TWI438260B - Light-emitting element material and light-emitting element - Google Patents

Description

發光元件材料及發光元件Light-emitting element material and light-emitting element

本發明係關於將電能轉換成光之元件，其係可用於顯示元件、平面顯示器、背光、照明、內裝、標示、看板、電子照相機及光信號產生器等領域之發光元件。The present invention relates to an element for converting electrical energy into light, which can be used for a light-emitting element in the fields of display elements, flat panel displays, backlights, illumination, interiors, signs, billboards, electronic cameras, and optical signal generators.

對於從陰極注入的電子及從陽極注入的電洞，在兩極所夾持的有機發光體內再結合時進行發光的有機積層薄膜發光元件之研究，近年來極為盛行。此發光元件因具有薄型且在低驅動電壓下的可高亮度發光，並可藉選擇螢光材料以作多色發光等特徵，而備受矚目。此研究自從Kodak公司的C. W. Tang等人發表可高亮度發光之有機積層薄膜元件以來(參考非專利文獻1)，已有諸多研究機構在進行相關研究。Kodak公司的研究團隊所揭示之有機積層薄膜發光元件的代表性構造，係於ITO玻璃基板上依序設有電洞輸送性之二胺化合物、發光層8-羥基喹啉鋁及作為陰極的Mg：Ag，以10V左右之驅動電壓可作1,000cd/m² 之綠色發光。現在的有機積層薄膜發光元件雖然有對設置上述元件構成要素以外的電子輸送層等構造做變更，但基本上仍沿襲Kodak公司的構造。The study of an organic laminated thin film light-emitting device that emits light when electrons injected from a cathode and a hole injected from an anode are recombined in an organic light-emitting body sandwiched between two electrodes has been extremely popular in recent years. The light-emitting element is attracting attention because of its high-brightness light emission at a low driving voltage and the ability to select a fluorescent material for multi-color light emission. Since the research by CW Tang et al. of Kodak Co., Ltd., which has published high-intensity organic thin film elements (refer to Non-Patent Document 1), many research institutes have conducted related research. A representative structure of an organic laminated thin film light-emitting device disclosed by Kodak's research team is provided with a hole transporting diamine compound, a light-emitting layer 8-hydroxyquinoline aluminum, and a cathode as a cathode on an ITO glass substrate. : Ag, with a driving voltage of about 10 V, can be used for green light emission of 1,000 cd/m ² . The organic laminated thin film light-emitting device of the present invention has a structure in which an electron transport layer other than the above-described component components is changed, but basically follows the structure of Kodak Co., Ltd.

藉由在發光層中使用各種螢光材料，有機薄膜發光元件可得到多種的發光顏色。特別是藉由在發光層組合主要材料及摻雜材料來使用，可得到呈現高效率藍、綠、紅三原色的發光元件。雖然摻雜劑通常使用發光量子產率高的色素，但例如具有亞甲吡咯骨架的錯合物具備得到高效率的必要要件之化合物，其係作為發光效率高、斯托克斯位移及發光光譜的峰值半值幅狹小的這種摻雜劑，並已知顯示有良好的元件特性(請參照專利文獻1)。The organic thin film light-emitting element can obtain various light-emitting colors by using various fluorescent materials in the light-emitting layer. In particular, by combining the main material and the doping material in the light-emitting layer, a light-emitting element exhibiting high-efficiency blue, green, and red primary colors can be obtained. Although a dopant generally uses a pigment having a high luminescence quantum yield, for example, a complex having a methylene pyrrole skeleton has a compound which is required to have high efficiency, and has high luminous efficiency, Stokes shift, and luminescence spectrum. Such a dopant having a small peak value and a small amplitude is known to exhibit good element characteristics (refer to Patent Document 1).

以習知的亞甲吡咯化合物作為呈現良好的綠色化合物，已知有1,3,5,7,8-五甲基-4,4-二氟-4-硼-3a,4a-二吖-s-苯并二茚，分子內具有複數亞甲吡咯骨架的化合物，或在亞甲吡咯骨架上導入具有橋頭位置之縮合環構造的化合物等(請參照專利文獻2~3)。A well-known green compound is known as a mesopyrrole compound, and 1,3,5,7,8-pentamethyl-4,4-difluoro-4-borane-3a, 4a-diindole is known. S-benzodioxime, a compound having a complex number of methylene pyrrole skeletons in the molecule, or a compound having a condensed ring structure having a bridgehead position introduced into the methylene pyrrole skeleton (see Patent Documents 2 to 3).

