KR20100092513A - Emissive polymeric materials for optoelectronic devices - Google Patents

Abstract

[화학식 II]

상기 식에서,
R¹, R³, R⁴ 및 R⁶은 독립적으로 수소, 알킬, 알콕시, 옥사알킬, 알킬아릴, 아릴, 아릴알킬, 헤테로아릴, 치환된 알킬, 치환된 알콕시, 치환된 옥사알킬, 치환된 알킬아릴, 치환된 아릴, 치환된 아릴알킬 또는 치환된 헤테로아릴이고;
R^1a는 수소 또는 알킬이고;
R²는 알킬렌, 치환된 알킬렌, 옥사알킬렌, CO 또는 CO₂이고;
R^2a는 알킬렌이고;
R⁵는 각각의 경우 독립적으로, 수소, 알킬, 알킬아릴, 아릴, 아릴알킬, 알콕시, 카복시, 치환된 알킬, 치환된 알킬아릴, 치환된 아릴, 치환된 아릴알킬 또는 치환된 알콕시이고;
X는, 2, 5- 또는 2, 7-위치에 존재하는, 할로, 트라이플레이트, -B(OR^1a)₂, 또는

이고;
L은, 페닐피리딘, 톨릴피리딘, 벤조티엔일피리딘, 페닐아이소퀴놀린, 다이벤조퀴노잘린, 플루오렌일피리딘, 케토피롤, 2-(1-나프틸)벤즈옥사졸)), 2-페닐벤즈옥사졸, 2-페닐벤조티아졸, 쿠마린, 티엔일피리딘, 페닐피리딘, 벤조티엔일피리딘, 3-메톡시-2-페닐피리딘, 티엔일피리딘, 페닐이민, 비닐피리딘, 피리딜나프탈렌, 피리딜피롤, 피리딜이미다졸, 페닐인돌, 이들의 유도체 또는 이들의 조합으로부터 유도된다.Polymers comprising at least one structural unit derived from a compound of formula (I) or comprising at least one pendant group of formula (II) can be used in the optoelectronic device:
(I)

[Formula II]

Where
R ¹ , R ³ , R ⁴ and R ⁶ are independently hydrogen, alkyl, alkoxy, oxaalkyl, alkylaryl, aryl, arylalkyl, heteroaryl, substituted alkyl, substituted alkoxy, substituted oxaalkyl, substituted alkyl Aryl, substituted aryl, substituted arylalkyl or substituted heteroaryl;
R ^1a is hydrogen or alkyl;
R ² is alkylene, substituted alkylene, oxaalkylene, CO or CO ₂ ;
R ^2a is alkylene;
R ⁵ is independently at each occurrence hydrogen, alkyl, alkylaryl, aryl, arylalkyl, alkoxy, carboxy, substituted alkyl, substituted alkylaryl, substituted aryl, substituted arylalkyl or substituted alkoxy;
X is halo, triplate, -B (OR ^1a ) ₂ , at the 2, 5- or 2, 7-position, or

ego;
L is phenylpyridine, tolylpyridine, benzothienylpyridine, phenylisoquinoline, dibenzoquinozaline, fluorenylpyridine, ketopyrrole, 2- (1-naphthyl) benzoxazole)), 2-phenylbenz Oxazole, 2-phenylbenzothiazole, coumarin, thienylpyridine, phenylpyridine, benzothienylpyridine, 3-methoxy-2-phenylpyridine, thienylpyridine, phenylimine, vinylpyridine, pyridylnaphthalene, pyridyl Derived from pyrrole, pyridylimidazole, phenylindole, derivatives thereof or combinations thereof.

Description

Luminescent polymeric materials for optoelectronic devices {EMISSIVE POLYMERIC MATERIALS FOR OPTOELECTRONIC DEVICES}

The present invention relates to a polymer having a pendant iridium complex for use in an optoelectronic device.

Statement on Federally Sponsored Research and Development

The present invention was made with federal support under contract number DOE NETL DE-FC26-05NT42343, recognized by the US Department of Energy. The federal government may have certain rights in the invention.

Organic light emitting devices (OLEDs), which use thin film materials that emit light when voltage bias is applied, are expected to become a more popular form of flat panel display technology. Possible uses include cell phones, personal digital assistants (PDAs), computer displays, vehicle information displays, television monitors, as well as light sources for general illumination. OLEDs have a cathode ray tube (CRT) because of their bright color, wide viewing angle, compatibility with full motion video, wide temperature range, thin and comfortable form factor, low power requirements and the possibility of low cost manufacturing processes. And liquid crystal display (LCD) as a future alternative technology. OLEDs are considered to have the potential to replace incandescent lamps for certain types of applications, and possibly even fluorescent lamps, thanks to their high luminous efficiency.

Light emission from the OLED typically occurs through electrofluorescence light emission, i.e., light emission from a singlet excited state formed by applying a voltage bias across the ground state electroluminescent material. Another mechanism, electrophosphorescence, ie OLEDs capable of generating light by emission from triplet excited states formed by applying a voltage bias across a ground state electrofluorescent material, produces light primarily by electrofluorescence. It is thought to exhibit substantially higher quantum efficiency than OLEDs. Since the triplet excited state in most luminescent organic materials tends to be non-radioactively attenuated to the ground state, the emission from the OLED by electrophosphorescence is limited. Thus, electrophosphorescent materials are expected as key components of OLED devices and other optoelectronic devices that exhibit greater efficiency compared to the current state of the art. For example, an OLED capable of generating light by electrophosphorescence emits a reduction in the amount of energy lost in the device due to a non-radioactive decay process (primarily compared to an OLED that generates light by electrofluorescence). It is expected to provide an additional means of controlling the temperature during the operation of the OLED.

