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

An organometallic compound represented by Formula 1:

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Korean Patent Applications Nos. 10-2018-0089511, filed on Jul. 31, 2018, and 10-2019-0091699, filed on Jul. 29, 2019, in the Korean Intellectual Property Office, and all the benefits accruing therefrom under 35 U.S.C. § 119, the content of which is incorporated herein in its entirety by reference.

BACKGROUND

One or more embodiments relate to an organometallic compound, an organic light-emitting device including the same, and a diagnostic composition including the organometallic compound.

2. Description of the Related Art

Organic light-emitting devices (OLEDs) are self-emission devices, which have superior characteristics in terms of a viewing angle, response time, brightness, driving voltage, and response speed, and which produce full-color images.

Luminescent compounds may be used to monitor, sense, or detect a variety of biological materials including cells and proteins. An example of such luminescent compounds is a phosphorescent luminescent compound.

Various types of organic light emitting devices are known. However, there still remains a need in OLEDs having low driving voltage, high efficiency, high brightness, and long lifespan.

SUMMARY

Aspects of the present disclosure provide a novel organometallic compound, an organic light-emitting device including the same, and a diagnostic composition including the novel organometallic compound.

An aspect of the present disclosure provides an organometallic compound represented by Formula 1:

In Formula 1,R1to R10and A7may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, —SF5, 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 C1-C60alkyl group, a substituted or unsubstituted C2-C60alkenyl group, a substituted or unsubstituted C2-C60alkynyl group, a substituted or unsubstituted C1-C60alkoxy group, a substituted or unsubstituted C3-C10cycloalkyl group, a substituted or unsubstituted C1-C10heterocycloalkyl group, a substituted or unsubstituted C3-C10cycloalkenyl group, a substituted or unsubstituted C1-C10heterocycloalkenyl group, a substituted or unsubstituted C6-C60aryl group, a substituted or unsubstituted C6-C60aryloxy group, a substituted or unsubstituted C6-C60arylthio group, a substituted or unsubstituted C7-C60arylalkyl group, a substituted or unsubstituted C1-C60heteroaryl group, a substituted or unsubstituted C1-C60heteroaryloxy group, a substituted or unsubstituted C1-C60heteroarylthio group, a substituted or unsubstituted C2-C60heteroarylalkyl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q1)(Q2), —Si(Q3)(Q4)(Q5), —Ge(Q3)(Q4)(Q5), —B(Q6)(Q7), —P(═O)(Q8)(Q9), or —P(Q8)(Q9),at least one of R1to R10may each independently be a substituted or unsubstituted C2-C60alkyl group, a substituted or unsubstituted C2-C60alkenyl group, a substituted or unsubstituted C2-C60alkynyl group, a substituted or unsubstituted C1-C60alkoxy group, a substituted or unsubstituted C3-C10cycloalkyl group, a substituted or unsubstituted C1-C10heterocycloalkyl group, a substituted or unsubstituted C3-C10cycloalkenyl group, a substituted or unsubstituted C1-C10heterocycloalkenyl group, a substituted or unsubstituted C6-C60aryl group, a substituted or unsubstituted C6-C60aryloxy group, a substituted or unsubstituted C6-C60arylthio group, a substituted or unsubstituted C7-C60arylalkyl group, a substituted or unsubstituted C1-C60heteroaryl group, a substituted or unsubstituted C1-C60heteroaryloxy group, a substituted or unsubstituted C1-C60heteroarylthio group, a substituted or unsubstituted C2-C60heteroarylalkyl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q1)(Q2), —Si(Q3)(Q4)(Q5), —Ge(Q3)(Q4)(Q5), —B(Q6)(Q7), —P(═O)(Q8)(Q9), or —P(Q8)(Q9),A1to A6may each independently be a substituted or unsubstituted C1-C60alkyl group, a substituted or unsubstituted C2-C60alkenyl group, a substituted or unsubstituted C2-C60alkynyl group, a substituted or unsubstituted C1-C60alkoxy group, a substituted or unsubstituted C3-C10cycloalkyl group, a substituted or unsubstituted C1-C10heterocycloalkyl group, a substituted or unsubstituted C3-C10cycloalkenyl group, a substituted or unsubstituted C1-C10heterocycloalkenyl group, a substituted or unsubstituted C6-C60aryl group, a substituted or unsubstituted C6-C60aryloxy group, a substituted or unsubstituted C6-C60arylthio group, a substituted or unsubstituted C7-C60arylalkyl group, a substituted or unsubstituted C1-C60heteroaryl group, a substituted or unsubstituted C1-C60heteroaryloxy group, a substituted or unsubstituted C1-C60heteroarylthio group, a substituted or unsubstituted C2-C60heteroarylalkyl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group,two or more of R1to R10may optionally be linked to form a C5-C60carbocyclic group unsubstituted or substituted with at least one R1aor a C1-C60heterocyclic group unsubstituted or substituted at least one R1a,two or more of A1to A6may optionally be linked to form a C5-C60carbocyclic group unsubstituted or substituted with at least one R1aor a C1-C10heterocyclic group unsubstituted or substituted with at least one R1a,R1ais understood by referring to the detailed description of R7,a substituent(s) of the substituted C1-C10alkyl group, the substituted C2-C60alkenyl group, the substituted C2-C60alkynyl group, the substituted C1-C10alkoxy group, the substituted C3-C10cycloalkyl group, the substituted C1-C10heterocycloalkyl group, the substituted C3-C10cycloalkenyl group, the substituted C1-C10heterocycloalkenyl group, the substituted C6-C60aryl group, the substituted C6-C60aryloxy group, the substituted C6-C60arylthio group, the substituted C7-C60arylalkyl group, the substituted C1-C10heteroaryl group, the substituted C1-C10heteroaryloxy group, the substituted C1-C10heteroarylthio group, the substituted C2-C60heteroarylalkyl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may each independently be:deuterium, —F, —Cl, —Br, —I, —CD3, —CD2H, —CDH2, —CF3, —CF2H, —CFH2, 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 C1-C10alkyl group, a C2-C60alkenyl group, a C2-C60alkynyl group, or a C1-C60alkoxy group;a C1-C60alkyl group, a C2-C60alkenyl group, a C2-C60alkynyl group, or a C1-C60alkoxy group, each substituted with deuterium, —F, —Cl, —Br, —I, —CD3, —CD2H, —CDH2, —CF3, —CF2H, —CFH2, 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 C3-C10cycloalkyl group, a C1-C10heterocycloalkyl group, a C3-C10cycloalkenyl group, a C1-C10heterocycloalkenyl group, a C6-C60aryl group, a C6-C60aryloxy group, a C6-C60arylthio group, a C7-C60arylalkyl group, a C1-C60heteroaryl group, a C1-C60heteroaryloxy group, a C1-C60heteroarylthio group, a C2-C60heteroarylalkyl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q11)(Q12), —Si(Q13)(Q14)(Q15), —Ge(Q13)(Q14)(Q15), —B(Q16)(Q17), —P(═O)(Q18)(Q19), —P(Q18)(Q19), or any combination thereof;a C3-C10cycloalkyl group, a C1-C10heterocycloalkyl group, a C3-C10cycloalkenyl group, a C1-C10heterocycloalkenyl group, a C6-C60aryl group, a C6-C60aryloxy group, a C6-C60arylthio group, a C7-C60arylalkyl group, a C1-C60heteroaryl group, a C1-C60heteroaryloxy group, a C1-C60heteroarylthio group, a C2-C60heteroarylalkyl group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group;a C3-C10cycloalkyl group, a C1-C10heterocycloalkyl group, a C3-C10cycloalkenyl group, a C1-C10heterocycloalkenyl group, a C6-C60aryl group, a C6-C60aryloxy group, a C6-C60arylthio group, a C7-C60arylalkyl group, a C1-C60heteroaryl group, a C1-C60heteroaryloxy group, a C1-C60heteroarylthio group, a C2-C60heteroarylalkyl group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group, each substituted with deuterium, —F, —Cl, —Br, —I, —CD3, —CD2H, —CDH2, —CF3, —CF2H, —CFH2, 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 C1-C60alkyl group, a C2-C60alkenyl group, a C2-C60alkynyl group, a C1-C60alkoxy group, a C3-C10cycloalkyl group, a C1-C10heterocycloalkyl group, a C3-C10cycloalkenyl group, a C1-C10heterocycloalkenyl group, a C6-C60aryl group, a C6-C60aryloxy group, a C6-C60arylthio group, a C7-C60arylalkyl group, a C1-C60heteroaryl group, a C1-C60heteroaryloxy group, a C1-C60heteroarylthio group, a C2-C60heteroarylalkyl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q21)(Q22), —Si(Q23)(Q24)(Q25), —Ge(Q23)(Q24)(Q25), —B(Q26)(Q27), —P(═O)(Q28)(Q29), —P(Q28)(Q29), or any combination thereof;—N(Q31)(Q32), —Si(Q33)(Q34)(Q35), —Ge(Q33)(Q34)(Q35), —B(Q36)(Q37), —P(═O)(Q38)(Q39), or —P(Q38)(Q39); orany combination thereof, andQ1to Q9, Q11to Q19, Q21to Q29, and Q31to Q39may each independently be hydrogen; deuterium; —F; —Cl; —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 C1-C60alkyl group; a C2-C60alkenyl group; a C2-C60alkynyl group; a C1-C60alkoxy group; a C3-C10cycloalkyl group; a C1-C10heterocycloalkyl group; a C3-C10cycloalkenyl group; a C1-C10heterocycloalkenyl group; a C6-C60aryl group; a C6-C60aryl group substituted with a C1-C60alkyl group, a C6-C60aryl group, or any combination thereof; a C6-C60aryloxy group; a C6-C60arylthio group; a C7-C60arylalkyl group; a C1-C60heteroaryl group; a C1-C60heteroaryloxy group; a C1-C60heteroarylthio group; a C2-C60heteroarylalkyl group; a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group.

