Organometallic compound, organic light-emitting device including the organometallic compound, and diagnostic composition including the organometallic compound

1. An organometallic compound represented by Formula 1:

wherein M in Formula 1 is selected from iridium (Ir), platinum (Pt), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), thulium (Tm), rhodium (Rh), ruthenium (Ru), and rhenium (Re),

in Formula 1, L 1 is a ligand represented by Formula 2, and n1 is 2 or 3, wherein, two or more groups L 1 are identical to each other,

in Formula 1, L 2 is selected from a monovalent organic ligand and a divalent organic ligand, and n2 is 0, 1, or 2, wherein, when n2 is two, two L 2 groups are identical to or different from each other,

L 1 and L 2 in Formula 1 are different from each other,

* and *′ in Formula 2 each indicate a binding site to M in Formula 1,

in Formula 2, Y 9 is carbon, and a bond between N and Y 9 in CY 1 is a single bond or a double bond,

CY 1 in Formula 2 is a benzoquinoline group or a benzoisoquinoline group,

X 1 in Formula 2 is O, S, S(═O) 2 , or Se,

in Formula 2, Y 1 is N, C(R 1 ), carbon bonded to Y 9 , or carbon bonded to M, Y 2 is N, C(R 2 ), carbon bonded to Y 9 , or carbon bonded to M, Y 3 is N, C(R 3 ), carbon bonded to Y 9 , or carbon bonded to M, Y 4 is N, C(R 4 ), carbon bonded to Y 9 , or carbon bonded to M, Y 5 is N or C(R 5 ), Y 6 is N or C(R 6 ), Y 7 is N or C(R 7 ), Y 8 is N or C(R 8 ), and one of Y 1 to Y 4 is carbon bonded to Y 9 while another of Y 1 to Y 4 is carbon bonded to M,

R 1 to R 8 , and R 10 are each independently selected from hydrogen, deuterium, —F, —C, —Br, —I, —SF 5 , a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C 1 -C 60 alkyl group, a substituted or unsubstituted C 2 -C 60 alkenyl group, a substituted or unsubstituted C 2 -C 60 alkynyl group, a substituted or unsubstituted C 1 -C 60 alkoxy group, a substituted or unsubstituted C 3 -C 10 cycloalkyl group, a substituted or unsubstituted C 1 -C 10 heterocycloalkyl group, a substituted or unsubstituted C 3 -C 10 cycloalkenyl group, a substituted or unsubstituted C 1 -C 10 heterocycloalkenyl group, a substituted or unsubstituted C 6 -C 60 aryl group, a substituted or unsubstituted C 6 -C 60 aryloxy group, a substituted or unsubstituted C 6 -C 60 arylthio group, a substituted or unsubstituted C 7 -C 60 arylalkyl group, a substituted or unsubstituted C 1 -C 60 heteroaryl group, a substituted or unsubstituted C 1 -C 60 heteroaryloxy group, a substituted or unsubstituted C 1 -C 60 heteroarylthio group, a substituted or unsubstituted C 2 -C 60 heteroarylalkyl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q 1 )(Q 2 ), —Si(Q 3 )(Q 4 )(Q 5 ), —Ge(Q 3 )(Q 4 )(Q 5 ), —B(Q 6 )(Q 7 ), —P(═O)(Q 8 )(Q 9 ), and —P(Q 8 )(Q 9 ),

a10 is an integer from 1 to 8,

two or more groups selected from R 1 to R 4 in Formula 2 are optionally linked to form a substituted or unsubstituted C 5 -C 30 carbocyclic group or a substituted or unsubstituted C 2 -C 30 heterocyclic group,

two or more groups selected from R 5 to R 8 in Formula 2 are optionally linked to form a substituted or unsubstituted C 5 -C 30 carbocyclic group or a substituted or unsubstituted C 2 -C 30 heterocyclic group,

two or more groups selected from a plurality of groups R 10 in Formula 2 are optionally linked to form a substituted or unsubstituted C 5 -C 30 carbocyclic group or a substituted or unsubstituted C 2 -C 30 heterocyclic group,

at least one substituent of the substituted C 5 -C 30 carbocyclic group, the substituted C 2 -C 30 heterocyclic group, the substituted C 1 -C 60 alkyl group, the substituted C 2 -C 60 alkenyl group, the substituted C 2 -C 60 alkynyl group, the substituted C 1 -C 60 alkoxy group, the substituted C 3 -C 10 cycloalkyl group, the substituted C 1 -C 10 heterocycloalkyl group, the substituted C 3 -C 10 cycloalkenyl group, the substituted C 1 -C 10 heterocycloalkenyl group, the substituted C 6 -C 60 aryl group, the substituted C 6 -C 60 aryloxy group, the substituted C 6 -C 60 arylthio group, the substituted C 7 -C 60 arylalkyl group, the substituted C 1 -C 60 heteroaryl group, the substituted C 1 -C 60 heteroaryloxy group, the substituted C 1 -C 60 heteroarylthio group, the substituted C 2 -C 60 heteroarylalkyl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group is selected from:

