KR20080081209A - Fluorinated phenylpyridine compounds - Google Patents

Abstract

The present invention is generally directed to electroluminescent Ir(III) compounds, the substituted 2-phenylpyridines, phenylpyrimidines, and phenylquinolines that are used to make the Ir(III) compounds, and devices that are made with the Ir(III) compounds.

Description

Fluorinated Phenylpyridine Compound {FLUORINATED PHENYLPYRIDINE COMPOUNDS}

Related Applications

This application claims the priority of US Provisional Application No. 60 / 215,362, filed on June 30, 2000 and US Provisional Application No. 60 / 224,273, filed on August 10, 2000, on June 12, 2001. US Patent Application No. 09 / 879,014 filed in US Pat.

Field of invention

The present invention relates to fluorinated phenylpyridine, phenylpyrimidine and electroluminescent complexes of phenylquinoline and iridium (III). The invention also relates to an electrical device in which the active layer comprises an electroluminescent Ir (III) complex.

Description of related technology

BACKGROUND OF THE INVENTION Organic electrical devices that emit light, such as light emitting diodes that make up displays, exist in many different kinds of electrical appliances. In all such devices, the organic active layer is sandwiched between two electrical contact layers. At least one of the electrical contact layers is light transmissive so that light can pass through the electrical contact layer. The organic active layer emits light through the light transmissive electrical contact layer when applying electricity across the electrical contact layer.

It is well known to use organic electroluminescent compounds as active components in light emitting diodes. Simple organic molecules such as anthracene, thiadiazole derivatives, and coumarin derivatives are known to exhibit electroluminescence. Semiconductor conjugated polymers are also described, for example, in US Pat. No. 5,247,190 to Friend et al., US Pat. No. 5,408,109 to Heeger et al., And European Patent Application No. 443 861 to Nakano et al. Used as luminescent component. Complexes of trivalent metal ions, especially aluminum and 8-hydroxyquinolate, have been used extensively as electroluminescent components, for example as disclosed in US Pat. No. 5,552,678 to Tang et al.

Burrows and Thompson reported that fac-tris (2-phenylpyridine) iridium can be used as an active ingredient in organic light emitting devices (Appl. Phys. Lett. 1999, 75, 4). Performance is maximized when the iridium compound is present as a host conductive material. Thompson also for the active layer is fac- tris [2- (4 ', 5'-difluorophenyl) pyridine -C' ^2, N] iridium (III) a poly (N- vinylcarbazole) doped with a device Reported (Polymer Preprints 2000, 41 (1), 770).

However, there is still a need for electroluminescent compounds with improved efficiency.

It is an object of the present invention to provide an electroluminescent compound with improved efficiency.

Summary of the Invention

The present invention relates to iridium compounds (generally called "Ir (III) compounds") having at least two 2-phenylpyridine ligands and having at least one fluorine or fluorinated group on the ligand. Iridium compounds have the general formula

IrL ^a L ^b L ^c _x L ' _y L " _z

Where

x = 0 or 1, y = 0, 1 or 2, z = 0 or 1,

With x = 0 or y + z = 0

if y = 2 then z = 0;

L 'is a bidentate ligand or a monodentate ligand and is not phenylpyridine, phenylpyrimidine or phenylquinoline,

Provided that when L 'is a monodentate ligand, y + z = 2,

If L ′ is a bidentate ligand, z = 0;

L ″ is a monodentate ligand and is not phenylpyridine and phenylpyrimidine or phenylquinoline;

L ^a , L ^b and L ^c are the same as or different from each other and each L ^a , L ^b and L ^c has the structure of Formula I:

<Formula I>

Where

Adjacent pairs of R ₁ to R ₄ and R ₅ to R ₈ may be joined to form a 5- or 6-membered ring,

At least one of R ₁ to R ₈ is selected from F, C _n F _{2n +1} , OC _n F _{2n +1} , and OCF ₂ X, wherein n is an integer from 1 to 6 and X is H, Cl or Br ,

A is C or N, provided there is no R ₁ if A is N.

In another embodiment, the present invention relates to substituted 2-phenylpyridine, phenylpyrimidine and phenylquinoline precursor compounds from which the Ir (III) compounds are prepared. The precursor compound has the structure of Formula II or III:

<Formula II>

Wherein A and R ₁ to R ₈ are as defined in formula (I) above and R ₉ is H.

<Formula III>

Where

_At least one of R ₁₀ to R ₁₉ is selected from F, C _n F _{2n +1} , OC _n F _{2n +1} , and OCF ₂ X, n is an integer from 1 to 6, X is H, Cl or Br R ₂₀ is H.

It is understood that there is a free rotation with respect to phenyl-pyridine, phenyl-pyrimidine and phenyl-quinoline bonds. However, when discussed herein, a compound will be described with respect to one orientation.

In another embodiment, the invention is directed to an organic electrical device having one or more emissive layers comprising the Ir (III) compound or a combination of Ir (III) compounds.

As used herein, the term "compound" is intended to mean an electrically uncharged material consisting of molecules of atoms, wherein the atoms are inseparable by physical means. The term "ligand" is intended to mean a molecule, ion or atom attached to the coordination zone of metal ions. The term "complex" is intended to mean a compound having at least one metal ion and at least one ligand when used as a noun. The term "group" is intended to mean part of a compound, such as a substituent in an organic compound or a ligand in a complex. The term "face isomer" is intended to mean an isomer having complex octahedral geometry, in which all three "a" groups in Ma ₃ b ₃ are adjacent, ie located at the corners of one side of the octahedron. The term "meridian isomer" is intended to mean an isomer having three octahedral geometries, three "a" groups occupying three positions such that the two "a" groups are trans to each other in Ma ₃ b ₃ . The term "adjacent" when used to refer to a layer in a device does not necessarily mean that one layer is located immediately after the other. On the other hand, the phrase “adjacent R groups” is used in the formula to refer to R groups next to each other (ie, R groups on atoms linked by bonds). The term "photoactive" refers to a material that exhibits electroluminescence and / or photosensitivity. The term "(H + F)" is intended to mean all combinations of hydrogen and fluorine, including fully hydrogenated, partially fluorinated or perfluorinated substituents. "Emission maximum" means the wavelength in nanometers at which maximum intensity electroluminescence is obtained. Electroluminescence is generally measured in diode structures in which the material to be tested is sandwiched between two electrical contact layers and voltage is applied. Light intensity and wavelength can be measured, for example, by photodiode and spectrogram, respectively.

The Ir (III) compound of the present invention has a structure of Ir (III) L ^a L ^b L ^c _x L ′ _y L ″ _z of Chemical Formula 1.

The Ir (III) compounds are often referred to as ring metallization complexes: Ir (III) compounds having the formula (2) are also often referred to as bis-cyclic metallization complexes:

IrL ^a L ^b L ' _y L " _z

In the above formula, y, z, L ^a , L ^b , L 'and L "are the same as defined in Chemical Formula 1.

Ir (III) compounds having the general formula (3) are also often referred to as tris-ring metallized complexes:

IrL ^a L ^b L ^c

In the above formula, L ^a , L ^b And L ^c is as defined in Formula 1 above.

