Monoamine compound, charge transport material, composition for charge transport film, organic electroluminescent element, organic EL display, and organic EL lighting

1. A monoamine compound represented by formula (1):

wherein R 1 to R 3 each independently represent a phenyl group which may have one or more substituents, provided that at least one of R 1 to R 3 independently represents a phenyl group having as a substituent an aromatic heterocyclic group which may have a substituent;

at least one of said substituents of each of R 1 to R 3 , when present, is in the ortho or meta positions;

said substituents may be bonded to each other to form a cyclic structure;

a difference between a carbon number of the group having the greatest carbon numbers among R 1 to R 3 and a carbon number of the group having the smallest carbon numbers among R 1 to R 3 is 10 or more; and

the carbon number also include a carbon number of the substituents of R 1 to R 3 ,

with the proviso that none of R 1 , R 2 and R 3 is a group which is the same as the other.

2. A monoamine compound represented by formula (1):

wherein R 1 to R 3 each independently represent a phenyl group which may have one or more substituents, provided that at least one of R 1 to R 3 independently represents a phenyl group having as a substituent an aromatic heterocyclic group which may have a substituent;

at least one of said substituents of each of R 1 to R 3 , when present, is in the ortho or meta positions;

said substituents may be bonded to each other to form a cyclic structure;

a difference between a carbon number of the group having the greatest carbon numbers among R 1 to R 3 and a carbon number of the group having the second greater carbon numbers among R 1 to R 3 is 5 or more; and

the carbon number also include a carbon number of the substituent of R 1 to R 3 ,

with the proviso that none of R 1 , R 2 and R 3 is a group which is the same as the other.

3. A monoamine compound represented by formula (1):

wherein R 1 to R 3 each independently represent a phenyl group which may have one or more substituents, provided that at least one of R 1 to R 3 independently represents a phenyl group having as a substituent an aromatic heterocyclic group which may have a substituent;

at least one of said substituents of each of R 1 to R 3 , when present, is in the ortho or meta positions;

said substituents may be bonded to each other to form a cyclic structure;

a difference between a carbon number of the group having the smallest carbon numbers among R 1 to R 3 and a carbon number of the group having the second greater carbon numbers among R 1 to R 3 is 5 or more; and

the carbon number also include a carbon number of the substituents of R 1 to R 3 ,

with the proviso that none of R 1 , R 2 and R 3 is a group which is the same as the other.

4. The monoamine compound according to claim 1 , wherein when one or more of R 1 to R 3 independently represent a group other than a phenyl group having as a substituent an aromatic heterocyclic group which may have a substituent, R 1 to R 3 each independently represent a phenyl group having as a substituent an aromatic hydrocarbon group which may have a substituent.

5. The monoamine compound according to claim 1 , wherein a difference between a carbon number of the group having the greatest carbon numbers among R 1 to R 3 and a carbon number of the group having the second greater carbon numbers among R 1 to R 3 is 5 or more.

6. The monoamine compound according to claim 1 , wherein a difference between a carbon number of the group having the smallest carbon numbers among R 1 to R 3 and a carbon number of the group having the second greater carbon numbers among R 1 to R 3 is 5 or more.

7. The monoamine compound according to claim 5 , wherein a difference between a carbon number of the group having the smallest carbon numbers among R 1 to R 3 and a carbon number of the group having the second greater carbon numbers among R 1 to R 3 is 5 or more.

8. The monoamine compound according to claim 2 , wherein when one or more of R 1 to R 3 independently represent a group other than a phenyl group having as a substituent an aromatic heterocyclic group which may have a substituent, R 1 to R 3 each independently represent a phenyl group having as a substituent an aromatic hydrocarbon group which may have a substituent.

9. The monoamine compound according to claim 3 , wherein when one or more of R 1 to R 3 independently represent a group other than a phenyl group having as a substituent an aromatic heterocyclic group which may have a substituent, R 1 to R 3 each independently represent a phenyl group having as a substituent an aromatic hydrocarbon group which may have a substituent.

10. The monoamine compound according to claim 1 , wherein at least one of R 1 to R 3 comprises a partial structure represented by formula (2-1):

wherein structural formula (2-1) may have one or more substituents, and the substituent may have been bonded to each other to form a cyclic structure.

11. The monoamine compound according to claim 1 , wherein in formula (1), R 1 to R 3 each independently are a phenyl group which may have a substituent in an m-position.

12. The monoamine compound according to claim 1 , wherein in formula (1), at least one of R 1 to R 3 is a group including a partial structure represented by formula (2-2):

wherein X represents any one of —NR 4 — where R 4 represents an aryl group which may have a substituent, —O—, and —S—; and the X-containing fused ring in formula (2-2) may have one or more substituents which may be bonded to each other to form a cyclic structure.

13. The monoamine compound according to claim 12 , wherein the partial structure represented by formula (2-2) is a partial structure represented by formula (3):

wherein the N-carbazole ring may further have one or more substituents, and the substituents may be bonded to each other to form a cyclic structure.

14. The monoamine compound according to claim 1 , wherein in formula (1) at least one of R 1 to R 3 is a group represented by the following formula (11):

wherein Q represents a direct bond or a linking group; Y represents any one of —NR 4 — where R 4 represents an aryl group which may have a substituent, —O—, and —S—; and the Y-containing fused ring in formula (11) may have one or more substituents which may be bonded to each other to form a cyclic structure.

15. The monoamine compound according to claim 1 , which has a solubility in m-xylene of 5% by mass or more at 25° C. and atmospheric pressure.

16. The monoamine compound according to claim 1 , wherein R 1 to R 3 each independently represent a phenyl group which may have as substituents one or more aromatic hydrocarbon groups or aromatic heterocyclic groups.

17. The monoamine compound according to claim 2 , wherein R 1 to R 3 each independently represent a phenyl group which may have as substituents one or more aromatic hydrocarbon groups or aromatic heterocyclic groups.

18. The monoamine compound according to claim 3 , wherein R 1 to R 3 each independently represent a phenyl group which may have as substituents one or more aromatic hydrocarbon groups or aromatic heterocyclic groups.