Organic electroluminescent element and composition for organic materials

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;
• A1 to A3, and B1 to B4 each independently represent a carbon atom or a nitrogen atom;
• among a bond between A1 and M, and f bond between B1 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 Z3 and a ring Z4, ligands represented by a ring Z5 and a ring Z6, and ligands represented by a ring Z7 and a ring Z8, or L may be the same or different;
• the ligands represented by the ring Z3 to Z8 may be linked to L,
• in Formula (3), the ring Z3 represents a 5-membered aromatic heterocyclic ring formed with A1 and A2, or an aromatic condensed ring containing the aforesaid ring;
• the ring Z4 represents a 5-membered aromatic heterocyclic ring formed with B1 to B3, or an aromatic condensed ring containing the aforesaid ring;
• R1 represents a substituent having 2 or more carbon atoms;
• the ring Z3 and the ring Z4 may have a substituent besides R1 and may form a condensed ring structure by bonding of the substituents of the ring Z3 and the ring Z4;
• the ligands represented by the ring Z3 and the ring Z4 may be linked to each other,
• in Formula (4), the ring Z5 represents a 6-membered aromatic hydrocarbon ring, a 6-membered aromatic heterocyclic ring formed with A1 to A3, or an aromatic condensed ring containing at least one of the aforesaid rings;
• the ring Z6 represents a 5-membered aromatic heterocyclic ring formed with B1 to B3, or an aromatic condensed ring containing at least one of the aforesaid rings;
• R2 and R3 each represent a hydrogen atom or a substituent, at least one of R2 and R3 represents a substituent having 2 or more carbon atoms;
• the ring Z5 and the ring Z6 may have a substituent besides R2 and R3 and may form a condensed ring structure by bonding of the substituents of the ring Z5 and the ring Z6, and the ligands represented by the ring Z5 and the ring Z6 may be linked to each other,
• in Formula (5), the ring Z7 represents a 6-membered aromatic hydrocarbon ring, a 6-membered aromatic heterocyclic ring formed with A1 and A2, or an aromatic condensed ring containing at least one of the aforesaid rings;
• the ring Z8 represents a 6-membered aromatic hydrocarbon ring or a 6-membered aromatic heterocyclic ring formed with B1 to B4, or an aromatic condensed ring containing at least one of the aforesaid rings;
• R4 and R5 each represent a hydrogen atom or a substituent, at least one of R4 and R5 represents a substituent having 2 or more carbon atoms;
• the ring Z7 and the ring Z8 may have a substituent besides R4 and R5 and may form a condensed ring structure by bonding of the substituents of the ring Z7 and the ring Z8, and the ligands represented by the ring Z7 and the ring Z8 may be linked to each other,
• {Vall/Vcore}>2 Expression (b):
• In Expression (b), Vall 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 Z8;
• when M represents Ir, n=3 and m=0 are fixed, and when M represents Pt, n=2 and m=0 are fixed;
• Vcore represents a molecular volume of a compound having a chemical structure in which the substituent bonded to the ring Z3 to the ring Z8 is replaced with a hydrogen atom from the chemical structure indicating the molecular volume of Vall;
• and when there are a plurality of ligands represented by the ring Z;
• and the ring Z4, ligands represented by the ring Z5 and the ring Z6, ligands represented by the ring Z7 and the ring Z8, Vall and Vcore satisfy Expression (b) in all cases expressed by the aforesaid conditions.

