents R ₁ and R ₂ is -0.6 or less, as in the general formula (2). There is. By selecting such a substituent, the biaryl ring, for example, each ring plane of the above-mentioned phenyl ring and pyridine ring is twisted due to steric hindrance, and twist (dihedral angle) is generated between the ring planes. It will be.

The compound represented by the general formula (2) is
A bulky group such as two aryls of a biaryl ligand
There are few ortho positions relative to the bonding position of each ring.
The feature is that both have one. General formula (2)
, N is a nitrogen atom, C is a carbon atom, and X is a carbon atom.
Represents an elementary atom, a nitrogen atom, an oxygen atom or a sulfur atom,
(However, when X is an oxygen atom or a sulfur atom, R₁Is
(Not present) M represents a carbon atom or a nitrogen atom, and Y represents
Represents a carbon atom or a nitrogen atom, and Z is a carbon atom or a nitrogen atom.
Represents an elementary atom, and A is a 5- or 6-membered heterocycle together with X-M-N.
Represents a group of atoms necessary to form B, and B is C-Y-Z.
Together to form a 5- or 6-membered hydrocarbon ring or heterocycle
Represents a necessary atomic group, and is. Me is iridium, plastic
Represents China or osmium. n is 1, 2, 3 or 4
Where m is 3-n when Me is iridium, platinum
For 4-n or 2-n, and for osmium 2-n
You W ₁Represents an oxygen atom, a nitrogen atom or a sulfur atom,
W₂Represents an oxygen atom, a nitrogen atom or a sulfur atom, and L₁Is
Represents a nitrogen atom or a carbon atom, L₂Is a nitrogen atom or
It represents an oxygen atom, and 1 represents 1 or 2. Note that W
₁And L₁, L₁And L₂, L₂And L₂(When l is 2), L₂And W₂
The bond of may be a single bond or a double bond. put it here,
R₁And R₂Represents a substituent or a hydrogen atom, and R₁When
R₂At least one of R represents a substituent,₁And R₂Three-dimensional
Select so that the sum of the parameter Es values is -0.6 or less.
Be exposed. This causes a twist between the two ring planes
The angle θ is generated.

Here, the Es value is a steric parameter derived from chemical reactivity, and the smaller this value, the more sterically bulky the substituent can be.

The Es value will be described below. In general,
It is known that in the hydrolysis reaction of an ester under acidic conditions, the effect of the substituent on the progress of the reaction may be considered to be only the steric hindrance. The Es value is obtained by digitizing.

The Es value of the substituent X is represented by the following chemical reaction formula: X-CH ₂ COOR _X + H ₂ O → X-CH ₂ COOH + R _X
Reaction rate constant k in the hydrolysis of an α-position mono-substituted acetic acid ester derived from an α-position mono-substituted acetic acid represented by OH 1 in which one hydrogen atom of the methyl group of acetic acid is substituted with a substituent X under acidic conditions _X and an acetic acid ester represented by the following chemical reaction formula CH ₃ COOR _Y + H ₂ O → CH ₃ COOH + R _Y OH (R _X is the same as R _Y ) corresponding to the above α-position monosubstituted acetic acid ester. It can be calculated from the reaction rate constant k _H during hydrolysis under acidic conditions by the following formula.

Es = log (k _X / k _H ) The reaction rate decreases due to the steric hindrance of the substituent X, and as a result, k _X <k _H , the Es value is usually negative.

When the Es value is actually obtained, the above two reaction rate constants k _X and k _H are obtained and calculated by the above equation.

Specific examples of Es values are described in Unger, S. et al.
H. Hansch, C .; , Prog. Phys. Or
g. Chem. , 12, 91 (1976). Also, "Structure-Activity Relationships of Drugs" (Chemical Area Special Issue No. 122, Nankodo), "American Ch
electrical Society Profession
al Reference Book, 'Explorer
ing QSAR'p. 81 Table 3-3 ”also describes the specific numerical values. Next, a part thereof is shown in Table 2.

It should be noted here that the Es value as defined in this specification does not define that of a methyl group as 0, but that of a hydrogen atom as 0 and that of a methyl group as 0. Is obtained by subtracting 1.24 from the Es value.

In the present invention, the Es value is −0.6 or less. Preferably, it is -7.0 or more and -0.6 or less.
Most preferably, it is -7.0 or more and -1.0 or less.

[0060]

[Table 2]

Therefore, as shown in the general formula (3),
Similar effects can be obtained even when another ring further forms a condensed ring at a position adjacent to the position where the ring formed by A together with N-M-X is bonded. For example, compound examples 13, 14, and 16 are mentioned as these examples.

Further, by substituting the two rings of the above-mentioned biaryl ligand such as phenylpyridine with electron withdrawing groups, the phosphorescence emission wavelength of these iridium complexes can be shortened. This can be represented by the general formula (4), which is represented by the general formula (4). In the general formula (4), an electron-withdrawing group that substitutes for each of two rings, EWG
The total σp value of 1 and EWG2 is selected to be 0.15 or more and 2 or less.

In the present invention, typical examples of the electron withdrawing group having a substituent σp value of 0 or more include a cyano group, a nitro group,
Halogen atom (fluorine atom, chlorine atom, bromine atom), formyl group, pentafluorophenyl group, carbamoyl group (eg, carbamoyl, morpholinocarbamoyl, N
-Each group such as methylcarbamoyl), trifluoromethyl group, trichloromethyl group, alkoxycarbonyl group (for example, each group such as methoxycarbonyl, ethoxycarbonyl, etc.), sulfamoyl group (for example, sulfamoyl, morpholinosulfonyl, N, N- Dimethylsulfamoyl etc.), acyl group (eg acetyl, benzoyl etc.), sulfonyl group (eg methanesulfonyl, ethanesulfonyl, benzenesulfonyl, toluenesulfonyl etc.) and the like.

The σp value is a substituent constant determined by Hammett et al. From the electronic effect of the substituent on the hydrolysis of the benzoic acid ester. Journal of Organic Chemistry, Vol. 23, 420-427 (1)
958), Experimental Chemistry Course 14 (Maruzen Publishing Co., Ltd.), Physical Organic Chemistry (McGrawHi)
ll Book: 1940), Drag Design VII
Volume (Academic Pres New Yor
k: 1976), structure-activity relationship of drugs (Nankodo: 197)
9) and the like.

A more preferred metal complex of the present invention is a complex represented by the general formula (4) in which the dihedral angle of NMYZ is 9 degrees or more and less than 90 degrees. That is, the biaryl-type ligand forming the metal complex is substituted with at least one substituent, and the sum of the σp values of the substituents is 0.15 or more and 2 or less, and the general formula In (4), the dihedral angle of N-M-Y-Z is 9 degrees or more 90.
It is less than degrees. More preferably, the general formula (4)
In which N-M-Y-Z has a dihedral angle of 9 degrees or more and less than 45 degrees, and has an electron-withdrawing group, and
There is a double effect that each ring plane constituting the biaryl has a twisted structure, which is preferable for shortening phosphorescence emission.

The metal complex represented by the general formula (5) is one in which one of the two rings constituting the biaryl ligand is a phenyl group, and shows a more preferable structure of the general formula (2). That is, in the general formula (5), the phenyl group has a substituent R ₆₁ adjacent to a position to which another (hetero) aryl ring is bonded, and the substituent has a steric parameter Es value of It is preferably −0.6 or less.

