ORGANIC ELECTROLUMINESCENT ELEMENT AND COMPOSITION FOR ORGANIC MATERIALS

1 . An organic electroluminescent element comprising an anode, a cathode and one or a plurality of organic functional layers interposed between the anode and the cathode, wherein the organic functional layer contains a phosphorescent metal complex and a fluorescent compound, the phosphorescent metal complex is a compound having a structure represented by Formula (1), and the phosphorescent metal complex satisfies the following Expression (a),

in Formula (1): M represents Ir or Pt; A 1 , A 2 , B 1 and B 2 each independently represent a carbon atom or a nitrogen atom; a ring Z 1 represents a 6-membered aromatic hydrocarbon ring, or a 5- or 6-membered aromatic heterocyclic ring formed with A 1 and A 2 , or an aromatic condensed ring containing at least one of the aforesaid rings; a ring Z 2 represents a 5- or 6-membered aromatic heterocyclic ring formed with B 1 and B2, or an aromatic condensed ring containing at least one of the aforesaid rings; among a bond between A 1 and M, and a bond between B 1 and M, one is a coordinate bond and the other is a covalent bond; the ring Z 1 and the ring Z 2 each independently may have a substituent, and the ring Z 1 and the ring Z 2 have at least one substituent represented by Formula (2); the substituent of the ring Z 1 and the substituent of the ring Z 12 may be bonded to form a condensed ring structure, and ligands represented by the ring Z 1 and the ring Z 2 may be linked to each other; L represents a monoanionic bidentate ligand coordinated to M, and L may have a substituent; m represents an integer of 0 to 2, n represents an integer of 1 to 3, when M represents Ir, m+n is 3, and when m represents Pt, m+n is 2, when m or n is 2 or more, the ligands represented by the ring Z 1 and the ring Z 2 , or L may be the same or different; the ligand represented by the ring Z 1 and the ring Z 2 may be linked to L,

*-L′-(CR 2 ) n′ -A  Formula (2)

in Formula (2), a symbol * represents a linking site with the ring Z 1 or the ring Z 2 in Formula (1); L′ represents a single bond or a linking group; R represents a hydrogen atom or a substituent; n′ represents an integer of 3 or more; a plurality of Rs may be the same or different; and A represents a hydrogen atom or a substituent,

{ V all /V core }>2  Expression (a):

in Expression (a), V all represents a molecular volume of a compound having a chemical structure represented by Formula (1) including the substituents bonded to the ring Z 1 and the ring Z 2 ; when M represents Ir, n=3 and m=0 are fixed, and when M represents Pt, n=2 and m=0 are fixed; V core represents a molecular volume of a compound having a chemical structure in which the substituent bonded to the ring Z 1 and the ring Z 2 is replaced with a hydrogen atom from the chemical structure indicating the molecular volume of V all ; and when there are plural types of ligands represented by the ring Z 1 and the ring Z 2 , V all and V core satisfy Expression (a) in all cases expressed by the aforesaid conditions.

2 . The organic electroluminescent element described in claim 1 , wherein L′ in Formula (2) represents a non-conjugated linking group.

3 . The organic electroluminescent element described in claim 1 , wherein the ligands represented by Z 1 and Z 2 in Formula (1) contain three or more substituents.

4 . An organic electroluminescent element comprising an anode, a cathode and one or a plurality of organic functional layers interposed between the anode and the cathode, wherein the organic functional layer contains a phosphorescent metal complex and a fluorescent compound, the phosphorescent metal complex is a compound having a structure represented by any one of Formulas (3) to (5), and the phosphorescent metal complex satisfies the following Expression (b),

