Abstract: A metal complex represented by the formula (1) is useful for production of a light emitting device excellent in light emission efficiency: M represents a rhodium, palladium, iridium, or a platinum atom; n1 represents 1, 2 or 3; n2 represents 0, 1 or 2; R1 to R6 represent a hydrogen atom, an alkyl group, or an aryl group; Ring RB1 and Ring RB2 represent an aromatic hydrocarbon ring or an aromatic hetero ring; one of Ya and Yb is a single bond, and the other is a group represented by the formula (C-1): RC represents a carbon atom, a silicon atom, a germanium atom, a tin atom or a lead atom; Ring RC1 and Ring RC2 represent an aromatic hydrocarbon ring or an aromatic hetero ring; and A1-G1-A2 represents an anionic bidentate ligand.

Abstract: A metal complex which is useful for production of a light emitting device showing improved luminance is provided. A composition containing the metal complex and a light emitting device containing the metal complex are also provided. The metal complex is represented by the following formula (0). The composition contains the metal complex and at least one material selected from the group consisting of a host material, a light emitting material other than the metal complex, an antioxidant and a solvent, and a light emitting device containing the metal complex.

Abstract: A metal complex which is useful for production of a light emitting device of which long-term degradation is suppressed is provided. The metal complex is represented by the formula (1): wherein, one of Ya and Yb is a single bond, and the other is a group represented by the formula (C-1): and wherein at least one of Ring RA, Ring RB1, Ring RB2, Ring RC1 and Ring RC2 has a group represented by the formula (D-A), the formula (D-B) or the formula (D-C) as a substituent.

Abstract: A compound with which the luminance life of a light emitting device is excellent is represented by formula (1): n represents an integer of 2 or more and 20 or less, R1 and R2 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group or a halogen atom. Ar1 represents a mono-cyclic or condensed-cyclic arylene group, a mono-cyclic or condensed-cyclic divalent heterocyclic group or a group represented by —N(RX1)—, and RX1 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group. At least two of Ar1 represent prescribed groups.

Abstract: A composition which is useful for producing a light emitting device having excellent luminance life contains a compound represented by formula (C-1), a metal complex represented by formula (1) and a metal complex represented by formula (2): Ring R1 C to Ring R4 C represent an aromatic hydrocarbon ring and RC represents a carbon atom. M1 represents an iridium atom, n1 and n2 are integers, Ring R1 A represents a diazole ring, Ring R2 represents an aromatic hydrocarbon ring, E1, E2 and E1 1 A to E1 3 A represent a nitrogen or carbon atom, R1 1 A to R1 3 A represent a hydrogen atom, an alkyl group, or an aryl group, and A1-G1-A2 represents an anionic bidentate ligand. M2 represents an iridium atom, n3 and n4 are integers, EL represents a carbon atom, Ring L1 represents a 6-membered aromatic hetero ring, Ring L2 represents an aromatic hydrocarbon ring, and A3-G2-A4 represents an anionic bidentate ligand.

Abstract: A light emitting device having excellent luminance life contains an anode, a cathode, and three layers disposed therebetween. The first layer contains a compound represented by formula (C-1), the second layer contains a simple substance composed only of an alkali metal element, a simple substance composed only of a group 2 element, a compound containing an alkali metal element and/or a compound containing a group 2 element, and the third layer contains a simple substance composed only of an alkali metal element, a simple substance composed only of a group 2 element, a compound containing an alkali metal element and/or a compound containing a group 2 element. The simple substances or compounds of the second and third layers are mutually different. Ring R1C to Ring R4C represent an aromatic hydrocarbon ring, and RC represents a carbon atom.

Abstract: A light emitting device having excellent luminance life contains an anode, a cathode, and two organic layers disposed between them. The first organic layer contains a compound represented by formula (C-1) and the second organic layer is Layer A or B. Layer A contains a polymer compound containing a constitutional unit having a group obtained by removing one or more hydrogen atoms and a cross-linked body of the polymer compound from a phosphorescent compound represented by formula (1), and Layer B contains a phosphorescent compound represented by formula (1) and a cross-linked body of a crosslinking material. Ring R1C to Ring R4C represent an aromatic hydrocarbon ring, RC represents a carbon atom, M represents an iridium atom, n1 and n2 represent integers, E1 and E2 represent a carbon atom, Ring L1 represents an aromatic hetero ring, Ring L2 represents an aromatic hydrocarbon ring, and A1-G1-A2 represents an anionic bidentate ligand.

Abstract: Provided is a polymer compound which is useful for production of a light emitting device excellent in light emission efficiency is provided. The polymer compound contains a constitutional unit represented by the formula (1) and a constitutional unit represented by the formula (Y) as follows: wherein R1 to R8 represent a hydrogen atom, an alkyl group, an aryl group or the like, and RA and RB represent an aryl group or a monovalent heterocyclic group, and ArY1??(Y) wherein ArY1 represents an arylene group or the like.

Abstract: Provided is a polymer compound which is useful for production of a light emitting device excellent in light emission efficiency is provided. The polymer compound contains a constitutional unit represented by the formula (1) and a constitutional unit represented by the formula (Y) as follows: wherein R1 to R8 represent a hydrogen atom, an alkyl group, an aryl group or the like, and RA and RB represent an aryl group or a monovalent heterocyclic group, and ?ArY1???(Y) wherein ArY1 represents an arylene group or the like.

Abstract: A polymer compound comprising a constituent unit represented by the formula (1?) and a constituent unit having a mono-valent cross-linkable group: wherein R1? to R4? represent an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a mono-valent heterocyclic group, R5 to R10 represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a mono-valent heterocyclic group, RA and RB represent a hydrogen atom, an alkyl group, an aryl group, a mono-valent heterocyclic group, and Ar1 and Ar2 represent an arylene group, a di-valent heterocyclic group.

Abstract: A polymer compound, is provided in which at least a part of repeating units has a group containing a carbon cluster structure. The polymer compound preferably one or more, more preferably two or more, units selected from an arylene unit, a heteroarylene unit and an aromatic amine unit, as repeating units.

Abstract: A polymer compound comprising a constituent unit represented by the formula (1?) and a constituent unit having a mono-valent cross-linkable group: [wherein R1? to R4? represent an alkyl group, an alkoxy group, an aryl group, an aryloxy group or a mono-valent heterocyclic group, R5 to R10 represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group or a mono-valent heterocyclic group, RA and RB represent a hydrogen atom, an alkyl group, an aryl group or a mono-valent heterocyclic group, and Ar1 and Ar2 represent an arylene group or a di-valent heterocyclic group.].

Abstract: A polymer compound, is provided in which at least a part of repeating units has a group containing a carbon cluster structure. The polymer compound preferably one or more, more preferably two or more, units selected from an arylene unit, a heteroarylene unit and an aromatic amine unit, as repeating units.