deuterium, —F, —Cl, —Br, —I, —CD 3 , —CD 2 H, —CDH 2 , —CF 3 , —CF 2 H, —CFH 2 , a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C 1 -C 60 alkyl group, a C 2 -C 60 alkenyl group, a C 2 -C 60 alkynyl group, and a C 1 -C 60 alkoxy group;

a C 1 -C 60 alkyl group, a C 2 -C 60 alkenyl group, a C 2 -C 60 alkynyl group, and a C 1 -C 60 alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, —CD 3 , —CD 2 H, —CDH 2 , —CF 3 , —CF 2 H, —CFH 2 , a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C 3 -C 10 cycloalkyl group, a C 1 -C 10 heterocycloalkyl group, a C 3 -C 10 cycloalkenyl group, a C 1 -C 10 heterocycloalkenyl group, a C 6 -C 60 aryl group, a C 6 -C 60 aryloxy group, a C 6 -C 60 arylthio group, a C 7 -C 60 arylalkyl group, a C 1 -C 60 heteroaryl group, a C 1 -C 60 heteroaryloxy group, a C 1 -C 60 heteroarylthio group, a C 2 -C 60 heteroarylalkyl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q 11 )(Q 12 ), —Si(Q 13 )(Q 14 )(Q 15 ), —Ge(Q 13 )(Q 14 )(Q 15 ), —B(Q 16 )(Q 17 ), —P(═O)(Q 18 )(Q 19 ), and —P(Q 18 )(Q 19 );

a C 3 -C 10 cycloalkyl group, a C 1 -C 10 heterocycloalkyl group, a C 3 -C 10 cycloalkenyl group, a C 1 -C 10 heterocycloalkenyl group, a C 6 -C 60 aryl group, a C 6 -C 60 aryloxy group, a C 6 -C 60 arylthio group, a C 7 -C 60 arylalkyl group, a C 1 -C 60 heteroaryl group, a C 1 -C 60 heteroaryloxy group, a C 1 -C 60 heteroarylthio group, a C 2 -C 60 heteroarylalkyl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group;

a C 3 -C 10 cycloalkyl group, a C 1 -C 10 heterocycloalkyl group, a C 3 -C 10 cycloalkenyl group, a C 1 -C 10 heterocycloalkenyl group, a C 6 -C 60 aryl group, a C 6 -C 60 aryloxy group, a C 6 -C 60 arylthio group, a C 7 -C 60 arylalkyl group, a C 1 -C 60 heteroaryl group, a C 1 -C 60 heteroaryloxy group, a C 1 -C 60 heteroarylthio group, a C 2 -C 60 heteroarylalkyl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, —CD 3 , —CD 2 H, —CDH 2 , —CF 3 , —CF 2 H, —CFH 2 , a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C 1 -C 60 alkyl group, a C 2 -C 60 alkenyl group, a C 2 -C 60 alkynyl group, a C 1 -C 60 alkoxy group, a C 3 -C 10 cycloalkyl group, a C 1 -C 10 heterocycloalkyl group, a C 3 -C 10 cycloalkenyl group, a C 1 -C 10 heterocycloalkenyl group, a C 6 -C 60 aryl group, a C 6 -C 60 aryloxy group, a C 6 -C 60 arylthio group, a C 7 -C 60 arylalkyl group, a C 1 -C 60 heteroaryl group, a C 1 -C 60 heteroaryloxy group, a C 1 -C 60 heteroarylthio group, a C 2 -C 60 heteroarylalkyl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q 21 )(Q 22 ), —Si(Q 23 )(Q 24 )(Q 25 ), —Ge(Q 23 )(Q 24 )(Q 25 ), —B(Q 26 )(Q 27 ), —P(═O)(Q 28 )(Q 29 ), and —P(Q 28 )(Q 29 ); and

—N(Q 31 )(Q 32 ), —Si(Q 33 )(Q 34 )(Q 35 ), —Ge(Q 33 )(Q 34 )(Q 35 ), —B(Q 36 )(Q 37 ), —P(═O)(Q 38 )(Q 39 ), and —P(Q 38 )(Q 39 ), and

Q 1 to Q 9 , Q 11 to Q 19 , Q 21 to Q 29 , and Q 31 to Q 39 are each independently selected from hydrogen, deuterium, —F, —C, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C 1 -C 60 alkyl group, a C 2 -C 60 alkenyl group, a C 2 -C 60 alkynyl group, a C 1 -C 60 alkoxy group, a C 3 -C 10 cycloalkyl group, a C 1 -C 10 heterocycloalkyl group, a C 3 -C 10 cycloalkenyl group, a C 1 -C 10 heterocycloalkenyl group, a C 6 -C 60 aryl group, a C 6 -C 60 aryl group substituted with at least one selected from a C 1 -C 60 alkyl group and a C 6 -C 60 aryl group, a C 6 -C 60 aryloxy group, a C 6 -C 60 arylthio group, a C 7 -C 60 arylalkyl group, a C 1 -C 60 heteroaryl group, a C 1 -C 60 heteroaryloxy group, a C 1 -C 60 heteroarylthio group, a C 2 -C 60 heteroarylalkyl group, a monovalent non-aromatic condensed polycyclic A group, and a monovalent non-aromatic condensed heteropolycyclic group.

