Composition and light emitting device using the same

A composition comprising two or more compounds represented by the formula (C-1) and a phosphorescent compound, wherein

• at least one of the two or more compounds represented by the formula (C-1) is a compound in which RC is a group represented by the formula (C′-1):
• wherein
• Ring R1C and Ring R2C each independently represent an aromatic hydrocarbon ring or an aromatic hetero ring, and the foregoing rings optionally have a substituent, and when a plurality of the substituents are present, they may be combined together to form a ring together with the atoms to which they are attached,
• RC represents an oxygen atom, a sulfur atom or a group represented by the formula (C′-1),
• wherein
• Ring R3C and Ring R4C each independently represent an aromatic hydrocarbon ring or an aromatic hetero ring, and the foregoing rings optionally have a substituent, and when a plurality of the substituents are present, they may be combined together to form a ring together with the atoms to which they are attached, and
• RC′ represents a carbon atom, a silicon atom, a germanium atom, a tin atom or a lead atom, and wherein in the compound represented by the formula (C-1) in which RC is a group represented by the formula (C′-1), at least one of Ring R1C, Ring R2C, Ring R3C and Ring R4C has a group represented by the formula (D-1), the formula (E-1), the formula (D-A) or the formula (D-B) as the substituent,
• wherein:
• Ring RD represents an aromatic hydrocarbon ring or an aromatic hetero ring, and the foregoing rings optionally have a substituent;
• when a plurality of the substituents are present, they may be combined together to form a ring together with the atoms to which they are attached,
• XD1 and XD2 each independently represent a single bond, an oxygen atom, a sulfur atom, a group represented by —N(RXD1)— or a group represented by —C(RXD2)2—;
• RXD1 and RXD2 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a monovalent heterocyclic group, a substituted amino group or a halogen atom, and the foregoing groups optionally have a substituent;
• a plurality of RXD2 may be the same or different and may be combined together to form a ring together with the carbon atoms to which they are attached,
• E1D, E2D, E3D and E4D each independently represent a nitrogen atom or a carbon atom;
• at least one of E1D, E2D, E3D and E4D is a carbon atom,
• R1D, R2D, R3D and R4D each independently represent, a connecting bond, a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a monovalent heterocyclic group, a substituted amino group or a halogen atom, and the foregoing groups optionally have a substituent;
• one of R1D, R2D, R3D and R4D is a connecting bond,
• when E1D is a nitrogen atom, R1D is absent, when E2D is a nitrogen atom, R2D is absent, when E3D is a nitrogen atom, R3D is absent, and when E4D is a nitrogen atom, R4D is absent,
• when R1D is a connecting bond, E1D is a carbon atom, when R2D is a connecting bond, E2D is a carbon atom, when R3D is a connecting bond, E3D is a carbon atom, when R4D is a connecting bond, E4D is a carbon atom,
• R1D and R2D may be combined together to form a ring together with the atoms to which they are attached, R2D and R3D may be combined together to form a ring together with the atoms to which they are attached, R3D and R4D may be combined together to form a ring together with the atoms to which they are attached, R1D and RXD1 may be combined together to form a ring together with the atoms to which they are attached, R1D and RXD2 may be combined together to form a ring together with the atoms to which they are attached, R4D and RXD1 may be combined together to form a ring together with the atoms to which they are attached, and R4D and RXD2 may be combined together to form a ring together with the atoms to which they are attached;
• the substituent which Ring RD optionally has and RXD1 may be combined together to form a ring together with the atoms to which they are attached:
• the substituent which Ring RD optionally has and RXD2 may be combined together to form a ring together with the carbon atoms to which they are attached,
• wherein:
• Ring RE1 and Ring RE2 each independently represent an aromatic hydrocarbon ring or an aromatic hetero ring, and the foregoing rings optionally have a substituent;
• when a plurality of the substituents are present, they may be combined together to form a ring together with the atoms to which they are attached,
• XE1 represents a single bond, an oxygen atom, a sulfur atom, a group represented by —N(RXE1)— or a group represented by —C(RXE2)2—;
• RXE1 and RXE2 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a monovalent heterocyclic group, a substituted amino group or a halogen atom, and the foregoing groups optionally have a substituent;
• a plurality of RXE2 may be the same or different and may be combined together to form a ring together with the carbon atoms to which they are attached,
• wherein:
• mDA1, mDA2 and mDA3 each independently represent an integer of 0 or more,
• GDA represents a nitrogen atom, an aromatic hydrocarbon group or a heterocyclic group, and the foregoing groups optionally have a substituent,
• ArDA1, ArDA2 and ArDA3 each independently represent an arylene group or a divalent heterocyclic group, and the foregoing groups optionally have a substituent;
• when a plurality of ArDA1, ArDA2 and ArDA3 are present, they may be the same or different at each occurrence,
• TDA represents an aryl group or a monovalent heterocyclic group, and the foregoing groups optionally have a substituent;
• a plurality of TDA may be the same or different,
• wherein:
• mDA1, mDA2, mDA3, mDA4, mDA5, mDA6 and mDA7 each independently represent an integer of 0 or more,
• GDA represents a nitrogen atom, an aromatic hydrocarbon group or a heterocyclic group, and the foregoing groups optionally have a substituent;
• a plurality of GDA may be the same or different,
• ArDA1, ArDA2, ArDA3, ArDA4, ArDA5, ArDA6 and ArDA7 each independently represent an arylene group or a divalent heterocyclic group, and the foregoing groups optionally have a substituent;
• when a plurality of ArDA1 ArDA2, ArDA3, ArDA4, ArDA5, ArDA6 and ArDA7 are present, they may be the same or different at each occurrence,
• TDA represents an aryl group or a monovalent heterocyclic group, and the foregoing groups optionally have a substituent;
• a plurality of TDA may be the same or different.