JP4934345B2 - Organic electroluminescence device - Google Patents

Description

  The present invention relates to an organic electroluminescent element (EL element) capable of emitting light by converting electric energy into light.

  An organic electroluminescence (EL) element has attracted attention as a promising display element because it can emit light with high luminance at a low voltage. An important characteristic value of this organic electroluminescence device is external quantum efficiency. The external quantum efficiency is calculated by “external quantum efficiency φ = number of photons emitted from the device / number of electrons injected into the device”, and it can be said that the larger this value, the more advantageous the device in terms of power consumption.

  The external quantum efficiency of the organic electroluminescence device is determined by “external quantum efficiency φ = internal quantum efficiency × light extraction efficiency”. In an organic EL device using fluorescence emission from an organic compound, the limit value of the internal quantum efficiency is 25%, and the light extraction efficiency is approximately 20%. Therefore, the limit value of the external quantum efficiency is approximately 5%. Has been.

As a means to further improve the characteristics of the light-emitting element, a green light-emitting element utilizing light emission from an ortho-metalated iridium complex (Ir (ppy) ₃ : Tris-Ortho-Metalated Complex of Iridium (III) with 2-Phenylpyridine) has been reported. (For example, refer to Patent Document 1). The phosphorescent light-emitting device described in Patent Document 1 has significantly improved green and red light-emitting efficiency as compared with the conventional singlet light-emitting device, but is desired to be improved in terms of durability.
US 2002/0034656 A1

  An object of the present invention is to provide an organic electroluminescent device exhibiting at least one of high luminous efficiency and high durability.

Ｍ ^２１ は白金イオン又はパラジウムイオンを表す。Ｑ ^２３ 、Ｑ ^２４ はそれぞれＭ ^２１ に炭素原子で配位するフェニル基又はＭ ^２１ に炭素原子で配位するトリアゾリル基若しくはピラゾリル基を表す。Ｌ ^２２ はジメチルメチレン基又はジフェニルメチレン基を表す。Ｍ ^２１ −Ｎ間の結合（点線部）は、配位結合を示す。Ｍ ^２１ −Ｑ ^２３ 間の結合及びＭ ^２１ −Ｑ ^２４ 間の結合は、共有結合である。
＜２＞
前記発光層が発光材料を含有し、該発光材料がりん光材料であることを特徴とする上記＜１＞に記載の有機電界発光素子。
なお、本発明は、上記＜１＞及び＜２＞に関するものであるが、参考のため、その他の事項（例えば下記項目１〜７に記載の事項等）についても記載した。
１．陽極と陰極とからなる一対の電極間に発光層を含む複数の有機化合物層を有する有機電界発光素子であって、発光層と陰極との間に、３座以上の配位子を有する金属錯体を含む層を少なくとも一層有することを特徴とする有機電界発光素子。
２．前記３座以上の配位子が、４座配位子であることを特徴とする上記１に記載の有機電界発光素子。
３．前記金属錯体の金属イオンが、ロジウムイオン、パラジウムイオン、レニウムイオン、イリジウムイオン、または、白金イオンであることを特徴とする上記１または２に記載の有機電界発光素子。
４．前記金属錯体が、下記一般式（１）で表される化合物であることを特徴とする上記１〜３のいずれかに記載の有機電界発光素子。 This object has been achieved by the following means.
<1>
An organic electroluminescent device having a plurality of organic compound layers including a light emitting layer between a pair of electrodes composed of an anode and a cathode, wherein at least one of the following general formula (2) is provided between the light emitting layer and the cathode: An organic electroluminescent device comprising at least one layer containing the represented compound.

M ²¹ represents a platinum ion or a palladium ion. Q ^{23, Q 24} represents a coordinating triazolyl group or a pyrazolyl group with a carbon atom to the phenyl group or ^{M 21} coordinated with the carbon atom to ^{M 21,} respectively. L ²² represents a dimethylmethylene group or a diphenylmethylene group. The bond between M ^{21 and} N (dotted line portion) indicates a coordination bond. The bond between M ^{21 and} Q ²³ and the bond between M ^{21 and} Q ²⁴ are covalent bonds.
<2>
The organic electroluminescent element according to <1>, wherein the light emitting layer contains a light emitting material, and the light emitting material is a phosphorescent material.
In addition, although this invention is related to said <1> and <2>, the other matter (For example, the matter of the following items 1-7 etc.) was also described for reference.
1. An organic electroluminescent device having a plurality of organic compound layers including a light emitting layer between a pair of electrodes consisting of an anode and a cathode, wherein the metal complex has a tridentate or more ligand between the light emitting layer and the cathode An organic electroluminescence device comprising at least one layer containing selenium.
2. 2. The organic electroluminescence device according to 1 above, wherein the tridentate or higher ligand is a tetradentate ligand.
3. 3. The organic electroluminescence device as described in 1 or 2 above, wherein the metal ion of the metal complex is rhodium ion, palladium ion, rhenium ion, iridium ion, or platinum ion.
4). 4. The organic electroluminescent element as described in any one of 1 to 3 above, wherein the metal complex is a compound represented by the following general formula (1).

M ¹¹ represents a metal ion. Q ¹¹ , Q ¹² , Q ¹³ and Q ¹⁴ each represent an atomic group coordinated to M ¹¹ . L ¹¹ , L ¹² , L ¹³ and L ¹⁴ each represent a single bond or a linking group. n ¹¹ represents 0 or 1. When n ¹¹ is 0, there is no bond through L ¹⁴ between Q ¹³ and Q ¹⁴ . The bond between M ^{11 and} Q ^11, the bond between M ^{11 and} Q ¹² , the bond between M ^{11 and} Q ^13, and the bond between M ^{11 and} Q ¹⁴ may be covalent bonds or coordinate bonds. There may be an ionic bond.
5. 5. The organic electroluminescence device as described in 4 above, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (2).

M ²¹ represents a metal ion. Q ²³ and Q ²⁴ each represent an atomic group coordinated to M ²¹ . L ²² represents a linking group. R ²¹ and R ²² each represent a substituent. m ²¹ and m ²² each represent an integer of 0 to 3. The bond between M ^{21 and} N (dotted line portion) indicates a coordination bond. The bond between M ^{21 and} Q ²³ and the bond between M ^{21 and} Q ²⁴ may be a covalent bond, a coordination bond, or an ionic bond.
6). 6. The organic electroluminescent element as described in any one of 1 to 5 above, wherein the light emitting layer contains a light emitting material, and the light emitting material is a phosphorescent material.
7). 7. The organic electroluminescent element as described in 1 to 6 above, wherein the light emitting material is a metal complex having a tetradentate or higher ligand.

  ADVANTAGE OF THE INVENTION According to this invention, the organic electroluminescent element which shows at least 1 of high luminous efficiency and high durability can be provided.

The organic electroluminescent element of the present invention has a plurality of organic compound layers including a light emitting layer between a pair of electrodes composed of an anode and a cathode, and has a tridentate or more ligand between the light emitting layer and the cathode. It has at least one layer containing a metal complex.
The layer containing at least a metal complex having a tridentate or higher ligand existing between the light emitting layer and the cathode may be adjacent to the light emitting layer, may be adjacent to the cathode, or the light emitting layer. Although not necessarily adjacent to both cathodes, it is preferable to be adjacent to the light emitting layer or the cathode, and more preferably adjacent to the light emitting layer.

