Abstract: An organometallic compound represented by Formula 1: M1(L1)n1(L2)n2??Formula 1 wherein, M1 is a transition metal, L1 is a ligand represented by Formula 1A, and L2 is a ligand represented by Formula 1B, and n1 and n2 are each independently 1 or 2, wherein X1 and X2 are each independently C or N, Y1 is O, S, Se, C(R5)(R6), or N(R7), X44 is N or C(R44), X45 is N or C(R45), X46 is N or C(R46), and X47 is N or C(R47), and the other substituent groups are as defined herein.

Abstract: An organometallic compound represented by Formula 1: M1(L1)n1(L2)n2??Formula 1 wherein M1 is a transition metal, L1 is a ligand represented by Formula 1A, L2 is a ligand represented by Formula 1B, and n1 and n2 are each independently 1 or 2, wherein X1 and X2 are each independently C or N, ring CY2 and ring CY4 are each independently a C5-C30 carbocyclic group or a C1-C30 heterocyclic group, ring CY3 is a 5-membered heterocyclic group; a 5-membered heterocyclic group condensed with a C5-C30 carbocyclic group; or a 5-membered heterocyclic group condensed with a C1-C30 heterocyclic group, Y1 is O, S, Se, C(R5)(R6), N(R7), Si(R8)(R9), or Ge(R8)(R9), at least one of R12 and R13 comprises deuterium, and the other substituent groups are as described herein.

Abstract: An organometallic compound represented by Formula 1: M1(Ln1)n1(Ln2)n2??Formula 1 wherein M1 is a transition metal, Ln1 is a ligand represented by Formula 1-1, Ln2 is a bidentate ligand, n1 is 1, 2, or 3, and n2 is 0, 1, or 2, wherein X1, X2, X11 to X14, Y1, R10, R20, ring CY2, b10, and b20 are as defined herein, and wherein * and *? each indicate a binding site to M1.

Abstract: An organometallic compound represented by Formula 1: M1(L1)n1(L2)n2??Formula 1 wherein, M1 is a transition metal, L1 is a ligand represented by Formula 1A, L2 is a ligand represented by Formula 1B, and n1 and n2 are each independently 1 or 2, wherein X1 is C or N; X2 is C or N; X3 is C or N; X4 is C or N; ring CY1 and ring CY2 are each independently a C5-C30 carbocyclic group or a C1-C30 heterocyclic group; Z1 and Z2 are each independently —Si(Q1)(Q2)(Q3) or —Ge(Q1)(Q2)(Q3); a1 and a2 are each independently an integer from 0 to 10; a sum of a1 and a2 is 1 or greater; Y1 and Y2 are each independently O, S, Se, N(R51), B(R52), C(R53)(R54), Si(R55)(R56), or Ge(R57)(R58); and the remaining substituent groups are as described herein.

Abstract: An organometallic compound represented by Formula 1: M1(L1)n1(L2)n2??Formula 1 wherein, M1 is a transition metal, L1 is ligand represented by Formula 1A, L2 is a ligand represented by Formula 1B, and n1 and n2 are each independently 1 or 2: wherein X1 to X4 are each independently C or N; Y1 is O, S, Se, C(R5)(R6), N(R7), or Si(R8)(R9); ring CY2 and ring CY4 are each independently a C5-C30 carbocyclic group or a C1-C30 heterocyclic group; ring CY3 is a 5-membered heterocyclic group, a 5-membered heterocyclic group condensed with a C5-C30 carbocyclic group, or a 5-membered heterocyclic group condensed with a C1-C30 heterocyclic group; * and *? each indicate a binding site to M1; and the remaining descriptions of Formulae 1A and 2B as described herein.

Abstract: An organometallic compound represented by Formula 1: M1(L1)n1(L2)n2??Formula 1 wherein, M1 is a transition metal, L1 is a ligand represented by Formula 1A, L2 is a ligand represented by Formula 1B, n1 and n2 are each independently 1 or 2, Formula 1A Formula 1B wherein X1 to X4 are each independently C or N, rings CY1 and ring CY2 are each independently a C5-C30 carbocyclic group or a C1-C30 heterocyclic group, Z1 and Z2 are each independently Si(Q1)(Q2)(Q3) or —Ge(Q1)(Q2)(Q3), provided that each of Z1 and Z2 is not —SiH3, a1 and a2 are each independently an integer from 0 to 10, a sum of a1 and a2 is 1 or greater, Y1 and Y2 are each independently O, S, Se, or C(R5)(R6), * and *? each indicates a binding site to M1, and R1 to R3, R5, R6, and R41 to R48 are as described herein.