【非專利文獻1】Appl.Phys.Lett.51(12)21,p.913,1987)[Non-Patent Document 1] Appl. Phys. Lett. 51 (12) 21, p. 913, 1987)

【專利文獻1】特開平9-118880號公報[Patent Document 1] JP-A-9-118880

【專利文獻2】特開2002-134274號公報[Patent Document 2] JP-A-2002-134274

【專利文獻3】特開2004-311030號公報[Patent Document 3] JP-A-2004-311030

然而，1,3,5,7,8-五甲基-4,4-二氟-4-硼-3a,4a-二吖-s-苯并二茚等在低溫下昇華的化合物很多，蒸鍍速度的控制困難，有所謂的因蒸鍍時的凝集或元件製作時的電荷輸送層之污染，而降低發光效率的問題。而且，因專利文獻2~~3記載的化合物雖然昇華溫度變高但是熱安定性欠缺，所以蒸鍍時有熱分解、發光波峰波長偏移而色純度低下等的問題。However, many compounds such as 1,3,5,7,8-pentamethyl-4,4-difluoro-4-boron-3a, 4a-difluorene-s-benzodioxime, which are sublimed at low temperatures, are steamed. The control of the plating rate is difficult, and there is a problem that the luminous efficiency is lowered due to aggregation at the time of vapor deposition or contamination of the charge transport layer at the time of component production. In addition, the compounds described in Patent Documents 2 to 3 have a high sublimation temperature and a lack of thermal stability. Therefore, there are problems such as thermal decomposition during vapor deposition, shifting of the emission peak wavelength, and low color purity.

如上所述，雖然亞甲吡咯化合物呈現出良好的綠色發光，但是在發光元件中，卻難以發現發光效率‧色純度‧耐久壽命全部都優異的發光特性。As described above, although the methylene pyrrole compound exhibits good green light emission, in the light-emitting element, it is difficult to find light-emitting characteristics which are excellent in luminous efficiency, color purity, and durability.

因此，本發明係關於解決習知技術的問題，穩定地提供高發光效率、壽命長且色純度高的綠色發光元件為目的。Accordingly, the present invention has been made in order to solve the problems of the prior art and stably provide a green light-emitting element having high luminous efficiency, long life, and high color purity.

即，本發明為一種發光元件材料，其具有一般式(1)所示之亞甲吡咯骨架，且分子量為450以上之化合物，That is, the present invention is a light-emitting device material having a methylene pyrrole skeleton represented by the general formula (1) and having a molecular weight of 450 or more.

(其中，R¹ ~R⁴ 為烷基、環烷基、烷氧基或芳醚基，其可各自相同或不同；R⁵ 及R⁶ 為鹵素、氫或烷基，其可各自相同或不同；R⁷ 為芳基、雜芳基或烯基中任一者，分子量為200以上；M係選自於由硼、鈹、鎂、鋁、鉻、鐵、鈷、鎳、銅、鋅及鉑所形成之群組中之至少一種；n為0~4的整數；m為1~3的整數；L係以選自鹵素、氫、烷基、芳基或雜芳基之1價或0價之基，通過分子內的1或2個原子與M鍵結；n為2~4的情況下，各L可彼此相同或不同；m為2或3的情況下，各亞甲吡咯骨架之R¹ ~R⁷ 可彼此相同或不同)。(wherein R ¹ to R ⁴ are alkyl, cycloalkyl, alkoxy or aryl ether groups, which may each be the same or different; and R ⁵ and R ⁶ are halogen, hydrogen or alkyl, which may each be the same or different R ⁷ is any of an aryl group, a heteroaryl group or an alkenyl group having a molecular weight of 200 or more; and M is selected from the group consisting of boron, bismuth, magnesium, aluminum, chromium, iron, cobalt, nickel, copper, zinc and platinum. At least one of the group formed; n is an integer from 0 to 4; m is an integer from 1 to 3; and L is a monovalent or zero valent selected from halogen, hydrogen, alkyl, aryl or heteroaryl The base is bonded to M through 1 or 2 atoms in the molecule; in the case where n is 2 to 4, each L may be the same or different from each other; and in the case where m is 2 or 3, R of each methylene pyrrole skeleton ¹ to R ⁷ may be the same or different from each other).