Another aspect of the present disclosure provides an organic light-emitting device including:a first electrode,a second electrode, andan organic layer disposed between the first electrode and the second electrode,wherein the organic layer includes an emission layer, andwherein the organic layer includes at least one organometallic compound represented by Formula 1.

Another aspect of the present disclosure provides a diagnostic composition including at least one organometallic compound represented by Formula 1.

DETAILED DESCRIPTION

An aspect of the present disclosure provides an organometallic compound represented by Formula 1 below:

In Formula 1,R1to R10and A7may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, —SF5, 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 C1-C60alkyl group, a substituted or unsubstituted C2-C60alkenyl group, a substituted or unsubstituted C2-C60alkynyl group, a substituted or unsubstituted C1-C60alkoxy group, a substituted or unsubstituted C3-C10cycloalkyl group, a substituted or unsubstituted heterocycloalkyl group, a substituted or unsubstituted C3-C10cycloalkenyl group, a substituted or unsubstituted heterocycloalkenyl group, a substituted or unsubstituted C6-C60aryl group, a substituted or unsubstituted C6-C60aryloxy group, a substituted or unsubstituted C6-C60arylthio group, a substituted or unsubstituted C7-C60arylalkyl group, a substituted or unsubstituted C1-C60heteroaryl group, a substituted or unsubstituted C1-C60heteroaryloxy group, a substituted or unsubstituted C1-C60heteroarylthio group, a substituted or unsubstituted C2-C60heteroarylalkyl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q1)(Q2), —Si(Q3)(Q4)(Q5), —Ge(Q3)(Q4)(Q5), —B(Q6)(Q7), —P(═O)(Q8)(C)9), or —P(Q8)(Q9),at least one of R1to R10(for example, at least one of R1to R6) may each independently be a substituted or unsubstituted C2-C60alkyl group, a substituted or unsubstituted C2-C60alkenyl group, a substituted or unsubstituted C2-C60alkynyl group, a substituted or unsubstituted C1-C60alkoxy group, a substituted or unsubstituted C3-C10cycloalkyl group, a substituted or unsubstituted C1-C10heterocycloalkyl group, a substituted or unsubstituted C3-C10cycloalkenyl group, a substituted or unsubstituted C1-C10heterocycloalkenyl group, a substituted or unsubstituted C6-C60aryl group, a substituted or unsubstituted C6-C60aryloxy group, a substituted or unsubstituted C6-C60arylthio group, a substituted or unsubstituted C7-C60arylalkyl group, a substituted or unsubstituted C1-C60heteroaryl group, a substituted or unsubstituted C1-C60heteroaryloxy group, a substituted or unsubstituted C1-C60heteroarylthio group, a substituted or unsubstituted C2-C60heteroarylalkyl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q1)(Q2), —Si(Q3)(Q4)(Q5), —Ge(Q3)(Q4)(Q5), —B(Q6)(Q7), —P(═O)(Q8)(Q9), or —P(Q8)(Q9), andA1to A6may each independently be a substituted or unsubstituted C1-C60alkyl group, a substituted or unsubstituted C2-C60alkenyl group, a substituted or unsubstituted C2-C60alkynyl group, a substituted or unsubstituted C1-C60alkoxy group, a substituted or unsubstituted C3-C10cycloalkyl group, a substituted or unsubstituted C1-C10heterocycloalkyl group, a substituted or unsubstituted C3-C10cycloalkenyl group, a substituted or unsubstituted C1-C10heterocycloalkenyl group, a substituted or unsubstituted C6-C60aryl group, a substituted or unsubstituted C6-C60aryloxy group, a substituted or unsubstituted C6-C60arylthio group, a substituted or unsubstituted C7-C60arylalkyl group, a substituted or unsubstituted C1-C60heteroaryl group, a substituted or unsubstituted C1-C60heteroaryloxy group, a substituted or unsubstituted C1-C60heteroarylthio group, a substituted or unsubstituted C2-C60heteroarylalkyl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group.Q1to Q9are the same as described herein.