2. The organometallic compound of claim 1 , wherein,

in Formula 1,

M is Ir or Os, and the sum of n1 and n2 is 3 or 4; or

M is Pt, and the sum of n1 and n2 is 2.

3. The organometallic compound of claim 1 , wherein

X 1 is O or S.

4. The organometallic compound of claim 1 , wherein

R 1 to R 8 , and R 10 are each independently selected from:

hydrogen, deuterium, —F, —C, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, —SF 5 , a C 1 -C 20 alkyl group, and a C 1 -C 20 alkoxy group;

a C 1 -C 20 alkyl group and a C 1 -C 20 alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, —CD 3 , —CD 2 H, —CDH 2 , —CF 3 , —CF 2 H, —CFH 2 , a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C 1 -C 10 alkyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a bicyclo[2.2.2]octyl group, a phenyl group, a naphthyl group, a pyridinyl group, and a pyrimidinyl group;

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a bicyclo[2.2.2]octyl group, a phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, and an imidazopyrimidinyl group;

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a bicyclo[2.2.2]octyl group, a phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, and an imidazopyrimidinyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, —CD 3 , —CD 2 H, —CDH 2 , —CF 3 , —CF 2 H, —CFH 2 , a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C 1 -C 20 alkyl group, a C 1 -C 20 alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a bicyclo[2.2.2]octyl group, a phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and —Si(Q 33 )(Q 34 )(Q 35 ); and

—N(Q 1 )(Q 2 ), —Si(Q 3 )(Q 4 )(Q 5 ), —Ge(Q 3 )(Q 4 )(Q 5 ), —B(Q 6 )(Q 7 ), —P(═O)(Q 8 )(Q 9 ), and —P(Q 8 )(Q 9 ), and

Q 1 to Q 9 and Q 33 to Q 35 are each independently selected from:

—CH 3 , —CD 3 , —CD 2 H, —CDH 2 , —CH 2 CH 3 , —CH 2 CD 3 , —CH 2 CD 2 H, —CH 2 CDH 2 , —CHDCH 3 , —CHDCD 2 H, —CHDCDH 2 , —CHDCD 3 , —CD 2 CD 3 , —CD 2 CD 2 H, and -CD 2 CDH 2 ;

an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group; and

an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group, each substituted with at least one selected from deuterium, a C 1 -C 10 alkyl group, and a phenyl group.

5. The organometallic compound of claim 1 , wherein

R 1 to R 8 , and R 10 are each independently selected from hydrogen, deuterium, —F, a cyano group, a nitro group, —SF 5 , —CH 3 , —CD 3 , —CD 2 H, —CDH 2 , —CF 3 , —CF 2 H, —CFH 2 , groups represented by Formulae 9-1 to 9-20, groups represented by Formulae 10-1 to 10-142, —Si(Q 3 )(Q 4 )(Q 5 ), and —Ge(Q 3 )(Q 4 )(Q 5 ), and

Q 3 to Q 5 are each independently selected from:

CH 3 , —CD 3 , —CD 2 H, —CDH 2 , —CH 2 CH 3 , —CH 2 CD 3 , —CH 2 CD 2 H, —CH 2 CDH 2 , —CHDCH 3 , —CHDCD 2 H, —CHDCDH 2 , —CHDCD 3 , —CD 2 CD 3 , —CD 2 CD 2 H, and -CD 2 CDH 2 ;

an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group; and

an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an iso-pentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, and a naphthyl group, each substituted with at least one selected from deuterium, a C 1 -C 10 alkyl group, and a phenyl group:

wherein, in Formulae 9-1 to 9-20 and 10-1 to 10-142, “Ph” indicates a phenyl group, “TMS” indicates a trimethylsilyl group, and * indicates a binding site to a neighboring atom.

6. The organometallic compound of claim 1 , wherein

a moiety represented by

in Formula 2 is selected from groups represented by Formulae CY1-1 to CY1-9:

wherein, in Formulae CY1-1 to CY1-9, R 11 to R 18 are each independently the same as described in connection with R 10 in claim 1 , and * indicates a binding site to M in Formula 1.