依據本發明可提供高發光效率、壽命長且色純度高的綠色發光元件。According to the present invention, a green light-emitting element having high luminous efficiency, long life, and high color purity can be provided.

實施發明的最佳形態Best form for implementing the invention

本發明的發光元件材料具有一般式(1)所示之亞甲吡咯骨架，且分子量為450以上之化合物，The light-emitting device material of the present invention has a methylene pyrrole skeleton represented by the general formula (1) and a compound having a molecular weight of 450 or more.

其中，R¹ ~R⁴ 為烷基、環烷基、烷氧基或芳醚基，其可各自相同或不同。R⁵ 及R⁶ 為鹵素、氫或烷基，其可各自相同或不同。R⁷ 為芳基、雜芳基或烯基中任一者，分子量為200以上。Wherein R ¹ to R ⁴ are an alkyl group, a cycloalkyl group, an alkoxy group or an aryl ether group, which may be the same or different. R ⁵ and R ⁶ are halogen, hydrogen or alkyl, which may be the same or different. R ⁷ is any of an aryl group, a heteroaryl group or an alkenyl group, and has a molecular weight of 200 or more.

於此等取代基之中，烷基表示例如甲基、乙基、正丙基、異丙基、正丁基、第二丁基、第三丁基等的飽和脂肪族烴基，該等係可具有或可不具有取代基。於有取代時，增加的取代基係沒有特別的限制，例如可列舉出烷基、芳基、雜芳基等，此點在以下的記載中亦相同。Among these substituents, the alkyl group represents a saturated aliphatic hydrocarbon group such as a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, a second butyl group, a t-butyl group or the like. With or without a substituent. In the case of the substitution, the substituent to be added is not particularly limited, and examples thereof include an alkyl group, an aryl group, and a heteroaryl group. The same applies to the following description.

環烷基表示例如環丙基、環己基、降基、金剛烷基等的飽和脂環式烴基，該等係可具有或可不具有取代基。Cycloalkyl represents, for example, cyclopropyl, cyclohexyl, or A saturated alicyclic hydrocarbon group such as a benzyl group or an adamantyl group, which may or may not have a substituent.

烷氧基表示例如甲氧基、乙氧基、丙氧基等之經由醚鍵而鍵結脂肪族烴基的官能基，此脂肪族烴基係可具有或可不具有取代基。The alkoxy group represents a functional group which bonds an aliphatic hydrocarbon group via an ether bond, such as a methoxy group, an ethoxy group, a propoxy group or the like, and the aliphatic hydrocarbon group may or may not have a substituent.

芳醚基表示例如經由苯氧基等的醚鍵而鍵結芳香族烴基的官能基，芳香族烴基係可具有或可不具有取代基。The aryl ether group means a functional group which bonds an aromatic hydrocarbon group via an ether bond such as a phenoxy group, and the aromatic hydrocarbon group may or may not have a substituent.

鹵素表示氟、氯、溴及碘。Halogen means fluorine, chlorine, bromine and iodine.

芳基表示例如苯基、萘基、聯苯基、茀基、菲基、聯三苯基、蒽基及芘基等的芳香族烴基、或此等複數鍵結的基，此等可無取代亦可經取代。此種芳基具有的取代基為烷基、環烷基、烯基、炔基、烷氧基、芳醚基、烷硫基、鹵素、氰基、胺基、矽烷基及硼烷基等。烷硫基係烷氧基的醚鍵之氧原子經硫原子所取代者。烷硫基的烴基係可具有取代基，也可不具有取代基。胺基表示例如聯苯胺基、苯萘胺基及二甲胺基等有鍵結於氮原子的官能基，此等可具有取代基，也可不具有取代基。矽烷基表示例如三甲基矽烷基等有鍵結於矽原子的官能基，此等可具有取代基，也可不具有取代基。硼烷基表示例如像雙(基)硼烷基有鍵結於硼原子的官能基，此等可具有取代基，也可不具有取代基。The aryl group means an aromatic hydrocarbon group such as a phenyl group, a naphthyl group, a biphenyl group, a fluorenyl group, a phenanthryl group, a terphenyl group, a fluorenyl group or a fluorenyl group, or a plurality of bonded groups, and these may be unsubstituted. Can also be replaced. The substituent of such an aryl group is an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryl ether group, an alkylthio group, a halogen group, a cyano group, an amine group, a decyl group, a borane group or the like. The oxygen atom of the ether bond of the alkylthio alkoxy group is substituted by a sulfur atom. The alkyl group of the alkylthio group may or may not have a substituent. The amine group means a functional group having a nitrogen atom bonded to, for example, a benzidine group, a phenylnaphthylamino group, and a dimethylamino group, and these may or may not have a substituent. The decyl group means a functional group bonded to a ruthenium atom such as a trimethyl decyl group, and these may or may not have a substituent. Borane group means, for example, like double The boryl group has a functional group bonded to a boron atom, and these may or may not have a substituent.