In an embodiment, Formula 1,R1to R10and A7may each independently be hydrogen, deuterium, a cyano group, a substituted or unsubstituted C1-C60alkyl group, or a substituted or unsubstituted C3-C10cycloalkyl group and/orat least one of R1to R10(for example, at least one of R1to R6) may each independently be a substituted or unsubstituted C2-C60alkyl group, or a substituted or unsubstituted C3-C10cycloalkyl group, and/orA1to A6may each independently be a substituted or unsubstituted C1-C60alkyl group or a substituted or unsubstituted C3-C10cycloalkyl group.

In one or more embodiments, in Formula 1,R1to R10and A7may each independently be hydrogen, deuterium, —F, a cyano group, a nitro group, —SF5, —CH3, —CD3, —CD2H, —CDH2, —CF3, —CF2H, —CFH2, a group represented by one of Formulae 9-1 to 9-66, a group represented by one of Formulae 9-1 to 9-66 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 10-1 to 10-249, a group represented by one of Formulae 10-1 to 10-249 in which at least one hydrogen is substituted with deuterium, —Si(Q3)(Q4)(Q5), or —Ge(Q3)(Q4)(Q5) (wherein Q3to Q5are the same as described herein), and/orat least one of R1to R10(for example, at least one of R1to R6) may each independently be a group represented by one of Formulae 9-1 to 9-66, a group represented by one of Formulae 9-1 to 9-66 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 10-1 to 10-249, a group represented by one of Formulae 10-1 to 10-249 in which at least one hydrogen is substituted with deuterium, —Si(Q3)(Q4)(Q5), or —Ge(Q3)(Q4)(Q5) (wherein Q3to Q5are the same as described herein), and/orA1to A6may each independently be —CH3, —CD3, —CD2H, —CDH2, —CF3, —CF2H, —CFH2, a group represented by one of Formulae 9-1 to 9-66, a group represented by one of Formulae 9-1 to 9-66 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 10-1 to 10-249, or a group represented by one of Formulae 10-1 to 10-249 in which at least one hydrogen is substituted with deuterium, but embodiments of the present disclosure are not limited thereto:

In Formulae 9-1 to 9-66 and 10-1 to 10-249, * indicates a binding site to a neighboring atom, Ph indicates a phenyl group, and TMS indicates a trimethylsilyl group.

The “group represented by one of Formulae 9-1 to 9-66 in which at least one hydrogen is substituted with deuterium” may be, for example, a group represented by one of Formulae 9-501 to 9-552:

The “group represented by one of Formulae 10-1 to 10-249 in which at least one hydrogen is substituted with deuterium” may be, for example, a group represented by one of Formulae 10-501 to 10-510:

In one or more embodiments, at least one of R1to R10(for example, at least one of R1to R6) in Formula 1 may be a group represented by Formula 2:

The number of carbon atoms included in Formula 2 may be 4 or more (for example, 4 to 20, 4 to 15 or 4 to 10).

* in Formula 2 indicates a binding site to a neighboring atom.

The terms “a deuterium-containing C1-C20alkyl group” and “a deuterium-containing C3-C10cycloalkyl group” as used herein each refer to a C1-C20alkyl group substituted with at least one deuterium and a C3-C10cycloalkyl group substituted with at least one deuterium, respectively. For example, a deuterium-containing methyl group may be —CDH2, —CD2H, and —CD3.

Non-limiting of the “C3-C10cycloalkyl group” include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cycloctyl group, an adamantanyl group, a norbornanyl group, a bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, a bicyclo[2.2.1]heptyl group, a bicyclo[2.2.2]octyl group, and the like, but embodiments of the present disclosure are not limited thereto.

For example, R13in Formula 2 may be hydrogen or deuterium.

In an embodiment, R14and R15in Formula 2 may be different from each other.

In one or more embodiments, R14and R15in Formula 2 may each independently be —CH3, —CDH2, —CD2H, —CD3, a group represented by one of Formulae 9-1 to 9-33, a group represented by one of Formulae 9-1 to 9-33 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 10-1 to 10-10, or a group represented by one of Formulae 10-1 to 10-10 in which at least one hydrogen is substituted with deuterium, but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, a case where R13to R15in Formula 2 are all the same may be excluded.

In one or more embodiments, a case where R13to R15in Formula 2 are all methyl groups may be excluded.

In an embodiment, at least one of R1to R6in Formula 1 may each independently be a group represented by Formula 2.

For example, R4in Formula 1 may be a group represented by Formula 2.

In an embodiment, R1to R3, R5, and R6in Formula 1 may each be hydrogen, and R4may be a group represented by Formula 2.

In an embodiment, at least one of R4, R7, and R9in Formula 1 may not be each hydrogen.

In one or more embodiments, each of R7and R9in Formula 1 may not be hydrogen.

In one or more embodiments, in Formula 1, each of R7and R9may not be hydrogen, and each of R8and R10may not be hydrogen.

In one or more embodiments, none of R4, R7, and R9in Formula 1 may be hydrogen.

In one or more embodiments, each of R7and R9in Formula 1 may not be hydrogen, and R7and R9may be identical to each other.

In one or more embodiments, each of R7and R9in Formula 1 may not be hydrogen, and R7and R9may be different from each other.

In one or more embodiments, in Formula 1, each of R7and R9may not be hydrogen, R7and R9may be different from each other, and the number of carbon atoms included in R7may be greater than that of carbon atoms included in R9.