More preferred metal complexes used in the present invention are
It is represented by the general formula (6). The general formula (6) is used as a ligand
With 2-phenylpyridine. The phenylpyridine
Substituents on the ligand, especially R₇₁And R₇₅Is hydrogen or a substituent
Represents, but R₇₁And R ₇₅At least one of is a substituent
Or R₇₁And R₇₅Of each three-dimensional parameter of
The sum is −0.6 or less. R₇₁And R₇₅One of
By introducing a group having a small Es value into both, phenyl and pi
Twisting occurs between the ring planes of the lysine skeleton.

The general formula (7) will be described. In the general formula (7), the aryl group is substituted as a bulky group at the ortho position with respect to the bonding position of the phenyl group with the pyridyl group. Taking a phenyl group as an example, the Es value is −1.01, the steric parameter is small, and the effect of the present invention is great.

The general formula (8) is a metal complex in which a biaryl ligand in which one of the ring structures is a phenyl group is coordinated. The phenyl substituents of R _{91 to} R ₉₄ have a total sum of σp values of 0.15.
It is preferable that it can be selected as above and below 2.0.

The general formula (9) is characterized in that the phenyl moiety of 2-phenylpyridine forms a condensed ring containing a position adjacent to the site to which the pyridyl group is bonded. The formation of the condensed ring also sterically hinders the structure in which the two rings are in the same plane, and therefore the above general formulas (3), (5) and (7)
It is preferable because it brings about the same effect as in.

The general formula (1) according to the present invention will be described below.
Specific examples of the metal complex represented by (9) to (9) are shown below, but the invention is not limited thereto.

[0072]

[Chemical 11]

[0073]

[Chemical 12]

[0074]

[Chemical 13]

[0075]

[Chemical 14]

[0076]

[Chemical 15]

[0077]

[Chemical 16]

[0078]

[Chemical 17]

[0079]

[Chemical 18]

[0080]

[Chemical 19]

[0081]

[Chemical 20]

[0082]

[Chemical 21]

[0083]

[Chemical formula 22]

[0084]

[Chemical formula 23]

[0085]

[Chemical formula 24]

Typical synthetic examples of these metal complex compounds according to the present invention are shown below, but the invention is not limited thereto.

Synthesis Example (Compound 27) Chem. Commun. Intermediate 1 was synthesized according to the prescription of No. 1998, 2439.

Further, using the intermediate 1, J. Am. Ch
em. Soc. , 2001, 123, 4304, the compound 27 was synthesized with reference to the formulation of the iridium complex. The yield based on the intermediate 1 was 45%. In addition,
The compound was identified by 1 H-NMR and elemental analysis.

[0089]   Anal. Found C, 62.45; H, 4.08; N, 3.91.             Calcd C, 62.30; H, 4.16; N, 3.73.

[0090]

[Chemical 25]

[0091]

[Chemical formula 26]

Synthesis Example (Compound 13) Heterocycl. Chem. , 1992, 2
According to the prescription of 9,1673, 2- (1-naph
The compound 13 was synthesized using the same formulation as the above compound 27.
The yield from 2- (1-naphthyl) pyridine was 58%. The compound was identified by 1H-NMR and elemental analysis.

Anal. Found C, 60.12; H, 3.99; N, 3.87 Calcd C, 60.07; H, 3.89; N, 4.00 These, for example, 350 nm to 440 nm, more preferably 390 nm to An organic EL that emits light in the green region by using a fluorescent compound having a maximum fluorescence wavelength in the range of 410 nm as a host compound and using the iridium metal complex having phosphorescence in the blue to blue-violet region according to the present invention.
A device can be obtained.

In the present invention, a fluorescent compound is a compound in which light emission from an excited singlet in which two electron spins are antiparallel to each other is observed by photoexcitation, and a phosphorescent compound is detected by photoexcitation. It is a compound in which light emission from an excited triplet in which electron spins are parallel is observed. Here, in the phosphorescent compound according to the present invention, an excited triplet state is formed at room temperature (15 to 30 ° C.) by energy transfer from the excited singlet state or the excited triplet state of the fluorescent compound. It is thought to be.

In the present invention, the fluorescence maximum wavelength of the fluorescent compound is a maximum value when the fluorescence spectrum of the vapor deposition film when the fluorescent compound is vapor-deposited on a glass substrate to a thickness of 100 nm is measured.

Therefore, in the organic electroluminescence device of the present invention, the light emitting layer preferably contains both a fluorescent compound and a phosphorescent compound, but when the above metal complex compound is used as the phosphorescent compound, a full color compound is obtained. An emission color in the blue to blue-green region, which was excellent as a primary color of blue when displaying, was recognized.

In the present invention, the maximum wavelength of phosphorescence emission of the phosphorescent compound incorporated as a dopant is longer than the maximum wavelength of fluorescence of the fluorescent compound of the host, and thus the excited triplet of the phosphorescent compound incorporated as a dopant. It is possible to obtain an organic electroluminescence (EL) element utilizing the light emission by Therefore, the maximum emission wavelength obtained by electroluminescence in the state where the device is constructed is the maximum fluorescence wavelength of the fluorescent compound used as the host alone (100 n of the fluorescent compound on glass).
m is a longer wave than the maximum value when the fluorescence spectrum is measured with the deposited film when vapor-deposited.

The phosphorescent compound of the present invention has a phosphorescence quantum yield in solution of 0.001 or more at 25 ° C. It is preferably 0.01 or more. More preferably, 0.1
That is all.

The means for measuring the quantum yield φ _p in the excited triplet state and its theory will be described below.

From the excited singlet state to the ground state, the excitation energy is lost at the rate constants k _sn and k _f due to non-radiative transition and fluorescence emission. In addition to this, a transition to an excited triplet state occurs with a rate constant, k _isc , and deactivates. Here, the lifetime of the excited singlet state, τ _s, is defined by the following equation.

Τ _s = (k _sn + k _f + _{ki sc} ) ⁻¹ The quantum yield of fluorescence, φ _f is defined by the following equation.

Φ _f = k _f · τ _{s The} deactivated triplet state is deactivated by the non-radiative transition and the phosphorescence emission with the rate constants k _tn and k _p , respectively. The lifetime of the excited triplet state, τ _t, is defined by the following equation.

Τ _t = (k _tn + k _p ) ⁻¹ τ _t is 10 ⁻⁶ to 10 ⁻³ seconds, and a long one may reach several seconds. The quantum yield of phosphorescence, φ _p, is defined as follows using the quantum yield of excited triplet state generation, φ _ST .

Φ _p = φ _ST · k _p · τ _{t The} above parameters are the same as those in Spectroscopic II of 4th edition Experimental Chemistry Course 7.
It can be measured by the method described on page 98 (1992 version, Maruzen). Among the above parameters, the phosphorescence quantum yield in a solution of the phosphorescent compound can be measured using various solvents, but in the present invention, it is measured using tetrahydrofuran as the solvent.

The phosphorescence emission wavelength of the compound according to the present invention is a short wave (close to the blue region) as compared with the emission region shown by the conventionally known metal complex such as iridium as described above, and the triple wavelength of the compound. In the light emitting device utilizing the above item, it is necessary to further shorten the emission wavelength of the host compound, which is a phosphor, as compared with the conventional case. That is, it is preferable to combine with a compound having a wide band gap.

Conventionally, the maximum fluorescent wavelength of the fluorescent compound used as the host compound is preferably 350 nm to 440 nm, and more preferably 390 nm to 410.
nm.

Examples of fluorescent compounds that can be advantageously used as host compounds in the present invention are shown below. Among these, triarylamines having a wide band gap, biphenyl compounds and the like are preferable as those used in the light emitting layer together with the phosphorescent compound according to the present invention. However, these compounds are preferably used in the hole transport layer as well as in the light emitting layer.