Improved luminous efficiency has been achieved by incorporating phosphorescent platinum-containing dyes into organic electroluminescent devices such as OLEDs (Baldo et al., "Highly Efficient Phosphorescent Emission from Organic Electroluminescent Devices", Nature, vol. 395, 151-). 154, 1998), phosphorescent iridium-containing dyes are also used (US Patent Application Publication No. 2003/0096138). Polymerizable phosphorescent iridium complexes based on ketopyrrole ligands have been disclosed in pending US patent application Ser. No. 11/504552, filed on August 14, 2006, and filed on July 28, 2006, in US Patent Provisional Application No. 60/833935. All rights are hereby incorporated by reference in their entirety. Despite previous advances, it is currently of great interest to discover new phosphorescent materials that not only increase efficiency while achieving improved lifetime of the device, but also provide a better means of controlling the color of light produced by the OLED. Is dragging.

It has been found that the change in the luminescent properties of the iridium (III) dye resulting from the conjugate effect in the solid state can be prevented by separating the iridium dye from the main chain of the polymer as pendant side chain substituents. Thus, in one embodiment, the present invention relates to a polymer comprising a compound of formula (I) and at least one structural unit derived therefrom:

[Formula I]

Where

R ¹ , R ³ , R ⁴ and R ⁶ are independently hydrogen, alkyl, alkoxy, oxaalkyl, alkylaryl, aryl, arylalkyl, heteroaryl, substituted alkyl, substituted alkoxy, substituted oxaalkyl, substituted alkyl Aryl, substituted aryl, substituted arylalkyl or substituted heteroaryl;

R ^1a is hydrogen or alkyl;

R ² is alkylene, substituted alkylene, oxaalkylene, CO or CO ₂ ;

R ^2a is alkylene;

R ⁵ is independently at each occurrence hydrogen, alkyl, alkylaryl, aryl, arylalkyl, alkoxy, carboxy, substituted alkyl, substituted alkylaryl, substituted aryl, substituted arylalkyl or substituted alkoxy;

이고;X is halo, triplate, -B (OR ^1a ) ₂ , at the 2, 5- or 2, 7-position, or

ego;

L is phenylpyridine, tolylpyridine, benzothienylpyridine, phenylisoquinoline, dibenzoquinozaline, fluorenylpyridine, ketopyrrole, 2- (1-naphthyl) benzoxazole)), 2-phenylbenz Oxazole, 2-phenylbenzothiazole, coumarin, thienylpyridine, phenylpyridine, benzothienylpyridine, 3-methoxy-2-phenylpyridine, thienylpyridine, phenylimine, vinylpyridine, pyridylnaphthalene, pyridyl Derived from pyrrole, pyridylimidazole, phenylindole, derivatives thereof or combinations thereof.

In another aspect, the invention relates to a polymer comprising at least one pendant group of formula II:

[Formula II]

Wherein R ² , R ³ , R ⁴ , R ⁶ and L are as defined for Formula (I).

In another aspect, the invention relates to a photovoltaic device comprising a polymer having at least one structural unit derived from a compound of formula (I) or a polymer having at least one pendant group of formula (II).

The present invention relates to a compound of formula (I), a polymer derived from said compound, a polymer having pendant groups of formula (II), and an optoelectronic device containing said polymers in at least one emitting layer.

The structural unit or pendant group may be derived from a fluorene or triarylamine compound. Examples of structural units derived from fluorene monomers containing pendant Ir complexes include the following formula:

And

Where

R ^1b is hydrogen, alkyl, alkoxy, oxaalkyl, substituted alkyl, substituted alkoxy, or substituted oxaalkyl,

R ^1c is hydrogen, alkyl or substituted alkyl.

In many embodiments, R ² is preferably oxaalkylene, in particular -CH ₂ CH ₂ O-.

Examples of triarylamine monomers containing pendant Ir complexes include the formula:

And

Wherein Z is O, S or a direct bond.

Polymers derived from compounds of formula (I) or polymers having pendant groups of formula (II) may additionally be added to other monomers, in particular US Patents 5,929,194, 5,948,552, 6,204,515, 6,605,373, 6,815,505 and Structural units derived from fluorene monomers as described in US Pat. No. 6,916,902. More particularly, the structural unit can be derived from dibromo 9,9-dioctyl fluorene monomer. The polymer may include structural units derived from one or more triarylamine monomers in addition to or instead of those derived from fluorene monomers. Suitable triarylamine monomers, and polymers containing the residues derived from triarylamine monomers and fluorene monomers, are described in US Pat. 6,900,285. For example, the polymer may include, in addition to the residue containing the iridium complex, the structural unit of formula III:

[Formula III]

In particular, the polymer may comprise structural units of formula IV:

[Formula IV]

Wherein piq is phenylisoquinolinyl.

More particularly, the polymer may contain about 95% of structural units of formula III and 5% of structural units of formula IV, as shown below:

Wherein piq is phenylisoquinolinyl.

이다.In some embodiments, pendant groups of Formula II

to be.

In some of such embodiments, L is phenylisoquinolinyl (piq).

The structural units derived from the compound of formula (I) or the pendant group of formula (II) range from about 0.01% to about 50% by weight of the polymer, in particular from about 0.1% to about 10% by weight, more particularly from about 0.5% to about 5% by weight It may be present in the polymer in an amount of%. The polymer typically has a number average molecular weight (Mn) of greater than 2,000 g / mol, especially greater than about 5,000 g / mol, greater than about 15,000 g / mol, more particularly greater than about 25,000 g / mol, as determined by gel permeation chromatography. Have

Optoelectronic devices according to the invention comprise at least one polymer derived from a compound of formula (I) or a polymer having pendant groups of formula (II). The polymer may be a fluorescent luminescent material such as a (co) polymer based on fluorene monomers such as F8-TFB, commercially available luminescent polymers such as ADS131BE, ADS231BE, ADS331BE, supplied by American Dye Sources, And can be blended with BP105 and BP361 available from ADS431BE, ADS429BE, ADS160BE, ADS329BE, ADS229BE, ADS129BE, ADS180BE, and Sumation Company Ltd. Other materials useful for blending with the polymers of the present invention are oligomeric compounds, such as fluorene trimers and derivatives thereof, polymeric or molecular triarylamine materials, such as those described in US Pat. Nos. 3,265,496 and 4,539,507. And triarylamines (eg, ADS254BE, ADS12HTM, and ADS04HTM) commercially available from American Die Sourse, substituted polyphenylene polymers (eg, ADS120BE from American Die Sourse), and US Patent Application Publication Polymers having oligomeric units linked through nonconjugated linking groups, as described in US 2005/0256290.