In one or more embodiments, R7and R9in Formula 1 may each independently be a substituted or unsubstituted C1-C60alkyl group, a substituted or unsubstituted C3-C10cycloalkyl group, or a substituted or unsubstituted C6-C60aryl group.

In one or more embodiments, at least one of R7and R9in Formula 1 may each independently be a substituted or unsubstituted C2-C60alkyl group, a substituted or unsubstituted C3-C10cycloalkyl group, or a substituted or unsubstituted C6-C60aryl group.

In an embodiment, at least one of A1to A6in Formula 1 may each independently be a group represented by one of Formulae 9-1 to 9-66, a group represented by one of Formulae 9-1 to 9-66 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 10-1 to 10-249, or a group represented by one of Formulae 10-1 to 10-249 in which at least one hydrogen is substituted with deuterium, but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, A7may not be hydrogen.

In one or more embodiments, in Formula 1, a group represented by *—C(A1)(A2)(A3) and a group represented by *—C(A4)(A5)(A6) may be identical to each other, and * indicates a binding site to a neighboring atom.

In one or more embodiments, in Formula 1 a group represented by *—C(A1)(A2)(A3) and a group represented by *—C(A4)(A5)(A6) may be different from each other, and * indicates a binding site to a neighboring atom.

In one or more embodiments, in Formula 1,A1an A2may be identical to each other, and A1and A3may be different from each other; and/orA4and A5may be identical to each other, and A4and A6may be different from each other.

In Formula 1, two or more of R1to R10may optionally be linked to form a C5-C60carbocyclic group unsubstituted or substituted with at least one R1aor a C1-C60heterocyclic group unsubstituted or substituted with at least one R1a, and two or more of A1to A6may optionally be linked to form a C5-C60carbocyclic group unsubstituted or substituted with at least one R1aor a C1-C60heterocyclic group unsubstituted or substituted with at least one R1a. Here, R1ais the same as defined in connection with R7.

For example, a C5-C60carbocyclic group unsubstituted or substituted with at least one R1aand a C1-C60heterocyclic group unsubstituted or substituted with at least one R1amay each independently be a cyclopentane group, a cyclohexane group, a cycloheptane group, a cyclooctane group, an adamantane group, a norbornane group, a norbornene group, a cyclopentene group, a cyclohexene group, a cycloheptene group, a bicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, a bicyclo[2.2.1]heptane group, a bicyclo[2.2.2]octane group, a benzene group, a naphthalene group, a fluorene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a pyrrole group, a thiophene group, a furan group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, an isoindole group, an indole group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a quinoxaline group, a quinazoline group, a cinnoline group, a carbazole group, a phenanthroline group, a benzimidazole group, a benzofuran group, a benzothiophene group, an isobenzothiophene group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a tetrazine group, a dibenzofuran group, a dibenzothiophene group, a benzocarbazole group, a dibenzocarbazole group, an imidazopyridine group, or an imidazopyrimidine group, each unsubstituted or substituted with at least one R1a, but embodiments of the present disclosure are not limited thereto.

In an embodiment, two or more of A1to A3(for example, all of A1to A3) in Formula 1 may be linked to form a C5-C60carbocyclic group unsubstituted or substituted with at least one R1aor a C1-C60heterocyclic group unsubstituted or substituted with at least one R1a, and/or two or more of A4to A6(for example, all of A4to A6) in Formula 1 may be linked to form a C5-C60carbocyclic group unsubstituted or substituted with at least one R1aor a C1-C60heterocyclic group unsubstituted or substituted with at least one R1a.

In one or more embodiments, in Formula 1, at least one of a group represented by *—C(A1)(A2)(A3) and a group represented by *-(A4)(A5)(A6) may each independently be a cyclopentane group, a cyclohexane group, a cycloheptane group, a cyclooctane group, an adamantane group, a norbornane group, a norbornene group, a cyclopentene group, a cyclohexene group, a cycloheptene group, a bicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, a bicyclo[2.2.1]heptane group, a bicyclo[2.2.2]octane group, a benzene group, a naphthalene group, a fluorene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a pyrrole group, a thiophene group, a furan group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, an isoindole group, an indole group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a quinoxaline group, a quinazoline group, a cinnoline group, a carbazole group, a phenanthroline group, a benzimidazole group, a benzofuran group, a benzothiophene group, an isobenzothiophene group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a tetrazine group, a dibenzofuran group, a dibenzothiophene group, a benzocarbazole group, a dibenzocarbazole group, an imidazopyridine group, or an imidazopyrimidine group, each unsubstituted or substituted with at least one R1a, but embodiments of the present disclosure are not limited thereto.

For example, the organometallic compound represented by Formula 1 may be one of Compounds 1 to 6, but embodiments of the present disclosure are not limited thereto:

At least one of R1to R10in Formula 1 may each independently be a substituted or unsubstituted C2-C60alkyl group, a substituted or unsubstituted C2-C60alkenyl group, a substituted or unsubstituted C2-C60alkynyl group, a substituted or unsubstituted C1-C60alkoxy group, a substituted or unsubstituted C3-C10cycloalkyl group, a substituted or unsubstituted C1-C10heterocycloalkyl group, a substituted or unsubstituted C3-C10cycloalkenyl group, a substituted or unsubstituted C1-C10heterocycloalkenyl group, a substituted or unsubstituted C6-C60aryl group, a substituted or unsubstituted C6-C60aryloxy group, a substituted or unsubstituted C6-C60arylthio group, a substituted or unsubstituted C7-C60arylalkyl group, a substituted or unsubstituted C1-C60heteroaryl group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted C1-C60heteroarylthio group, a substituted or unsubstituted C2-C60heteroarylalkyl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q1)(Q2), —Si(Q3)(Q4)(Q5), —Ge(Q3)(Q4)(Q5), —B(Q6)(Q7), —P(═O)(Q8)(Q9), or —P(Q8)(Q9). For example, at least one of R1to R10(for example, at least one of R1to R6) in Formula 1 may not be hydrogen nor a methyl group, but may be a substituent described above. In this regard, the organometallic compound represented by Formula 1 may have an increased electron-donating effect so that a wavelength of the light emitted by the organometallic compound may be shifted to a relatively short wavelength side. Accordingly, the non-radiative transition of the organometallic compound may decrease while the photoluminescence quantum yield (PLQY) of the organometallic compound may increase. As a result, an electronic device, for example, an organic light-emitting device, including the organometallic compound may have increased external quantum efficiency (EQE), and the full width at half maximum (FWHM) of the electroluminescence (EL) spectrum peak of such an organic light-emitting device may be reduced.