  The metal ion of the metal complex having a tridentate or higher ligand is preferably a transition metal ion, and is a ruthenium ion, rhodium ion, palladium ion, silver ion, tungsten ion, rhenium ion, osmium ion, iridium ion, platinum. Ions and gold ions are preferable, rhodium ions, palladium ions, rhenium ions, iridium ions, and platinum ions are more preferable, platinum ions and palladium ions are further preferable, and platinum ions are particularly preferable.

The metal complex preferably has a tetradentate ligand.
The ligand is not particularly limited as long as it is an atomic group coordinated to the above metal ion. For example, the ligand is coordinated by an atomic group coordinated by a carbon atom, an atomic group coordinated by a nitrogen atom, or an oxygen atom. An atomic group, an atomic group coordinated with a sulfur atom, an atomic group coordinated with a phosphorus atom, and the like can be given, and an atomic group coordinated with a carbon atom is more preferable. That is, the metal complex is more preferably a complex (organometallic complex) having a ligand coordinated with carbon.
Examples of the bond between the metal ion formed by coordination and the ligand include coordination bond, covalent bond, and ionic bond.

  The metal complex according to the present invention may be a low molecular compound, and an oligomer compound or a polymer compound having a metal complex in the main chain or side chain (weight average molecular weight (polystyrene conversion) is preferably 1000 to 5000000, more preferably. May be from 2,000 to 1,000,000, more preferably from 3,000 to 100,000. The compound of the present invention is preferably a low molecular compound.

  The metal complex having a tridentate or higher ligand is preferably a compound represented by the general formula (1), and more preferably a compound represented by the general formula (2).

The general formula (1) will be described. M ¹¹ represents a metal ion, preferably a transition metal ion, preferably a ruthenium ion, a rhodium ion, a palladium ion, a silver ion, a tungsten ion, a rhenium ion, an osmium ion, an iridium ion, a platinum ion, or a gold ion. Ions, palladium ions, rhenium ions, iridium ions, and platinum ions are more preferable, platinum ions and palladium ions are further preferable, and platinum ions are particularly preferable.

Q ¹¹ , Q ¹² , Q ¹³ , and Q ¹⁴ each form an atomic group that coordinates to M ¹¹ (the bond formed by coordination includes, for example, a coordinate bond, a covalent bond, and an ionic bond). Q ¹¹ ,
Q ¹² , Q ¹³ , and Q ¹⁴ are not particularly limited as long as they are an atomic group coordinated to M ¹¹ , but are coordinated by an atomic group coordinated by a carbon atom, an atomic group coordinated by a nitrogen atom, or an oxygen atom. An atomic group, an atomic group coordinated with a sulfur atom, an atomic group coordinated with a phosphorus atom are preferred, an atomic group coordinated with a carbon atom, an atomic group coordinated with a nitrogen atom, and an atomic group coordinated with an oxygen atom More preferably, an atomic group coordinated by a carbon atom and an atomic group coordinated by a nitrogen atom are more preferable.

Examples of an atomic group coordinated by a carbon atom include an imino group, an aromatic hydrocarbon ring group (benzene, naphthalene, etc.), a heterocyclic group (thiophene, pyridine, pyrazine, pyrimidine, pyridazine, triazine, thiazole, oxazole, pyrrole, Imidazole, pyrazole, triazole, etc.) and condensed rings containing them, and tautomers thereof. These groups may further have a substituent. Examples of the substituent include groups described for R ²¹ described later.

Examples of the atomic group coordinated by the nitrogen atom include nitrogen-containing heterocyclic groups (pyridine, pyrazine, pyrimidine, pyridazine, triazine, thiazole, oxazole, pyrrole, imidazole, pyrazole, triazole, etc.), amino groups (preferably alkylamino groups (preferably , Having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as methylamino), arylamino groups (for example, phenylamino) and the like), acylamino groups ( Preferably it has 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include acetylamino, benzoylamino and the like, and an alkoxycarbonylamino group (preferably having a carbon number). 2 to 30, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino), aryloxycarbonylamino group (preferably 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, particularly preferably 7 to 12 carbon atoms). Such as phenyloxycarbonylamino), sulfonylamino groups (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 12 carbon atoms, for example, methanesulfonyl Amino, benzenesulfonylamino, etc.), and imino groups. These groups may be further substituted. Examples of the substituent include groups described for R ²¹ described later.

As an atomic group coordinated by an oxygen atom, an alkoxy group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, such as methoxy, ethoxy, butoxy, 2 -Ethylhexyloxy and the like), an aryloxy group (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyloxy, 1-naphthyl). Oxy, 2-naphthyloxy, etc.), a heterocyclic oxy group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as pyridyloxy, Pyrazyloxy, pyrimidyloxy, quinolyloxy, etc.), acyloxy group (preferably having 2 to 30 carbon atoms, more preferred) Has 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms such as acetoxy and benzoyloxy), silyloxy group (preferably 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, Particularly preferred are those having 3 to 24 carbon atoms, such as trimethylsilyloxy, triphenylsilyloxy, etc.), carbonyl groups (for example, ketone groups, ester groups, amide groups, etc.), ether groups (for example, dialkyl ether groups, diaryls). Ether group, furyl group, etc.). These groups may be further substituted. Examples of the substituent include groups described for R ²¹ described later.

As an atomic group coordinated by a sulfur atom, an alkylthio group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include methylthio and ethylthio. ), An arylthio group (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenylthio), a heterocyclic thio group (preferably C1-C30, More preferably, it is C1-C20, Most preferably, it is C1-C12, for example, pyridylthio, 2-benzimidazolylthio, 2-benzoxazolylthio, 2-benzthiazolylthio, etc. ), A thiocarbonyl group (for example, a thioketone group, a thioester group, etc.), a thioether group (for example, a dialkylthioe group). Ether groups, diaryl thioether, etc. thiofuryl group). These groups may be further substituted. Examples of the substituent include groups described for R ²¹ described later.

Examples of the atomic group coordinated by the phosphorus atom include a dialkylphosphino group, a diarylphosphino group, a trialkylphosphine, a triarylphosphine, and a phosphinin group. These groups may be further substituted. Examples of the substituent include groups described for R ²¹ described later.

Q ¹¹ and Q ¹² are preferably an atom group coordinated by a nitrogen atom, an atom group coordinated by an oxygen atom, or an atom group coordinated by a phosphorus atom, more preferably an atom group coordinated by a nitrogen atom, A nitrogen-containing heterocyclic group that coordinates is more preferable, and a monocyclic nitrogen-containing heterocyclic group that coordinates with a nitrogen atom is particularly preferable.

Q ¹³ and Q ¹⁴ are preferably an atom group coordinated by a carbon atom, an atom group coordinated by a nitrogen atom, or an atom group coordinated by an oxygen atom, and coordinated by an aryl group coordinated by a carbon atom or a carbon atom. More preferred are a heteroaryl group, a heteroaryl group coordinated with a nitrogen atom, a carboxyl group coordinated with an oxygen atom, an aryloxy group coordinated with an oxygen atom, and a heteroaryloxy group coordinated with an oxygen atom. More preferred are an aryl group to be coordinated, a heteroaryl group to be coordinated with a carbon atom, a heteroaryl group to be coordinated with a nitrogen atom, and a carboxyl group to be coordinated with an oxygen atom, an aryl group coordinated with a carbon atom, A coordinating heteroaryl group is particularly preferred.