When blending a polymer of the present invention with another material, the lowest triplet energy level of the other material (as measured by photoluminescence or other techniques) is higher than the triplet energy of the pendant iridium-based emitters of the polymer of the present invention. Larger is preferred. In particular, the polymer may be blended with one or more fluorescent materials, such as a blue-emitting fluorene (co) polymer, which typically has a lowest triplet energy less than the lowest luminescent singlet energy level of the polymer of the present invention and exhibits blue luminescence. have.

The polymers of the invention and / or blends of such polymers with blue-emitting fluorene (co) polymers are contained in one light emitting layer of the device and contain at least one fluorene polymer or copolymer such as BP105 or F8-TFB. It may be disposed adjacent to other light emitting layers to form a two layer structure. In such devices, the two layer structure can be formed through several different methods as described in International Patent Application No. PCT / US07 / 68620. For example, the two layers may be insolubilized after the first layer deposition, by heat treatment only, or by including a crosslinkable polymeric formulation in the first layer to connect the polymer chains together or form an interpenetrating network. have. The polymerization can be initiated via UV irradiation or thermal activation. The polymerization process can be improved through the addition of a small amount of initiator, such as IRGACURE® 754, ESACURE® initiator from Sartomer, BPO or AIBN. Alternatively, the layer structure may be modified by applying a second layer through contact lamination (Ramsdale et al. J. Appl. Phys, vol 92, pg. 4266 (2002)) or deposition from a solvent that does not dissolve the first layer. Can be formed. If desired, the methods above may be applied continuously to produce a multilayer structure in which one or more layers comprise one or more polymers of the present invention.

The photovoltaic device according to the invention additionally comprises at least one photoluminescent (“PL”) material optically coupled with the polymer such that the phosphor material absorbs a portion of the emitted EM radiation and thereby emits EM radiation in the third wavelength range. It may include. Exemplary device structures containing PL materials and materials for use as PL materials are described in US Pat. No. 7,063,900, which is incorporated herein by reference in its entirety.

 Optoelectronic devices illustrated as organic light emitting devices typically contain, in the simplest case, a multilayer comprising an anode layer, a corresponding cathode layer and an organic electroluminescent layer disposed between the anode and the cathode. When a voltage bias is applied across the electrode, electrons are injected into the electroluminescent layer by the cathode while removed from the anode (or “holes” are “injected” into the electroluminescent layer) from the anode. Luminescence occurs when holes combine with electrons in the electroluminescent layer to form singlet or triplet excitons, and when the singlet excitons transfer energy to the environment by radioactive decay. Triplet excitons, unlike singlet excitons, typically cannot be radioactively attenuated and therefore do not emit light except at cryogenic temperatures. Theoretical considerations are that triplet excitons are generated about three times more often than singlet excitons. Thus, the generation of triplet excitons represents a fundamental limitation on efficiency in organic light emitting devices that typically operate at or near ambient temperature. The polymers according to the invention can act as precursors to species in the luminescent short-lived excited state which are formed when encountering said common non-productive triplet excitons and transfer energy.

In addition to the anode, cathode and luminescent material, other elements that may be present in the organic light emitting device include a hole injection layer, an electron injection layer and an electron transport layer. During operation of an organic light emitting device comprising an electron transport layer, most of the charge carriers (ie, holes and electrons) present in the electron transport layer are electrons, and light is emitted through recombination of holes and electrons present in the electron transport layer. This can happen. Additional elements that may be present in the organic light emitting device include a hole transport layer, a hole transport light emitting layer, a hole blocking layer and an electron transport light emitting layer.

The organic electroluminescent layer is a layer in an organic light emitting device that contains both significant concentrations of electrons and holes in operation and provides a site for exciton formation and light emission. The hole injection layer is generally a layer that is in contact with the anode to facilitate the injection of holes from the anode into the inner layer of the OLED, and the electron injection layer is generally a layer that is in contact with the cathode to facilitate the injection of electrons from the cathode to the OLED. to be. The hole injection layer or the electron transport layer needs to be in contact with the cathode. Often, the electron transport layer is not an effective hole transporter and therefore serves to block the movement of holes towards the cathode. The electron transport layer is a layer that promotes the conduction of electrons from the cathode to the charge recombination site. The hole transport layer is a layer that, in the operation of the OLED, promotes the conduction of holes from the anode to the charge recombination site and does not need to contact the anode. The hole transport luminescent layer is a layer that promotes the conduction of holes to the charge recombination site in the operation of the OLED, where most of the charge carriers are holes and from other charge recombination zones within the device as well as through recombination of residual electrons. Luminescence occurs through energy transfer. The electron transporting light emitting layer is a layer that promotes the conduction of electrons to the charge recombination site in the operation of the OLED, where most of the charge carriers are electrons and from other charge recombination zones within the device as well as through recombination of residual holes. Luminescence occurs through energy transfer.

Materials suitable for use as the anode include materials having a bulk conductivity of at least about 100 Ω / □ as measured by the four-point probe technique. Indium tin oxide (ITO) is often used as an anode because it is substantially transparent to light transmission and thus facilitates the emission of light emitted from the electro-active organic layer. Other materials that can be used as the anode layer include tin oxide, indium oxide, zinc oxide, indium zinc oxide, zinc indium tin oxide, antimony oxide and mixtures thereof.