Although not limited to a particular theory, an α-proton has chemical reactivity that is about 105greater than that of a β-proton. That is, the α-proton may cause a side reaction due to production of intermediates in various forms during synthesis and/or storage of a compound. However, each A1to A6in Formula 1 as described above may not include the α-proton, and in this regard, the organometallic compound represented by Formula 1 may have a stable chemical structure with minimal occurrence of a side reaction before/after synthesis, and at the same time, an intermolecular interaction of the organometallic compound may be minimized during the operation of an electronic device (for example, an organic light-emitting device) including the organometallic compound. Thus, an electronic device, for example, an organic light-emitting device, including the organometallic compound represented by Formula 1 may have improved luminescence efficiency and lifespan characteristics.

A highest occupied molecular orbital (HOMO) energy level, a lowest unoccupied molecular orbital (LUMO) energy level, a singlet (S1) energy level, and a triplet (T1) energy level of some compounds of the organometallic compound represented by Formula 1 are evaluated by a density functional theory (DFT) of Gaussian program with molecular structure optimization based on B3LYP, and results are shown in Table 1.

Referring to Table 1, it is confirmed that the organometallic compound represented by Formula 1 has such electrical characteristics that are suitable for use as a dopant for in an electronic device, for example, for an organic light-emitting device.

Synthesis methods of the organometallic compound represented by Formula 1 may be recognizable by one of ordinary skill in the art by referring to Synthesis Examples provided below.

Therefore, the organometallic compound represented by Formula 1 may be suitable for use as a dopant in an organic layer of an organic light-emitting device, for example, in an emission layer of the organic layer. Another aspect of the present disclosure provides an organic light-emitting device including: a first electrode, a second electrode, and an organic layer disposed between the first electrode and the second electrode and including an emission layer, wherein the organic layer includes at least one organometallic compound represented by Formula 1.

The organic light-emitting device may have, due to the inclusion of an organic layer including the organometallic compound represented by Formula 1, an improved driving voltage, an improved external quantum efficiency, an improved low roll-off ratio, and an improved long lifespan.

The organometallic compound represented by Formula 1 may be used between a pair of electrodes of an organic light-emitting device. For example, the organometallic compound represented by Formula 1 may be included in the emission layer. In this regard, the organometallic compound may act as a dopant, and the emission layer may further include a host (that is, an amount of the organometallic compound represented by Formula 1 is smaller than an amount of the host). The emission layer may emit red light having a maximum emission wavelength in a range of, for example, about 550 nanometers (nm) or more (for example, about 550 nm or more and about 900 nm or less).

The expression “(an organic layer) includes at least one organometallic compound” as used herein may include an embodiment in which “(an organic layer) includes identical organometallic compounds represented by Formula 1” and an embodiment in which “(an organic layer) includes two or more different organometallic compounds represented by Formula 1”.

For example, the organic layer may include, as the organometallic compound, only Compound 1. In this regard, Compound 1 may be included only in the emission layer of the organic light-emitting device. In one or more embodiments, the organic layer may include, as the organometallic compound, Compound 1 and Compound 2. In this regard, Compound 1 and Compound 2 may be included in an identical layer (for example, Compound 1 and Compound 2 all may exist in an emission layer).

The first electrode may be an anode, which is a hole injection electrode, and the second electrode may be a cathode, which is an electron injection electrode; or the first electrode may be a cathode, which is an electron injection electrode, and the second electrode may be an anode, which is a hole injection electrode.

For example, the organic light-emitting device, the first electrode is an anode, and the second electrode is a cathode, and the organic layer further includes a hole transport region between the first electrode and the emission layer and an electron transport region between the emission layer and the second electrode, and the hole transport region includes a hole injection layer, a hole transport layer, an electron blocking layer, or any combination thereof, and the electron transport region includes a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.

The term “organic layer” as used herein refers to a single layer and/or a plurality of layers disposed between the first electrode and the second electrode of an organic light-emitting device. The “organic layer” may include, in addition to an organic compound, an organometallic complex including metal.

The FIGURE is a schematic cross-sectional view of an organic light-emitting device10according to an embodiment. Hereinafter, the structure of an organic light-emitting device according to an embodiment and a method of manufacturing an organic light-emitting device according to an embodiment will be described in connection with the FIGURE. The organic light-emitting device10includes a first electrode11, an organic layer15, and a second electrode19, which are sequentially stacked.

A substrate may be additionally disposed under the first electrode11or above the second electrode19. For use as the substrate, any substrate that is used in general organic light-emitting devices may be used, and the substrate may be a glass substrate or a transparent plastic substrate, each having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and water resistance.

The first electrode11may be formed by depositing or sputtering a material for forming the first electrode11on the substrate. The first electrode11may be an anode. The material for forming the first electrode11may be a material with a high work function to facilitate hole injection. The first electrode11may be a reflective electrode, a semi-reflective electrode, or a transmissive electrode. The material for forming the first electrode may be, for example, indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), and zinc oxide (ZnO). In one or more embodiments, the material for forming the first electrode11may be metal, such as magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), or magnesium-silver (Mg—Ag).

The first electrode11may have a single-layered structure or a multi-layered structure including two or more layers. For example, the first electrode11may have a three-layered structure of ITO/Ag/ITO, but the structure of the first electrode11is not limited thereto.

The organic layer15is disposed on the first electrode11.

The hole transport region may be disposed between the first electrode11and the emission layer.

The hole transport region may include a hole injection layer, a hole transport layer, an electron blocking layer, a buffer layer, or any combination thereof.

The hole transport region may include only either a hole injection layer or a hole transport layer. In one or more embodiments, the hole transport region may have a hole injection layer/hole transport layer structure or a hole injection layer/hole transport layer/electron blocking layer structure, which are sequentially stacked in this stated order from the first electrode11.

When the hole transport region includes a hole injection layer, the hole injection layer may be formed on the first electrode11by using one or more suitable methods, for example, vacuum deposition, spin coating, casting, and/or Langmuir-Blodgett (LB) deposition.

When a hole injection layer is formed by vacuum deposition, the deposition conditions may vary according to a material that is used to form the hole injection layer, and the structure and thermal characteristics of the hole injection layer. For example, the deposition conditions may include a deposition temperature of about 100° C. to about 500° C., a vacuum pressure of about 10−8to about 10−3torr, and a deposition rate of about 0 Angstroms per second (Å/sec) to about 100 Å/sec. However, the deposition conditions are not limited thereto, but embodiments of the present disclosure are not limited thereto.