L ¹¹ , L ¹² , L ¹³ and L ¹⁴ each represent a single bond or a linking group. The linking group is not particularly limited, but an alkylene group (eg, methylene group, dimethylmethylene group, diisopropylmethylene group, diphenylmethylene group, ethylene group, tetramethylethylene group, etc.), alkenylene group (vinylene group, dimethylvinylene group, etc.) , Alkynylene groups (such as ethynylene groups), arylene groups (such as phenylene groups and naphthylene groups), heteroarylene groups (such as pyridylene groups, pyrazylene groups, and quinolylene groups), oxygen linking groups, sulfur linking groups, nitrogen linking groups (methylamino linking) Group, a phenylamino linking group, a tbutylamino linking group, etc.), a silicon linking group, and a linking group combining these (for example, an oxylenmethylene group).

L ¹¹ and L ¹³ are preferably a single bond, an alkylene group or an oxygen linking group, more preferably a single bond or an alkylene group, and even more preferably a single bond.

L ¹² and L ¹⁴ are preferably a single bond, an alkylene group, an oxygen linking group or a nitrogen linking group, more preferably an alkylene group or an oxygen linking group, and particularly preferably an alkylene linking group.

n ¹¹ represents 0 or 1. When n ¹¹ is 0, there is no bond through L ¹⁴ between Q ¹³ and Q ¹⁴ .

The bond between M ^{11 and} Q ^11, the bond between M ^{11 and} Q ¹² , the bond between M ^{11 and} Q ^13, and the bond between M ^{11 and} Q ¹⁴ may be covalent bonds or coordinate bonds. There may be an ionic bond.

The bond between M ^{11 and} Q ¹¹ and the bond between M ^{11 and} Q ¹² are preferably coordination bonds, and the bond between M ^{11 and} Q ¹³ and the bond between M ^{11 and} Q ¹⁴ are covalent bonds, Alternatively, an ionic bond is preferable, and a covalent bond is more preferable.

The general formula (2) will be described.
M ²¹ has the same meaning as M ¹¹ , and the preferred range is also the same. Q ²³ and Q ²⁴ each represent an atomic group coordinated to M ²¹ .

Q ²³ and Q ²⁴ are preferably an atom group coordinated by a carbon atom, an atom group coordinated by a nitrogen atom, or an atom group coordinated by an oxygen atom, and is coordinated by an aryl group coordinated by a carbon atom or a carbon atom. More preferred are a heteroaryl group, a heteroaryl group coordinated with a nitrogen atom, a carboxyl group coordinated with an oxygen atom, an aryloxy group coordinated with an oxygen atom, and a heteroaryloxy group coordinated with an oxygen atom. More preferred are an aryl group to be coordinated, a heteroaryl group to be coordinated with a carbon atom, a heteroaryl group to be coordinated with a nitrogen atom, and a carboxyl group to be coordinated with an oxygen atom, an aryl group coordinated with a carbon atom, and a carbon atom A coordinating heteroaryl group is particularly preferred.

L ²² represents a linking group, and specific examples include the linking groups described above. L ²² is preferably an alkylene linking group, an oxygen linking group, or a nitrogen linking group.

R ²¹ and R ²² each represent a substituent. Examples of the substituent include an alkyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 10 carbon atoms such as methyl, ethyl, iso-propyl, tert-butyl. , N-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, and particularly preferably carbon atoms). 2 to 10 such as vinyl, allyl, 2-butenyl, 3-pentenyl, etc.), an alkynyl group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, and particularly preferably carbon). 2-10, for example, propargyl, 3-pentynyl, etc.), aryl group (preferably carbon number) To 30, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include phenyl, p-methylphenyl, naphthyl, anthranyl, and the like, and amino groups (preferably having 0 to 0 carbon atoms). 30, more preferably 0 to 20 carbon atoms, particularly preferably 0 to 10 carbon atoms, and examples thereof include amino, methylamino, dimethylamino, diethylamino, dibenzylamino, diphenylamino, ditolylamino, and the like. (Preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, and examples thereof include methoxy, ethoxy, butoxy, 2-ethylhexyloxy and the like), aryloxy Group (preferably having 6 to 30 carbon atoms, more preferably having 6 to 20 carbon atoms, particularly preferably carbon 6-12, for example, phenyloxy, 1-naphthyloxy, 2-naphthyloxy, etc.), a heterocyclic oxy group (preferably having 1-30 carbons, more preferably having 1-20 carbons, especially Preferably it is C1-C12, for example, pyridyloxy, pyrazyloxy, pyrimidyloxy, quinolyloxy etc.), an acyl group (preferably C1-C30, more preferably C1-C20, especially preferably carbon) 1 to 12, for example, acetyl, benzoyl, formyl, pivaloyl, etc.), an alkoxycarbonyl group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 2 carbon atoms). 12 and examples thereof include methoxycarbonyl, ethoxycarbonyl and the like. Xoxycarbonyl group (preferably having 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, particularly preferably 7 to 12 carbon atoms, and examples thereof include phenyloxycarbonyl. ), An acyloxy group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms such as acetoxy and benzoyloxy), an acylamino group (preferably 2-30 carbon atoms, more preferably 2-20 carbon atoms, particularly preferably 2-10 carbon atoms, and examples thereof include acetylamino, benzoylamino, and the like, and an alkoxycarbonylamino group (preferably having 2-2 carbon atoms). 30, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino, etc.), aryloxycarbonylamino group (preferably 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonyl And sulfonylamino groups (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 12 carbon atoms, such as methanesulfonylamino and benzenesulfonylamino). ), A sulfamoyl group (preferably having 0 to 30 carbon atoms, more preferably 0 to 20 carbon atoms, particularly preferably 0 to 12 carbon atoms, such as sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, phenyl Sulfamoyl, etc.), a carbamoyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as carbamoyl, methylcarbamoyl, diethylcarbamoyl, Phenylcarbamoyl etc.), alkylthio group ( Preferably, it has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include methylthio, ethylthio and the like, and an arylthio group (preferably 6 to 30 carbon atoms). , More preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenylthio, etc.), a heterocyclic thio group (preferably 1 to 30 carbon atoms, more preferably 1 to carbon atoms). 20, particularly preferably 1 to 12 carbon atoms, such as pyridylthio, 2-benzimidazolylthio, 2-benzoxazolylthio, 2-benzthiazolylthio and the like, and a sulfonyl group (preferably having a carbon number). 1 to 30, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as mesyl and tosyl). Rufinyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include methanesulfinyl and benzenesulfinyl. ), A ureido group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 12 carbon atoms, such as ureido, methylureido, phenylureido, etc.), phosphoric acid. An amide group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as diethyl phosphoric acid amide and phenylphosphoric acid amide), a hydroxy group , Mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group ( Preferably it is C1-C30, More preferably, it is C1-C12, As a hetero atom, for example, a nitrogen atom, oxygen Children, sulfur atoms, specifically imidazolyl, pyridyl, quinolyl, furyl, thienyl, piperidyl, morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, carbazolyl group, azepinyl group, etc.), silyl group (preferably). Has 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms, and examples thereof include trimethylsilyl, triphenylsilyl, and the like, and a silyloxy group (preferably 3 to 40 carbon atoms). More preferably, it has 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms, and examples thereof include trimethylsilyloxy, triphenylsilyloxy, and the like. These substituents may be further substituted.

R ²¹ and R ²² are preferably an alkyl group, an alkoxy group, or a substituted amino group, more preferably an alkyl group or a substituted amino group, and even more preferably an alkyl group.

m ²¹ and m ²² each represent an integer of 0 to 3, preferably 0 or 1, and more preferably 0. When there are a plurality of m ²¹ and m ²² , the plurality of R ²¹ and R ²² may be the same or different.