Preferred ring metallized complexes are neutral and non-ionic and can be sublimed as such. Thin films of this material obtained through vacuum deposition show good to good electroluminescent properties. Introduction of fluorine substituents to the ligand on the iridium atom increases both the stability and the volatility of the complex. As a result, vacuum deposition can be performed at low temperatures and the decomposition of the complex can be avoided. Incorporation of fluorine substituents into ligands often reduces the rate of non-radiative decay and self quenching in the solid state. By this reduction, the luminous efficiency can be enhanced. Modification of substituents with electron-gathering and electron-gripping properties allows fine tuning of the electroluminescent properties of the compounds, thereby enabling optimization of brightness and efficiency in electroluminescent devices.

While not wishing to be bound by theory, the release from the iridium compound is believed to be based on the ligand, due to charge transport from the metal to the ligand. Thus, the compounds capable of exhibiting electroluminescence are IrL ^a L ^b L ' _y L " _z of Formula 2, and Formula 3 IrL ^a L ^b L ^c In Formula 3, L ^a , L ^b, and L ^c all include phenylpyridine, phenylpyrimidine, or phenylquinoline. R ₁ to R ₈ groups of formula (I) and (II), and R ₁₀ to R ₁₉ of formula (III) are conventional substituents for organic compounds, such as alkyl, alkoxy, halogen, nitro and cyano groups, as well as fluoro, Fluorinated alkyl, fluorinated alkoxy groups. These groups may be partially or fully fluorinated (perfluorinated). Preferred iridium compounds are those in which all of the R ₁ to R ₈ and R ₁₀ to R ₁₉ substituents are fluoro, perfluorinated alkyl (C _n F _{2n + 1} ) and perfluorinated alkoxy groups (OC _n F _{2n +1} ) (and Fluorinated alkyl and alkoxy groups have 1 to 6 carbon atoms) or a group of formula OCF ₂ X, wherein X is H, Cl or Br.

The electroluminescent properties of the ring metallized iridium complexes are worse when at least one of the R ₁ to R ₈ and R ₁₀ to R ₁₉ groups is a nitro group. Therefore, it is preferable that none of the R ₁ to R ₈ and R ₁₀ to R ₁₉ groups are nitro groups.

It has been found that the luminous efficiency of cyclic metallized iridium complexes can be improved by using phenylpyridine, phenylpyrimidine, and phenylquinoline ligands in which all or part of hydrogen is substituted with deuterium.

The nitrogen-containing ring can be a pyridine ring, pyrimidine or quinoline. It is preferred that at least one fluorinated substituent is on the nitrogen containing ring, most preferably CF ₃ .

L 'and L "ligands are suitable conventional ligands known in transition metal coordination chemistry. Examples of bidentate ligands include compounds having two coordination groups, such as ethylenediamine and acetylacetonate which may be substituted. Examples of anionic bidentate ligands include, but are not limited to, beta-enolates, for example acetylacetonates; anionic forms of hydroxyquinolines, such as 8-hydroxyquinoline, which may be substituted (H is extracted from the hydroxy group); aminocarboxyl Rates; iminocarboxylates such as pyridine carboxylate; salicylates; salicylidinines such as 2-[(phenylimino) methyl] phenol; and phosphinoalkoxides such as 3 -(Diphenylphosphino) -1-propoxide Examples of monodentate ligands include chlorine and nitrate ions; phosphine; isonitrile; carbon monoxide; and mono-amines. It is preferable to be sine and sublimable If one bidentate ligand is used, the net charge must be minus 1 (-1) If two bidentate ligands are used, they must have a net charge of −1 in total. The complex may be useful for preparing tris-ring metallized complexes that do not all have the same ligand.

In a preferred embodiment, the iridium compound has IrL ^a L ^b L ^c of Formula 3 above.

In a more preferred embodiment, L ^a = L ^b = L ^c . This more preferred compound often exhibits planar isomers in which nitrogen atoms coordinated in iridium are trans with respect to carbon atoms coordinated in iridium as measured by single crystal X-ray diffraction. This more preferred compound has the formula

fac-Ir (L ^a ) ₃

Wherein L ^a has the structure of formula (I).

 The compound may exhibit a meridian geometry in which two nitrogen atoms coordinated in iridium are trans from each other. This compound has the formula

mer-Ir (L ^a ) ₃

Wherein L ^a has the structure of formula (I).

Examples of compounds of Formula 4 and Formula 5 are shown in Table 1 below:

TABLE 1

Examples of the compound of IrL ^a L ^b L ' _y L " _z of Formula 2 include compounds 1-n, 1-o, 1-p, 1- having the structures of Formulas IV, V, VI, IX, and X, respectively: w and 1-x.

<Formula IV>

<Formula V>

<Formula VI>

<Formula IX>

<Formula X>

The iridium complex IrL ^a L ^b L ^c of Formula 3 is generally prepared from suitable substituted 2-phenylpyridine, phenylpyrimidine or phenylquinoline. Substituted 2-phenylpyridine, phenylpyrimidine and phenylquinoline of formula II are described in O. Using Suzuki coupling of 2-chloropyridine, 2-chloropyrimidine or 2-chloroquinoline substituted with arylboronic acid as described by Lohse, P. Thevenin, E. Waldvogel Synlett , 1999, 45-48. It is produced in good to excellent yield. This reaction is described in Scheme 1 below for pyridine derivatives (X and Y represent substituents):

Examples of 2-phenylpyridine and 2-phenylpyrimidine compounds of Formula II are shown in Table 2 below:

TABLE 2

One example of a substituted 2-phenylquinoline compound having Formula (III) is a compound of Formula 2-u wherein R ₁₇ is CF ₃ and R ₁₀ to R ₁₆ and R ₁₈ to R ₂₀ are H.

Thus, 2-phenylpyridine, pyrimidine and quinoline are used in the synthesis of cyclometalated iridium complexes. A simple one step method was developed using commercially available iridium hydrate and silver trifluoroacetate. The reaction is generally carried out in the presence of 3 equivalents of AgOCOCF ₃ without solvent using excess 2-phenylpyridine, pyrimidine, or quinoline. This reaction is illustrated for 2-phenylpyridine of Scheme (2) below.

Tris-cyclometalated iridium complexes are isolated, purified and also subjected to elemental analysis, ¹ H and ¹⁹ F NMR spectral data, and for compounds of 1-b , 1-c and 1-e , single crystal X-ray diffraction Is fully characterized. In certain cases, mixtures of isomers are obtained. Often mixtures can be used without isolating individual isomers.

The iridium complex of formula (2) of IrL ^a L ^b L'yL "z may be isolated from the reaction mixture using the same synthetic method as the method for preparing the compounds of formula (3) of IrL ^a L ^b L ^c if certain. The complex may also be prepared by first preparing an intermediate iridium dimer of formula (VII):

<Formula VII>

[In the formula,

B = H, CH ₃ , or C ₂ H ₅ ,

L ^a , L ^b , L ^c , and L ^d may be the same as or different from each other, and each of L ^a , L ^b , L ^c , and L ^d has the structure of (I) above]

Iridium dimers can generally be prepared by first reacting iridium trichloride hydrate with 2-phenylpyridine, phenylpyrimidine or phenylquinoline and adding NaOB.

One particularly useful iridium dimer is the hydroxyl iridium dimer of formula (VIII):

<Formula VIII>

This intermediate may be used to prepare 1-p compound by the addition of ethyl acetoacetate.