When the hole injection layer is formed using spin coating, coating conditions may vary according to the material used to form the hole injection layer, and the structure and thermal properties of the hole injection layer. For example, a coating speed may be from about 2,000 revolutions per minute (rpm) to about 5,000 rpm, and a temperature at which a heat treatment is performed to remove a solvent after coating may be from about 80° C. to about 200° C. However, the coating conditions are not limited thereto.

Conditions for forming a hole transport layer and an electron blocking layer may be understood by referring to conditions for forming the hole injection layer.

xa and xb in Formula 201 may each independently be an integer from 0 to 5, or may be 0, 1 or 2. For example, xa may be 1 and xb may be 0, but xa and xb are not limited thereto.R101to R108, R111to R119, and R121to R124in Formulae 201 and 202 may each independently be:hydrogen, deuterium, —F, —Cl, —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 C1-C10alkyl group (for example, a methyl group, an ethyl group, a propyl group, a butyl group, pentyl group, a hexyl group, and the like), or a C1-C10alkoxy group (for example, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group, and the like);a C1-C10alkyl group or a C1-C10alkoxy group, each substituted with deuterium, —F, —Cl, —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, or any combination thereof; ora phenyl group, a naphthyl group, an anthracenyl group, a fluorenyl group, or a pyrenyl group, each unsubstituted or substituted with deuterium, —F, —Cl, —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 C1-C10alkyl group, a C1-C10alkoxy group, or any combination thereof,but embodiments of the present disclosure are not limited thereto.

In an embodiment, the compound represented by Formula 201 may be represented by Formula 201A, but embodiments of the present disclosure are not limited thereto:

Detailed descriptions of R101, R111, R112, and R109in Formula 201A are the same as described provided herein.

For example, the compound represented by Formula 201 and the compound represented by Formula 202 may each include one of Compounds HT1 to HT20 or any combination thereof, but embodiments of the present disclosure are not limited thereto:

The hole transport region may include a buffer layer.

Also, the buffer layer may compensate for an optical resonance distance according to a wavelength of light emitted from the emission layer, and thus, efficiency of a formed organic light-emitting device may be improved.

Meanwhile, when the hole transport region includes an electron blocking layer, a material for the electron blocking layer may be materials for the hole transport region described above, materials for a host to be explained later, or any combination thereof. However, the material for the electron blocking layer is not limited thereto. For example, when the hole transport region includes an electron blocking layer, a material for the electron blocking layer may be mCP, which will be explained later.

Then, an emission layer may be formed on the hole transport region by vacuum deposition, spin coating, casting, LB deposition, or the like. When the emission layer is formed by vacuum deposition or spin coating, the deposition or coating conditions may be similar to those applied in forming the hole injection layer although the deposition or coating conditions may vary according to a compound that is used to form the emission layer.

The emission layer may include a host and a dopant, and the dopant may include the organometallic compound represented by Formula 1.

When the organic light-emitting device is a full-color organic light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, and/or a blue emission layer. In one or more embodiments, due to a stacked structure including a red emission layer, a green emission layer, and/or a blue emission layer, the emission layer may emit white light.

When the emission layer includes a host and a dopant, an amount of the dopant may be in a range of about 0.01 parts by weight to about 15 parts by weight based on 100 parts by weight of the host, but embodiments of the present disclosure are not limited thereto.

A thickness of the emission layer may be in a range of about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. While not wishing to be bound by theory, it is understood that when the thickness of the emission layer is within this range, excellent light-emission characteristics may be obtained without a substantial increase in driving voltage.

Then, an electron transport region may be disposed on the emission layer.

The electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.

For example, the electron transport region may have a hole blocking layer/electron transport layer/electron injection layer structure or an electron transport layer/electron injection layer structure, but the structure of the electron transport region is not limited thereto. The electron transport layer may have a single-layered structure or a multi-layered structure including two or more different materials.

Conditions for forming the hole blocking layer, the electron transport layer, and the electron injection layer which constitute the electron transport region may be understood by referring to the conditions for forming the hole injection layer.

When the electron transport region includes a hole blocking layer, the hole blocking layer may include, for example, BCP, BPhen, BAlq, or any combination thereof, but embodiments of the present disclosure are not limited thereto:

A thickness of the hole blocking layer may be from about 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å. While not wishing to be bound by theory, it is understood that when the thickness of the hole blocking layer is within these ranges, the hole blocking layer may have excellent hole blocking characteristics without a substantial increase in driving voltage.

The electron transport layer may include BOP, BPhen, Alq3, BAlq, TAZ, NTAZ, or any combination thereof:

In one or more embodiments, the electron transport layer may include at least one of ET1 to ET25, but are not limited thereto:

A thickness of the electron transport layer may be from about 100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. While not wishing to be bound by theory, it is understood that when the thickness of the electron transport layer is within the range described above, the electron transport layer may have satisfactory electron transport characteristics without a substantial increase in driving voltage.

The metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (LiQ), Compound ET-D2, or combination thereof:

The electron transport region may include an electron injection layer that promotes flow of electrons from the second electrode19thereinto.

The electron injection layer may include LiF, NaCl, CsF, Li2O, BaO, or any combination thereof.

A thickness of the electron injection layer may be from about 1 Å to about 100 Å, for example, about 3 Å to about 90 Å. While not wishing to be bound by theory, it is understood that when a thickness of the electron injection layer is within these ranges, satisfactory electron injection characteristics may be obtained without substantial increase in driving voltage.

The second electrode19is disposed on the organic layer15. The second electrode19may be a cathode. A material for forming the second electrode19may be a metal, an alloy, an electrically conductive compound, or a combination thereof, which have a relatively low work function. For example, lithium (Li), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), or magnesium-silver (Mg—Ag) may be formed as the material for forming the second electrode19. To manufacture a top-emission type light-emitting device, a transmissive electrode formed using ITO or IZO may be used as the second electrode19.

Hereinbefore, the organic light-emitting device according to an embodiment has been described in connection with the FIGURE.

Another aspect of the present disclosure provides a diagnostic composition including at least one of the organometallic compound represented by Formula 1.

The organometallic compound represented by Formula 1 provides high luminescent efficiency. Accordingly, a diagnostic composition including the organometallic compound may have high diagnostic efficiency.

The diagnostic composition may be used in various applications including a diagnosis kit, a diagnosis reagent, a biosensor, and a biomarker.