  Specific examples of the compound represented by the general formula (1) or (2) are shown below, but the present invention is not limited to the following.

  The metal complex which concerns on the said specific example can be manufactured with reference to a well-known method. For example, the compound represented by the above (1-9) can be synthesized by the following synthesis scheme by a method similar to the method for synthesizing the compound (79) described on page 111 of WO2004 / 108857A2, for example. Also, Tetrahedron Lett44 (2003) 2861. The tetrakis (N-oxopyridyl) methane described in 1) is converted to tetrakis (2-bromopyridyl) methane by phosphoryl bromide, which is coupled with phenylboric acid to form tetrakis (2-phenylpyridyl) methane (ligand) ) And reacting this with platinum chloride can also be synthesized.

The complexing reaction is performed by, for example, ligand and metal source (for example, platinum chloride, palladium chloride, potassium chloroplatinate, sodium chloropalladate, platinum bromide, platinum acetylacetone complex) in a solvent (acetonitrile, benzonitrile, In the presence or absence of acetic acid, ethanol, methoxyethanol, glycerol, water, and mixed solvents thereof). An additive that activates the reaction (such as silver trifluoromethanesulfonate) may be added, or the reaction may be performed in the presence of an inert gas (such as nitrogen or argon).
Although reaction temperature is not specifically limited, -30 degreeC-400 degreeC is preferable, 0 degreeC-350 degreeC is more preferable, and 25 degreeC-300 degreeC is further more preferable.

  In addition to the compounds shown in the above specific examples, the metal complex according to the present invention includes compound (1) to compound (242) described in WO2004 / 108857A1 and compound (1) to compound (1) to WO2004 / 099339A1. Compound (154) can also be preferably used.

  The ionization potential of the metal complex is preferably 5 eV or more and 7 eV or less, more preferably 5.5 eV or more and 6.5 eV or less, and further preferably 5.8 eV or more and 6.3 eV or less.

The electron mobility of the metal complex is preferably 1 × 10 ⁻⁷ cm ² / Vs or more and 1 × 10 ⁰ cm ² / Vs or less, and preferably 1 × 10 ⁻⁶ cm ² / Vs or more and 1 × 10 ⁻¹ cm ^2. Is more preferably 1 × 10 ⁻⁵ cm ² / Vs or more and 1 × 10 ⁻¹ cm ² / Vs or less, more preferably 1 × 10 ⁻⁴ cm ² / Vs or more and 1 × 10. It is particularly preferably ¹ cm ² / Vs or less.

The hole mobility of the metal complex is preferably 1 × 10 ⁻⁷ cm ² / Vs or more and 1 × 10 ⁰ cm ² / Vs or less, preferably 1 × 10 ⁻⁶ cm ² / Vs or more and 1 × 10 ⁻¹ cm. ² / Vs or less, more preferably 1 × 10 ⁻⁵ cm ² / Vs or more and 1 × 10 ⁻¹ cm ² / Vs or less, and further preferably 1 × 10 ⁻⁴ cm ² / Vs or more and 1 ×. It is especially preferable that it is 10 < ^-1 > cm < ² > / Vs or less.

  When the glass transition point of the metal complex can be measured, the glass transition point is preferably 80 ° C. or higher and 1000 ° C. or lower, more preferably 90 ° C. or higher and 500 ° C. or lower, and 100 ° C. or higher and 500 ° C. or lower. More preferably, it is 120 degreeC or more and 500 degrees C or less especially.

  The formation method of the organic compound layer containing the metal complex according to the present invention is not particularly limited, but resistance heating vapor deposition, electron beam, sputtering, molecular lamination method, coating method (spray coating method, dip coating method, Impregnation method, roll coat method, gravure coat method, reverse coat method, roll brush method, air knife coat method, curtain coat method, spin coat method, flow coat method, bar coat method, micro gravure coat method, air doctor coat, blade Coating methods, squeeze coating methods, transfer roll coating methods, kiss coating methods, cast coating methods, extrusion coating methods, wire bar coating methods, screen coating methods, etc.), inkjet methods, printing methods, transfer methods, etc. are used, In terms of characteristics and manufacturing, resistance heating vapor deposition, coating Ingu method, a transfer method is preferable.

As described above, the layer containing the metal complex is disposed between the light emitting layer and the cathode, and the layer containing the metal complex is a layer that functions as an electron injection layer or an electron transport layer. A layer functioning as an electron transport layer adjacent to the light emitting layer is preferable.
In order to function as an electron injection layer or an electron transport layer, a material having any one of a function of injecting electrons from the cathode, a function of transporting electrons, and a function of blocking holes injected from the anode is added to the layer. That's fine. Specific examples of such materials include the above metal complexes, triazole, oxazole, oxadiazole, imidazole, fluorenone, anthraquinodimethane, anthrone, diphenylquinone, thiopyran dioxide, carbodiimide, fluorenylidenemethane, Various metal complexes represented by metal complexes of aromatic ring tetracarboxylic acid anhydrides such as distyrylpyrazine, naphthalene and perylene, metal complexes of phthalocyanine and 8-quinolinol, metal phthalocyanine, benzoxazole and benzothiazole, And organic silanes and derivatives thereof, and the above metal complexes, triazoles, oxazoles, oxadiazoles, imidazoles, 8-quinolinol metal complexes, metal phthalocyanines, benzoxazoles and benzothiazos. More preferred are various metal complexes typified by metal complexes having a ligand as a ligand, and metal complexes having the above metal complexes, metal complexes of 8-quinolinol, metal phthalocyanine, benzoxazole and benzothiazole as ligands. Most preferred are various metal complexes.

When the layer containing the metal complex is an electron injection layer or an electron transport layer, the film thickness is not particularly limited, but is usually preferably in the range of 1 nm to 5 μm, more preferably 5 nm to 1 μm. And more preferably 10 nm to 500 nm. The electron injection layer and the electron transport layer may have a single layer structure composed of one or more of the above-described materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions.
As a method for forming the electron injection layer and the electron transport layer, a vacuum vapor deposition method, an LB method, a method in which the electron injection transport material is dissolved or dispersed in a solvent, a coating method, an ink jet method, a printing method, a transfer method, and the like are used. In the case of the coating method, it can be dissolved or dispersed together with the resin component. As the resin component, for example, those exemplified in the case of the hole injection transport layer can be applied.

The light emitting material used in the light emitting layer is preferably a phosphorescent material (an iridium complex, a platinum complex, a rhenium complex, an osmium complex, a ruthenium complex, or the like). As the light-emitting material, a metal complex having a tetradentate or higher ligand is preferably used, and a metal complex phosphorescent material having a tetradentate or higher ligand is more preferably used.
Examples of the metal complex-based phosphorescent material having a tetradentate or higher ligand include, for example, general formulas (1) to (12), (X1), (X2), (X3), and compounds (WO 2004 / 108857A1) 1) to (242), general formulas (1) to (18) of WO2004 / 099339A1, compounds (1) to (159), and the like.
Among metal complex phosphorescent materials having a tetradentate or higher ligand, a platinum complex having a tetradentate ligand is preferable. In the general formula (1), a platinum complex represented by M11 = Pt is More preferably, in the general formula (2), a platinum complex represented by M21 = Pt is more preferable.
In the general formula (2), among platinum complexes represented by M21 = Pt, Q23 and Q24 are coordinated by an aryl group coordinated by a carbon atom, a heteroaryl group coordinated by a carbon atom, or a nitrogen atom. A heteroaryl group and a carboxyl group coordinated with an oxygen atom are preferred, an aryl group coordinated with a carbon atom, a heteroaryl group coordinated with a carbon atom, and a carboxyl group coordinated with an oxygen atom are more preferred.
As the aromatic hydrocarbon ring forming an aryl group coordinated with a carbon atom, a benzene ring and a naphthalene ring are preferable, and a benzene ring is more preferable. Furthermore, it may have a condensed ring or a substituent.
Aromatic heterocycles that form heteroaryl groups coordinated by carbon atoms include pyridine ring, pyrazine ring, pyrimidine ring, pyrazole ring, imidazole ring, triazole ring, oxazole ring, thiazole ring, oxadiazole ring, thiadiazole A ring, a thiophene ring and a furan ring are preferred, a pyridine ring, a pyrazole ring, an imidazole ring, a triazole ring, an oxazole ring, a thiazole ring, a thiophene ring and a furan ring are more preferred, and a pyridine ring, a pyrazole ring and an imidazole ring are still more preferred. Furthermore, it may have a condensed ring or a substituent.