Of particular importance are complexes having a maximum emission in the visible spectrum at 570-625 nm for red-orange and 625-700 nm for red. Formula 2 and 3 when L has the structure of formula (XI) derived from the phenylquinoline compound of formula (III) above, or L has the structure of formula (XII) which is derived from phenyl-isoquinoline compound It has been found that the maximum release of the complex of shifts to red:

<Formula XI>

[In the formula,

At least one R _1O to R ₁₉ is selected from F, C _n F _{2n + l} , OC _n F _{2n +1} , and OCF ₂ X, wherein n is an integer from 1 to 6 and X is H, Cl, or Br]

<Formula XII>

[In the formula,

At least one R ₂₁ to R ₃₀ is selected from F, C _n F _{2n + l} , OC _n F _{2n +1} , and OCF ₂ X, wherein n is an integer from 1 to 6 and X is H, Cl, or Br]

The ligands of the present invention may also have perfluoroalkyl and perfluoroalkoxy substituents of up to 12 carbon atoms.

In formula (2), the L 'and L "ligands in the complex may be selected from any of those listed above, and are preferably selected such that the entire molecule does not change. Preferably, z is O and L' is It is a bidentate monoanionic ligand, which is not phenylpyridine, phenylpyrimidine, or phenylquinoline.

Although not preferred, the complex of formula (2) also has a maximum release shifting to red when L is a phenylpyridine ligand of the structure of formula (I) and L 'is a bidentate hydroxy hydroxyquinoline ligand.

Examples of compounds of Formula 2 wherein L ^a is the same as L ^b , L 'is a bidentate ligand, y is 1 and z is 0, and a compound of Formula 3 wherein L ^a , L ^b , and L ^c are the same Presented in 8. When L is the structure of formula (I), A is C. In this table, "acac" represents 2,4-pentanedionate; "8hq" refers to 8-hydroxyquinolinate; "Me-8hq" refers to 2-methyl-8-hydroxyquinolinate.

TABLE 8

The complexes of Table 8 have a maximum emission in the range of about 590 to 650 nm.

Of particular importance is a complex having a maximum emission in the blue region of the visible light spectrum of about 450-500 nm. It has been found that the photoluminescence and electroluminescence of the complex shifts to blue when L ^a and L ^b are phenyl-pyridine ligands and the compound of formula (2) having an additional ligand selected from phosphine, isonitrile and carbon monoxide is a complex. Suitable complexes have the formula

IrL ^a L ^b L'L "

[In the formula,

L 'is selected from phosphine, isonitrile and carbon monoxide;

L ″ is selected from F, Cl, Br, and I;

L ^a and L ^b are the same or different and each L ^a and L ^b has the structure of formula (I) wherein R ₁ to R ₈ are independently alkyl, alkoxy, halogen, nitro, cyano, fluorine Is selected from fluorinated alkyl and fluorinated alkoxy groups, at least one R ₁ to R ₈ is selected from F, C _n F _{2n +1} , OC _n F _{2n + l} and OCF ₂ X, wherein n Is an integer of 1 to 6, X is H, Cl, or Br,

A is C]

The phosphine ligands in formula 6 preferably have the following formula 7:

P (Ar) ₃

[In the formula,

Ar is an aromatic group, preferably a phenyl group, which may have an alkyl or aryl substituent. Most preferably, the Ar group is a phenyl group having at least one fluorine or fluorinated alkyl substituent. Suitable phosphine ligands include compounds triphenylphosphine [PPh3] and tris [3,5-bis (trifluoromethyl) phenyl] phosphine [PtmPh3] (abbreviations in parentheses).

Some phosphine compounds are commercially available or can be prepared by any of a number of known synthetic methods, such as alkylation or arylation methods using organolithium or organomagnesium compounds of PCl ₃ or other P-electrophiles. Can be.

The isonitrile ligand of formula 6 preferably has an isonitrile substituent on the aromatic group. Suitable isonitrile ligands include 2, 6-dimethylphenyl isocyanide [NC-1], 3-trifluoromethylphenyl isocyanide [NC-2], and 4-toluenesulfonylmethyl isocyanide [NC-3] (In parentheses is an abbreviation).

Some isonitrile compounds are commercially available. They can also be prepared using known methods such as the Hoffmann reaction in which dichlorocarbene is produced from chloroform and base in the presence of primary amines.

Preferably L ″ in the formula 6 is chlorine. Preferably L ^a is the same as L ^b .

Examples of compounds of Formula 6 wherein L ^a is the same as L ^b and L ″ is chlorine are provided in Table 9, wherein R ₁ to R ₈ are as shown in the above formula (I) structure.

TABLE 9

NC-1 is 2,6- (CH ₃ ) ₂ C ₆ H ₃ NC;

NC-2 is 3-CF ₃ C ₆ H ₄ NC;

NC-3 is 4-CH ₃ C ₆ H ₄ S0 ₂ CH ₂ NC;

PPh ₃ is P (C ₆ H ₅ ) ₃

PtmPh ₃ is (Ar _f ) ₃ P, wherein Ar _f = 3,5- (CF ₃ ) ₂ C ₆ H ₃ ;

The complexes of Table 9 have a maximum emission in the range of about 450-550 nm.

Electronic device

The invention also relates to an electronic device comprising at least one photoactive layer positioned between two or more electrical contact layers, wherein at least one layer of the device comprises an iridium complex of the invention. Devices often have additional hole transport layers and electron transport layers. A typical structure is shown in FIG. The device 100 has an anode layer 110 and a cathode layer 150. Adjacent to the anode layer is a layer 120 comprising a hole transport material. Adjacent to the cathode layer is a layer 140 comprising an electron transport material. There is a photoactive layer 130 between the hole transport layer and the electron transport layer. Layers 120, 130, and 140 are individually and collectively referred to as active layers.

Depending on the application of the device 100, the photoactive layer 130 may be a light-emitting layer that may be activated by an applied voltage (eg, a light-emitting diode or a light-emitting electrochemical cell), and the material layer may be It responds to radiation energy and emits a signal with or without an applied bias voltage (eg, a photodetector). Examples of photodetectors include photoconductive cells, photoresistors, optical switches, phototransistors and phototubes and photovoltaic cells, and these terms are described in Markus, John, Electronics and Nucleonics Dictionary, 470 and 476 (McGraw-Hill, Inc. 1966). )].

Iridium compounds of the present invention are particularly useful as photoactive materials in layer 130 or electron transport materials in layer 140. Preferably, the iridium complex of the present invention is used as a light-emitting material in a diode. In these applications, the fluorinated compounds of the present invention need not be present in the solid matrix diluent to be effective. Layers having an iridium compound of more than 20% and 100% by weight based on the total weight of the layer may be used as the emissive layer. This is in contrast to tris (2-phenylpyridine) iridium of formula (III) which is an unfluorinated iridium compound found to achieve maximum efficiency when only 6 to 8% by weight in the emissive layer is present. This was necessary to reduce the self-quenching effect. Additional materials may be present in the emissive layer with the iridium compound. For example, fluorescent dyes may be present to change the emission color. Diluents may also be added. Diluents can be polymeric materials such as poly (N-vinyl carbazole) and polysilane. It may also be a small molecule, such as 4,4'-N, N'-dicarbazole biphenyl or tertiary aromatic amine. If diluents are used, the iridium compound is generally present in small amounts, generally less than 20% by weight, preferably less than 10% by weight, based on the total weight of the layer.