The term “C3-C10cycloalkenyl group” as used herein refers to a monovalent monocyclic group that has 3 to 10 carbon atom, at least one carbon-carbon double bond in its ring, and no aromaticity, and a non-limiting example thereof includes a cycloheptenyl group. The term “C3-C10cycloalkenylene group” as used herein refers to a divalent group having the same structure as the C3-C10cycloalkenyl group.

The term “C6-C60aryloxy group” as used herein indicates —OA102(wherein A102is the C6-C60aryl group), the term “C6-C60arylthio group” as used herein indicates —SA103(wherein A103is the C6-C60aryl group), and the term “C7-C60arylalkyl group” as used herein indicates -A104A105(wherein A105is the C6-C59aryl group and A104is the C1-C53alkylene group).

The term “C1-C60heteroaryloxy group” as used herein refers to —OA106(wherein A106is the C2-C60heteroaryl group), the term “C1-C60heteroarylthio group” as used herein indicates —SA107(wherein A107is the C1-C60heteroaryl group), and the term “C2-C60heteroarylalkyl group” as used herein refers to -A108A109(A109is a C1-C59heteroaryl group, and A108is a C1-C59alkylene group).

The term “monovalent non-aromatic condensed polycyclic group” as used herein refers to a monovalent group (for example, having 8 to 60 carbon atoms) having two or more rings condensed to each other, only carbon atoms as ring-forming atoms, and no aromaticity in its entire molecular structure. A non-limiting example of the monovalent non-aromatic condensed polycyclic group includes a fluorenyl group. The term “divalent non-aromatic condensed polycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein refers to a monovalent group (for example, having 2 to 60 carbon atoms) having two or more rings condensed to each other, a heteroatom selected from N, O, P, Si, and S, other than carbon atoms, as a ring-forming atom, and no aromaticity in its entire molecular structure. A non-limiting example of the monovalent non-aromatic condensed heteropolycyclic group includes a carbazolyl group. The term “divalent non-aromatic condensed heteropolycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed heteropolycyclic group.

The term “C5-C60carbocyclic group” as used herein refers to a saturated or unsaturated cyclic group having, as a ring-forming atom, 5 to 60 carbon atoms only. The C5-C60carbocyclic group may be a monocyclic group or a polycyclic group.

The term “C1-C60heterocyclic group” as used herein refers to a saturated or unsaturated cyclic group having, as a ring-forming atom, at least one heteroatom selected from N, O, Si, P, and S other than 1 to 60 carbon atoms. The C1-C60heterocyclic group may be a monocyclic group or a polycyclic group.

In the present specification, Q1to Q9, Q11to Q19, Q21to Q29, and Q31to Q39may each independently be hydrogen; deuterium; —F; —Cl; —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 C1-C60alkyl group; a C2-C60alkenyl group; a C2-C69alkynyl group; a C1-C60alkoxy group; a C3-C10cycloalkyl group; a C1-C10heterocycloalkyl group; a C3-C10cycloalkenyl group; a C1-C10heterocycloalkenyl group; a C6-C69aryl group; a C6-C69aryl group substituted with a C1-C60alkyl group, a C6-C69aryl group, or any combination thereof; a C6-C69aryloxy group; a C6-C69arylthio group; a C7-C69arylalkyl group; a C1-C60heteroaryl group; a C1-C60heteroaryloxy group; a C1-C60heteroarylthio group; a C2-C60heteroarylalkyl group; a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group.

Hereinafter, a compound and an organic light-emitting device according to embodiments are described in detail with reference to Synthesis Example and Examples. However, the organic light-emitting device is not limited thereto. The wording “B was used instead of A” used in describing Synthesis Examples means that an amount of A used was identical to an amount of B used, in terms of a molar equivalent.

EXAMPLES

Synthesis Example 1: Synthesis of Compound 2

Synthesis of Intermediate 2-L1

1-bromo-6-(sec-butyl)isoquinoline (5.48 grams (g), 20.76 millimoles, mmol), (3,5-dimethylphenyl)boronic acid (4.67 g, 31.14 mmol), Pd(PPh3)4(1.92 g, 1.66 mmol), and K2CO3(7.17 g, 51.90 mmol), tetrahydrofuran (THF) (60 milliliters, mL), and distilled water (30 mL) were mixed together, and the mixed solution was stirred under reflux for 18 hours. Then, the reaction temperature was lowered to room temperature, and the reaction mixture was extracted by using methylene chloride (MC). The organic layer was dried by using anhydrous magnesium sulfate (MgSO4) to remove moisture, and filtered. The filtrate was decompressed, and the residue was purified by using column chromatography under conditions of EA:Hexane=1:10, thereby obtaining 5.60 g (93%) of Intermediate 2-L1.

Synthesis of Intermediate 2-L2

Intermediate 2-L1 (5.58 g, 19.3 mmol), iridium chloride (3.02 g, 8.58 mmol), ethoxyethanol (45 mL), and distilled water (15 mL) were mixed together, and the mixed solution was stirred under reflux for 24 hours. The reaction temperature was lowered to room temperature, and a solid produced therefrom was separated by filtration. A filtrate was thoroughly washed by using water/methanol/hexane in the stated order, and a solid obtained therefrom was dried in a vacuum oven, thereby obtaining 3.9 g (57%) of Intermediate 2-L2.

Synthesis of Compound 2

Synthesis Example 2: Synthesis of Compound 1

Compound 1 (74%) was obtained in the same manner as in the synthesis of Compound 2 of Synthesis Example 1, except that 2,2,6,6-tetramethylheptane-3,5-dione (9.69 mmol) was used instead of 3,3,7,7-tetramethylnonane-4,6-dione.

Synthesis Example 3: Synthesis of Compound 3

Compound 3 (74%) was obtained in the same manner as in the synthesis of Compound 2 of Synthesis Example 1, except that 3,7-diethyl-3,7-dimethylnonane-4,6-dione (9.69 mmol) was used instead of 3,3,7,7-tetramethylnonane-4,6-dione.

Evaluation Example 1: Evaluation of HOMO and LUMO Energy Levels

According to the methods shown in Table 2, HOMO and LUMO energy levels of Compounds 1 to 3 were evaluated. The results are shown in Table 3.

