Organometallic iridium complex, light-emitting element, light-emitting device, electronic device, and lighting device
An organometallic iridium complex has high emission efficiency and a long lifetime. The iridium complex includes the structure represented by Formula (G1). In the formula, Ar represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms. R 1 to R 6 independently represent any one of hydrogen and a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and one of R 2 and R 6 represents the alkyl group. X represents a carbon atom or a nitrogen atom, and when X represents a carbon atom, hydrogen or an alkyl group having 1 to 6 carbon atoms is bonded to the carbon atom. A dihedral angle between a ring bonded to R 1 and a phenyl group bonded to R 2 to R 6 is 30° or more and 90° or less. An interior angle of the pyridine/pyrimidine ring facing R 1 is within a range of 118° to 122°.
1. A compound represented by Formula (G5):
wherein:
R 1 to R 9 independently represent hydrogen or an unsubstituted alkyl group having 1 to 6carbon atoms;
at least one of R 2 and R 6 represents a tert-butyl group;
X represents a nitrogen atom;
L represents a monoanionic ligand;
the monoanionic ligand is represented by any one of Formulae (L1) to (L7):
R 71 to R 109 independently represent any one of hydrogen, an alkyl group having 1 to 6carbon atoms, a halogen, a vinyl group, a haloalkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and an alkylthio group having 1 to 6 carbon atoms;
A 1 to A 3 independently represent any one of nitrogen and carbon bonded to hydrogen or to a substituent R;
the substituent R is any one of an alkyl group having 1 to 6 carbon atoms, a halogen, a haloalkyl group having 1 to 6 carbon atoms, and a phenyl group;
when X represents the nitrogen atom, the other of R 2 and R 6 represents hydrogen, or one of R 1 , R 3 to R 5 and R 7 to R 9 represents an unsubstituted alkyl group having 1 to 6 carbon atoms,
a dihedral angle between a ring bonded to R 1 and a phenyl group bonded to R 2 to R 6 is greater than or equal to 30° and less than or equal to 90°;
a dihedral angle between the ring bonded to R 7 to R 9 is greater than or equal to 0° and less than 2°; and
a bond angle denoted by α is greater than or equal to 120° and less than 129°.
2. The compound according to claim 1 , wherein R 3 to R 5 represent hydrogen.
3. The compound according to claim 1 , wherein R l represents hydrogen.
4. The compound according to claim 1 , wherein one of R 2 and R 6 represents hydrogen.
5. A compound represented by Formula (G6):
wherein:
R 1 , R 2 and R 6 to R 9 independently represent hydrogen or an unsubstituted alkyl group having 1 to 6 carbon atoms;
one of R 2 and R 6 represents an alkyl group having 1 to 6 carbon atoms;
the other one of R 2 and R 6 represents hydrogen;
X represents a nitrogen atom;
the monoanionic ligand is represented by any one of Formulae (L1) to (L7):
R 71 to R 109 independently represent any one of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a halogen, a vinyl group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1to 6 carbon atoms, and a substituted or unsubstituted alkylthio group having 1 to 6 carbon atoms;
A 1 to A 3 independently represent any one of nitrogen and carbon bonded to hydrogen or to a substituent R;
the substituent R is any one of an alkyl group having 1 to 6 carbon atoms, a halogen, a haloalkyl group having 1 to 6 carbon atoms, and a phenyl group;
L represents a monoanionic ligand,
wherein a dihedral angle between a ring bonded to R 1 and a phenyl group bonded to R 2 to R 6 is greater than or equal to 30° and less than or equal to 90° ;
wherein a dihedral angle between the ring bonded to R 1 and a phenyl group bonded to R 7 to R 9 is greater than or equal to 0° and less than 2° ; and
a bond angle denoted by α is greater than or equal to 120° and less than 129°.
6. The compound according to claim 5 , wherein the compound is represented by Formula (134):
7. A light-emitting device comprising the compound according to claim 5 .
8. A lighting device comprising the compound according to claim 5 .
9. An electronic device comprising the light-emitting device according to claim 7 .