Suitable materials for use as the cathode include zero valent metals that can inject negative charge carriers (electrons) into the inner layer (s) of the OLED. Various zero-valent metals suitable for use as the cathode include K, Li, Na, Cs, Mg, Ca, Sr, Ba, Al, Ag, Au, In, Sn, Zn, Zr, Sc, Y, lanthanide elements, and their Alloys and mixtures thereof. Alloy materials suitable for use as the cathode layer include Ag-Mg, Al-Li, In-Mg, Al-Ca and Al-Au alloys. A layered non-alloy structure, for example a thin layer of metal (eg calcium) or metal fluoride (eg LiF) coated with a thicker layer of zero valent metal (eg aluminum or silver), may also be used as the cathode. . In particular, the cathode may consist of a single zero valent metal, in particular aluminum metal.

Suitable materials for use in the hole injection layer are 3,4-ethylenedioxythiophene (PEDOT) and blends of PEDOT and polystyrene sulfonate (PSS). Commercially available from HC Stark, Inc. under the tradename BAYTRON®, and polymers based on thieno [3,4b] thiophene (TT) monomers [Air Products Corporation ( Commercially available from Air Products Corporation.

Suitable materials for use in the hole transport layer are 1,1-bis ((di-4-tolylamino) phenyl) cyclohexane, N, N'-bis (4-methylphenyl) -N, N'-bis (4-ethyl Phenyl) (1,1 '-(3,3'-dimethyl) biphenyl) -4,4'-diamine, tetrakis- (3-methylphenyl) -N, N, N', N'-2, 5-phenylenediamine, phenyl-4-N, N-diphenylaminostyrene, p- (diethylamino) benzaldehyde diphenylhydrazone, triphenylamine, 1-phenyl-3- (p- (di Ethylamino) styryl) -5- (p- (diethylamino) phenyl) pyrazoline, 1,2-trans-bis (9H-carbazol-9-yl) cyclobutane, N, N, N ', N '-Tetrakis (4-methylphenyl)-(1,1'-biphenyl) -4,4'-diamine, copper phthalocyanine, polyvinylcarbazole, (phenylmethyl) polysilane; Poly (3,4-ethylene dioxythiophene) (PEDOT), polyaniline, polyvinylcarbazole, triaryldiamine, tetraphenyldiamine, aromatic tertiary amines, hydrazone derivatives, carbazole derivatives, triazole derivatives, Imidazole derivatives, oxadiazole derivatives having amino groups, and polythiophenes as disclosed in US Pat. No. 6,023,371.

Suitable materials for use in the electron transport layer include poly (9,9-dioctyl fluorene), tris (8-hydroxyquinolato) aluminum (Alq ₃ ), 2,9-dimethyl-4,7-diphenyl- 1,1-phenanthroline, 4,7-diphenyl-1,1O-phenanthroline, 2- (4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4 Oxadiazole, 3- (4-biphenylyl) -4-phenyl-5- (4-tert-butylphenyl) -1,2,4-triazole, 1,3,4-oxadiazole- Containing polymers, 1,3,4-triazole-containing polymers, quinoxaline-containing polymers, and cyano-PPV.

Justice

"Alkyl" in the context of the present application is intended to include linear, branched or cyclic hydrocarbon structures and combinations thereof, including lower alkyl and higher alkyl. Preferred alkyl groups are those of C ₂₀ or below. "Lower alkyl" refers to an alkyl group of 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, and methyl, ethyl, n-propyl, isopropyl, and n-, secondary- and tertiary- Butyl. "Higher alkyl" refers to an alkyl group having 7 or more carbon atoms, preferably 7 to 20 carbon atoms, and includes n-, secondary- and tert-heptyl, octyl, and dodecyl. "Cycloalkyl" is a subset of alkyl and includes cyclic hydrocarbon groups of 3 to 8 carbon atoms. Examples of cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl and norbornyl. "Alkenyl" and "alkynyl" refer to alkyl groups, each of which two or more hydrogen atoms are replaced by double or triple bonds.

"Aryl" and "heteroaryl" mean a 5- or 6-membered aromatic or heteroaromatic ring containing 0 to 3 heteroatoms selected from nitrogen, oxygen or sulfur; Bicyclic 9- or 10-membered aromatic or heteroaromatic ring systems containing 0 to 3 heteroatoms selected from nitrogen, oxygen or sulfur; Or a tricyclic 13- or 14-membered aromatic or heteroaromatic ring system containing 0 to 3 heteroatoms selected from nitrogen, oxygen or sulfur. Aromatic 6- to 14-membered carbocyclic rings include, for example, benzene, naphthalene, indane, tetralin and fluorene, and 5- to 10-membered aromatic heterocyclic rings are, for example, imidazole, pyridine, indole , Thiophene, benzopyranone, thiazole, furan, benzimidazole, quinoline, isoquinoline, quinoxaline, pyrimidine, pyrazine, tetrazole and pyrazole.

"Arylalkyl" means an alkyl moiety attached to an aryl ring. Examples are benzyl and phenethyl. "Heteroarylalkyl" means an alkyl moiety attached to a heteroaryl ring. Examples are pyridinylmethyl and pyrimidinylethyl. "Alkylaryl" means an aryl moiety to which one or more alkyl groups are attached. Examples are tolyl and mesityl.

"Alkoxy" or "alkoxyl" refers to groups of linear, branched, cyclic structures having 1 to 8 carbon atoms, and combinations thereof, attached to the parent structure through oxygen. Examples include methoxy, ethoxy, propoxy, isopropoxy, cyclopropyloxy and cyclohexyloxy. "Lower alkoxy" refers to a group containing 1 to 4 carbons.

"Acyl" refers to saturated, unsaturated and aromatic groups of 1 to 8 carbon atoms, linear, branched, cyclic structures, and combinations thereof, attached to the parent structure via a carbonyl functional group. One or more carbons in the acyl moiety can be substituted with nitrogen, oxygen or sulfur as long as the point of attachment to the parent structure is maintained with carbonyl. Examples include acetyl, benzoyl, propionyl, isobutyryl, tert-butoxycarbonyl and benzyloxycarbonyl. "Lower-acyl" refers to a group containing 1 to 4 carbons.