[0108]

[Chemical 27]

[0109]

[Chemical 28]

[0110]

[Chemical 29]

[0111]

[Chemical 30]

[0112]

[Chemical 31]

[0113]

[Chemical 32]

[0114]

[Chemical 33]

[0115]

[Chemical 34]

[0116]

[Chemical 35]

[0117]

[Chemical 36]

[0118]

[Chemical 37]

[0119]

[Chemical 38]

[0120]

[Chemical Formula 39]

[0121]

[Chemical 40]

[0122]

[Chemical 41]

[0123]

[Chemical 42]

[0124]

[Chemical 43]

[0125]

[Chemical 44]

[0126]

[Chemical formula 45]

[0127]

[Chemical formula 46]

[0128]

[Chemical 47]

[0129]

[Chemical 48]

[0130]

[Chemical 49]

[0131]

[Chemical 50]

[0132]

[Chemical 51]

[0133]

[Chemical 52]

[0134]

[Chemical 53]

[0135]

[Chemical 54]

[0136]

[Chemical 55]

[0137]

[Chemical 56]

[0138]

[Chemical 57]

[0139]

[Chemical 58]

[0140]

[Chemical 59]

[0141]

[Chemical 60]

[0142]

[Chemical formula 61]

[0143]

[Chemical formula 62]

[0144]

[Chemical formula 63]

[0145]

[Chemical 64]

[0146]

[Chemical 65]

[0147]

[Chemical formula 66]

[0148]

[Chemical formula 67]

[0149]

[Chemical 68]

[0150]

[Chemical 69]

[0151]

[Chemical 70]

[0152]

[Chemical 71]

[0153]

[Chemical 72]

[0154]

[Chemical formula 73]

[0155]

[Chemical 74]

[0156]

[Chemical 75]

[0157]

[Chemical 76]

[0158]

[Chemical 77]

[0159]

[Chemical 78]

[0160]

[Chemical 79]

[0161]

[Chemical 80]

[0162]

[Chemical 81]

[0163]

[Chemical formula 82]

[0164]

[Chemical 83]

[0165]

[Chemical 84]

[0166]

[Chemical 85]

[0167]

[Chemical 86]

[0168]

[Chemical 87]

[0169]

[Chemical 88]

[0170]

[Chemical 89]

[0171]

[Chemical 90]

[0172]

[Chemical Formula 91]

[0173]

[Chemical Formula 92]

[0174]

[Chemical formula 93]

[0175]

[Chemical 94]

[0176]

[Chemical 95]

The band gap referred to in the present invention represents the difference between the ionization potential and the electron affinity of a compound, and the ionization potential and the electron affinity are determined based on the vacuum level. Ionization potential is HO of compound
It is defined as the energy required to release the electron at the MO (highest occupied molecular orbital) level to the vacuum level, and the electron affinity drops to the LUMO (lowest unoccupied molecular orbital) level of the electron at the vacuum level. Is defined as the energy that stabilizes. The difference between the ionization potential and the electron affinity can be calculated from the absorption edge of the absorption spectrum of the compound. In the present invention, the compound is 100% on glass.
nm to measure the absorption spectrum of the vapor deposition film,
The wavelength Ynm at the absorption edge is X (e
It can be obtained by converting into V).

X = 1240 / Y The light emitting layer will be described below.

In a broad sense, the light emitting layer as used herein means a layer which emits light when a current is applied to an electrode composed of a cathode and an anode. Specifically, it refers to a layer containing a fluorescent compound that emits light when a current is applied to an electrode composed of a cathode and an anode. Usually, electroluminescence elements (EL
The element) has a structure in which a light emitting layer is sandwiched between a pair of electrodes. The organic EL device of the present invention has a hole transport layer, an electron transport layer, an anode buffer layer, a cathode buffer layer, and the like in addition to the light emitting layer as necessary, and has a structure sandwiched between a cathode and an anode.

Specifically, (i) anode / light emitting layer / cathode (ii) anode / hole transport layer / light emitting layer / cathode (iii) anode / light emitting layer / electron transport layer / cathode (iv) anode / positive Hole transport layer / light emitting layer / electron transport layer / cathode (v) anode / anode buffer layer / hole transport layer / light emitting layer /
There is a structure represented by electron transport layer / cathode buffer layer / cathode.

As a method of forming a light emitting layer using the above compound, there is a method of forming a thin film by a known method such as a vapor deposition method, a spin coating method, a casting method and an LB method. Preferably there is. Here, the molecular deposition film is a thin film formed by depositing the above compound in a vapor phase state, or a film formed by solidifying a molten state or a liquid phase state of the compound. Usually, this molecular deposition film can be distinguished from a thin film (molecular cumulative film) formed by the LB method, based on the difference in aggregation structure, higher order structure, and functional difference caused by it.

Further, this light emitting layer is disclosed in JP-A-57-517.
No. 81, it can be obtained by dissolving the above compound as a light emitting material together with a binder such as a resin in a solvent to form a solution, and then applying this solution by a spin coating method or the like to form a thin film. it can.

The thickness of the light emitting layer thus formed is not particularly limited and can be appropriately selected depending on the situation, but is usually in the range of 5 nm to 5 μm.

Here, the phosphorescent compound according to the present invention is
Specifically, it is a heavy metal complex compound, preferably a complex compound having a Group VIII metal as a central metal in the periodic table of elements, and more preferably an osmium, iridium or platinum complex compound. Of these, iridium is particularly preferable.

These phosphorescent compounds have a phosphorescence quantum yield of 0.001 or more at 25 ° C. as described above, and also have a phosphorescence emission maximum wavelength longer than the fluorescence maximum wavelength of the host fluorescent compound. Accordingly, for example, by using a phosphorescent compound having a wavelength longer than the maximum emission wavelength of the fluorescent compound as a host, the emission of the phosphorescent compound, that is, the maximum fluorescence wavelength of the host compound using the triplet state is obtained. It is possible to obtain an EL element that emits light at longer wavelengths. The concentration of the phosphorescent compound is preferably 0.01 to 15 mol% with respect to the host compound. More preferably, it is 2 to 10%.

In the present invention, the host compound preferably has a high glass transition temperature (Tg) and a high thermal stability as a material of the organic electroluminescence device. T
It is preferable that g is 100 degrees or more.

The molecular weight of these compounds is preferably 600 or more. When the molecular weight is within this range, the light emitting layer can be easily produced by the vacuum vapor deposition method, and the production of the organic EL device becomes easy. Further, the thermal stability of the fluorescent compound in the organic EL device is improved.

Although the fluorescent compound is used as a host compound, it may be used in a hole transport layer or a hole injection layer and exhibits an excellent effect.

Next, other layers constituting the EL device in combination with the light emitting layer such as the hole injecting layer, the hole transporting layer, the electron injecting layer and the electron transporting layer will be described.

The hole injection layer and the hole transport layer have a function of transmitting the holes injected from the anode to the light emitting layer, and the hole injection layer and the hole transport layer are provided between the anode and the light emitting layer. By interposing, many holes are injected into the light emitting layer at a lower electric field, and moreover, the electrons injected from the cathode, the electron injection layer or the electron transport layer into the light emission layer, the holes are injected into the light emitting layer and the hole injection layer or the positive electrode Due to the electron barrier existing at the interface of the hole transport layer, the element is accumulated at the interface in the light emitting layer and the light emission efficiency is improved. The material of the hole injecting layer and the hole transporting layer (hereinafter referred to as the hole injecting material and the hole transporting material) has a property of transmitting the holes injected from the anode to the light emitting layer. There is no particular limitation as long as it is one
Conventionally, in an optical transmission material, an arbitrary material is selected and used from materials conventionally used as charge injection / transport materials for holes and known materials used in hole injection layers and hole transport layers of EL elements. be able to.