雜芳基表示例如呋喃基、噻吩基、唑基、吡啶基、喹啉基及咔唑基等之含有碳以外的原子之芳香族環狀構造基、或此等複數連結之基、或此等與芳香族烴基所連結之基，此等可無取代亦可經取代。此種雜芳基所亦可具有的取代基係和芳基所亦可具有的取代基相同。雜芳基的連結位置任何部分都可以，例如2-吡啶基、3-吡啶基、或4-吡啶基的任一者都可以。Heteroaryl represents, for example, furyl, thienyl, An aromatic cyclic structural group containing an atom other than carbon such as an azolyl group, a pyridyl group, a quinolyl group or an oxazolyl group, or a plurality of such groups bonded to an aromatic hydrocarbon group, or the like It can be substituted or substituted. The substituent which the heteroaryl group may have may be the same as the substituent which the aryl group may have. Any part of the linking position of the heteroaryl group may be used, for example, any of 2-pyridyl, 3-pyridyl or 4-pyridyl.

雖然烯基表示例如乙烯基、烯丙基及丁二烯基等之含碳-碳雙鍵的不飽和脂肪族烴基，但在亦包含此不飽和脂肪族烴基與芳基及/或雜芳基和有連結基的概念。不飽和脂肪族烴基可無取代亦可經取代，可具有的取代基為烷基、烷基、烯基、炔基、烷氧基、烷硫基、芳硫醚基、鹵素、氰基、胺基、矽烷基及硼烷基等。Although the alkenyl group represents a carbon-carbon double bond-containing unsaturated aliphatic hydrocarbon group such as a vinyl group, an allyl group, and a butadienyl group, the unsaturated aliphatic hydrocarbon group and the aryl group and/or heteroaryl group are also included. And the concept of a link base. The unsaturated aliphatic hydrocarbon group may be unsubstituted or substituted, and may have an alkyl group, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an alkylthio group, an aryl sulfide group, a halogen, a cyano group, an amine. Base, decyl and borane.

在上述取代基中，從色純度的觀點來看，R¹ ~R⁴ 較佳為烷基；從熱安定性佳的觀點來看，烷基中較佳為甲基或第三丁基。再者，從合成的容易度來看較佳為使用甲基。In the above substituent, R ¹ to R ^{4 are} preferably an alkyl group from the viewpoint of color purity; and from the viewpoint of good heat stability, a methyl group or a third butyl group is preferred. Further, it is preferred to use a methyl group from the viewpoint of easiness of synthesis.

從熱安定性的觀點來看，R⁵ 及R⁶ 較佳為烷基或氫，從容易得到高色純度的綠色發光的觀點來看，較佳為氫。From the viewpoint of thermal stability, R ⁵ and R ^{6 are} preferably an alkyl group or hydrogen, and hydrogen is preferred from the viewpoint of easily obtaining green light having a high color purity.

此外，一般式(1)所表示的化合物中，M係選自於由硼、鈹、鎂、鋁、鉻、鐵、鈷、鎳、銅、鋅及鉑所形成的群組中之至少一種，較佳為硼、鋁、鋅；從可賦予較陡峭的發光光譜、得到較高色純度發光的觀點來看，特佳為硼。L係以選自鹵素、氫、烷基、芳基或雜芳基之1價或0價之基，通過分子內的1或2個原子與M鍵結。在此的0價係例如所謂的吡啶基係透過非共用電子對與M配位的情況等。通過2個原子與M鍵結係所謂的螯合配位。Further, in the compound represented by the general formula (1), M is selected from at least one selected from the group consisting of boron, lanthanum, magnesium, aluminum, chromium, iron, cobalt, nickel, copper, zinc, and platinum. Boron, aluminum, and zinc are preferred; boron is particularly preferred from the viewpoint of imparting a steeper luminescence spectrum and obtaining higher color purity luminescence. L is bonded to M through one or two atoms in the molecule at a monovalent or zero-valent group selected from a halogen, a hydrogen, an alkyl group, an aryl group or a heteroaryl group. The zero valence here is, for example, a case where a so-called pyridyl group is coordinated to M by a non-shared electron pair. The so-called chelation coordination is carried out by two atoms and M bonds.