in Formula (3) to (5): M represents Ir or Pt; A 1 to A 3 , and B 1 to B 4 each independently represent a carbon atom or a nitrogen atom; among a bond between A 1 and M, and f bond between B 1 and M, one is a coordinate bond and the other is a covalent bond; L represents a monoanionic bidentate ligand coordinated to M, and L may have a substituent; m represents an integer of 0 to 2, n represents an integer of 1 to 3, when M represents Ir, m+n is 3, and when m represents Pt, m+n is 2, when m or n is 2 or more, ligands represented by a ring Z 3 and a ring Z 4 , ligands represented by a ring Z 5 and a ring Z 6 , and ligands represented by a ring Z 7 and a ring Z 8 , or L may be the same or different; the ligands represented by the ring Z 3 to Z 8 may be linked to L,

in Formula (3), the ring Z 3 represents a 5-membered aromatic heterocyclic ring formed with A 1 and A 2 , or an aromatic condensed ring containing the aforesaid ring; the ring Z 4 represents a 5-membered aromatic heterocyclic ring formed with B 1 to B 3 , or an aromatic condensed ring containing the aforesaid ring; R 1 represents a substituent having 2 or more carbon atoms; the ring Z 3 and the ring Z 4 may have a substituent besides R 1 and may form a condensed ring structure by bonding of the substituents of the ring Z 3 and the ring Z4; the ligands represented by the ring Z 3 and the ring Z 4 may be linked to each other,

in Formula (4), the ring Z 5 represents a 6-membered aromatic hydrocarbon ring, a 6-membered aromatic heterocyclic ring formed with A 1 to A 3 , or an aromatic condensed ring containing at least one of the aforesaid rings; the ring Z 6 represents a 5-membered aromatic heterocyclic ring formed with B 1 to B 3 , or an aromatic condensed ring containing at least one of the aforesaid rings; R 2 and R 3 each represent a hydrogen atom or a substituent, at least one of R 2 and R 3 represents a substituent having 2 or more carbon atoms; the ring Z 5 and the ring Z 6 may have a substituent besides R 2 and R 3 and may form a condensed ring structure by bonding of the substituents of the ring Z 5 and the ring Z 6 , and the ligands represented by the ring Z 5 and the ring Z 6 may be linked to each other,

in Formula (5), the ring Z 7 represents a 6-membered aromatic hydrocarbon ring, a 6-membered aromatic heterocyclic ring formed with A 1 and A 2 , or an aromatic condensed ring containing at least one of the aforesaid rings; the ring Z 8 represents a 6-membered aromatic hydrocarbon ring or a 6-membered aromatic heterocyclic ring formed with B 1 to B 4 , or an aromatic condensed ring containing at least one of the aforesaid rings; R 4 and R 5 each represent a hydrogen atom or a substituent, at least one of R 4 and R 5 represents a substituent having 2 or more carbon atoms; the ring Z 7 and the ring Z 8 may have a substituent besides R 4 and R 5 and may form a condensed ring structure by bonding of the substituents of the ring Z 7 and the ring Z 8 , and the ligands represented by the ring Z 7 and the ring Z 8 may be linked to each other,

{ V all /V core }>2  Expression (b):

In Expression (b), V all represents a molecular volume of a compound having a chemical structure represented by any one of Formulas (3) to (5) including the substituents bonded to the ring Z to the ring Z 8 ; when M represents Ir, n=3 and m=0 are fixed, and when M represents Pt, n=2 and m=0 are fixed; V core represents a molecular volume of a compound having a chemical structure in which the substituent bonded to the ring Z 3 to the ring Z 8 is replaced with a hydrogen atom from the chemical structure indicating the molecular volume of V all ; and when there are a plurality of ligands represented by the ring Z; and the ring Z 4 , ligands represented by the ring Z 5 and the ring Z 6 , ligands represented by the ring Z 7 and the ring Z 8 , V all and V core satisfy Expression (b) in all cases expressed by the aforesaid conditions.

5 . The organic electroluminescent element described in claim 4 , wherein the ligands represented by the ring Z 3 and the ring Z 4 in Formula (3), the ligands represented by the ring Z 5 and the ring Z 6 in Formula (4), or the ligands represented by the ring Z 7 and the ring Z 8 in Formula (5) have three or more substituents.

6 . The organic electroluminescent element described in claim 1 , having an overlap between an emission spectrum of the phosphorescent metal complex and an absorption spectrum of the fluorescent compound.