In certain cases, iridium complexes may be present in one or more isomeric forms, or mixtures of different complexes may be present. In the discussion of OLEDs above, it will be understood that the term "iridium compound" is intended to include mixtures of compounds and / or isomers.

To achieve high efficiency LEDs, the HOMO (maximum occupied molecular orbital) of the hole transporting material must be adjusted with the work function of the anode, and the LUMO (minimum unoccupied molecular orbital) of the electron transporting material must be adjusted with the work function of the cathode. do. In addition, the chemical compatibility and the sublimation temperature of the materials are considered important in the selection of electron and hole transport materials.

Other layers of the OLED can be made of any material known to be useful as such layers. The anode 110 is an electrode that is particularly effective for injecting positive charge carriers. It may for example be made of a material containing a metal, a mixed metal, an alloy, a metal oxide or a mixed-metal oxide, or it may be a conductive polymer. Suitable metals include metals of Group 11, metals of Groups 4, 5 and 6 and transition metals of Groups 8-10. If the anode should be light-transmissive, mixed-metal oxides of group 12, 13 and 14 metals, for example iridium-tin-oxides, are generally used. The IUPAC nomenclature was used throughout, where the families of the periodic table are numbered from 1 to 18 from left to right (CRC Habdbook of Chemistry and Physics, 81 ^st Edition, 2000). In addition, the anode 110 is described in "Flexible light-emitting Diodes made from soluble conducting polymer," Nature vol. 357, pp 477-479 (11 June 1992), such as polyaniline. At least one anode and cathode should be at least partially transparent so that the light produced can be observed.

Examples of hole transport materials in layer 120 are described, for example, in Kirk-Othmer Encyclopedia of Chemical Technology, Fourth Edition, Vol. 18, p. 837-860,1996, by Y. Wang. Both hole transport molecules and polymers can be used. Commonly used hole transport molecules are N, N'-diphenyl-N, N'-bis (3-methylphenyl)-[1,1'-biphenyl] -4,4'-diamine (TPD), 1, 1-bis [(di-4-tolylamino) phenyl] cyclohexane (TAPC), N, N'-bis (4-methylphenyl) -N, N'-bis (4-ethylphenyl)-[1,1 ' -(3,3'-dimethyl) biphenyl] -4,4'-diamine (ETPD), tetrakis- (3-methylphenyl) -N, N, N ', N'-2,5-phenylenediamine ( PDA), a-phenyl-4-N, N-diphenylaminostyrene (TPS), p- (diethylamino) benzaldehyde diphenylhydrazone (DEH), triphenylamine (TPA), bis [4- (N , N-diethylamino) -2-methylphenyl] (4-methylphenyl) methane (MPMP), 1-phenyl-3- [p- (diethylamino) styryl] -5- [p- (diethylamino) Phenyl] pyrazoline (PPR or DEASP), 1,2-trans-bis (9H-carbazol-9-yl) cyclobutane (DCZB), N, N, N ', N'-tetrakis (4-methylphenyl) -(1,1'-biphenyl) -4,4'-diamine (TTB), and porphrine-based compounds such as copper phthalocyanine. Commonly used hole transport polymers are polyvinylcarbazole, (phenylmethyl) polysilane and polyaniline. It is also possible to obtain hole transport polymers by doping hole transport molecules such as those mentioned above into polymers such as polystyrene and polycarbonate.

Examples of the electron transporting material of layer 140 include metal complexed oxynoid compounds, such as tris (8-hydroxyquinolato) aluminum (Alq ₃ ); Phenanthroline-based compounds such as 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (DDPA) or 4,7-diphenyl-1,10-phenanthroline ( DPA), and azole compounds such as 2- (4-biphenylyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole (PBD) and 3- (4- Biphenylyl) -4-phenyl-5- (4-t-butylphenyl) -1,2, 4-triazole (TAZ). Layer 140 may act to facilitate electron transport and may also act as a limiting layer to prevent quenching of excitons at the buffer layer or at the interface of the layer. Preferably, this layer promotes electron transfer and reduces exciton quenching.

Cathode 150 is an electrode that is particularly effective for injecting carriers of electrons or negative charges. The negative electrode can be any metal or nonmetal having a lower work shoe than the positive electrode. The material of the negative electrode may be selected from Group 1 metals including alkali metals of Group 1 (eg, Li, Cs), Group 2 (alkaline earth) metals, rare earth elements and lanthanide elements, and actinides. Combinations of these may be used with materials such as aluminum, indium, calcium, barium, samarium and magnesium. In addition, Li-containing organometallic compounds may be precipitated between the organic layer and the cathode layer to lower the operating voltage.

It is known that other layers may be included in the organic electronic device. For example, a layer between conductive polymer layer 120 and active layer 130 to facilitate positive charge transport and / or band-gap matching, or to act as a protective layer. Not shown). Similarly, there may be additional layers (not shown) between active layer 130 and cathode layer 150 to facilitate negative charge transport and / or band-gap matching, or to act as a protective layer. have. Layers known in the art can be used. In addition, any of the layers described above may be made of two or more layers. Alternatively, some or all of the inorganic anode layer 110, conductive polymer layer 120, active layer 130 and cathode layer 150 may be surface treated to increase the charge carrier transport efficiency. The choice of material of each component layer is preferably determined in balance with the purpose of device provision and high device efficiency.

Each functional layer can be made of one or more layers.

The device can be manufactured by depositing the individual layers sequentially on a suitable substrate. Substrates such as glass and polymer films can be used. Conventional deposition techniques such as thermal vapor deposition, chemical vapor deposition and the like can be used. Alternatively, the organic layer can be coded using conventional coating techniques from a solution or a dispersion in a suitable solvent. In general, the different layers will have a thickness in the following range: anode 110, 500-5000 kPa, preferably 1000-2000 kPa; Hole transport layer 120, 50-1000 kPa, preferably 200-800 kPa; Light-emitting layer 130, 10-1000 mW, preferably 100-800 mW; Electron transport layer 140, 50-1000 A, preferably 200-800 mm 3; Cathode 150, 200 to 10000 Hz, preferably 300 to 5000 Hz. The location of the electron-hole recombination zone in the device and the emission spectrum of the device are affected by the relative thickness of each layer. Therefore, the thickness of the electron-transport layer should be chosen such that the electron-hole recombination zone is a light-emitting layer. The ratio of the desired layer thickness will depend on the exact nature of the material used.

The efficiency of the device made of the iridium compound of the present invention can be further improved by optimizing other layers in the device. For example, more effective cathodes such as Ca, Ba or LiF can be used. In addition, novel hole transport materials may be used that result in reduced molding substrate and operating voltage or increased quantum efficiency. In addition, additional layers may be added to adjust the energy levels of the various layers and to facilitate electroluminescence.

Iridium complexes of the present invention are often phosphors and are also photoluminescent and would be useful for applications other than OLEDs. For example, organometallic complexes of iridium have been used as oxygen sensitive indicators, as phosphor indicators in biological assays, and as catalysts. Bis cyclometalated complexes may be used to synthesize tris cyclometalated complexes in which the third ligand is the same or different.