"Heterocycle" means a cycloalkyl or aryl moiety in which one or two carbons are replaced by heteroatoms (eg, oxygen, nitrogen, or sulfur). Examples of heterocycles within the scope of the present invention are pyrrolidine, pyrazole, pyrrole, indole, quinoline, isoquinoline, tetrahydroisoquinoline, benzofuran, benzodioxane, benzodioxole (when present as a substituent, usually methylene Tetraoxy, morpholine, thiazole, pyridine, pyridazine, pyrimidine, thiophene, furan, oxazole, oxazoline, isoxazole, dioxane and tetrahydrofuran.

"Substituted" includes, but is not limited to, alkyl, alkylaryl, aryl, arylalkyl and heteroaryl, wherein up to three H atoms of the residues are lower alkyl, substituted alkyl, aryl, substituted aryl, halo Alkyl, alkoxy, carbonyl, carboxy, carboxalkoxy, carboxamido, acyloxy, amidino, nitro, halo, hydroxy, OCH (COOH) ₂ , cyano, primary amino, secondary amino, acyl Amino, alkylthio, sulfoxide, sulfone, phenyl, benzyl, phenoxy, benzyloxy, heteroaryl or heteroaryloxy.

"Haloalkyl" refers to an alkyl moiety in which one or more H atoms is replaced with a halogen atom, and the term haloalkyl includes perhaloalkyl. Examples of haloalkyl groups falling within the scope of the present invention include CH ₂ F, CHF ₂ and CF ₃ .

Many of the compounds described herein may include one or more asymmetric centers and, thus, enantiomeric, diastereomeric and other stereoisomeric forms that may be defined as (R)-or (S)-in absolute stereochemical aspects. Can be generated. The present invention is intended to include all such possible isomers and their racemic mixtures and optically pure forms. Optically active (R)-and (S) -isomers may be prepared using chiral synthons or separated using conventional techniques. Where the compounds described herein contain olefinic double bonds or other geometrically asymmetric centers, unless otherwise specified, the compounds are intended to include both E and Z geometric isomers. Likewise, it is intended to include all tautomeric forms.

"Oxaalkyl" refers to an alkyl moiety in which one or more carbons have been replaced by oxygen. It is attached to the parent structure via an alkyl moiety. Examples include methoxypropoxy, 3,6,9-trioxadecyl and the like. The term "oxaalkyl" refers to a compound in which oxygen is bonded to an adjacent atom (forming an ether bond) via a single bond, but it does not refer to a double bonded oxygen as found in carbonyl groups. Similarly, "thiaalkyl" and "azaalkyl" refer to alkyl residues in which one or more carbons are replaced with sulfur or nitrogen, respectively. Examples include ethylaminoethyl and methylthiopropyl.

By "silyl" is meant an alkyl moiety wherein one to three of the carbons are substituted with tetravalent silicon and attached to the parent structure via a silicon atom. Siloxy is an alkoxy moiety wherein both of the carbons are substituted with tetravalent silicon end-capped by an alkyl moiety, an aryl moiety or a cycloalkyl moiety and attached to the parent structure via an oxygen atom.

"Bidentate ligands" are ligands that can bind metal through two sites. Similarly, a "tridentate ligand" is a ligand capable of binding to a metal via three sites. "Cyclometallated ligand" refers to a bidentate or tridentate ligand that is bonded to a metal atom by a carbon-metal single bond and one or two metal-heteroatom bonds to form a cyclic structure, wherein Heteroatoms may be N, S, P, As or O.

Any numerical value cited herein includes all values increasing by one unit from the lower limit to the upper limit, provided that at least two units are separated between any lower limit and any upper limit. By way of example, the amount of a component or a process variable value, such as temperature, pressure, time, etc., is for example 1 to 90, preferably 20 to 80, more preferably 30 to 70. Values such as 85, 22-68, 43-51, 30-32 and the like are also intended to be explicitly listed herein. For values less than 1, one unit is considered to be 0.0001, 0.001, 0.01 or 0.1 as the case may be. This is merely an example of what is specifically intended, and all combinations of the possible numerical values between the listed lower and upper limits should be considered to be expressly recited herein in a similar manner.

[Example]

General Procedure for Monomer Preparation

Preferred synthetic routes for preparing 2,7-dibromofluorene starting material are described in Chinese Patent No. 1634839 (Scheme 1). This procedure uses bromine in water, provides high conversion of fluorene to the desired dibromo product with little or no formation of monobrominated compounds, and is substantially free of unknown by-products. When fluorene is brominated using a method using N-bromosuccinimide in methanesulfonic acid, the under-brominated unknown product is typically present in substantially higher amounts.

Scheme 1

After three large scale crystallization reactions, 150 g of high quality 2,7-dibromofluorene (more than 99.9% purity, LC analysis) were obtained for use in subsequent reactions. A portion of the 2,7-dibromofluorene was converted over four steps into tosylated ethylene glycol 9,9'-disubstituted fluorene (5) (Scheme 2).

Scheme 2

By using a slight modification of the synthetic method described in Japanese Patent No. 1997255609 for glycosylation, the target fluorene (4) can be produced in a substantially shorter reaction time (12 hours) under neutral conditions, with a high conversion (95%). Obtained. The tosylated fluorene (5) was used to prepare monomers for incorporation into polyfluorene materials having pendant benzoylpyrrole acid Ir (III) phosphors covalently bonded on the periphery. The benzoylpyrrole Ir (III) phosphor is covalently bonded to the fluorene monomer by replacing the tosyl substituent with a phenolic nucleophile.