7 . The organic electroluminescent element described in claim 1 , wherein the phosphorescent metal complex and the fluorescent compound satisfy at least one of the following Expression (c) and Expression (d),

P (HOMO)> FL (HOMO)  Expression (c):

In Expression (c), P(HOMO) represents a HOMO energy level of the phosphorescent metal complex, and FL(HOMO) represents a HOMO energy level of the fluorescent compound.

P (LUMO)< FL (LUMO)  Expression (d):

In Expression (d), P(LUMO) represents a LUMO energy level of the phosphorescent metal complex, and FL(LUMO) represents a LUMO energy level of the fluorescent compound.

8 . The organic electroluminescent element described in claim 1 , having a gas barrier layer which has a water vapor permeability in the range of 0.001 to 1 g/(m 2 ·day) measured by a method in accordance with JIS K 7129-1992 and an oxygen permeability in the range of 0.001 to 1 mL/(m 2 ·day) measured by a method in accordance with JIS K 7126-1987.

9 . A composition for organic materials containing a phosphorescent metal complex and a fluorescent compound, wherein the phosphorescent metal complex is a compound having a structure represented by Formula (1), and the phosphorescent metal complex satisfies the following Expression (a),

in Formula (1): M represents Ir or Pt; A 1 , A 2 , B 1 and B 2 each independently represent a carbon atom or a nitrogen atom; a ring Z 1 represents a 6-membered aromatic hydrocarbon ring, or a 5- or 6-membered aromatic heterocyclic ring formed with A 1 and A 2 , or an aromatic condensed ring containing at least one of the aforesaid rings; a ring Z 2 represents a 5- or 6-membered aromatic heterocyclic ring formed with B 1 and B2, or an aromatic condensed ring containing at least one of the aforesaid rings; among a bond between A 1 and M, and a bond between B 1 and M, one is a coordinate bond and the other is a covalent bond; the ring Z 1 and the ring Z 2 each independently may have a substituent, and the ring Z 1 and the ring Z 2 have at least one substituent represented by Formula (2); the substituent of the ring Z 1 and the substituent of the ring Z 12 may be bonded to form a condensed ring structure, and ligands represented by the ring Z 1 and the ring Z 2 may be linked to each other; L represents a monoanionic bidentate ligand coordinated to M, and L may have a substituent; m represents an integer of 0 to 2, n represents an integer of 1 to 3, when M represents Ir, m+n is 3, and when m represents Pt, m+n is 2, when m or n is 2 or more, the ligands represented by the ring Z 1 and the ring Z 2 , or L may be the same or different; the ligand represented by the ring Z 1 and the ring Z 2 may be linked to L,

*-L′-(CR 2 ) n′ -A  Formula (2)

in Formula (2), a symbol * represents a linking site with the ring Z 1 or the ring Z 2 in Formula (1); L′ represents a single bond or a linking group; R represents a hydrogen atom or a substituent; n′ represents an integer of 3 or more; a plurality of Rs may be the same or different; and A represents a hydrogen atom or a substituent,

{ V all /V core }>2  Expression (a):

in Expression (a), V all represents a molecular volume of a compound having a chemical structure represented by Formula (1) including the substituents bonded to the ring Z 1 and the ring Z 2 ; when M represents Ir, n=3 and m=0 are fixed, and when M represents Pt, n=2 and m=0 are fixed; V core represents a molecular volume of a compound having a chemical structure in which the substituent bonded to the ring Z 1 and the ring Z 2 is replaced with a hydrogen atom from the chemical structure indicating the molecular volume of V all ; and when there are plural types of ligands represented by the ring Z 1 and the ring Z 2 , V all and V core satisfy Expression (a) in all cases expressed by the aforesaid conditions.