The following examples illustrate the features and advantages of the present invention. These are intended to illustrate the invention and are not intended to be limiting. All percentages are by weight unless otherwise stated.

Example  One

This example illustrates the preparation of 2-phenylpyridine and 2-phenylpyrimidine used to form iridium compounds.

General procedures used are described in O. Lohse, P. Thevenin, E. Waldvogel Synlett, 1999, 45-48. In a typical experiment, 200 ml of degassed water, 20 g of potassium carbonate, 150 ml of 1,2-dimethoxyethane, 0.5 g of Pd (PPh ₃ ) ₄ , 0.05 mol of substituted 2-chloropyridine (quinoline or pyrimidine) and substituted phenylborone A mixture of 0.05 mol of acid was refluxed at 80-90 ° C. for 16-30 h. The resulting reaction mixture was diluted with 300 ml of water and extracted with CH ₂ Cl ₂ (2 × 100 ml). The combined organic layers were dried over MgSO ₄ and the solvent was removed in vacuo. The liquid product was purified using fractional vacuum distillation. Solid material was recrystallized from hexane. The general purity of the isolated material exceeded 98%. The starting materials, yields, melting points and boiling points of the new materials are shown in Table 3. NMR data and analytical data are shown in Table 4.

TABLE 3

2- Phenyl  Pyridine, Phenylpyrimidine  And Phenylquinoline  Produce

TABLE 4

2- Phenyl  Pyridine, Phenylpyrimidine  And Phenylquinoline  Property

Table 4 (continued)

Table 4 (continued)

Example  2

This example illustrates the preparation of an iridium compound of formula 4 fac-Ir (L ^a ) ₃ .

In a typical _{experiment, IrCl 3 · nH 2 O (} 53-55% Ir), AgOCOCF 3 (3.1 equiv per Ir), 2- aryl pyridine (excess), and optionally a small amount of water in the mixture ℃ 180-195 (oil bath) Stir vigorously under N ₂ for 2-8 hours. The resulting mixture was extracted sufficiently with CH ₂ Cl ₂ until the extract was colorless. The extract was filtered through a silica column to give a clear yellow solution. This solution was evaporated to give a residue, which was treated with methanol to give colored crystalline tris-ring metallized Ir complex. The complex was separated by filtration, washed with methanol, dried under vacuum and optionally purified by crystallization, vacuum sublimation or Soxhlet extraction. Yield: 10-82% All materials were characterized by NMR spectroscopic data and basic analysis, and the products are shown in Table 5 below. Single crystal x-ray structures were obtained for a series of three complexes.

Compound 1-b

_{IrCl 3 · nH 2 O (54} % Ir; 508 mg), 2- ( 4-fluorophenyl) -5-trifluoromethyl pyridine, the compound _{kk (2.20g), AgOCOCF 3 (} 1.01g) and water (1ml ) Was stirred vigorously under injection of N _{2 with} increasing slowly (30 minutes) to 185 ° C. (oil bath). After 2 hours at 185-190 ° C the mixture solidified. The mixture was cooled to below room temperature. The solid was extracted with dichloromethane until the extract was colorless. The combined dichloromethane solution was filtered through a short silica column and evaporated. After adding methanol (50 ml) as a residue, the flask was left at -10 ° C overnight. The tris-ring metallized complex, the yellow precipitate of compound b, was separated, washed with methanol and dried under vacuum. Yield: 1.07 g (82%). X-ray crystallinity of the complex was obtained by slowly cooling the warm solution in 1,2-dichloroethane.

Compound 1-e

A mixture of 2- (3-trifluoromethylphenyl) -5-trifluoromethyl pyridine (Compound bb) (1.60g) and _{AgOCOCF 3 (1.01g); IrCl 3} · nH 2 O (504mg 54% Ir) The temperature was vigorously stirred under N ₂ injection while slowly raising the temperature to 192 ° C. (for 15 minutes) (oil bath). After 6 hours at 190-195 ° C., the mixture solidified. The mixture was cooled to below room temperature. The solid was allowed to stand on a silica column and then washed with a large amount of dichloromethane. After evaporation of the filtrate, the residue was treated with methanol to give a yellow solid. The solid was collected and purified by extraction with dichloromethane in a 25 ml micro-soxhre extractor. The yellow precipitate of the tris-cyclometallate complex (Compound e) was isolated, washed with methanol and dried under vacuum. Yield: 0.59 g (39%). X-ray crystallinity of the complex was obtained from hot 1,2-dichloroethane.

Compound 1-d

_{IrCl 3 · nH 2 O (54} % Ir; 508mg) and the mixture of 2- (2-fluoro-phenyl) -5-trifluoromethyl pyridine (Compound aa) (1.53g) and AgOCOCF ₃ (1.01g) N ₂ was vigorously stirred for 6 hours and 15 minutes at 190-195 ° C. (oil bath) under injection of ₂ . The mixture was cooled to below room temperature and then extracted with hot 1,2-dichloroethane. The extract was filtered through a short silica column and evaporated. The residue was treated with methanol (20 ml) to give a precipitate of the desired product (compound d) which was separated by filter, washed with methanol and dried under vacuum. Yield: 0.63 g (49%). X-ray crystallinity of the complex was obtained from dichloromethane / methanol.

Compound 1-i

Mixture of 2- (4-trifluoromethoxyphenyl) -5-trifluoromethyl pyridine (Compound ee) (2.00g) and _{AgOCOCF 3 (1.10g); IrCl 3} · nH 2 O (503mg 54% Ir) Was stirred vigorously under N ₂ injection at 190-195 ° C. (oil bath) for 2 h 45 min. The mixture was cooled to below room temperature and then extracted with dichloromethane. The extract was filtered through a short silica column and evaporated. The residue was treated with methanol (20 ml) to give a precipitate of the desired product (compound i) which was separated by filtration, washed with methanol and dried under vacuum. Yield was 0.86 g. In addition, 0.27 g of the complex was obtained by evaporating the stock solution and adding petroleum ethyr as a residue. Overall yield: 1.13 g (72%).

Compound 1-q

A mixture of 2- (3-methoxyphenyl) -5-trifluoromethyl-pyridine _{(2.50g), AgOCOCF 3 (1.12g} ) and water _{(1ml); IrCl 3 · nH} 2 O (530mg 54% Ir) The temperature was vigorously stirred under N ₂ injection while slowly raising the temperature to 185 ° C. (30 minutes) (oil bath). After 1 hour at 185 ° C., the mixture solidified. The mixture was cooled to room temperature. The solid was extracted with dichloromethane until the extract was colorless. The combined dichloromethane solution was filtered through a short silica column and evaporated. The residue was washed with hexanes and then recrystallized from 1,2-dichloroethane-hexanes (twice). Yield: 0.30 g.

¹⁹ F NMR (CD ₂ Cl ₂ , 20 ° C.), δ: -63 (s). ¹ H NMR (CD ₂ Cl ₂ , 20 ° C.), δ: 8.1 (1H), 7.9 (1H), 7.8 (1H), 7.4 (1H), 6.6 (2H), 4.8 (3H).

X-ray crystallinity of the complex (1,2-dichloroethane, hexane solvate) was obtained from 1,2-dichloroethane-hexane. The isomeric complex was orange-photoluminescent.