  The content of the light emitting material is preferably 0.1 to 50% by mass, more preferably 1 to 40% by mass, and 3 to 20% by mass with respect to the total mass of the light emitting layer. Further preferred.

The T ₁ level (lowest triplet excited state energy level) of the light emitting material is preferably 60 Kcal / mol or more (251.4 KJ / mol or more), 90 Kcal / mol or less (377.1 KJ / mol or less), and 62 Kcal / mol or more. (259.78 KJ / mol or more), 85 Kcal / mol or less (356.15 KJ / mol or less) is more preferable, 65 Kcal / mol or more (272.35 KJ / mol or more), 80 Kcal / mol or less (335.2 KJ / mol or less) Is more preferable.

  Further, the light emitting layer may contain a host material together with the light emitting material as described above. The host material is capable of injecting holes from the anode or hole injection layer and hole transport layer when an electric field is applied, and can also inject electrons from the cathode or electron injection layer and electron transport layer. Any layer can be used as long as it can form a layer having a function of moving the generated charge and a function of emitting light by providing a recombination field of holes and electrons. For example, benzoxazole, benzimidazole, benzothiazole, styrylbenzene, polyphenyl, diphenylbutadiene, tetraphenylbutadiene, naphthalimide, coumarin, perylene, perinone, oxadiazole, aldazine, pyralidine, cyclopentadiene, bisstyrylanthracene, quinacridone, pyrrolo Pyridine, thiadiazolopyridine, cyclopentadiene, styrylamine, aromatic dimethylidin compounds, various metal complexes typified by metal complexes and rare earth complexes of 8-quinolinol, polymer compounds such as polythiophene, polyphenylene, polyphenylene vinylene, organic silane, iridium Examples include transition metal complexes represented by trisphenylpyridine complexes and platinum porphyrin complexes, and derivatives thereof. .

  The ionization potential of the host material contained in the light emitting layer is preferably 5.8 eV or more and 6.3 eV or less, more preferably 5.95 eV or more and 6.25 eV or less, and 6.0 eV or more and 6.2 eV. More preferably, it is as follows.

The electron mobility of the host material in the light emitting layer is preferably 1 × 10 ⁻⁶ cm ² / Vs or more and 1 × 10 ⁻¹ cm ² / Vs or less, preferably 5 × 10 ⁻⁶ cm ² / Vs or more. It is more preferably 10 × 10 ⁻² cm ² / Vs or less, further preferably 1 × 10 ⁻⁵ cm ² / Vs or more and 1 × 10 ⁻² cm ² / Vs or less, and more preferably 5 × 10 ⁻⁵ cm ^2. It is particularly preferred that it is not less than / Vs and not more than 1 × 10 ⁻² cm ² / Vs.

The hole mobility of the host material in the light emitting layer is preferably 1 × 10 ⁻⁶ cm ² / Vs or more and 1 × 10 ⁻¹ cm ² / Vs or less, preferably 5 × 10 ⁻⁶ cm ² / Vs or more. It is more preferably 10 × 10 ⁻² cm ² / Vs or less, further preferably 1 × 10 ⁻⁵ cm ² / Vs or more and 1 × 10 ⁻² cm ² / Vs or less, and more preferably 5 × 10 ⁻⁵ cm ^2. It is particularly preferred that it is not less than / Vs and not more than 1 × 10 ⁻² cm ² / Vs.

The T ₁ level (energy level in the lowest triplet excited state) of the host material in the light emitting layer is preferably 60 Kcal / mol or more (251.4 KJ / mol or more), 90 Kcal / mol or less (377.1 KJ / mol or less), 62 Kcal / mol or more (259.78 KJ / mol or more), 85 Kcal / mol or less (356.15 KJ / mol or less) is more preferable, 65 Kcal / mol or more (272.35 J / mol or more), 80 Kcal / mol or less (335. 2 KJ / mol or less) is more preferable.

  The glass transition point of the host material contained in the light emitting layer is preferably 90 ° C. or higher and 400 ° C. or lower, more preferably 100 ° C. or higher and 380 ° C. or lower, and further preferably 120 ° C. or higher and 370 ° C. or lower, It is particularly preferably 140 ° C. or higher and 360 ° C. or lower.

  The method for forming the light emitting layer is not particularly limited, and methods such as resistance heating vapor deposition, electron beam, sputtering, molecular lamination method, coating method, ink jet method, printing method, LB method, and transfer method are used. Of these, resistance heating vapor deposition and coating are preferred.

  Although the film thickness of a light emitting layer is not specifically limited, Usually, the thing of the range of 1 nm-5 micrometers is preferable, More preferably, it is 5 nm-1 micrometer, More preferably, it is 10 nm-500 nm.

The light emitting layer may have a laminated structure. The number of stacked layers is preferably 2 or more and 50 or less, more preferably 4 or more and 30 or less, and still more preferably 6 or more and 20 or less.
The thickness of each layer constituting the stack is not particularly limited, but is preferably 0.2 nm or more and 20 nm or less, more preferably 0.4 nm or more and 15 nm or less, further preferably 0.5 nm or more and 10 nm or less, and more preferably 1 nm or more and 5 nm or less. Particularly preferred.
When the light emitting layer is composed of a plurality of layers, each layer may be formed of a single material or may be formed of a plurality of compounds.

  Moreover, when a light emitting layer is comprised from several layers as mentioned above, each layer may light-emit by the light emission color from which it differs, for example, you may light-emit white. When the light emitting layer is composed of a single layer, white light may be emitted from the single layer.

The light emitting layer may have a plurality of domain structures. For example, the light emitting layer may be composed of a region made of a mixture of a host material and a light emitting material and a region made of a mixture of another host material and a light emitting material. Each region can be about 1 nm ³ . The size of each domain is preferably from 0.2 nm to 10 nm, more preferably from 0.3 nm to 5 nm, still more preferably from 0.5 nm to 3 nm, and particularly preferably from 0.7 nm to 2 nm.

  The formation method of the light emitting layer is not particularly limited, but resistance heating vapor deposition, electron beam, sputtering, molecular lamination method, coating method (spray coating method, dip coating method, impregnation method, roll coating method, gravure coating method) , Reverse coat method, roll brush method, air knife coat method, curtain coat method, spin coat method, flow coat method, bar coat method, micro gravure coat method, air doctor coat, blade coat method, squeeze coat method, transfer roll coat Method, kiss coating method, cast coating method, extrusion coating method, wire bar coating method, screen coating method, etc.), inkjet method, printing method, LB method, transfer method, etc. Use heat evaporation, coating, and transfer methods. It is preferred.