The hole injecting material and hole transporting material have any of hole injecting or transporting property and electron barrier property, and may be either organic or inorganic.
Examples of the hole injection material and the hole transport material include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazoles. Examples thereof include derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline-based copolymers, and conductive polymer oligomers, especially thiophene oligomers. As the hole injecting material and the hole transporting material, the above materials can be used, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound. preferable.

Typical examples of the aromatic tertiary amine compounds and styrylamine compounds are N, N, N ', N'.
-Tetraphenyl-4,4'-diaminophenyl; N,
N'-diphenyl-N, N'-bis (3-methylphenyl)-[1,1'-biphenyl] -4,4'-diamine (TPD); 2,2-bis (4-di-p-tolyl) Aminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′,
N'-tetra-p-tolyl-4,4'-diaminobiphenyl; 1,1-bis (4-di-p-tolylaminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl ) Phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N'-di (4-methoxyphenyl) -4,4'-diaminobiphenyl; N,
N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- ( Di-p-tolylamino) -4'-
[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4'-N, N-diphenylaminostilbenzene; N-phenyl Carbazole, more preferably the triarylamine compound and the biphenyl compound mentioned above as the host compound, are particularly preferable, and have two fused aromatic rings described in US Pat. No. 5,061,569 in the molecule. Such as 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-3086
No. 88, 4,4 ', 4 "in which three triphenylamine units are linked in a starburst type.
-Tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (MTDATA) and the like can also be mentioned.

Further, it is also possible to use a polymer material in which these materials are introduced into the polymer chain or where these materials are used as the polymer main chain.

Inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injecting material and the hole transporting material. The hole injecting layer and the hole transporting layer are formed by thinning the above hole injecting material and hole transporting material by a known method such as a vacuum vapor deposition method, a spin coating method, a casting method, and an LB method. Can be formed. The thickness of the hole injection layer and the hole transport layer is not particularly limited, but is usually about 5 nm to 5 μm. The hole injection layer and the hole transport layer may have a single layer structure composed of one or more of the above materials, or may have a laminated structure composed of a plurality of layers having the same composition or different compositions.

Further, the electron-transporting layer used as required may have a function of transmitting the electrons injected from the cathode to the light-emitting layer, and its material is any known compound. One can be selected and used.

Materials used for this electron transport layer (hereinafter, referred to as
Examples of the electron transport material) include nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, heterocyclic tetracarboxylic acid anhydrides such as naphthaleneperylene, carbodiimides, fluorenylidene methane derivatives, anthraquinodimethane and Examples thereof include anthrone derivative and oxadiazole derivative. Furthermore, in the above oxadiazole derivative, a thiadiazole derivative in which an oxygen atom of the oxadiazole ring is substituted with a sulfur atom, or a quinoxaline derivative having a quinoxaline ring known as an electron-withdrawing group can also be used as the electron transport material.

Further, it is also possible to use a polymer material in which these materials are introduced into a polymer chain or where these materials are used as a polymer main chain.

Further, metal complexes of 8-quinolinol derivative, for example, tris (8-quinolinol) aluminum (Alq), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-).
Quinolinol) aluminum, tris (2-methyl-8)
-Quinolinol) aluminum, tris (5-methyl-)
8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), etc., and the central metal of these metal complexes is In, Mg, Cu, Ca, Sn, Ga or Pb.
The metal complex replaced with can also be used as an electron transport material. In addition, metal-free or metal phthalocyanine, or those whose terminal is substituted with an alkyl group, a sulfonic acid group, or the like can be preferably used as the electron transport material. Further, the distyrylpyrazine derivative exemplified as the material of the light emitting layer can also be used as the electron transporting material, and like the hole injecting layer and the hole transporting layer, it is an inorganic material such as n-type-Si or n-type-SiC. Semiconductors can also be used as electron transport materials.

Preferred compounds used for the electron transport layer include the following boron compounds. These compounds can also be used as a host compound for the phosphorescent compound.

[0200]

[Chemical 96]

[0201]

[Chemical 97]

[0202]

[Chemical 98]

[0203]

[Chemical 99]

[0204]

[Chemical 100]

[0205]

[Chemical 101]

[0206]

[Chemical 102]

[0207]

[Chemical 103]

[0208]

[Chemical 104]

[0209]

[Chemical 105]

[0210]

[Chemical formula 106]

[0211]

[Chemical formula 107]

This electron transporting layer can be formed by forming the above compound into a film by a known thin film forming method such as a vacuum deposition method, a spin coating method, a casting method and an LB method. The thickness of the electron transport layer is not particularly limited, but is usually selected in the range of 5 nm to 5 μm. The electron-transporting layer may have a single-layer structure composed of one or more of these electron-transporting materials, or a laminated structure composed of a plurality of layers having the same composition or different compositions.

Further, in the present invention, the fluorescent compound is not limited to the light emitting layer, and a fluorescent compound which becomes a host compound of the phosphorescent compound in the hole transport layer or the electron transport layer adjacent to the light emitting layer. At least one fluorescent compound having a fluorescence maximum wavelength may be contained in the same region as the compound, which can further increase the emission efficiency of the EL device. The fluorescent compound contained in these hole transporting layer or electron transporting layer has a fluorescence maximum wavelength in the range of 350 nm to 440 nm, more preferably 390 nm to 410 nm, like the one contained in the light emitting layer. A compound is used.

Further, in another embodiment, in addition to the fluorescent compound (A) as the host compound and the phosphorescent compound, it has a maximum fluorescent wavelength in a region longer than the maximum wavelength of the light emitted from the phosphorescent compound. In some cases, at least one fluorescent compound (B) may be contained. In this case, energy transfer from the fluorescent compound (A) and the phosphorescent compound causes the organic E
As electroluminescence as the L element, light emission from the fluorescent compound (B) can be obtained. The fluorescent compound (B) is preferably one having a high fluorescence quantum yield in a solution state. Here, the fluorescence quantum yield is preferably 10% or more, and particularly preferably 30% or more. Specifically, coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squaryl dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes, perylene dyes, stilbene dyes ， Polythiophene dye,
Alternatively, a rare earth complex-based phosphor may be used.

The fluorescence quantum yield here can also be measured by the method described in the fourth edition Experimental Chemistry Lecture 7, Spectroscopy II, page 362 (1992 edition, Maruzen), and in the present invention, in tetrahydrofuran. To measure.

The substrate preferably used in the organic EL device of the present invention is not particularly limited in the kind of glass, plastic and the like, and is not particularly limited as long as it is transparent.
Examples of the substrate preferably used for the electroluminescent element of the present invention include glass, quartz, and a light-transmissive plastic film.

As the light-transmissive plastic film,
For example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether sulfone (PES), polyetherimide, polyether ether ketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC), cellulose Examples thereof include films made of acetate propionate (CAP) and the like.

Next, a suitable example for producing the organic EL device will be described. As an example, a method for manufacturing an EL device composed of the above-mentioned anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode will be described.

First, on a suitable substrate, the desired electrode material,
For example, a thin film made of an anode material is formed by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably in the range of 10 to 200 nm to produce an anode. Then, a thin film composed of a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer / electron injection layer, which are element materials, is formed thereon.

Further, a buffer layer (electrode interface layer) may be present between the anode and the light emitting layer or the hole injection layer and between the cathode and the light emitting layer or the electron injection layer.