Scheme 3

Scheme 4

Example  1: 9- (4- Hexyloxyphenyl ) -9H- Fluorene Synthesis of -9-ol (2)

Under reflux for 12 hours, 4-bromophenol (91.2 g, 527 mmol) was dissolved using bromohexane (86.0 g, 520 mmol) and K ₂ CO ₃ (80.0 g, 580 mmol) in acetone (200 mL). By alkylation, bromo- (4-hexyloxy) -benzene was prepared. After removing the salt by filtration, the reaction mixture was concentrated to dryness to afford an oil. This oil was dissolved in EtOAc (100 mL), transferred to a separatory funnel and washed with 5% NaOH (4 × 200 mL). An additional 200 mL volume of EtOAc was added to the separatory funnel and the contents were washed with NaHCO ₃ (1 × 200 mL) and finally dried over MgSO ₄ . EtOAc solvent was removed to give a pale yellow oil which was used without further purification.

A dry 250 mL three neck flask was charged with a small amount of Mg fragment (2.80 g, 118 mmol) followed by anhydrous THF (100 mL). A little iodine crystals were added and the heterogeneous mixture was heated to reflux for 15 minutes and then cooled to room temperature. Stirring was stopped and 1,2-dibromoethane (0.25 mL) was added to this reaction vessel. After 5 minutes, an exothermic reaction occurred and stirring was resumed for 20 minutes. The reaction was then cooled to 20 ° C. and bromo- (4-hexyloxy) -benzene (27.8 g, 108 mmol) was added over an hour while maintaining the temperature at 14-18 ° C. The cooling bath was removed and when the temperature of the reaction rose to 28 ° C., the reaction was stirred for an additional 10 minutes. The reaction was cooled to room temperature and the contents were pipetted with a suspension of 2,7-dibromofluorene (30.0 g, 90.4 mmol) toluene (250 mL) using a cooling bath and stirred. Transported using. The cooling bath was removed and the reaction mixture was stirred for 20 minutes at room temperature and subsequently treated with 20 mL of EtOH, and a saturated solution of NH ₄ Cl (5 mL). The reaction mixture was filtered to remove insoluble material and transferred to a separatory funnel containing EtOAc (100 mL) and H ₂ O (100 mL). The layers were separated and the organic layer was washed with H ₂ O (2 × 100 mL) and brine (1 × 100 mL) and dried over MgSO ₄ . The solvent was removed to dryness to afford a crude yellow solid (50.8 g). This crude material was recrystallized from hexane / CH ₂ Cl ₂ to give the product of an off-white microcrystalline material.

Example 2: Synthesis of 9- (4-hexyloxyphenyl) -9 '-(4-hydroxyphenyl) -fluorene (3)

20 drops of a solution of CH ₂ Cl ₂ (75 mL) of phenol (24 g, 256 mmol) and 9- (4-hexyloxyphenyl) -9H-fluorene-9-ol (2) (30.0 g, 55.7 mmol) Treated with methanesulfonic acid, thereby turning the solution purple. The reaction was stirred at room temperature until TLC analysis indicated that the starting fluorenol was consumed. The reaction mixture was transferred to a separatory funnel, washed with a saturated solution of NaHCO ₃ (1 × 200 mL) and H ₂ O (3 × 150 mL), and then the organic layer was dried over MgSO ₄ . The solvent was removed to dryness to afford an oil. This oil was adsorbed onto silica gel from the CH ₂ Cl ₂ solution and the solvent was dried off. The dried silica gel was transferred to a glass frit funnel (500 mL) containing a charged H ₂ O slurry of silica gel (200 mL) mounted on a vacuum flask. By applying a vacuum to the flask, the contents of the funnel were flushed with H ₂ O to elute phenol from the silica gel. After the excess phenol was removed, the product was eluted from the silica gel using CH ₃ CN. The solvent was removed on a rotary evaporator with a bath at 45 ° C. to produce a milky solution from which white solids formed. The product was collected by filtration, washed with water and dried. A mixture of para- and ortho-isomers (90:10) of hydroxyphenol adducts was isolated.

Example 3: Synthesis of 9- (4-hexyloxyphenyl) -9 '-(4- (2-hydroxyethoxy) phenyl) fluorene (4)

Phenol (3) (33.0 g, 53.7 mmol) was dissolved in xylene (30 mL), dried over MgSO ₄ and filtered. This solution was concentrated on a rotary evaporator until the contents of the flask became 70 g. The xylene solution of phenol (3) was then placed under an inert atmosphere of N ₂ , treated with ethylene carbonate (3.9 mL, 59.0 mmol) and then heated to reflux for 15 hours. After this time, the reaction was cooled to room temperature and the solvent was removed to yield a yellow oil. Treating the oil by chromatography over SiO ₂ of 2 L, and eluted with CH ₂ Cl _2. After removal of the solvent, the product was isolated as a colorless oil.

Example 4: Synthesis of 9- (4-hexyloxyphenyl) -9 '-(4- (2-p-toluenesulfonylethoxy) phenyl) -fluorene (5)

Toluene solution (200 mL) of ethylene glycol (4) (29.1 g, 44.2 mmol) was treated with p-toluenesulfonyl chloride (13.3 g, 69.8 mmol) and triethylamine (19.4 mL, 140 mmol), Stir for 60 hours at room temperature under an inert atmosphere of N ₂ . This reaction mixture was then filtered to remove triethylamine hydrochloride and concentrated to dryness. The residue was dissolved in EtOAc, washed with 5% HCl (1 × 100 mL) and saturated NaHCO ₃ (2 × 200 mL), dried over MgSO ₄ , and the solvent was dried off. The crude oil was chromatographed through 1.4 L of SiO ₂ (CH ₂ Cl ₂ : hexane, 1: 1). After removal of the solvent, the product was isolated as a white amorphous solid.