Compounds 1-a , 1-c , 1-f to 1-h , 1-j to 1-m and 1-r were similarly prepared. A mixture of isomers in the preparation of compounds 1-j was obtained using fluorine at the R ₆ or R ₈ position.

TABLE 5

Table 5 (continued)

Example  3

This example illustrates the preparation of an iridium complex of IrL ^a L ^b L ^c _x L ′ _y L ″ _z of Formula 2 above.

Compound 1-n

_{IrCl 3 · nH 2 O (54} % Ir; 510mg) and the mixture of 2- (3-trifluoromethylphenyl) quinoline (1.80g) and acetate (1.10g), silver trifluoroacetate at 190-195 ℃ for 4 hours Stir vigorously. The resulting solid was chromatographed on silica with dichloromethane to give a mixture of bicyclic metallized complexes and unreacted ligands. Unreacted ligand was extracted with warm hexanes and removed from the mixture. After the extract became colorless, the hexane-insoluble solid was collected and dried in vacuo. Yield 0.29 g. ¹⁹ F NMR: -63.5 (s, 6F), -76.5 (s, 3F). The structure of this complex was confirmed by single crystal x-ray diffraction analysis.

Compound 1-o

_{IrCl 3 · nH 2 O (54} % Ir; 500mg), 2- a (2-fluorophenyl) -3-chloro-5-trifluoromethyl pyridine (2.22g), water (0.3ml) and silver trifluoroacetate The mixture of acetate (1.00 g) was stirred at 190 ° C. for 1.5 h. The solid product was chromatographed on silica with dichloromethane to give 0.33 g of a 2: 1 cocrystallisation adduct of a bicyclic metallized aqueous trifluoroacetoto complex (Compound 1-p) and an unreacted ligand.

Co-crystallized phenylpyridine ligand was removed by recrystallization from dichloromethane-hexane. The structure of both adducts and complexes was confirmed by single crystal x-ray diffraction analysis.

Example  4

This example illustrates the preparation of hydroxyl iridium dimers having the above formula VIII.

Mixture of methyl pyridine (725mg), water (5ml), and ethoxyethanol (20ml) for 2-2- (4-fluorophenyl) _{-5-trifluoromethyl; IrCl 3 · nH 2 O (} 510mg 54% Ir) Was stirred vigorously under reflux for 4.5 h. A solution of NaOH (2.3 g) in water (5 ml) was added, followed by 20 ml of water and the mixture was stirred at reflux for 2 hours. The mixture was cooled to rt, diluted with 50 ml of water and filtered. The solid was stirred vigorously under reflux for 6 hours using 1,2-dichloroethane and aqueous NaOH (2.2 g in 8 ml water). The organic solvent was evaporated from the mixture and left a suspension of orange solid in the aqueous phase. The orange solid was separated by filtration, washed thoroughly with water and dried in vacuo to yield 0.94 g (95%) of iridium hydroxyl dimer (purified by spectroscopic analysis).

Example  5

This example illustrates the preparation of bis-ring metallization complexes from iridium dimers.

Compound 1-p

The mixture of iridium hydroxyl dimer (100 mg), ethyl acetoacetate (0.075 ml; 4 fold excess) and dichloromethane (4 ml) of Example 4 was stirred overnight at room temperature. The solution was filtered through a short silica plug and evaporated to give an orange solid, which was washed with hexanes and dried. Yield of the complex was 109 mg (94%).

Chemical analysis: calcd: C, 44.9; H, 2.6; N, 3.5

           Found: C, 44.4; H, 2.6; N, 3.3

Compound 1-w

A solution of the hydroxyl dimer (0.20 g) from Example 4 in THF (6 ml) was treated with 50 mg of trifluoroacetic acid, filtered through a short silica plug, evaporated to about 0.5 ml, and hexane (8 ml) Used and left overnight. The yellow crystalline solid was separated, washed with hexanes and dried under vacuum. Yield (1: 1 THF solvate): 0.24 g (96%).

Compound 1-x

A mixture of triacetate intermediate, compound 1-w (75 mg) and 2- (4-bromophenyl) -5-bromopyridine (130 mg) was stirred under N ₂ at 150-155 ° C. for 30 minutes. The resulting solid was cooled to room temperature and dissolved in CH ₂ Cl ₂ . The resulting solution was filtered through silica gel and evaporated. The residue was washed several times with warm hexanes and dried in vacuo to give a yellow, yellow-photoluminescent solid. Yield: 74 mg (86%).

As confirmed by X-ray analysis, the complex was a meridian isomer using nitrogen of the transin fluorinated ligand.

Example  6

This example illustrates the preparation of an iridium compound of mer-Ir (L ^a ) ₃ of Formula 5 above.

Compound 1-s

This complex was synthesized in a similar manner to compound 1-n. According to NMR, TLC and TGA data, the product was a roughly 1: 1 mixture of isomers and meridian isomers.

Compound 1-t

_{IrCl 3 · nH 2 O (54} % Ir; 0.40g), 2- (3,5- difluorophenyl) -5-trifluoromethyl-pyridine _{(1.40g), AgOCOCF 3 (0.81g} ) and water (0.5 ml) was stirred vigorously under N ₂ injection while slowly raising the temperature to 165 ° C. (oil bath). After 40 minutes at 165 ° C., the mixture was solidified. The mixture was cooled to below room temperature. The solid was extracted with dichloromethane until the extract was colorless. The combined dichloromethane solution was filtered through a short silica column and evaporated. The residue was washed thoroughly with hexanes and dried under vacuum. Yield: 0.53 g (49%).

As confirmed by X-ray analysis, the complex was an meridian.

Compound 1-u

This complex was prepared analogously to compound 1-q, isolated and then purified by crystallization from 1,2-dichloroethane hexanes. The yield of purified product was 53%. The complex was an meridian as shown by NMR data.

Compound 1-v

This mer-complex was prepared using trifluoroacetate bicyclic metallized intermediate, compound 1-x and 2- (4-fluorophenyl) -5-trifluoromethylpyridine in a similar manner to compound 1-w. .

This yellow-emitting meridian complex was sublimed to 1 atm with a green light emitting isomer (compound 1-b) to isomerize.

Example  7

This example illustrates the fabrication of an OLED using the iridium of the present invention.

A thin film OLED device including a hole transport layer (HT layer), an electroluminescent layer (EL layer) and one or more electron transport layer (ET layer) was fabricated using thermal evaporation technology. Edward Auto 306 evaporator with oil diffusion puff was used. The basic vacuum for all thin film depositions is in the range of 10-6 Torr. The deposition chamber can deposit five different films without having to break the vacuum.

An iridium tin oxide (ITO) coated glass substrate with an ITO layer of about 1000-2000 Angstroms was used. The substrate was first patterned by etching an undesired ITO region with 1 HCl solution to form the first electrode pattern. Polyimide tape was used as a mask. The patterned ITO substrate was then ultrasonically cleaned in an aqueous cleaning solution. The substrate was then rinsed with distilled water, then with isopropanol and degassed in toluene vapor for 3 hours.