TABLE 2HOMO energyCyclic voltammetry (CV) (electrolyte: 0.1M Bu4NClO4/solvent: CH2Cl2/level evaluationelectrode: 3-electrode system (working electrode: GC, referencemethodelectrode: Ag/AgCl, auxiliary electrode: Pt)) was used to obtain avoltage (V)-current (A) graph for each compound. Then, a HOMOenergy level of each compound was calculated from a reduction onsetof the graph.LUMO energyEach compound was diluted in CHCl3at a concentration of 1 × 10−5M,level evaluationand a Shimadzu UV-350 spectrometer was used to measure UBmethodabsorption spectra at room temperature. Then, a LUMO energy levelwas calculated by using an optical band gap (Eg) from the edge of theUV absorption spectrum.

Referring to Table 3, it was confirmed that Compounds 1 to 3 had suitable electrical characteristics for use as materials for organic light-emitting devices.

Evaluation Example 2: Evaluation of Photoluminescence Quantum Yield (PLQY)

PMMA solution in CH2Cl2was mixed with 5 percent by weight (weight %) of a mixture including CBP and Compound 2 (wherein an amount of Compound 2 was 10 parts by weight of 100 parts by weight of the mixture). The resulting product was spin-coated on a quartz substrate, and the substrate was heat-treated in an oven at a temperature of 80° C., and then, cooled to room temperature, thereby preparing a film.

A PLQY in film of Compound 2 was evaluated by using a Hamamatsu Photonics absolute PL quantum yield measurement system using a xenon light source, equipped with a monochromator, a photonic multichannel analyzer, and an integrating sphere, and utilizing a PLQY measurement software (Hamamatsu Photonics, Ltd., Shizuoka, Japan). The same process was repeated with respect to Compounds 1, 3, and C, and the results are shown in Table 4.

Referring to Table 4, it was confirmed that Compounds 1 to 3 each had a greater PLQY in film than Compound C.

Evaluation Example 3: Measurement of Decay Time

A quarts substrate washed with chloroform and pure water was prepared first, and predetermined materials shown in Table 5 were vacuum-(co)-deposited on the quarts substrate at a vacuum degree of 10−7torr, thereby preparing Films 1 to 3, each having a thickness of 50 nm.

Subsequently, a PL spectrum of Film 1 prepared as described above was evaluated at room temperature by using FluoTime 300 which is a TRPL measurement system manufactured by PicoQuant Company and a PLS340 (excitation wavelength=340 nm, spectral width=20 nm) which is a pumping source manufactured by PicoQuant Company. Then, a wavelength of the main peak of the spectrum was determined, and the number of photons emitted at the wavelength of the main film upon a photon pulse (pulse width=500 picoseconds) applied on each film by the PLS340 was measured based on the Time-Correlated Single Photon Counting (TCSPC). This measurement was repeated to obtain a TRPL curve with sufficient fitting. Two or more exponential decay functions were fitted to the obtained results to obtain Tdecay(Ex), i.e., decay time, of Film 1, and the results are shown in Table 6. The functions used for the fitting is shown in Equation 1 below, and the greatest value among Tdecayvalues obtained from each exponential decay function used in the fitting was indicates as Tdecay(Ex). Here, during the measurement time equal to the measurement time used to obtain the TRPL curve, the same measurement was repeated one more time in a dark state (i.e., a state where a pumping signal incident on the predetermined film was blocked) to obtain a baseline curve or a background signal curve to be used as a baseline for the fitting. The same process was repeated for Films 2 and 3, and the results are shown in Table 6.

Referring to Table 6, it was confirmed that Compounds 1 to 3 each had excellent decay time.

As an anode, a glass substrate on which ITO/Ag/ITO was formed to a thickness of 70 Å/1,000 Å/70 Å was cut to a size of 50 mm×50 mm×0.5 mm, sonicated with isopropyl alcohol and pure water each for 5 minutes, and then, cleaned by exposure to ultraviolet rays and ozone for 30 minutes. Then, the anode was provided to a vacuum deposition apparatus.

2-TNATA was vacuum-deposited on the anode to form a hole injection layer having a thickness of 600 Å, and 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (hereinafter, referred to as NPB) was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 1,350 Å.

Next, CBP (as a host) and Compound 1 (as a dopant) were co-deposited at a weight ratio of 98:2 on the hole transport layer to form an emission layer having a thickness of 400 Å.

Then, BCP was vacuum-deposited on the emission layer to form a hole blocking layer having a thickness of 50 Å, and Alq3was vacuum-deposited on the hole blocking layer to form an electron transport layer having a thickness of 350 Å. LiF was vacuum-deposited on the electron transport layer to form an electron injection layer having a thickness of 10 Å, and Mg and Ag were co-deposited at a weight ratio of 90:10 on the electron injection layer to form a cathode having a thickness of 120 Å, thereby completing the manufacture of an organic light-emitting device:

Examples 2 and 3 and Comparative Examples A to C

Organic light-emitting devices were manufactured in the same manner as in Example 1, except that compounds listed in Table 7 below were each used as a dopant instead of Compound 1 in forming an emission layer.

Evaluation Example 4: Evaluation of Characteristics of Organic Light-Emitting Device

The driving voltage, current density, maximum external quantum efficiency (Max EQE), roll-off ratio, emission peak wavelength of EL spectrum, FWHM of EL spectrum, emission color, color coordinates (CIEx), and/or lifespan (T97) of the organic light-emitting devices manufactured according to Examples 1 to 3 and Comparative Examples A to C were evaluated, and the results are shown in Table 7. Here, as a device used for the evaluation, a current-voltage meter (Keithley 2400) and a luminance meter (Minolta Cs-1000A) were used. The lifespan (T97) (at 3,500 nit) was obtained by evaluating time (hours, hr) that lapsed when luminance was 97% of initial luminance (100%). The roll-off ratio was calculated according to Equation 20 below:
Roll off ratio={1−(efficiency (at 3,500 nit)/maximum luminance efficiency)}×100%  Equation 20

Referring to Table 7, it was confirmed that the organic light-emitting devices manufactured according to Examples 1 to 3 emitted red light having excellent color purity, and also had an improved driving voltage, an improved external quantum efficiency, an improved roll-off ratio, and an improved lifespan, as compared with the organic light-emitting devices manufactured according to Comparative Examples A to C.

According to the one or more embodiments, the organometallic compound has excellent electric characteristics and stability, and thus, an electronic device, for example, an organic light-emitting device, including the organometallic compound may have a low driving voltage, good external quantum efficiency, a low roll-off ratio, and a long lifespan. In addition, since the organometallic compound has excellent phosphorescence characteristics, a diagnostic composition including the organometallic compound may be provided with a high diagnosis efficiency.