Abstract: Disclosed is a composition containing a compound having a benzotriazole ring structure and a phosphorescent compound.

Abstract: 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 R1 independently represent a hydrogen atom or a univalent group and multiple R's and multiple R1'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.

Abstract: A polymer compound comprising as repeating units an optionally substituted fluorenediyl group and a phenylene group having one or more substituents, and comprising a repeating unit of the following formula (1) and/or a group of the following formula (2): (in the formula (1), Ar1 and Ar2 represent an arylene group or di-valent aromatic heterocyclic group, and Ar1 and may be the same or different.) (in the formula (2), Ar1 represents the same meaning as described above. Ar3 represents an aryl group or mono-valent aromatic heterocyclic group.).

Abstract: Disclosed is a composition containing a compound having a benzimidazole ring structure and a phosphorescent compound.

Abstract: Disclosed is a composition containing a compound having an indazole ring structure and a phosphorescent compound.

Abstract: A composition which comprises a compound having a pyrimidine ring structure and a phosphorescent compound.

Abstract: An organic electroluminescent device excellent in light emission efficiency and driving voltage, having electrodes composed of an anode and a cathode, a first organic layer arranged in contact with or adjacent to the anode between the electrodes and containing a hole transporting polymer compound and a second organic layer arranged in contact with the first organic layer between the first organic layer and the cathode and containing an electron transporting polymer compound, wherein the hole transporting polymer compound and the electron transporting polymer compound are regulated by specific parameters, at least one of the first organic layer and the second organic layer contains a light emitting material regulated by specific parameters, and light of specific color is emitted from the first organic layer or from the first organic layer or the second organic layer.

Abstract: A metal complex having a structure of the following general formula (1): (wherein, X1 and X2 represent independently a carbon atom or nitrogen atom. Bonds represented by X1C and X2N are a single bond or double bond. M represents a transition metal atom. A dihedral angle defined by a plane containing a structure represented by CX1—X2 and a plane containing a structure represented by X1—X2N is 9° to 16°, and the proportion of the sum of squares of orbital coefficients of the outermost d orbital of the metal atom M, in the highest occupied molecular orbital of the metal complex, occupying with respect to the sum of squares of all atom orbital coefficients, is divided by an energy difference S1?T1 between the lowest excitation singlet energy S1 and the lowest excitation triplet energy T1 of the metal complex, to give a value of 200 to 600%/eV.).