The buffer layer is a layer provided between the electrode and the organic layer for the purpose of lowering the driving voltage and improving the light emission efficiency, and is referred to as “organic EL device and its industrial front line (1998 1998).
2nd volume of "January 30 issued by TS Co., Ltd."
It is described in detail in Chapter “Electrode Materials” (pages 123 to 166), and includes an anode buffer layer and a cathode buffer layer.

The anode buffer layer is described in JP-A-9-4547.
The details are also described in No. 9, No. 9-260062, No. 8-288069 and the like, and as a specific example, a phthalocyanine buffer layer represented by copper phthalocyanine,
Examples thereof include an oxide buffer layer typified by vanadium oxide, an amorphous carbon buffer layer, and a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) and polythiophene.

The cathode buffer layer is described in JP-A-6-3258.
No. 71, No. 9-17574, No. 10-74586, etc., the details are also described, and specifically, a metal buffer layer typified by strontium, aluminum, etc.,
Examples thereof include an alkali metal compound buffer layer typified by lithium fluoride, an alkaline earth metal compound buffer layer typified by magnesium fluoride, and an oxide buffer layer typified by aluminum oxide and lithium oxide.

It is desirable that the buffer layer is a very thin film, and the film thickness is 0.1 to 10 depending on the material.
The range of 0 nm is preferred.

In addition to the above-mentioned basic constituent layers, if desired, layers having other functions may be laminated. For example, JP-A Nos. 11-204258 and 11-204359, and "organic EL element and its industrialization." Frontline (1998 1
It may have a functional layer such as a hole blocking (hole blocking) layer described in page 237, etc. of January 30, 30).

The buffer layer may function as a light emitting layer when at least one kind of the compound of the present invention is present in at least one of the cathode buffer layer and the anode buffer layer.

Next, the electrodes of the organic EL element will be described. The electrodes of the organic EL element consist of a cathode and an anode.

As the anode in this organic EL device,
A material having a high work function (4 eV or more), an alloy, an electrically conductive compound or a mixture thereof as an electrode material is preferably used. Specific examples of such electrode substances include conductive transparent materials such as metals such as Au, CuI, indium tin oxide (ITO), SnO ₂ and ZnO.

For the above-mentioned anode, a thin film of these electrode materials may be formed by a method such as vapor deposition or sputtering, and a pattern of a desired shape may be formed by a photolithography method, or when pattern accuracy is not required so much. (About 100 μm or more), a pattern may be formed through a mask having a desired shape during vapor deposition or sputtering of the electrode material. When the emitted light is taken out from this anode, it is desirable that the transmittance is higher than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, the film thickness depends on the material, but is usually 10 nm to 1 μm.
m, preferably 10 nm to 200 nm.

On the other hand, as the cathode, a metal having a low work function (4 eV or less) (referred to as an electron injecting metal), an alloy, an electrically conductive compound, or a mixture thereof as an electrode substance is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum /
Aluminum oxide (Al ₂ O ₃ ) mixture, indium, lithium / aluminum mixture, rare earth metal and the like can be mentioned. Among these, from the viewpoint of electron injecting property and durability against oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function value, for example, a magnesium / silver mixture or magnesium. Aluminium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) mixture, lithium / aluminum mixture and the like are suitable. The cathode is
These electrode materials can be produced by forming a thin film by a method such as vapor deposition or sputtering. The sheet resistance of the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 1 μm, preferably 50 to 200 nm. In addition, since light is transmitted, it is convenient that either the anode or the cathode of the organic EL element is transparent or semi-transparent so that the light emission efficiency is improved.

Next, a method for manufacturing an organic EL element will be described. As a method for thinning the film, there are the spin coating method, the casting method, the vapor deposition method and the like as described above, but the vacuum vapor deposition method is preferable from the viewpoints that a uniform film is easily obtained and pinholes are not easily generated. When a vacuum vapor deposition method is used for thinning, the vapor deposition conditions are the type of compound used,
Generally, the boat heating temperature is 50 to 450 ° C., the degree of vacuum is 10 ⁻⁶ to 10 ⁻³ Pa, and the deposition rate is 0.01 to 50 nm, although it depends on the desired crystal structure, association structure, etc. of the molecular deposited film.
Second, substrate temperature is preferably -50 to 300 [deg.] C. and film thickness is 5 nm to 5 [mu] m.

As described above, a thin film of a desired electrode material, for example, an anode material, is vapor-deposited or sputtered on a suitable substrate so as to have a film thickness of 1 μm or less, preferably 10 to 200 nm. Etc. to form an anode, and after forming a thin film of each layer consisting of a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer / electron injection layer on the anode as described above, By forming a thin film made of a substance for a cathode on it by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably in the range of 50 to 200 nm, and by providing a cathode,
A desired organic EL device can be obtained. In this organic EL device, it is preferable to consistently manufacture from the hole injection layer to the cathode in this way by vacuuming once, but the manufacturing order is reversed, and the cathode, the electron injection layer, the light emitting layer, It is also possible to fabricate the hole injection layer and the anode in this order. When a direct current voltage is applied to the thus obtained organic EL element, light emission can be observed by applying a voltage of about 5 to 40 V with the anode having a positive polarity and the cathode having a negative polarity. Moreover, even if a voltage is applied with the opposite polarity, no current flows and no light emission occurs. Further, when an AC voltage is applied, light is emitted only when the anode is in the + state and the cathode is in the − state. The waveform of the alternating current applied may be arbitrary.

[0233]

The present invention will be described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

Example 1 After patterning was performed on a substrate (NA-45 manufactured by NH Techno Glass Co., Ltd.) on which ITO was formed in a thickness of 150 nm on glass as an anode, a transparent support substrate provided with this ITO transparent electrode was formed into i-propyl. Ultrasonic cleaning with alcohol, drying with dry nitrogen gas, and UV ozone cleaning for 5 minutes. This transparent support substrate was fixed to a substrate holder of a commercially available vacuum vapor deposition device, while 5 molybdenum resistance heating boats were set up with 1-
57, 3-1, Comparative Compound 1, BC, and Alq3 were put in each and attached to a vacuum vapor deposition apparatus.

Then, the vacuum chamber was decompressed to 4 × 10 ^-4 Pa, and the heating boat containing 1-57 was energized to heat it, and the transparent support substrate was deposited at a deposition rate of 0.1 to 0.2 nm / sec. Was vapor-deposited to a thickness of 50 nm to provide a hole injection / transport layer. Further, the heating boat containing 3-1 and the boat containing Comparative Compound 1 were independently energized so that the vapor deposition rates of 3-1 and Comparative Compound 1 were 100: 7.
Was adjusted so as to have a thickness of 30 nm, and vapor deposition was performed to form a light emitting layer.

Then, the heating boat containing BC was energized and heated to provide an electron transport layer having a thickness of 10 nm at a vapor deposition rate of 0.1 to 0.2 nm / sec. Further, the heating boat containing Alq3 is energized and heated, and the vapor deposition rate is set to 0.
An electron injection layer having a film thickness of 40 nm was provided at a rate of 1 to 0.2 nm / sec.

Next, the vacuum chamber was opened, a rectangular perforated mask made of stainless steel was placed on the electron transport layer, while 3 g of magnesium was placed in a molybdenum resistance heating boat,
0.5 g of silver was placed in a tungsten vapor deposition basket, the vacuum chamber was decompressed again to 2 × 10 ⁻⁴ Pa, and a boat containing magnesium was energized to deposit a vapor deposition rate of 1.5 to 2.
Magnesium is vapor-deposited at 0 nm / sec, and at the same time, a silver basket is heated at a vapor deposition rate of 0.1 nm / se.
Comparative organic E was prepared by vapor-depositing silver at c to form a cathode (200 nm) composed of a mixture of magnesium and silver.
L element OLED1-1 was produced. FIG. 1 shows a schematic diagram showing the configuration of the organic EL element OLED1-1.