Example  5: [( piq ) ₂ Ir (7)]- Fluorene  Synthesis of Monomer (6)

To a stirred DMF solution (25 mL) containing tosylated fluorene (5) (3.00 g, 4.00 mmol) and benzoylpyrrole iridium complex (7) (3.00 g, 3.8 mmol), solid K ₂ CO ₃ (1.00 g, 7.24 mmol) was added. After stirring this solution at 80 ° C. for 1.5 h, the reaction is cooled, H ₂ O (75 mL) is added, the formed red precipitate is sonicated, collected by filtration, washed with water and MeOH, Then dried in air. The product was chromatographed through SiO ₂ : toluene and after removal of the solvent it was isolated as a red solid.

Example  6: 2- (4- Hydroxybenzoyl ) - Of pyrrole (7)  synthesis

To a stirred suspension of 4-hydroxybenzoic acid (5.50 g, 40.0 mmol) in CH ₃ CN cooled to 0 ° C., trifluoroacetic anhydride (10 mL, 72.0 mmol) was added. After 15 minutes, the benzoic acid dissolved. To this solution cooled to 0 ° C., at this temperature, 1- (p-tolylsulfonyl) pyrrole (8.85 g, 40.0 mmol) and then sufficient CH ₂ Cl ₂ to dissolve the pyrrole were added. While stirring rapidly, an additional volume of trifluoroacetic anhydride (10 mL, 72.0 mmol) was added followed by H ₃ PO ₄ (2 mL, 37.0 mmol). The reaction mixture was stirred at rt for 12 h, additional trifluoroacetic anhydride (6 mL, 43.2 mmol) and 4-hydroxybenzoic acid (4.00 g, 29.0 mmol) were added and stirring continued for 12 h. After this time, the solvent was removed to dryness and the residue suspended in 5% NaOH (250 mL) and stirred overnight. This suspension was removed by filtration and the filter cake was washed with 5% NaOH (250 mL). To the filtrate, a saturated solution of NaHCO ₃ (200 mL) was added and the pH of this solution was neutralized by addition of concentrated HCl. The pink microcrystalline material formed was collected by filtration, washed with water and dried.

Example  7: [( piq ) ₂ Synthesis of Ir (7)] (8)

To a stirred and cooled (-10 ° C.) EtOH solution (100 mL) containing ketopyrrole (7) (1.20 g, 6.40 mmol) was added solid sodium hydride (288 mg, 12.0 mmol), thereby This solution turned from yellow to orange. After the solution was stirred for 5 minutes, [(piq) ₂ Ir (μ-Cl)] ₂ (3.33 g, 2.56 mmol) was added and the mixture was then heated to reflux for 10 hours. The reaction mixture was cooled to room temperature and the red precipitate collected by filtration. The product was washed with EtOH and dried in air.

Example  8: 9,9- Dioctylfluorene - Triarylamine  Preparation of Copolymer

All monomers were dried in a vacuum oven at 50 ° C. for at least 2 hours and then weighed. A 50 mL two-necked flask with a nitrogen inlet to the bubbler and a magnetic stirrer was charged with all monomers, tri-o-tolylphosphine and 15-18 mL of toluene. The solution was degassed with argon for 5-10 minutes, then Pd (OAc) ₂ was added and the weighing funnel was washed with the remaining toluene. At the same time, in separate vials, the aqueous component was degassed with argon. After at least 15 minutes of degassing, the aqueous component was added to the organic solution and the flask was immersed in a 70 ° C. oil bath. Stirring and heating was continued for 16-20 hours under a positive pressure of nitrogen, at which point the solution was allowed to warm to room temperature and 20 mg of phenylboric acid was added. This flask was again immersed in a heating bath and stirred for an additional 3 hours under nitrogen. Again, the mixture was cooled and then diluted with 10 mL of toluene and water, respectively. This mixture was transferred to a separatory funnel, the aqueous phase was discarded, and the organic phase was washed with 3 × 50 mL of water and 1 × 50 mL of saturated NaCl. This organic solution was then passed through a funnel containing Celite and Drierite, and the filtered solution was stirred with amine-functional silica gel for at least 30 minutes. Again, this solution was filtered, concentrated to a volume of 20-30 mL on a rotary evaporator, and then loaded onto a toluene saturated silica gel cartridge (about 20-30 g silica / g polymer-note 6). Toluene (100 mL) was used to elute the polymer from the column and this toluene solution was concentrated to about 20 mL. With vigorous stirring, the polymer was isolated by precipitating this solution into 10 volumes of methanol. This polymer was collected by filtration, washed with methanol and dried in a vacuum oven at 40-50 ° C. The yield after drying was 403 mg (55%). Gel permeation chromatography showed Mw 92.4K, Mn 23.0K on polystyrene standards.

Example  9: device fabrication

On a clean, UV-ozone treated, 2.5 cm × 2.5 cm ITO patterned glass substrate, PEDOT / PSS (Baytron P VP 8000, HC Starck, Inc., about 60 nm). Layer of poly (3,4-ethylenedioxythiophene) -poly (styrenesulfonate)], obtained as a solution, from D.), was deposited by spin coating. The coated substrate was then baked at 160 ° C. for 30 minutes on a hot plate. Next, a PE8T / PSS coated F8-TFB (octylfluorene-triarylamine copolymer) hole transport layer obtained from Sumation, Inc., having a thickness of about 10-20 nm was Spin coated onto the substrate. The F8-TFB-PEDOT / PSS coated substrate was then calcined for 30 minutes at 170 ° C. on a hot plate under argon. On the F8-TFB layer, the last layer of a 1: 1 blend of electroluminescent polymer BP104 (Sumation) and the polymer of Example 8 was deposited via spin coating from xylene solution. This layer had a thickness of about 40-50 nm. The coated substrate was then placed in a bell jar evaporator and the system was pumped until a pressure of about 1 × 10 ⁻⁶ torr was obtained. A layer of sodium fluoride, about 3 nm thick (as measured through calibrated quartz crystal microbalance), was then deposited on top of the final layer of the coated substrate by physical vapor deposition. Subsequently, a layer of about 130 nm thick aluminum metal on top of the sodium fluoride was deposited by evaporation under reduced pressure to form the cathode element of the OLED.