The washed and patterned ITO substrate was then filled with a vacuum chamber and the chamber was pumped to ^10-6 Torr. The substrate was then further washed using oxygen plasma for about 5-10 minutes. After washing, multilayer thin films were deposited successively on the substrate by thermal evaporation. Finally, Al patterned metal electrode was deposited through the mask. The thickness of the film was measured during deposition using a quartz crystal monitor (Sycon STC-200). All film thicknesses presented in the examples are nominal values calculated assuming the density of the material deposited on one. The intact OLED device was then removed from the vacuum chamber and immediately characterized without encapsulation.

An overview of the device layers and thicknesses is presented in Table 6. In all cases the cathode was ITO as described above and the anode was Al with a thickness in the range of 700-760 Angstroms. In some samples, two layers of electron transfer layers were used. The first presented layer was applied adjacent to the EL layer.

TABLE 6

Alq ₃ = tris (8-hydroxyquinolato) aluminum

DDPA = 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline

Ir (ppy) ₃ = fac-tris (2-phenylpyridine) iridium

MPMP = bis [4- (N, N-dimethylamino) -2-methylphenyl] (4-methylphenyl) methane

OLED samples were characterized by measuring (1) current-voltage (IV) curves, (2) electroluminescent radiance versus voltage, and (3) electroluminescence spectrum versus voltage. The apparatus 200 used is shown in FIG. 2. The IV curve of OLED sample 220 was measured using ketry source-measurement unit models 237, 280. Electroluminescent radiance (CD / m ² ) versus voltage was measured using a Minolta LS-110 luminometer 210 and the voltage was scanned using a Catri SMU. Electroluminescence spectra were collected by an electronic shutter 240 using a pair of lenses 230, dispersed through a spectrograph 250, and measured using a diode array detector 260. All three measurements were made simultaneously and controlled by computer 270. The efficiency of the device at a specific voltage was measured by dividing the electroluminescent radiance of the LED by the current density required to operate the device. The unit is Cd / A.

The results are shown in Table 7 below.

TABLE 7

Electroluminescent Properties of Iridium Compounds

Table 7 (continued)

Electroluminescent Properties of Iridium Compounds

Peak efficiency is an optimal indicator of the value of the electroluminescent compound in the device. This provides a measure of how many electrons must be introduced into the device to emit a certain number of photoelectrons (radiation luminance). This is basically an important number and reflects the inherent efficiency of the luminescent material. High efficiency also means that fewer electrons are needed to achieve the same luminous intensity, which is important for practical applications because it means less power consumption. Higher efficiency devices tend to have longer lifetimes because the injected electrons are converted to photoelectrons at a higher rate instead of causing heat generation or undesirable chemical side reactions. Most of the iridium complexes of the present invention have a much higher peak efficiency than the parent compound fac-tris (2-phenylpyridine) iridium complex. Complexes with low efficiencies may also find utility as phosphorescent or luminescent materials or as catalysts, as described above.

Example  8

This example illustrates the preparation of a ligand parent compound having the formula XI, 1- (2,4-difluoro-phenyl) -isoquinoline.

2,4-difluorophenylboronic acid (Aldrich Chemical Co., 13.8 g, 87.4 mmol), 1-chloroisoquinoline (Aldrich Chemical Co., 13 g, 79.4 mmol), tetrakistriphenylphosphine palladium (0) (Aldrich, 3.00 g, 2.59 mmol), potassium carbonate (EM Science, 24.2 g, 175 mmol), water (300 ml) and dimethoxyethane (Aldrich, 300 ml) were stirred under reflux for 20 hours under nitrogen and then the mixture Was cooled to room temperature and the organic and aqueous layers were separated. The aqueous layer was extracted with 3 x 150 ml of diethyl ether and the combined organic fractions were dried using sodium sulfate, filtered and the filtrate was evaporated to dryness. The crude material was eluted _first with catalyst byproduct with 4: 1 hexanes / CH ₂ Cl ₂ on silica gel column, and finally the product was eluted with CH ₂ Cl _{2 /} MeOH (9.5: 0.5, product R _f = 0.7). By chromatography. The pure product fractions were collected and dried in vacuo to yield 17.7 g (92% isolation yield) of a pale yellow solid (> 95% purity NMR spectroscopy).

Example  9

This example illustrates the preparation of a branched dichloro dimer, [IrCl {2- (2,4-difluoro-phenyl) -isoquinoline} ₂ ] ₂ .

1- (2,4-difluoro-phenyl) -isoquinoline (1.00 g, 4.15 mmol), IrCl ₃ (H ₂ O) ₃ (Strem Chemical, 703 mg, 1.98 mmol) and 2- in Example 8 After oxyethanol (Aldrich Chemical Co., 25 ml) was stirred under reflux for 15 hours, the precipitate was isolated by filtration, washed with methanol and dried in vacuo to afford 1.04 g (74%) of a product as a reddish solid. Got it.

Example  10

This example illustrates the preparation of the bis-ring metallized iridium complex of Table 8, [Ir (acac) {1- (2,4-difluoro-phenyl) -isoquinoline} ₂ ], complex 8-r. .

[IrCl {1- (2,4-Difluoro-phenyl) -isoquinoline} ₂ ] ₂ (300 mg, 0.212 mmol), sodium acetylacetonate (Aldrich Chemital Co., 78 mg, 0.636 mmol) of Example 9 And 10 ml of 2-ethoxyethanol were stirred at 120 ° C. for 0.5 h. The volatile components were then removed in vacuo. The residue was added in dichloromethane and the solution passed through a pad of silica gel using dichloromethane as elution solvent. The resulting crimson filtrate was evaporated to dryness and then suspended in methanol. The precipitated product was isolated by filtration and dried in vacuo. Isolation yield = 230 mg (70%).

Compounds 8-a through 8-k and compound 8-s in Table 8 were prepared in a similar manner.

Compounds 8-l to 8-q in Table 8 were prepared using the procedure of Example 2.

Example  11

A thin film OLED device was prepared following the procedure of Example 7. An overview of the layers and thicknesses of the devices is given in Table 10. In all cases, the cathode was ITO described above and the anode was Al having a thickness in the range of 700 to 760 kPa.

TABLE 10

MPMP = bis [4- (N, N-diethylamino) -2-methylphenyl] (4-methylphenyl) -methane

DPA = 4,7-diphenyl-1,10-phenanthroline

Table 10 (continued)

MPMP = bis [4- (N, N-diethylamino) -2-methylphenyl] (4-methylphenyl) -methane

DPA = 4,7-diphenyl-1,10-phenanthroline

The OLED sample was characterized as in Example 7, and the results are shown in Table 12 below.

TABLE 11

Electroluminescent Properties of Iridium Compounds

Example  12

This example illustrates the preparation of additional phenylpyridine ligands.

Phenylpyridine compounds 12-a through 12-j shown in Table 12 below were prepared as described in Example 1.

TABLE 12

Analysis and NMR data are presented in Table 13 below.

TABLE 13

2- (2 ', 4'-dimethoxyphenyl) -5-trifluoromethylpyridine was converted to _{2 in the} presence of [(dppb) PdCl ₂ ] catalyst (dppb = 1,4-bis (diphenylphosphino) butane). -Chloro-5-trifluoromethylpyridine and 2,4-dimethoxyphenylmagnesium bromide were coupled to form via kumada.

Example  13

This example illustrates the preparation of a dichloro-branched binuclear bis-ring metallized Ir complex.