10 . A composition for organic materials containing a phosphorescent metal complex and a fluorescent compound, wherein the phosphorescent metal complex is a compound having a structure represented by any one of Formulas (3) to (5), and the phosphorescent metal complex satisfies the following Expression (b),

in Formulas (3) to (5): M represents Ir or Pt; A 1 to A 3 , and B 1 to B 4 each independently represent a carbon atom or a nitrogen atom; among a bond between A 1 and M, and a bond between B 1 and M, one is a coordinate bond and the other is a covalent bond; L represents a monoanionic bidentate ligand coordinated to M, and L may have a substituent; m represents an integer of 0 to 2, n represents an integer of 1 to 3, when M represents Ir, m+n is 3, and when m represents Pt, m+n is 2, when m or n is 2 or more, ligands represented by a ring Z 3 and a ring Z 4 , ligands represented by a ring Z 5 and a ring Z 6 , and ligands represented by a ring Z 7 and a ring Z 8 , or L may be the same or different; the ligands represented by the ring Z 3 to Z 8 may be linked to L,

in Formula (3), the ring Z 3 represents a 5-membered aromatic heterocyclic ring formed with A 1 and A 2 , or an aromatic condensed ring containing the aforesaid ring; the ring Z 4 represents a 5-membered aromatic heterocyclic ring formed with B 1 to B 3 or an aromatic condensed ring containing the aforesaid ring; R 1 represents a substituent having 2 or more carbon atoms; the ring Z 3 and the ring Z 4 may have a substituent besides R 1 and may form a condensed ring structure by bonding of the substituents of the ring Z 3 and the ring Z 4 ; the ligands represented by the ring Z 3 and the ring Z 4 may be linked to each other,

in Formula (4), the ring Z 5 represents a 6-membered aromatic hydrocarbon ring, a 6-membered aromatic heterocyclic ring formed with A to A 3 , or an aromatic condensed ring containing at least one of the aforesaid rings; the ring Z 6 represents a 5-membered aromatic heterocyclic ring formed with B 1 to B 3 , or an aromatic condensed ring containing at least one of the aforesaid rings; R 2 and R 3 each represent a hydrogen atom or a substituent, at least one of R 2 and R 3 represents a substituent having 2 or more carbon atoms; the ring Z 5 and the ring Z 6 may have a substituent besides R 2 and R 3 and may form a condensed ring structure by bonding of the substituents of the ring Z 5 and the ring Z 6 , and the ligands represented by the ring Z 5 and the ring Z 6 may be linked to each other,

in Formula (5), the ring Z 7 represents a 6-membered aromatic hydrocarbon ring, a 6-membered aromatic heterocyclic ring formed with A 1 and A 2 , or an aromatic condensed ring containing at least one of the aforesaid rings; the ring Z 8 represents a 6-membered aromatic hydrocarbon ring or a 6-membered aromatic heterocyclic ring formed with B 1 to B 4 , or an aromatic condensed ring containing at least one of the aforesaid rings; R 4 and R 5 each represent a hydrogen atom or a substituent, at least one of R 4 and R 5 represents a substituent having 2 or more carbon atoms; the ring Z 7 and the ring Z 8 may have a substituent besides R 4 and R 5 and may form a condensed ring structure by bonding of the substituents of the ring Z 7 and the ring Z 8 , and the ligands represented by the ring Z 7 and the ring Z 8 may be linked to each other,

{ V all /V core }>2  Expression (b):

in Expression (b), V all represents a molecular volume of a compound having a chemical structure represented by any one of Formulas (3) to (5) including the substituents bonded to the ring Z 3 to the ring Z 8 ; when M represents Ir, n=3 and m=0 are fixed, and when M represents Pt, n=2 and m=0 are fixed; V core represents a molecular volume of a compound having a chemical structure in which the substituent bonded to the ring Z 3 to the ring Z 8 is replaced with a hydrogen atom from the chemical structure indicating the molecular volume of V all ; and when there are a plurality of ligands represented by the ring Z 3 and the ring Z 4 , ligands represented by the ring Z 5 and the ring Z 6 , ligands represented by the ring Z 7 and the ring Z 8 , V all and V core satisfy Expression (b) in all cases expressed by the aforesaid conditions.