The brightness and current versus applied voltage of each device were measured using a Keithley 236 Source Measure unit and a silicon diode coupled to a picoammeter (Kisley). The current response of the diode was converted to OLED luminance (cd / m ² ) by calibrating the silicon diode and measuring the active area of the OLED against a Minolta LS 100 luminance meter. Luminance ("cd / A") is a measure of how effectively the injected charge is converted into visible light, and LPW is a power efficiency measure (how much visible light is produced for a certain amount of input power). to be. LPW data includes the effects of both operating voltage and charge on visible light conversion efficiency. The combination of Cd / A and LPW data indicates a relatively efficient operation of the device, which includes a polymeric material, which material is compatible with the low voltage operation of the device.

The color of the light (EL spectrum) emitted from each OLED device sample was measured using a calibrated spectrometer while operating the device over a range from about 390 nm to about 750 nm at a current density of about 1 mA. Blue light emission from BP 104 material and red light emission from red light emitting polymer material occurred. Luminescence from this particular device was dominated by red luminescent compounds, indicating that the performance shown in the LPW and Cd / A graphs is an indication of the performance of the side branched luminescent polymer.

Although only certain features of the invention have been illustrated and described herein, those skilled in the art will contemplate many variations and changes. Accordingly, it is to be understood that the appended claims are intended to cover all such modifications and variations as fall within the spirit of the invention.

Claims (19)

A compound of formula (I)
(I)

Where
R ¹ , R ³ , R ⁴ and R ⁶ are independently hydrogen, alkyl, alkoxy, oxaalkyl, alkylaryl, aryl, arylalkyl, heteroaryl, substituted alkyl, substituted alkoxy, substituted oxaalkyl, substituted alkyl Aryl, substituted aryl, substituted arylalkyl or substituted heteroaryl;
R ^1a is hydrogen or alkyl;
R ² is alkylene, substituted alkylene, oxaalkylene, CO or CO ₂ ;
R ^2a is alkylene;
R ⁵ is independently at each occurrence hydrogen, alkyl, alkylaryl, aryl, arylalkyl, alkoxy, carboxy, substituted alkyl, substituted alkylaryl, substituted aryl, substituted arylalkyl or substituted alkoxy;
X is halo, triplate, -B (OR ^1a ) ₂ , at the 2, 5- or 2, 7-position, or

ego;
L is phenylpyridine, tolylpyridine, benzothienylpyridine, phenylisoquinoline, dibenzoquinozaline, fluorenylpyridine, ketopyrrole, 2- (1-naphthyl) benzoxazole)), 2-phenylbenz Oxazole, 2-phenylbenzothiazole, coumarin, thienylpyridine, phenylpyridine, benzothienylpyridine, 3-methoxy-2-phenylpyridine, thienylpyridine, phenylimine, vinylpyridine, pyridylnaphthalene, pyridyl Derived from pyrrole, pyridylimidazole, phenylindole, derivatives thereof or combinations thereof. The method of claim 1,
A compound of formula la:
Formula Ia

Wherein R ^1b is hydrogen, alkyl, alkoxy, oxaalkyl, substituted alkyl, substituted alkoxy, or substituted oxaalkyl. The method of claim 2,
R ² is oxaalkylene. The method of claim 1,
A compound of formula (Ib)
Formula Ib

The method of claim 1,
A compound of formula (Ic)
Formula Ic

Where
R ^1c is hydrogen, alkyl or substituted alkyl,
piq is phenylisoquinolinyl. A polymer comprising at least one structural unit derived from a compound according to claim 1. A polymer comprising at least one pendant group of formula (II)
[Formula II]

Where
R ² is alkylene, substituted alkylene, oxaalkylene, CO or CO ₂ ;
R ³ , R ⁴ and R ⁶ are independently hydrogen, alkyl, alkoxy, alkylaryl, aryl, arylalkyl, heteroaryl, substituted alkyl, substituted alkoxy, substituted alkylaryl, substituted aryl, substituted arylalkyl or Substituted heteroaryl;
L is phenylpyridine, tolylpyridine, benzothienylpyridine, phenylisoquinoline, dibenzoquinozaline, fluorenylpyridine, ketopyrrole, 2- (1-naphthyl) benzoxazole)), 2-phenylbenzoxoxa Sol, 2-phenylbenzothiazole, coumarin, thienylpyridine, phenylpyridine, benzothienylpyridine, 3-methoxy-2-phenylpyridine, thienylpyridine, phenylimine, vinylpyridine, pyridylnaphthalene, pyridylpyrrole , Pyridylimidazole, phenylindole, derivatives thereof or combinations thereof. The method of claim 7, wherein
Further comprising structural units derived from one or more fluorene monomers. The method of claim 7, wherein
The polymer further comprising structural units derived from dibromo 9,9-dioctyl fluorene monomer. The method of claim 7, wherein
Further comprising structural units derived from one or more triarylamine monomers. The method of claim 7, wherein
The polymer of L is derived from phenylisoquinoline. The method of claim 7, wherein
The polymer wherein R ² is oxaalkylene. The method of claim 7, wherein
And said pendant group is of formula (IIa).
[Formula IIa]

The method of claim 7, wherein
A polymer, wherein said pendant group is of formula IIb:
[Formula IIb]

Wherein piq is phenylisoquinolinyl. The method of claim 7, wherein
The pendant group is derived from a compound according to claim 1 The method of claim 7, wherein
Wherein said pendant group is derived from a compound selected from the formula:

Wherein Z is O, S or a direct bond. The method of claim 7, wherein
A polymer comprising the structural unit of formula III:
[Formula III]

The method of claim 7, wherein
A polymer comprising the structural unit of formula IV:
[Formula IV]

Wherein piq is phenylisoquinolinyl. The method of claim 7, wherein
Polymers comprising structural units of the formula:

Wherein piq is phenylisoquinolinyl.