Abstract: An organometallic compound represented by Formula 1: M1(L1)n1(L2)n2??Formula 1 wherein, M1 is a transition metal, L1 is a ligand represented by Formula 1A, L2 is a ligand represented by Formula 1B, and n1 and n2 are each independently 1 or 2, wherein ring CY1, ring CY2, ring CY4, R1, R2, R4, R31, R32, X1 to X4, Y1, Z1, Z2, a1, a2, b1, b2, b31, b32, and b4 in Formulae 1A and 1B are respectively as described herein, and * and *? each indicate a binding site to M1.

Abstract: An organic light-emitting device including: a first electrode; a second electrode; and an organic layer arranged between the first electrode and the second electrode, the organic layer includes an emission layer, wherein the organic layer further includes a hole transport region arranged between the first electrode and the emission layer, the hole transport region includes an emission auxiliary layer, the emission layer includes a first compound that is an organometallic compound represented by Formula 1, the emission auxiliary layer includes a second compound that is a heterocyclic compound represented by Formula 2: wherein, in Formulae 1 and 2, Y2 is C, ring A2 is a C5-C30 carbocyclic group or a C1-C30 heterocyclic group, and R1 to R8, R13 to R20, R31 to R37, d2, X30, Z1, are as described in the detailed description.

Abstract: An organometallic compound represented by Formula 1: M1(Ln1)n1(Ln2)n2??Formula 1 wherein M1 is a transition metal, Ln1 is a ligand represented by Formula 1A, Ln2 is a ligand represented by Formula 1B, n1 is 1 or 2, and n2 is 1 or 2, wherein ring CY1 and ring CY2 are each independently a C5-C30 carbocyclic group or a C1-C30 heterocyclic group, ring CY41 is a phenyl group, ring CY42 is a 5-membered aromatic heterocyclic group, and the other substituents are as described herein.

Abstract: An organometallic compound represented by Formula 1: wherein M1 is a transition metal, Ln1 is a ligand represented by Formula 1A, Ln2 is a ligand represented by Formula 1B, n1 is 1 or 2, and n2 is 1 or 2: wherein ring CY3 is: a 5-membered N-containing heterocyclic group; or a 5-membered N-containing heterocyclic group condensed with a C5-C30 carbocyclic group or a C1-C30 heterocyclic group, ring CY4 is: a 6-membered carbocyclic group; a 6-membered heterocyclic group; a 6-membered carbocyclic group condensed with a C5-C30 carbocyclic group or a C1-C30 heterocyclic group; or a 6-membered heterocyclic group condensed with a C5-C30 carbocyclic group or a C1-C30 heterocyclic group, Y1 is O, S, Se, or C(R1)(R2), Y2 is O or S, and b30, b40, R1, R2, R11 to R14, R21 to R26, R30, and R40 are as defined herein.

Abstract: An organometallic compound represented by Formula 1: M1(Ln1)n1(Ln2)n2??Formula 1 wherein, in Formula 1, M1 is a transition metal; Ln1 is a ligand represented by Formula 1A; Ln2 is a ligand represented by Formula 1B; n1 is 1 or 2, and n2 is 1 or 2: wherein ring CY1 and ring CY2 are each independently a C5-C30 carbocyclic group or a C1-C30 heterocyclic group; ring CY41 is a group represented by Formula 41; X1 is C or N, and X2 is C or N; Y41 is O, S, Se, C(R3)(R4), N(R3), or B(R3); Y42 is O, S, Se, C(R5)(R6), N(R5), or B(R5); and the other substituents are as described in the detailed description.

Abstract: An organometallic compound represented by Formula 1: M1(Ln1)n1(Ln2)n2 wherein, in Formula 1, M1 is a transition metal; Ln1 is a ligand represented by Formula 1A; Ln2 is a ligand represented by Formula 1B; n1 is 1 or 2; and n2 is 1 or 2, wherein X1 is C or N, X2 is C or N, Y2 is O or S, and the other substituents are as described in the detailed description.

Abstract: An organometallic compound, represented by Formula 1: M1(Ln1)n1(Ln2)n2 ??Formula 1 wherein Ln1 is a ligand represented by Formula 1A, Ln2 is a ligand represented by Formula 1B, n1 is 1 or 2, and n2 is 1 or 2: wherein, in Formulae 1, 1A, and 1B, X1 is C or N, X2 is C or N, CY1 and CY2 are each independently a C5-C30 carbocyclic group or a C1-C30 heterocyclic group, CY3 is a 6-membered N-containing heterocyclic group, a 6-membered N-containing heterocyclic group condensed with a C5-C30 carbocyclic group, or a 6-membered N-containing heterocyclic group condensed with a C5-C30 carbocyclic group or a C1-C30 heterocyclic group, CY41 is a 5-membered carbocyclic group or a 5-membered heterocyclic group, * and *? each represent a bonding site to M1, and wherein R10, R20 to R30, R40 to R42, and b10 to b40 are as provided herein.