In the same manner as the organic electroluminescence element OLED1-1, except that the compound 1 shown in Table 1 was used instead of the comparative compound 1 of the organic EL element OLED1-1.
Organic electroluminescence element OLED1-2-1
4 was produced.

[0239]

[Chemical 108]

[0240]

[Chemical 109]

These devices were continuously lit by applying a DC voltage of 10 V in a dry nitrogen gas atmosphere at a temperature of 23 ° C.
The emission luminance (L) [cd / m ² ] at the start of lighting, the external extraction quantum efficiency (η), and the time (τ) at which the luminance was reduced by half were measured. In addition, the chromaticity at the start of lighting was measured, and the color name on the CIE chromaticity diagram was evaluated.

The emission luminance [cd / m ² ] was measured using Minolta CS-1000.

External extraction quantum efficiency (%) = organic E
The number of photons emitted to the outside of the L element / the number of electrons flowing to the organic EL element × 100.
The emission spectrum measured by the spectral radiance meter CS-1000 is calculated from the energies of photons of respective wavelengths at 380 to 780.
The number of photons in nm was calculated, and the number of photons emitted from the light emitting surface was calculated based on the Lambertian assumption. The number of electrons was calculated from the amount of current.

The emission luminance is represented by a relative value when the organic electroluminescence element OLED1-1 is 100.
The external extraction quantum efficiency is also represented by a relative value when the organic electroluminescence element OLED1-1 is set to 100,
The time for which the luminance is reduced to half (half-life) is expressed as a relative value with the time for which the luminance of the organic electroluminescent element OLED1-1 is reduced by half as 100. Regarding the color name, the hue on the chromaticity diagram of each device is shown. The results are shown in Table 3.

[0245]

[Table 3]

In the present invention, the preferred emission colors (color names) are in the following order (desired) Blue> Greenish Blue>
Blue Green> Blue Green> G
reen (undesirable) From Table 1, although the device using Comparative Compound 1 has considerably good emission luminance, quantum efficiency, and half-life, the emission color is B.
Since it is a light green, it cannot be said to be desirable in the present invention aiming at blue light emission. Further, the device using the comparative compound 2 has a green emission color, which is completely out of the scope of the present invention, and the other performances are also worse than the device using the comparative compound 1. In the device using the comparative compound 3, the emission color is greenish.
Blue, which is preferable to the device using Comparative Compound 1, but has significantly low emission luminance, quantum efficiency, and half-life.

On the other hand, it can be seen that the organic EL device using the compound of the present invention has improved emission luminance, quantum efficiency and half-time of luminance in any case. It was also found that the emission color was the same or higher than that of the device using the comparative compound 1.

Further, in the same manner as in the organic electroluminescence element OLED1-1 except that the comparative compound 1 of the organic EL element OLED1-1 was replaced with the comparative compound 3,
Organic electroluminescence elements OLED1-15 were produced. The emission color was Blue Green. Furthermore, an organic electroluminescence device OLED1-15 except that the comparative compound 3 was replaced with the compound 120.
Similarly to the organic electroluminescence element OL
ED1-16 was produced. Emitting color is Blue Green
It was n. Organic electroluminescence device OLE
When the emission luminance of D1-15, the external extraction quantum efficiency, and the half-life are 100, respectively, the emission luminance, the external extraction quantum efficiency, and the half-life of the organic electroluminescent element OLED1-16 are 146, 152, and 147, respectively. From the above results, it can be seen that even when platinum is used, the emission luminance, the quantum efficiency, and the time for which the luminance is halved are improved. It was also found that in terms of emission color, the color was more bluish and preferable than that obtained using Comparative Compound 3.

Similarly, except that the comparative compound 1 of the organic EL element OLED1-1 was replaced with the comparative compound 4, the same procedure as for the organic electroluminescent element OLED1-1 was conducted.
Organic electroluminescence element OLED1-17 was produced. The emission color was Blue Green. Furthermore, an organic electroluminescence device OLED1-17 except that the comparative compound 4 was replaced with the compound 145.
Similarly to the organic electroluminescence element OL
ED1-18 was produced. Emitting color is Blue Green
It was n. Organic electroluminescence device OLE
When the emission luminance of D1-17, the external extraction quantum efficiency, and the half-life were each set to 100, the emission luminance, the external extraction quantum efficiency, and the half-life of the organic electroluminescent element OLED1-18 were 143, 144, and 136, respectively. From the above results, it can be seen that even when osmium is used, the emission luminance, the quantum efficiency, and the time for which the luminance is reduced by half are improved. It was also found that the color of emitted light was more preferable than that of Comparative Compound 4.

[0250]

[Chemical 110]

Example 2 The cathode of the organic electroluminescence device OLED1-10 prepared in Example 1 was replaced with Al, and lithium fluoride was vapor-deposited to a thickness of 0.5 nm between the electron transport layer and the cathode to form a cathode buffer layer. An organic electroluminescence element OLED2-1 was produced in the same manner except that it was provided.

As in Example 1, the emission luminance (L) [cd / m ² ] at the start of lighting, the external extraction quantum efficiency (η), and the luminance halving time (τ) were measured. In addition, when the chromaticity at the start of lighting was measured and the color name on the CIE chromaticity diagram was evaluated, the organic electroluminescent element OLE
Relative comparison with D1-1, emission brightness 211, quantum efficiency 1
74, and the time required to reduce the luminance to half was 244. Further, regarding the organic electroluminescence elements OLED1 to 3 to 9 and OLEDs 1 to 11 to 14, similarly, it was more effective to introduce the cathode buffer layer.

Example 3 The transparent supporting substrate with the ITO transparent electrode used in Example 1 was washed under the same conditions as in Example 1, and then in the same manner as in Example 1 with the same configuration as that shown in FIG. However, in addition to using Compound 1-63 for the hole injecting / transporting layer, Compound 1-7 as the host material for the light emitting layer, and Comparative compound 5 as the dopant, Compound 8-17 was used for the electron transporting layer in place of BC. Thus, a comparative organic EL element OLED3-1 was produced. The light emitting layer was formed by co-evaporating the host material (1-7) and the dopant material (comparative compound 5) in a mass ratio of 100: 7.

In the same manner as the organic electroluminescence device OLED3-1, except that the compound 5 shown in Table 4 was used instead of the comparative compound 5 of the organic EL device OLED3-1.
Organic electroluminescence device OLED3-2 to 6
Was produced.

[0255]

[Chemical 111]

These devices were continuously lit by applying a 10 V DC voltage in a dry nitrogen gas atmosphere at a temperature of 23 ° C.
The emission luminance (L) [cd / m ² ] at the start of lighting, the external extraction quantum efficiency (η), and the time (τ) at which the luminance was reduced by half were measured. In addition, the chromaticity at the start of lighting was measured, and the color name on the CIE chromaticity diagram was evaluated. The light emission brightness is represented by a relative value when the organic electroluminescence element OLED3-1 is 100, and the external extraction quantum efficiency is represented by a relative value when the organic electroluminescence element OLED3-1 is 100, and the time for which the brightness is reduced to half is It was expressed as a relative value with the time at which the luminance of the organic electroluminescence element OLED3-1 is halved as 100. Regarding the color name, the hue on the chromaticity diagram of each device is shown. The results are shown in Table 4.