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;
• A1, A2, B1 and B2 each independently represent a carbon atom or a nitrogen atom;
• a ring Z1 represents a 6-membered aromatic hydrocarbon ring, or a 5- or 6-membered aromatic heterocyclic ring formed with A1 and A2, or an aromatic condensed ring containing at least one of the aforesaid rings;
• a ring Z2 represents a 5- or 6-membered aromatic heterocyclic ring formed with B1 and B2, or an aromatic condensed ring containing at least one of the aforesaid rings;
• among a bond between A1 and M, and a bond between B1 and M, one is a coordinate bond and the other is a covalent bond;
• the ring Z1 and the ring Z2 each independently may have a substituent, and the ring Z1 and the ring Z2 have at least one substituent represented by Formula (2);
• the substituent of the ring Z1 and the substituent of the ring Z12 may be bonded to form a condensed ring structure, and ligands represented by the ring Z1 and the ring Z2 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 Z1 and the ring Z2, or L may be the same or different;
• the ligand represented by the ring Z1 and the ring Z2 may be linked to L,
• *-L′-(CR2)n′-A Formula (2)
• in Formula (2), a symbol * represents a linking site with the ring Z1 or the ring Z2 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,
• {Vall/Vcore}>2 Expression (a):
• in Expression (a), Vall represents a molecular volume of a compound having a chemical structure represented by Formula (1) including the substituents bonded to the ring Z1 and the ring Z2;
• when M represents Ir, n=3 and m=0 are fixed, and when M represents Pt, n=2 and m=0 are fixed;
• Vcore represents a molecular volume of a compound having a chemical structure in which the substituent bonded to the ring Z1 and the ring Z2 is replaced with a hydrogen atom from the chemical structure indicating the molecular volume of Vall;
• and when there are plural types of ligands represented by the ring Z1 and the ring Z2, Vall and Vcore satisfy Expression (a) in all cases expressed by the aforesaid conditions.

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;
• A1 to A3, and B1 to B4 each independently represent a carbon atom or a nitrogen atom;
• among a bond between A1 and M, and a bond between B1 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 Z3 and a ring Z4, ligands represented by a ring Z5 and a ring Z6, and ligands represented by a ring Z7 and a ring Z8, or L may be the same or different;
• the ligands represented by the ring Z3 to Z8 may be linked to L,
• in Formula (3), the ring Z3 represents a 5-membered aromatic heterocyclic ring formed with A1 and A2, or an aromatic condensed ring containing the aforesaid ring;
• the ring Z4 represents a 5-membered aromatic heterocyclic ring formed with B1 to B3 or an aromatic condensed ring containing the aforesaid ring;
• R1 represents a substituent having 2 or more carbon atoms;
• the ring Z3 and the ring Z4 may have a substituent besides R1 and may form a condensed ring structure by bonding of the substituents of the ring Z3 and the ring Z4;
• the ligands represented by the ring Z3 and the ring Z4 may be linked to each other,
• in Formula (4), the ring Z5 represents a 6-membered aromatic hydrocarbon ring, a 6-membered aromatic heterocyclic ring formed with A to A3, or an aromatic condensed ring containing at least one of the aforesaid rings;
• the ring Z6 represents a 5-membered aromatic heterocyclic ring formed with B1 to B3, or an aromatic condensed ring containing at least one of the aforesaid rings;
• R2 and R3 each represent a hydrogen atom or a substituent, at least one of R2 and R3 represents a substituent having 2 or more carbon atoms;
• the ring Z5 and the ring Z6 may have a substituent besides R2 and R3 and may form a condensed ring structure by bonding of the substituents of the ring Z5 and the ring Z6, and the ligands represented by the ring Z5 and the ring Z6 may be linked to each other,
• in Formula (5), the ring Z7 represents a 6-membered aromatic hydrocarbon ring, a 6-membered aromatic heterocyclic ring formed with A1 and A2, or an aromatic condensed ring containing at least one of the aforesaid rings;
• the ring Z8 represents a 6-membered aromatic hydrocarbon ring or a 6-membered aromatic heterocyclic ring formed with B1 to B4, or an aromatic condensed ring containing at least one of the aforesaid rings;
• R4 and R5 each represent a hydrogen atom or a substituent, at least one of R4 and R5 represents a substituent having 2 or more carbon atoms;
• the ring Z7 and the ring Z8 may have a substituent besides R4 and R5 and may form a condensed ring structure by bonding of the substituents of the ring Z7 and the ring Z8, and the ligands represented by the ring Z7 and the ring Z8 may be linked to each other,
• {Vall/Vcore}>2 Expression (b):
• in Expression (b), Vall 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 Z3 to the ring Z8;
• when M represents Ir, n=3 and m=0 are fixed, and when M represents Pt, n=2 and m=0 are fixed;
• Vcore represents a molecular volume of a compound having a chemical structure in which the substituent bonded to the ring Z3 to the ring Z8 is replaced with a hydrogen atom from the chemical structure indicating the molecular volume of Vall;
• and when there are a plurality of ligands represented by the ring Z3 and the ring Z4, ligands represented by the ring Z5 and the ring Z6, ligands represented by the ring Z7 and the ring Z8, Vall and Vcore satisfy Expression (b) in all cases expressed by the aforesaid conditions.