Ir complexes was prepared by the reaction of the corresponding of the aqueous 2-ethoxyethanol, and 2-aryl pyridine IrCl _{3 ·} nH ₂ O. The method was similar to the literature method for 2-phenylpyridine (Sprouse, S .; King, KA: Spellane, PJ; Watts, RJ, J. Am. Chem. Soc., 1984, 106, 6647-53; Graces, FO; King, KA; Watts, RJ, Inorg. Chem., 1988, 27, 3464-71). IrCl _{3 ·} nH ₂ O, 2- aryl pyridine (2.2 to 2.8 equivalents per Ir), ethoxyethanol (IgCl _{3 ·} nH ₂ O of about 30ml per 1g) and (about 5ml per 30ml 2-ethoxyethanol) of water in 2- The mixture of was stirred under reflux (N ₂ ) for 4-10 hours. After cooling to room temperature, concentrated hydrochloric acid ( ₃ ml per 1 g of IrCl ₃ nH ₂ O) was added and the mixture was stirred for 30 minutes. The mixture was diluted with water, stirred for 1-2 hours and filtered. The solid product was washed with water, methanol and dried in vacuo. Yields ranged from 65 to 99%.

Example  14

This example illustrates the preparation of an Ir complex of the invention having compound 6 wherein L ″ is Cl.

A bicyclic metallized arylpyridine iridium (III) mononuclear complex comprising a monodentate tertiary phosphine, CO, or isonitrile ligand.

A mixture of dichloro-branched dinuclear bis-ring metallized Ir complex, monodentate ligand L 'and 1,2-dichloroethane (DCE) or toluene prepared as in Example 13 was refluxed (L' is CO Or under N ₂ ), then all solids were dissolved and stirred for an additional 3 minutes to 1 hour. The product was isolated, purified by evaporation and crystallized in air. The detailed procedure for the selected complex is shown below. All complexes were characterized by NMR spectroscopic data ( ³¹ P NMR = ³¹ P- { ¹ H} NMR). Satisfactory combustion analysis has not been obtained due to insufficient thermal stability of the complex. The isomers of compound 9-k were both characterized by single crystalline X-ray diffraction, with multiple isomers with trans nitrogen and minor isomers with cis nitrogen.

Complex  9-d (Table 9)

Dichloro-branched dinuclear bis-cyclic metallized Ir complex (100 mg) prepared using the phenylpyridine compound 12-f of Example 12, ligand 2,6- (CH ₃ ) ₂ C ₆ H ₃ NC as ligand L ' A mixture of NC-1 (26 mg) (from Sigma Aldrich, purchased from Chemical's Fluka line) and DCE (1.5 ml) was stirred at reflux for 5 minutes. After cooling to room temperature, the dark cyan photoluminescent solution was treated with hexane (15 ml) little by little. The yellow crystals were separated, washed with hexane (3 x 3 ml) and dried under vacuum. Yield: 0.115 g (96%).

Complex  9-g (Table 9)

Dichloro-branched dinuclear bis-ring metallized Ir complex (120 mg) prepared using the phenylpyridine compound 2-y of Example 1, ligand 2,6- (CH ₃ ) ₂ C ₆ H ₃ NC as ligand L ' A mixture of NC-1 (26 mg) (from Sigma Aldrich, purchased from Chemical's Fluka line) and DCE (2 ml) was stirred under reflux for 10 minutes. After cooling to room temperature, the dark cyan photoluminescent solution was treated with hexane (4 ml) little by little. The yellow crystals were separated, washed with hexane (3 x 3 ml) and dried under vacuum. Yield: 0.13 g (93%).

Complex  9-i (Table 9)

A mixture of dichloro-branched dinuclear bis-ring metallized Ir complex (300 mg) prepared as Example 1, phenylpyridine compound 2-k, triphenylphosphine (120 mg) and toluene (6 ml) as ligand L 'was prepared. Stirred to reflux for minutes. Upon cooling to room temperature yellow crystals precipitated from the green photoluminescent solution. After 2 days at room temperature, hexane (8 ml) was added. After 1 day, the yellow crystals were separated, washed with hexane (3 x 3 ml) and dried under vacuum. Yield: 0.41 g (97%).

The product includes minority isomers (about 10%) with the following NMR factors:

Complex  9-k (Table 9)

Dichloro-branched dinuclear bis-ring metallized Ir complex (102 mg) prepared using the phenylpyridine compound 2-k of Example 1, triarylphosphine compound (Ar _f ) ₃ P as ligand L ', wherein Ar _f A mixture of = 3,5- (CF ₃ ) ₂ C ₆ H ₃ (102 mg) and toluene (8 ml) was stirred under reflux for 10 minutes until all solids dissolved, after cooling to room temperature, the mixture was hexane. (10 ml) and left for 3 hours at about 10 ° C. The yellow crystalline solid was separated, washed with hexane and dried under vacuum The compound showed light blue photoluminescence. ¹⁹ F NMR analysis showed about 10% of the unreacted dichloro branched complex, heating the solid in boiling toluene in the presence of L ₅ (30 mg), cooling at about 10 ° C. for 12 hours and then complex 9-k. It was isolated to be free of any dichloro branched complex. Washed with and dried under vacuum to yield:. 0.17g (86%)

These complexes have nitrogen atoms that are trans relative to each other (X-rays). Small numbers of crystals of other shapes were also found in the single crystal cluster provided from the x-ray analysis. One of these small numbers was analyzed by X-ray diffraction to determine the cis arrangement of N elements around Ir for the minor isomers.

Complex  9-l (Table 9)

Carbon monoxide as L 'was passed through the bubble through a boiling solution of the dichloro-branched dinuclear bis-cyclometallate Ir complex prepared using the phenylpyridine compound 2-k of Example 1 in DCE (8 ml). The heater was turned off and the solution was slowly cooled to room temperature while passing carbon monoxide through the mixture into the bubble. When light yellow crystals started to precipitate, hexane (10 ml) was slowly added in 2 ml portions. After 30 minutes at room temperature, the crystals (white blue photoluminescence) were separated, washed with hexanes and dried under vacuum for 15 minutes. Yield: 0.145 (78%).

Complexes 9-a, 9-b, 9-c, 9-e, 9-f, 9-h and 9-i use the same procedure as complex 9-d, 12-a, 12-c and 12, respectively. Prepared using -g, 12-d, 2-k, 12-f and 2-k.

Example  15

A thin film OLED device was manufactured using the procedure of Example 7. An overview of the layers and thicknesses of the devices is given in Table 14. In all cases, the cathode was ITO described above and the anode was Al with a thickness in the range of 700 to 760 kPa.

TABLE 14

MPMP = bis [4- (N, N-diethylamino) -2-methylphenyl] (4-methylphenyl) -methane

DPA = 4,7-diphenyl-1,10-phenanthroline

The OLED sample was characterized as in Example 7, and the results are shown in Table 15 below.

TABLE 15

Electroluminescent Properties of Iridium Compounds

Table 15 (continued)

Electroluminescent Properties of Iridium Compounds

1 is a schematic diagram of a light emitting device (LED).

It is a schematic diagram of an LED test apparatus.

Claims (1)

A compound selected from compounds 12-a to 12-j shown in the table below having formula II. <Formula II>

Wherein A and R ₁ to R ₉ are as defined in the following table.

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