7. The organometallic compound of claim 6 , wherein

a moiety represented by

in Formula 2 is a group represented by Formula CY1-1.

8. The organometallic compound of claim 6 , wherein

a moiety represented by

in Formula 2 is a group represented by Formula CY1-1, and R 11 in Formula CY1-1 is not hydrogen.

9. The organometallic compound of claim 1 , wherein

L 1 in Formula 1 is selected from ligands represented by Formulae 2-1 to 2-6:

wherein, in Formulae 2-1 to 2-6, CY 1 , X 1 , Y 1 to Y 9 , R 10 , a10, *, and *′ are each independently the same as described in claim 1 .

10. The organometallic compound of claim 1 , wherein

L 1 in Formula 1 is a ligand represented by Formula 2A:

wherein, in Formula 2A,

Y 8 is N or C(R 8 ),

X 1 , R 3 to R 8 , *, and *′ are each independently the same as described in claim 1 , and

R 11 to R 18 are each independently the same as described in connection with R 10 in claim 1 .

11. The organometallic compound of claim 10 , wherein

at least one of R 3 and R 11 is not hydrogen.

12. The organometallic compound of claim 1 , wherein

L 2 in Formula 1 is selected from ligands represented by Formulae 3A to 3F:

wherein, in Formulae 3A to 3F,

Y 11 is selected from O, N, N(Z 1 ), P(Z 1 )(Z 2 ), and As(Z 1 )(Z 2 ),

Y 12 is O, N, N(Z 3 ), P(Z 3 )(Z 4 ), and As(Z 3 )(Z 4 ),

T 11 is selected from a single bond, a double bond, *—C(Z 11 )(Z 12 )—*′, *—C(Z 11 )═C(Z 12 )—*′, *═C(Z 11 )—*′, *—C(Z 11 )═*′, *═C(Z 11 )—C(Z 12 )═C(Z 13 )—*′, *—C(Z 11 )═C(Z 12 )—C(Z 13 )═*′, *—N(Z 11 )—*′, and a substituted or unsubstituted C 6 -C 30 arylene group,

a11 is an integer from 1 to 5,

Y 13 to Y 16 are each independently carbon (C) or nitrogen (N), a bond between Y 13 and Y 14 is a single bond or a double bond, and a bond between Y 15 and Y 16 is a single bond or a double bond,

CY 11 to CY 13 are each independently a C 5 -C 30 carbocyclic group or a C 2 -C 30 heterocyclic group,

A 1 is P or As,

Z 1 to Z 4 and Z 11 to Z 13 are each independently the same as described in connection with R 10 in claim 1 ,

d1 and d2 are each independently an integer from 0 to 10, and

* and *′ each indicate a binding site to M in Formula 1.

13. The organometallic compound of claim 12 , wherein CY 11 to CY 13 are each independently selected from a benzene group, a naphthalene group, a pyridine group, a pyrimidine group, a triazine group, a pyrrole group, a pyrazole group, an imidazole group, and a triazole group.

14. The organometallic compound of claim 1 , wherein

L 2 in Formula 1 is selected from ligands represented by Formulae 3-1 to 3-15:

wherein, in Formulae 3-1 to 3-7 and 3-9 to 3-15,

X 31 is N or C(Z 1a ), X 32 is N or C(Z 1b ),

X 41 is O, S, N(Z 1c ), or C(Z 1d )(Z 1e ),

Z 1 to Z 4 , Z 1a to Z 1e , and Z 11 to Z 14 are each independently the same as described in connection with R 10 in claim 1 ,

e2 is an integer from 0 to 2,

e3 is an integer from 0 to 3,

e4 is an integer from 0 to 4, and

* and *′ each indicate a binding site to M in Formula 1.

15. The organometallic compound of claim 1 , wherein

the organometallic compound is one of Compounds 1 to 144:

wherein i Bu in Compounds 1 to 144 indicates an iso-butyl group.

16. An organic light-emitting device comprising:

a first electrode;

a second electrode; and

an organic layer disposed between the first electrode and the second electrode,

wherein the organic layer comprises an emission layer and at least one organometallic compound of claim 1 .

17. The organic light-emitting device of claim 16 , wherein

the first electrode is an anode,

the second electrode is a cathode, and

the organic layer further comprises a hole transport region disposed between the first electrode and the emission layer and an electron transport region disposed between the emission layer and the second electrode,

wherein the hole transport region comprises a hole injection layer, a hole transport layer, an electron blocking layer, or any combination thereof, and

wherein the electron transport region comprises a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.

18. The organic light-emitting device of claim 16 , wherein

the emission layer comprises the organometallic compound.

19. The organic light-emitting device of claim 18 , wherein

the emission layer further comprises a host, and an amount of the host in the emission layer is larger than an amount of the organometallic compound in the emission layer.

20. A diagnostic composition comprising at least one organometallic compound of claim 1 .