  The organic electroluminescent element of the present invention has the light emitting layer between a pair of electrodes consisting of an anode and a cathode, and further has an organic compound layer containing the metal complex as an electron injection layer or an electron transport layer. Although it can, it can also have a layer with other functions. Examples of other functional layers include a hole injection layer, a hole transport layer, a protective layer, a charge block layer, and an exciton block layer. The organic electroluminescent element of the present invention preferably has at least three layers of a hole transport layer, a light emitting layer, and an electron transport layer. Each of these layers may have other functions. Various known materials can be used for forming each layer.

The anode supplies holes to a hole injection layer, a hole transport layer, a light emitting layer, and the like, and a metal, an alloy, a metal oxide, an electrically conductive compound, or a mixture thereof can be used. A material having a work function of 4 eV or more is preferable. Specific examples include conductive metal oxides such as tin oxide, zinc oxide, indium oxide and indium tin oxide (ITO), metals such as gold, silver, chromium and nickel, and these metals and conductive metal oxides. Inorganic conductive materials such as copper iodide and copper sulfide, organic conductive materials such as polyaniline, polythiophene, and polypyrrole, and laminates of these with ITO, preferably conductive metals It is an oxide, and ITO is particularly preferable from the viewpoint of productivity, high conductivity, transparency, and the like.
Although the film thickness of the anode can be appropriately selected depending on the material, it is usually preferably in the range of 10 nm to 5 μm, more preferably 50 nm to 1 μm, still more preferably 100 nm to 500 nm.

As the anode, a layer formed on a soda-lime glass, non-alkali glass, a transparent resin substrate or the like is usually used. When glass is used, it is preferable to use non-alkali glass as the material in order to reduce ions eluted from the glass. Moreover, when using soda-lime glass, it is preferable to use what gave barrier coatings, such as a silica. The thickness of the substrate is not particularly limited as long as it is sufficient to maintain the mechanical strength, but when glass is used, a thickness of 0.2 mm or more, preferably 0.7 mm or more is usually used.
Various methods are used for producing the anode depending on the material. For example, in the case of ITO, an electron beam method, a sputtering method, a resistance heating vapor deposition method, a chemical reaction method (sol-gel method, etc.), a coating of a dispersion of indium tin oxide, etc. A film is formed by this method.
The anode can be subjected to cleaning or other treatments to lower the drive voltage of the element or increase the light emission efficiency. For example, in the case of ITO, UV-ozone treatment, plasma treatment, etc. are effective.

  The cathode supplies electrons to the electron injection layer, the electron transport layer, the light emitting layer, etc., and the adhesion, ionization potential, and stability between the negative electrode and the adjacent layer such as the electron injection layer, the electron transport layer, and the light emitting layer. It is selected in consideration of etc. As a material for the cathode, a metal, an alloy, a metal halide, a metal oxide, an electrically conductive compound, or a mixture thereof can be used. Specific examples include an alkali metal (for example, Li, Na, K, etc.) and its fluoride. Or oxides, alkaline earth metals (eg Mg, Ca, etc.) and fluorides or oxides thereof, gold, silver, lead, aluminum, sodium-potassium alloys or their mixed metals, lithium-aluminum alloys or their mixtures Examples thereof include metals, magnesium-silver alloys or mixed metals thereof, rare earth metals such as indium and ytterbium, preferably materials having a work function of 4 eV or less, more preferably aluminum, lithium-aluminum alloys or mixed metals thereof. , Magnesium-silver alloys or mixed metals thereof. The cathode can take not only a single layer structure of the compound and the mixture but also a laminated structure including the compound and the mixture. For example, a laminated structure of aluminum / lithium fluoride and aluminum / lithium oxide is preferable.

The film thickness of the cathode can be appropriately selected depending on the material, but is usually preferably in the range of 10 nm to 5 μm, more preferably 50 nm to 1 μm, still more preferably 100 nm to 1 μm.
For production of the cathode, methods such as an electron beam method, a sputtering method, a resistance heating vapor deposition method, a coating method, and a transfer method are used, and a metal can be vapor-deposited alone or two or more components can be vapor-deposited simultaneously. Furthermore, a plurality of metals can be vapor-deposited simultaneously to form an alloy electrode, or a previously prepared alloy may be vapor-deposited.
The sheet resistance of the anode and the cathode is preferably low, and is preferably several hundred Ω / □ or less.

  As in the case of the anode, the cathode can be provided on the substrate. The base material is not particularly limited, but inorganic materials such as zirconia-stabilized yttrium and glass, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyethylene, polycarbonate, polyethersulfone, polyarylate, and allyl diester. High molecular weight materials such as glycol carbonate, polyimide, polycycloolefin, norbornene resin, poly (chlorotrifluoroethylene), Teflon (registered trademark), and polytetrafluoroethylene-polyethylene copolymer may be used.

  The material of the hole injection layer and the hole transport layer may be any one having a function of injecting holes from the anode, a function of transporting holes, or a function of blocking electrons injected from the cathode. Good. Specific examples include carbazole, triazole, oxazole, oxadiazole, imidazole, polyarylalkane, pyrazoline, pyrazolone, phenylenediamine, arylamine, amino-substituted chalcone, styrylanthracene, fluorenone, hydrazone, stilbene, silazane, aromatic group Tertiary amine compounds, styrylamine compounds, aromatic dimethylidin compounds, porphyrin compounds, polysilane compounds, poly (N-vinylcarbazole), aniline copolymers, thiophene oligomers, conductive polymer oligomers such as polythiophene, organic Examples include silane, carbon films, compounds of the present invention, and derivatives thereof.

  The film thicknesses of the hole injection layer and the hole transport layer are not particularly limited, but are usually preferably in the range of 1 nm to 5 μm, more preferably 5 nm to 1 μm, and still more preferably 10 nm to 500 nm. . The hole injection layer and the hole transport layer may have a single-layer structure composed of one or more of the materials described above, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions.

  As a method for forming the hole injection layer and the hole transport layer, a vacuum deposition method, an LB method, a method in which the hole injection transport material is dissolved or dispersed in a solvent, a coating method, an ink jet method, a printing method, or a transfer method is used. It is done. In the case of the coating method, it can be dissolved or dispersed together with the resin component. Examples of the resin component include polyvinyl chloride, polycarbonate, polystyrene, polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, and poly (N -Vinyl carbazole), hydrocarbon resin, ketone resin, phenoxy resin, polyamide, ethyl cellulose, vinyl acetate, ABS resin, polyurethane, melamine resin, unsaturated polyester resin, alkyd resin, epoxy resin, silicone resin, and the like.

As a material for the protective layer, any material may be used as long as it has a function of preventing substances that promote device deterioration such as moisture and oxygen from entering the device. Specific examples thereof include metals such as In, Sn, Pb, Au, Cu, Ag, Al, Ti, Ni, MgO, SiO, SiO ₂ , Al ₂ O ₃ , G
Metal oxides such as eO, NiO, CaO, BaO, Fe ₂ O ₃ , Y ₂ O ₃ , TiO ₂ , metal fluorides such as MgF ₂ , LiF, AlF ₃ , CaF ₂ , SiN _x , SiO _x N _y, etc. Nitride, polyethylene, polypropylene, polymethyl methacrylate, polyimide, polyurea, polytetrafluoroethylene, polychlorotrifluoroethylene, polydichlorodifluoroethylene, copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene, tetrafluoroethylene and A copolymer obtained by copolymerizing a monomer mixture containing at least one comonomer, a fluorinated copolymer having a cyclic structure in the copolymer main chain, a water-absorbing substance having a water absorption of 1% or more, a water absorption of 0. A moisture-proof substance of 1% or less is included.
There is no particular limitation on the method for forming the protective layer. For example, vacuum deposition, sputtering, reactive sputtering, MBE (molecular beam epitaxy), cluster ion beam, ion plating, plasma polymerization (high frequency excitation ions) Plating method), plasma CVD method, laser CVD method, thermal CVD method, gas source CVD method, coating method, printing method, and transfer method can be applied.