Abstract: An organometallic compound represented by Formula 1: M1(Ln1)n1(Ln2)n2??Formula 1 wherein, in Formula 1, Ln1 is a ligand represented by Formula 1A, Ln2 is a ligand represented by Formula 1B, n1 is 1 or 2, and n2 is 1 or 2: wherein CY1 is a 6-membered N-containing heterocyclic group, a 6-membered N-containing heterocyclic group condensed with a C1-C30 carbocyclic group, or a 6-membered N-containing heterocyclic group condensed with a C5-C30 heterocyclic group, CY21 is a 5-membered carbocyclic group or a 5-membered heterocyclic group, X31 and X32 are each independently O or S, * and *? each indicate a binding site to M1, and R10, R20 to R22, R31 to R37, b10, and b20 are as provided herein.

Abstract: An organometallic compound, represented by Formula 1: M1(Ln1)n1(Ln2)n2??Formula 1 wherein Ln1 is a ligand represented by Formula 1A, Ln2 is a ligand represented by Formula 1B, n1 is 1 or 2, and n2 is 1 or 2: wherein ring CY21 is a 5-membered carbocyclic group or a 5-membered heterocyclic group, X31 and X32 are each independently O or S, b20 is an integer from 0 to 6, R11 to R18, R20 to R22, and R31 to R37 are as defined herein, and * and *? each indicates a binding site to M1.

Abstract: An organometallic compound represented by Formula 1: M1(Ln1)n1(Ln2)n2??Formula 1 wherein, Ln1 is a ligand represented by Formula 1A, Ln2 is a ligand represented by Formula 1B, n1 is 1 or 2, and n2 is 1 or 2, wherein ring CY1 and ring CY2 are each independently a C5-C30 carbocyclic group or a C1-C30 heterocyclic group, ring CY41 is a benzene group, ring CY42 is a 5-membered aromatic heterocyclic group, X1 is C or N, X2 is C or N, Y1 is O, S, Se, C(R3)(R4), N(R3), or B(R3), and R1 to R4, R10, R20, R31 to R34, R40, b10, b20, and b40 are as described herein.

Abstract: An organometallic compound represented by Formula 1: M1(Ln1)n1(Ln2)n2??Formula 1 wherein M1 is a transition metal, Ln1 is a ligand represented by Formula 1A, Ln2 is a ligand represented by Formula 1B, n1 is 1 or 2, and n2 is 1 or 2: wherein ring CY1, ring CY2, ring CY3, X1, X2, X41, X42, R1 to R6, R10, R20, R30, R40, b10, b20, b30, and b40 are as described in the detailed description, and * and *? each indicate a binding site to M1.

Abstract: An organometallic compound, represented by Formula 1: M1(Ln1)n1(Ln2)n2??Formula 1 wherein, Ln1 is a ligand represented by Formula 1-1, Ln2 is a ligand represented by Formula 2-1 or Formula 2-2, n1 may be 1 or 2, and n2 may be 1 or 2, wherein the other substituents may be understood by referring to the descriptions thereof provided herein:

Abstract: An organometallic compound, represented by Formula 1: M1(L1)n1(Ln2)n2??Formula 1 wherein M1 is a transition metal, Ln1 is a ligand represented by Formula 1-1, Ln2 is a ligand represented by Formula 2-1 or Formula 2-2, n1 is 1 or 2, and n2 is 1 or 2: wherein CY11, CY12, X31, X32, R10A, R10B, R21 to R28, R31 to R37, R41 to R44, b11, and b12 are as defined herein, and * and *? each indicate a binding site to M1.

Abstract: An organometallic compound, represented by Formula 1: M1(Ln1)n1(Ln2)n2??Formula 1 wherein, in Formula 1, Ln1 is a ligand represented by Formula 1A, Ln2 is a ligand represented by Formula 1B, n1 is 1 or 2, and n2 is 1 or 2: wherein X1, X2, Y1, Y2, Y3, Y4, Y5, Y6, Y7, Y8, Y9, Y10, CY1, CY2, CY3, T1, T2, a1, a2, R10, R20, R30, b10, b20, and b30 are each as described herein.