Abstract: A composition which is useful for providing a light emitting device having excellent light emission efficiency contains a compound represented by formula (C-1) and a phosphorescent compound represented by formula (1): Ring R1C to Ring R4C each represents an aromatic hydrocarbon ring or an aromatic hetero ring, RC represents a carbon, silicon, germanium, tin, or lead atom, and M represents a rhodium, palladium, iridium, or a platinum atom. n1 represents an integer of 1 or more, and n2 represents an integer of 0 or more. n1+n2 is 2 or 3. Ring R1A represents a triazole ring, Ring R2 represents an aromatic hydrocarbon ring or an aromatic hetero ring, E1, E2 and E11A to E13A represent a nitrogen atom or a carbon atom, R11A to R13A represent a hydrogen atom, an alkyl group, an aryl group, and A1-G1-A2 represents an anionic bidentate ligand.

Abstract: A light emitting device containing an anode, a cathode, and a light emitting layer provided between the anode and the cathode is described. The light emitting layer contains a metal complex represented by formula (1).

Abstract: A polymer compound is provided having constitutional units of formula (1) and formula (2), and a constitutional unit of formula (3) and/or (4?): wherein Ar1 to Ar4, Ar20, Ar30? and Ar40 represent arylene groups or the like; Ar5 to Ar7 represent aryl groups or the like; Ar8 represents (2+p)-valent aromatic hydrocarbon group or the like; Ar10 represents (2+n)-valent aromatic hydrocarbon group or the like; R1 represents alkyl group or the like; La, Lb, Lg and Lh represent alkylene groups or the like; LA and LD represent oxygen atoms or the like; Q1 represents monovalent crosslinkable group; Q2? to Q4? represent monovalent crosslinkable groups or the like; x, y, c, nA and nD represent 0 or 1; p represents integer of 1 or greater; na and ng represent integer of 0 to 3; nb and nh represent integer of 0 to 12; and n represents integer of 1 to 4.

Abstract: A polymer compound is provided having constitutional units of formula (1) and formula (2), and a constitutional unit of formula (3) and/or (4?): wherein Ar1 to Ar4, Ar20, Ar30? and Ar40 represent arylene groups or the like; Ar5 to Ar7 represent aryl groups or the like; Ar8 represents (2+p)-valent aromatic hydrocarbon group or the like; Ar10 represents (2+n)-valent aromatic hydrocarbon group or the like; R1 represents alkyl group or the like; La, Lb, Lg and Lh represent alkylene groups or the like; LA and LD represent oxygen atoms or the like; Q1 represents monovalent crosslinkable group; Q2? to Q4? represent monovalent crosslinkable groups or the like; x, y, c, nA and nD represent 0 or 1; p represents integer of 1 or greater.; na and ng represent integer of 0 to 3; nb and nh represent integer of 0 to 12; and n represents integer of 1 to 4.

Abstract: A metal complex is provided represented by Formula (1): wherein M represents a prescribed metal atom; RP1, RP2, RP3, RP4, RP5, and RP6 each independently represent a hydrogen atom or a prescribed group, wherein RP1 and RP2 may be bonded together to form a ring structure, RP2 and RP3 may be bonded together to form a ring structure, and RP3 and RP4 may be bonded together to form a ring structure, provided that at least one of RP1, RP2, RP3, and RP4 is a dendron and at least one of RP5 and RP6 is an aryl group or a monovalent heterocyclic group; m is an integer of 1 to 3 and n is an integer of 0 to 2, wherein m+n is 2 or 3; and a moiety represented by Formula (2) represents a bidentate ligand: wherein Rx and Ry each independently represent a prescribed atom.