Note that the T ₁ level (energy level of the lowest triplet excited state) of a layer adjacent to the light emitting layer (hole transport layer, electron transport layer, charge block layer, exciton block layer, etc.) is 60 Kcal / mol or more (251 .4 KJ / mol or more), 90 Kcal / mol or less (377.1 KJ / mol or less) is preferable, 62 Kcal / mol or more (259.78 KJ / mol or more), 85 Kcal / mol or less (356.15 KJ / mol or less) is more preferable. 65 Kcal / mol or more (272.35 KJ / mol or more), 80 Kcal / mol or less (335.2 KJ / mol or less).

  The organic electroluminescent device of the present invention may contain a blue fluorescent light emitting compound, or a blue light emitting device containing a blue fluorescent compound and the light emitting device of the present invention are used simultaneously to produce a multicolor light emitting device or a full color light emitting device. A device may be manufactured.

  In the organic electroluminescent element of the present invention, the maximum wavelength of light emission is preferably 390 nm or more and 495 nm or less, more preferably 400 nm or more and 490 nm or less, from the viewpoint of blue color purity. The light emitting device of the present invention may have a light emission maximum wavelength of 500 nm or more, or may be a white light emitting device.

In the organic electroluminescent element of the present invention, from the viewpoint of blue color purity, the x value of the CIE chromaticity value of light emission is preferably 0.22 or less, more preferably 0.20 or less. The y value of the CIE chromaticity value of luminescence is preferably 0.25 or less, more preferably 0.20 or less, and even more preferably 0.15 or less.
In the organic electroluminescent element of the present invention, from the viewpoint of blue color purity, the half-value width of the emission spectrum is preferably 100 nm or less, more preferably 90 nm or less, further preferably 80 nm or less, and particularly preferably 70 nm or less.

The external quantum efficiency of the organic electroluminescent element of the present invention is preferably 5% or more, more preferably 10% or more, and further preferably 13% or more. The value of the external quantum efficiency should be the maximum value of the external quantum efficiency when the device is driven at 20 ° C., or the value of the external quantum efficiency near 100 to 300 cd / m ² when the device is driven at 20 ° C. Can do.

The internal quantum efficiency of the organic electroluminescence device of the present invention is preferably 30% or more, more preferably 50% or more, and further preferably 70% or more. The internal quantum efficiency of the device is calculated as internal quantum efficiency = external quantum efficiency / light extraction efficiency. In a normal organic EL element, the light extraction efficiency is about 20%. However, the shape of the substrate, the shape of the electrode, the thickness of the organic layer, the thickness of the inorganic layer, the refractive index of the organic layer, the refractive index of the inorganic layer, etc. By devising it, it is possible to increase the light extraction efficiency to 20% or more.

  The organic electroluminescence device of the present invention can improve the light extraction efficiency by various known devices. For example, by processing the substrate surface shape (for example, forming a fine concavo-convex pattern), controlling the refractive index of the substrate / ITO layer / organic layer, controlling the film thickness of the substrate / ITO layer / organic layer, etc. It is possible to improve light extraction efficiency and external quantum efficiency.

  The organic electroluminescent element of the present invention is a so-called top emission method (explained in JP 2003-208109A, 2003-248441, 2003-257651, 2003-282261, etc.) that takes out light emission from the cathode side. May be.

  The organic electroluminescent element of the present invention is not particularly limited, such as a system, a driving method, and a usage form. An organic EL (electroluminescence) element can be mentioned as a typical organic electroluminescent element.

  The use of the organic electroluminescence device of the present invention is not particularly limited, but in the fields of display device, display, backlight, electrophotography, illumination light source, recording light source, exposure light source, reading light source, sign, signboard, interior, optical communication, etc. It can be used suitably.

  Specific examples of the present invention will be described below, but the embodiments of the present invention are not limited thereto.

[Synthesis Example 1] Synthesis of Exemplified Compound (1-33) Under a nitrogen atmosphere, ligand D-1 (100 mg, 0.237 mmol) and bis (acetonitrile) palladium (II) dichloride (61 mg, 0.237 mmol) were placed in an eggplant flask. ), Trimethyl phosphate (5 mL) was added, and the mixture was heated and stirred at 130 ° C. for 4 hours. After cooling to room temperature, the precipitated solid was filtered, washed with methanol, and dried under reduced pressure to obtain 74 mg of Exemplified Compound (1-33) as a pale yellow solid (yield 59%).
Other compounds were synthesized by the same method or the method described in International Publication Pamphlet WO-108857.

¹ H-NMR (CDCl ₃ ): δ (ppm) = 8.06 (dt, J = 1.0, 8.4Hz, 2H), 7.80 (t, J = 9.0Hz, 2H), 7.55 (dd, J = 2.4, 8.4Hz ), 7.42 (d, J = 7.6Hz, 2H), 6.62 (ddd, J = 2.4, 8.6, 12.8Hz, 2H), 2.07 (s, 6H)

[Comparative Example 1]
The cleaned ITO substrate was put in a vapor deposition apparatus, and copper phthalocyanine was vapor-deposited to 5 nm, and NPD (N, N′-di-α-naphthyl-N, N′-diphenyl) -benzidine) was vapor-deposited thereon to 40 nm. On top of this, Ir (ppy) ₃ and CBP were vapor-deposited at a ratio of 6:94 (mass ratio) of 30 nm, and BAlq was vapor-deposited thereon at a thickness of 6 nm, on which Alq (tris (8-hydroxyquinoline) aluminum was deposited. Complex) was deposited by 20 nm. On top of this, 3 nm of lithium fluoride was deposited, and then 60 nm of aluminum was deposited to produce an EL device. As a result of applying a DC constant voltage to the EL element to emit light using a source measure unit type 2400 manufactured by Toyo Technica, green light emission derived from Ir (ppy) ₃ was obtained.

[Example 1]
The compound (1-3) was used in place of BAlq of Comparative Example 1, and the device was evaluated in the same manner as in Comparative Example 1. As a result, green light emission derived from Ir (ppy) ₃ was obtained. The luminance half-life of the element driven at 1 mA (light emitting area 4 mm ² ) was 2.3 times that of the element of Comparative Example 1.

[Example 2]
The compound (1-1) was used in place of Alq in Comparative Example 1, and the device was evaluated in the same manner as in Comparative Example 1. As a result, green light emission derived from Ir (ppy) ₃ was obtained. The luminance half life of the element driven at 1 mA (light emitting area 4 mm ² ) was 1.5 times that of the element of Comparative Example 1.