[0257]

[Table 4]

In the present invention, the preferred emission colors (color names) are in the following order (desired) Blue> Greenish Blue>
Blue Green> Blue Green> G
reen (undesirable) From Table 4, it can be seen that the organic EL device using the compound of the present invention has improved emission luminance at the start of lighting, emission efficiency, and the half-time of the luminance. In particular, it can be seen that the time for the luminance to be reduced to half is improved.

[0259]

EFFECT OF THE INVENTION Using a phosphorescent compound as a dopant,
It was possible to obtain an organic electroluminescence device having an excellent color tone in the blue to blue-green region and high emission brightness.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of an organic EL element OLED1-1.

[Explanation of symbols]

1 transparent support substrate 2 anode 3 Hole injection / transport layer 4 Light emitting layer 5 Electron transport layer 6 Electron injection layer 7 cathode

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C07F 15/00 C07F 15/00 F (72) Inventor Tomohiro Oshiyama 1 Sakura-cho, Hino-shi, Tokyo Konica Stock Association In-house F-term (reference) 3K007 AB02 AB04 DB03 4C055 AA01 BA02 BA08 CA01 DA01 FA01 GA02 4H050 AA03 AB91

Claims (13)

[Claims] 1. N-MY represented by the following general formula (1):
-Z dihedral angle (that is, twist angle of two rings) is 9 degrees or more 9
An organic electroluminescence device comprising a light emitting layer containing a metal complex having a degree of less than 0 degree. [Chemical 1] [Wherein N represents a nitrogen atom, C represents a carbon atom, X represents a carbon atom, a nitrogen atom or an oxygen atom, M represents a carbon atom or a nitrogen atom, Y represents a carbon atom or a nitrogen atom, and Z represents Represents a carbon atom or a nitrogen atom, and A represents X-M-
Represents an atomic group necessary for forming a 5- or 6-membered heterocyclic ring with N, and B represents an atomic group necessary for forming a 5- or 6-membered hydrocarbon ring or heterocyclic ring with C-Y-Z. Represent Also,
The two rings may each independently have a substituent,
Adjacent substituents may further form a condensed ring.
Me represents iridium, platinum or osmium.
n represents 1, 2, 3 or 4, m represents 3-n when Me is iridium, 4-n or 2-n when Me is platinum, and 2-n when Me is osmium. W ₁ represents an oxygen atom, a nitrogen atom or a sulfur atom, W ₂ represents an oxygen atom, a nitrogen atom or a sulfur atom, L ₁ represents a nitrogen atom or a carbon atom, L ₂ represents a nitrogen atom or an oxygen atom, l represents 1 or 2. Note that W ₁ and L ₁ , L ₁ and L ₂ , L ₂ and L ₂ (l
Is 2), the bond between L ₂ and W ₂ may be a single bond or a double bond. ] 2. An organic electroluminescence device comprising a light emitting layer containing a metal complex represented by the following general formula (2). [Chemical 2] [In the formula, N represents a nitrogen atom, C represents a carbon atom, X represents a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, M represents a carbon atom or a nitrogen atom, and Y represents a carbon atom or a nitrogen atom. , Z represents a carbon atom or a nitrogen atom, and A
Represents an atomic group necessary to form a 5- or 6-membered heterocycle with X-M-N, and B represents a 5- or 6-membered hydrocarbon ring or heterocycle with C-Y-Z. It represents a necessary atomic group, and R ₁ and R ₂ represent a substituent or a hydrogen atom. However, R ₁ does not exist when X is an oxygen atom or a sulfur atom. Further, at least one of R ₁ and R ₂ represents a substituent,
The sum of the stereo parameter Es values of R ₁ and R ₂ is −0.6 or less. Me represents iridium, platinum or osmium. n represents 1, 2, 3 or 4, m is 3-n when Me is iridium, and 4-n or 2-n when platinum is
Represents 2-n for osmium. W ₁ represents an oxygen atom, a nitrogen atom or a sulfur atom, W ₂ represents an oxygen atom, a nitrogen atom or a sulfur atom, L ₁ represents a nitrogen atom or a carbon atom, L ₂ represents a nitrogen atom or an oxygen atom, l represents 1 or 2. The bonds between W ₁ and L ₁ , L ₁ and L ₂ , L ₂ and L ₂ (when 1 is 2), and L ₂ and W ₂ may be single bonds or double bonds. ] 3. An organic electroluminescence device comprising a light emitting layer containing a metal complex represented by the following general formula (3). [Chemical 3] [In the formula, N represents a nitrogen atom, C represents a carbon atom, X represents a carbon atom, a nitrogen atom or an oxygen atom, M represents a carbon atom or a nitrogen atom, Y represents a carbon atom or a nitrogen atom, and Z represents Z. Represents a carbon atom or a nitrogen atom, T represents a carbon atom or a nitrogen atom, A represents an atomic group necessary for forming a 5- or 6-membered heterocycle with X-M-N, and B ₂ represents C _2.
Represents a group of atoms necessary for forming a 5- or 6-membered hydrocarbon ring or heterocycle with —Y—Z—T, and B ₃ forms a 5- or 6-membered hydrocarbon ring or heterocycle with Z—T. Represents the atomic group required to do so. Me represents iridium, platinum or osmium. n represents 1, 2, 3 or 4, and m
Is 3-n when Me is iridium and 4-when platinum is
n or 2-n represents 2-n when osmium. W ₁ represents an oxygen atom, a nitrogen atom or a sulfur atom, W ₂ represents an oxygen atom, a nitrogen atom or a sulfur atom, L ₁ represents a nitrogen atom or a carbon atom, L ₂ represents a nitrogen atom or an oxygen atom, l represents 1 or 2. In addition, W ₁ and L ₁ , L ₁
And L ₂ , L ₂ and L ₂ (when 1 is 2), and the bond between L ₂ and W ₂ may be a single bond or a double bond. ] 4. An organic electroluminescence device comprising a light emitting layer containing a metal complex represented by the following general formula (4). [Chemical 4] [In the formula, N represents a nitrogen atom, C represents a carbon atom, X represents a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, M represents a carbon atom or a nitrogen atom, and Y represents a carbon atom or a nitrogen atom. , Z represents a carbon atom or a nitrogen atom, and A
Represents an atomic group necessary to form a 5- or 6-membered aromatic heterocycle together with X-M-N, and B represents 5 to 6 together with C-Y-Z.
Represents a group of atoms necessary to form a membered aromatic hydrocarbon ring or aromatic heterocycle. However, the aromatic heterocycle formed by X-M-N and A and the aromatic hydrocarbon ring or aromatic heterocycle formed by C-Y-Z and B are substituted with at least one substituent. Moreover, the sum of the σp values of the substituents is 0.15 or more and 2 or less. EWG1 and EW
G2 has a substituent constant σp value of 0 independently in Hammett
The above represents the electron-withdrawing group, and the sum of σp values is 0.15 or more and 2 or less. S1 represents an integer of 0 to 3, and S2 is 0.
Represents an integer of 3; However, the sum of S1 and S2 is 1 or more and 5 or less. Me represents iridium, platinum or osmium. n represents 1, 2, 3 or 4, m is 3-n when Me is iridium, and 4-n or 2-when platinum is platinum.
n represents 2-n when osmium. W ₁ is an oxygen atom,
