COMPOSITION AND LIGHT-EMITTING ELEMENT COMPRISING THE COMPOSITION
Disclosed is a composition comprising a compound having a pyrazine ring structure and a phosphorescent compound, wherein the compound having a pyrazine ring structure has a pyrazine ring structure represented by the general formula (1), (2) or (3): wherein R and R 1 independently represent a hydrogen atom or a univalent group and multiple R's and multiple R 1 's may be the same as or different from one another. Also disclosed is a polymer having a residue derived from the phosphorescent compound and the pyrazine ring structure.
1 . A composition comprising a compound having a pyrazine ring structure and a phosphorescence-emitting compound.
2 . The composition according to claim 1 , wherein the compound having a pyrazine ring structure is a polymer having a pyrazine ring structure.
3 . The composition according to claim 1 , wherein the compound having a pyrazine ring structure has a pyrazine ring structure represented by the following general formula (1), (2) or (3):
wherein R and R 1 each independently represent a hydrogen atom or a monovalent group, and a plurality of R or R 1 may be the same or different.
4 . The composition according to claim 1 , wherein the compound having a pyrazine ring structure has a pyrazine ring structure represented by the following general formula (5), (6) or (7):
wherein R and R 1 are as defined above, and a plurality of R 1 may be the same or different.
5 . The composition according to claim 3 , wherein at least one of the R is a monovalent group having three or more atoms in total exclusive of hydrogen atoms.
6 . The composition according to claim 3 , wherein at least one of the R and the R 1 is an alkyl group, an alkoxy group, a phenyl group which may have a substituent or a heteroaryl group which may have a substituent.
7 . The composition according to claim 3 , wherein the compound having a pyrazine ring structure has a pyrazine ring structure represented by the general formula (1), (2), (3), (5), (6) or (7) and a partial structure which is adjacent to the pyrazine ring structure and which has at least two π-conjugated electrons, wherein the pyrazine ring structure and the partial structure form a dihedral angle of 20° or larger therebetween.
8 . The composition according to claim 7 , wherein the pyrazine ring structure and the partial structure form a dihedral angle of 40° or larger therebetween.
9 . The composition according to claim 1 , wherein the compound having a pyrazine ring structure has a residue of a compound represented by the following general formula (A-1) or (A-2):
wherein Y 1 represents —C(R a )(R b )—, —C(═O)—, —N(R c )—, —O—, —Si(R d )(R e )—, —P(R f )—, —S— or —S(═O) 2 —; n is an integer of 0 to 5; Ar 1 represents a monovalent aryl group which may have a substituent or a monovalent heterocyclic group which may have a substituent; when a plurality of Y 1 are present, they may be the same or different; R a to R f each independently represent a hydrogen atom or a monovalent group; and R is as defined above, and a plurality of R may be the same or different.
10 . The composition according to claim 1 , wherein the compound having a pyrazine ring structure has the lowest triplet excitation energy larger than 2.7 eV calculated by a computational chemical approach.
11 . The composition according to claim 1 , wherein the compound having a pyrazine ring structure has an absolute value of the lowest unoccupied molecular orbital energy level of 2.1 eV or larger calculated by a computational chemical approach.
12 . The composition according to claim 1 , wherein the lowest triplet excitation energy (ETP) of the compound having a pyrazine ring structure satisfies, with the lowest triplet excitation energy (ETT) of the phosphorescence-emitting compound, the following formula:
ETT>ETP− 0.20 (eV).
13 . A polymer having a residue of the phosphorescence-emitting compound and the pyrazine ring structure.
14 . A light-emitting thin film comprising a composition according to claim 1 .
15 . An organic semiconductor thin film comprising a composition according to claim 1 .
16 . A light-emitting device comprising a composition according to claim 1 .
17 . A planar light source comprising a light-emitting device according to claim 16 .
18 . A segment display device comprising a light-emitting device according to claim 16 .
19 . A dot matrix display device comprising a light-emitting device according to claim 16 .
20 . A liquid-crystal display device comprising a light-emitting device according to claim 16 as a backlight.
21 . An illumination device comprising a light-emitting device according to claim 16 .