[Example 3]
The cleaned ITO substrate was put in a vapor deposition apparatus, and copper phthalocyanine was vapor-deposited to 5 nm, and NPD (N, N′-di-α-naphthyl-N, N′-diphenyl) -benzidine) was vapor-deposited thereon to 40 nm. On top of this, Ir (ppy) ₃ and CBP were deposited at a ratio (mass ratio) of 6:94 for 30 nm, and the compound (1-3) was deposited thereon at 26 nm. On top of this, 3 nm of lithium fluoride was deposited, and then 60 nm of aluminum was deposited to produce a device. As a result of applying a constant DC voltage to the EL element to emit light using a source measure unit type 2400 manufactured by Toyo Technica, green light emission derived from Ir (ppy) ₃ was obtained. The luminance half life of the element driven at 1 mA (light emitting area 4 mm ² ) was 2.0 times that of the element of Comparative Example 1.

[Example 4]
The cleaned ITO substrate was put in a vapor deposition apparatus, and copper phthalocyanine was vapor-deposited to 5 nm, and NPD (N, N′-di-α-naphthyl-N, N′-diphenyl) -benzidine) was vapor-deposited thereon to 40 nm. On top of this, Ir (ppy) ₃ and CBP were vapor-deposited at a ratio of 6:94 (mass ratio) of 30 nm, and the compound (1-19) was vapor-deposited thereon at 26 nm. On top of this, 3 nm of lithium fluoride was deposited, and then 60 nm of aluminum was deposited to produce a device. As a result of applying a constant DC voltage to the EL element to emit light using a source measure unit type 2400 manufactured by Toyo Technica, green light emission derived from Ir (ppy) ₃ was obtained. The luminance half-life of the element driven at 1 mA (light emitting area 4 mm ² ) was 2.1 times that of the element of Comparative Example 1.

[Comparative Example 2]
The cleaned ITO substrate was put in a vapor deposition apparatus, and copper phthalocyanine was vapor-deposited to 5 nm, and NPD (N, N′-di-α-naphthyl-N, N′-diphenyl) -benzidine) was vapor-deposited thereon to 40 nm. On top of this, Ir (ppy) ₃ and CBP were vapor-deposited at a ratio of 6:94 (mass ratio) for 30 nm, and BAlq and Compound A were vapor-deposited at a ratio of 50:50 (mass ratio) at 6 nm. On top of this, Alq was deposited by 20 nm. On top of this, 3 nm of lithium fluoride was deposited, and then 60 nm of aluminum was deposited to produce a device. As a result of applying a constant DC voltage to the EL element to emit light using a source measure unit type 2400 manufactured by Toyo Technica, green light emission derived from Ir (ppy) ₃ was obtained.

[Example 5]
The compound (1-3) was used in place of BAlq of Comparative Example 2, and as a result of device creation evaluation as in Comparative Example 2, green light emission derived from Ir (ppy) ₃ was obtained. The luminance half-life of the element driven at 1 mA (light emitting area 4 mm ² ) was 2.2 times that of the element of Comparative Example 2.

[Example 6]
The compound (1-33) was used in place of BAlq in Comparative Example 2 and the device was evaluated in the same manner as in Comparative Example 2. As a result, green light emission derived from Ir (ppy) ₃ was obtained. The luminance half-life of the element driven at 1 mA (light emitting area 4 mm ² ) was 1.9 times that of the element of Comparative Example 2.

[Comparative Example 3]
The cleaned ITO substrate was put in a vapor deposition apparatus, and copper phthalocyanine was vapor-deposited to 5 nm, and NPD (N, N′-di-α-naphthyl-N, N′-diphenyl) -benzidine) was vapor-deposited thereon to 40 nm. On this, platinum tetradentate complex B and mCP were vapor-deposited by 30 nm in the ratio (mass ratio) of 15:85, BAlq was vapor-deposited by 6 nm, and Alq was vapor-deposited by 20 nm on this. On top of this, 3 nm of lithium fluoride was deposited, and then 60 nm of aluminum was deposited to produce a device. As a result of emitting light by applying a DC constant voltage to the EL element using a source measure unit 2400 type manufactured by Toyo Technica, green light emission derived from the platinum tetradentate complex B was obtained.

[Example 7]
The compound (1-3) was used in place of BAlq of Comparative Example 3 and the device was evaluated in the same manner as in Comparative Example 3. As a result, green light emission derived from the platinum tetradentate complex B was obtained. The luminance half life of the element driven at 1 mA (light emitting area 4 mm ² ) was 1.8 times that of the element of Comparative Example 3.

[Comparative Example 4]
The cleaned ITO substrate was put in a vapor deposition apparatus, and copper phthalocyanine was vapor-deposited to 5 nm, and NPD (N, N′-di-α-naphthyl-N, N′-diphenyl) -benzidine) was vapor-deposited thereon to 40 nm. On this, platinum tetradentate complex C and mCP were vapor-deposited by 30 nm in the ratio (mass ratio) of 15:85, BAlq was vapor-deposited 6 nm on this, and Alq was vapor-deposited 20 nm on this. On top of this, 3 nm of lithium fluoride was deposited, and then 60 nm of aluminum was deposited to produce a device. As a result of emitting light by applying a DC constant voltage to the EL element using a source measure unit type 2400 manufactured by Toyo Technica, green light emission derived from the platinum tetradentate complex C was obtained.

[Example 8]
The compound (1-3) was used in place of BAlq of Comparative Example 4, and as a result of device creation evaluation as in Comparative Example 4, green light emission derived from the platinum tetradentate complex C was obtained. The luminance half-life of the element driven at 1 mA (light emitting area 4 mm ² ) was 1.9 times that of the element of Comparative Example 4.

[Comparative Example 5]
The cleaned ITO substrate was put in a vapor deposition apparatus, and copper phthalocyanine was vapor-deposited to 5 nm, and NPD (N, N′-di-α-naphthyl-N, N′-diphenyl) -benzidine) was vapor-deposited thereon to 40 nm. On this, platinum tetradentate complex D and mCP were vapor-deposited by 30 nm in the ratio (mass ratio) of 15:85, BAlq was vapor-deposited 6 nm on this, and Alq was vapor-deposited 20 nm on this. On top of this, 3 nm of lithium fluoride was deposited, and then 60 nm of aluminum was deposited to produce a device. As a result of emitting light by applying a DC constant voltage to the EL element using a source measure unit type 2400 manufactured by Toyo Technica, blue light emission derived from the platinum tetradentate complex D was obtained.

[Example 9]
The compound (1-3) was used in place of BAlq of Comparative Example 5 and the device was evaluated in the same manner as in Comparative Example 5. As a result, blue light emission derived from the platinum tetradentate complex D was obtained. The luminance half-life of the element driven at 1 mA (light emitting area 4 mm ² ) was 1.6 times that of the element of Comparative Example 5.

  Even with an element using another compound of the present invention, a highly durable EL element can be manufactured.

Claims (2)

An organic electroluminescence device having a plurality of organic compound layers including a light emitting layer between a pair of electrodes composed of an anode and a cathode, wherein at least one of the following general formula ( 2 ) is provided between the light emitting layer and the cathode: An organic electroluminescent device comprising at least one layer containing the represented compound.

M ²¹ represents a platinum ion or a palladium ion. Q ^{23, Q 24} represents a coordinating triazolyl group or a pyrazolyl group with a carbon atom to the phenyl group or ^{M 21} coordinated with the carbon atom to ^{M 21,} respectively. L ²² represents a dimethylmethylene group or a diphenylmethylene group. The bond between M ^{21 and} N (dotted line portion) indicates a coordination bond. The bond between M ^{21 and} Q ²³ and the bond between M ^{21 and} Q ²⁴ are covalent bonds. The organic electroluminescent device of claim 1, wherein the light emitting layer contains a luminescent material, characterized in that the luminescent material is a phosphorescent material.