Represents a nitrogen atom or a sulfur atom, W ₂ represents an oxygen atom, a nitrogen atom or a sulfur atom, L ₁ represents a nitrogen atom or a carbon atom, L ₂ represents a nitrogen atom or an oxygen atom, and
Represents 1 or 2. Note that W ₁ and L ₁ , L ₁ and L ₂ , L ₂
And L ₂ (when 1 is 2), and the bond between L ₂ and W ₂ may be a single bond or a double bond. ] 5. In the general formula (4), N-M-Y
-Z dihedral angle (that is, twist angle of two rings) is 9 degrees or more 9
It is less than 0 degree, The organic electroluminescent element of Claim 4 characterized by the above-mentioned. 6. A metal complex represented by the following general formula (5):
Organic electroluminescence characterized by being contained in a light emitting layer
Ness element. [Chemical 5] [In the formula, N is a nitrogen atom, X is a carbon atom, a nitrogen atom, oxygen
Represents an atom or a sulfur atom, M is a carbon atom or a nitrogen atom
Represents a child, and A is a 5- or 6-membered aromatic complex together with X-M-N.
Represents a group of atoms necessary for forming a ring, R₆₁Is a three-dimensional para
R represents a substituent having a meter Es value of −0.6 or less, R₆₂, R
₆₃And R₆₄Represents a hydrogen atom or a substituent. Also, X-
The aromatic heterocycle formed by MN and A has a substituent
May form a condensed ring between adjacent substituents.
Good. Me is iridium, platinum or osmium
Represents n represents 1, 2, 3 or 4, and m is Me
3-n for rhidium, 4-n or 2-n for platinum
Represents 2-n for osmium. W₁Is an oxygen atom, nitrogen
Represents an elementary atom or a sulfur atom, W₂Is oxygen atom, nitrogen source
Represents a child or a sulfur atom, L₁Is nitrogen atom or carbon atom
Represents a child, L₂Represents a nitrogen atom or an oxygen atom, and l is
Represents 1 or 2. Note that W₁And L₁, L₁And L₂, L ₂When
L₂(When l is 2), L₂And W₂Is a single bond or a double bond
It may be a combination. ] 7. An organic electroluminescence device comprising a light emitting layer containing a metal complex represented by the following general formula (6). [Chemical 6] [Wherein, R ₇₁ and R ₇₅ represent a hydrogen atom or a substituent, and
_At least one of ₇₁ and R ₇₅ represents a substituent. The sum of the three-dimensional parameter Es values of R ₇₁ and R ₇₅ is −0.6 or less. _R72 , _R73 , _R74 , _R76 , _R77 and _R78 represent a hydrogen atom or a substituent. Further, adjacent substituents may be bonded to each other to form a condensed ring. Me represents iridium, platinum or osmium. n is 1, 2, 3
Or 4 represents, m is 3-n when Me is iridium,
4-n or 2-n for platinum, 2-for osmium
represents n. W ₁ represents an oxygen atom, a nitrogen atom or a sulfur atom, W ₂ represents an oxygen atom, a nitrogen atom or a sulfur atom, L ₁ represents a nitrogen atom or a carbon atom, L ₂ represents a nitrogen atom or an oxygen atom, l represents 1 or 2. Note that W ₁ and L ₁ , L ₁ and L ₂ , L ₂ and L ₂ (when 1 is 2), L
The bond between ₂ and W ₂ may be a single bond or a double bond. ] 8. An organic electroluminescence device comprising a light emitting layer containing a metal complex represented by the following general formula (7). [Chemical 7] [In the formula, Ar represents an aromatic group, and R _{81 to} R ₈₇ represent a hydrogen atom or a substituent. Further, adjacent substituents may be bonded to each other to form a condensed ring. Me represents iridium or platinum or osmium. n is 1, 2,
Represents 3 or 4, m is 3-n when Me is iridium
Represents 4-n or 2-n for platinum and 2-n for osmium. W ₁ represents an oxygen atom, a nitrogen atom or a sulfur atom, W ₂ represents an oxygen atom, a nitrogen atom or a sulfur atom, L ₁ represents a nitrogen atom or a carbon atom, L ₂ represents a nitrogen atom or an oxygen atom, l represents 1 or 2. Note that W ₁ and L ₁ , L ₁ and L ₂ , L ₂ and L ₂ (when 1 is 2), L
The bond between ₂ and W ₂ may be a single bond or a double bond. ] 9. A metal complex represented by the following general formula (8):
Organic electroluminescence characterized by being contained in a light emitting layer
Ness element. [Chemical 8] [In the formula, N is a nitrogen atom, X is a carbon atom, a nitrogen atom, oxygen
Represents an atom or a sulfur atom, M is a carbon atom or a nitrogen atom
Represents a child, and A is a 5- or 6-membered aromatic complex together with X-M-N.
Represents a group of atoms necessary for forming a ring, R₉₁~ R₉₄Is water
Represents an elementary atom or a substituent. However, R₉₁~ R₉₄That of
The sum of the σp values of each substituent is 0.15 or more and 2 or less.
It In addition, an aromatic heterocycle formed by X-MN and A
May have a substituent, and the adjacent substituents may be condensed with each other.
A ring may be formed. Me is iridium or platinum
Or osmium. n represents 1, 2, 3 or 4,
m is 3-n when Me is iridium and 4 when it is platinum
-N or 2-n represents 2-n when osmium. W₁
Represents an oxygen atom, a nitrogen atom or a sulfur atom, and W₂Is acid
Represents an elementary atom, a nitrogen atom or a sulfur atom, L₁Is nitrogen source
Represents a child or carbon atom, L₂Is a nitrogen atom or oxygen source
Represents a child, and 1 represents 1 or 2. Note that W₁And L ₁, L
₁And L₂, L₂And L₂(When l is 2), L₂And W₂Is a single
It may be a bond or a double bond. ] 10. An organic electroluminescence device comprising a light emitting layer containing a metal complex represented by the following general formula (9). [Chemical 9] [Wherein R _{101 to} R ₁₀₆ represent a hydrogen atom or a substituent,
B ₁₀ represents an atomic group necessary for forming a 5- or 6-membered ring with two carbon atoms. Further, adjacent substituents may be bonded to each other to form a condensed ring. Me represents iridium, platinum or osmium. n is 1, 2, 3
Or 4 represents, m is 3-n when Me is iridium,
4-n or 2-n for platinum, 2-for osmium
represents n. W ₁ represents an oxygen atom, a nitrogen atom or a sulfur atom, W ₂ represents an oxygen atom, a nitrogen atom or a sulfur atom, L ₁ represents a nitrogen atom or a carbon atom, L ₂ represents a nitrogen atom or an oxygen atom, l represents 1 or 2. Note that W ₁ and L ₁ , L ₁ and L ₂ , L ₂ and L ₂ (when 1 is 2), L
The bond between ₂ and W ₂ may be a single bond or a double bond. ] 11. An aromatic hydrocarbon ring in which the aromatic group represented by Ar in the general formula (7) is substituted with an electron-withdrawing group having a Hammett's substituent constant σp value of 0.02 or more and 2 or less. It is a group, The organic electroluminescent element of Claim 8 characterized by the above-mentioned. 12. An aromatic hydrocarbon ring in which the aromatic group represented by Ar in the general formula (7) is substituted with an electron-withdrawing group having a Hammett's substituent constant σp value of 0.02 or more and 2 or less. 9. The organic electroluminescent device according to claim 8, wherein the substituent represented by R ₈₂ is an electron-withdrawing group having a Hammett's specified number of substitutions σp value of 0.02 or more and 2 or less. . 13. At least one of the substituents represented by R _{101 to} R ₁₀₆ in the general formula (9) is an electron-withdrawing group having a Hammett's specified substitution number σp value of 0.02 or more and 2 or less. The organic electroluminescence device according to claim 10, wherein