M為硼的情況下，L較佳為氟、含氟芳基、含氟雜芳基及含氟烷基，從得到較高的螢光量子產率來看，較佳為氟。含氟芳基為含氟的芳基，例如可列舉氟苯基、三氟甲苯基及五氟苯基等。含氟雜芳基為含氟的雜芳基，例如可列舉氟吡啶基、三氟甲吡啶基及三氟吡啶基等。含氟烷基為含氟的烷基，可列舉三氟甲基或五氟乙基等。再者，M為硼以外的情況下，L較佳為螯合配位子。When M is boron, L is preferably fluorine, a fluorine-containing aryl group, a fluorine-containing heteroaryl group, and a fluorine-containing alkyl group, and fluorine is preferred from the viewpoint of obtaining a high fluorescence quantum yield. The fluorine-containing aryl group is a fluorine-containing aryl group, and examples thereof include a fluorophenyl group, a trifluoromethylphenyl group, and a pentafluorophenyl group. The fluorine-containing heteroaryl group is a fluorine-containing heteroaryl group, and examples thereof include a fluoropyridyl group, a trifluoromethylpyridyl group, and a trifluoropyridyl group. The fluorine-containing alkyl group is a fluorine-containing alkyl group, and examples thereof include a trifluoromethyl group and a pentafluoroethyl group. Further, when M is other than boron, L is preferably a chelate ligand.

m為1~3的整數，較佳係M為硼時m=1、M為鋁時m=3、M為鋅時m=2。n為0~4的整數，較佳係M為硼時n=2、M為鋁時n=0、M為鋅時n=0。m為2或3的情況下，各亞甲吡咯骨架的R¹ ~R⁷ 可相同亦可相異。再者，n為2~4的情況下，L可相同亦可相異。m is an integer of 1 to 3, preferably m = 1 when M is boron, m = 3 when M is aluminum, and m = 2 when M is zinc. n is an integer of 0 to 4, preferably n = 2 when boron is boron, n = 0 when M is aluminum, and n = 0 when M is zinc. When m is 2 or 3, R ¹ to R ^{7 of} each methylene pyrrole skeleton may be the same or different. Furthermore, when n is 2 to 4, L may be the same or different.

因為一般式(1)所表示的化合物的分子量為450以上，昇華溫度變得相當高，因為可防止腔室內的污染，所以顯示安定的高輝度發光，容易得到高效率發光。尤其，因為R⁷ 為芳基、雜芳基、或烯基之任一者，且分子量為200以上，所以可容易得到滿足上述分子量的化合物，且得到的化合物之發光係可達成良好的色純度。即，芳基、雜芳基、或烯基等取代基導入吡咯環中，若是得到分子量為450以上之化合物，則雖然色純度低下，但一般式(1)所表示的化合物可得到無色純度低下的高發光效率、壽命長者。此外，從賦予相當高的昇華溫度、可控制在較安定的蒸鍍速度的觀點來看，R⁷ 的分子量較佳為300以上。Since the molecular weight of the compound represented by the general formula (1) is 450 or more, the sublimation temperature becomes relatively high, and since contamination in the chamber can be prevented, stable high-luminance luminescence is exhibited, and high-efficiency luminescence is easily obtained. In particular, since R ⁷ is any of an aryl group, a heteroaryl group, or an alkenyl group and has a molecular weight of 200 or more, a compound satisfying the above molecular weight can be easily obtained, and the obtained light-emitting system can achieve good color purity. . That is, a substituent such as an aryl group, a heteroaryl group or an alkenyl group is introduced into the pyrrole ring, and when a compound having a molecular weight of 450 or more is obtained, although the color purity is lowered, the compound represented by the formula (1) can be obtained with a low colorless purity. High luminous efficiency and long life. Further, from the viewpoint of imparting a relatively high sublimation temperature and controlling the vapor deposition rate at a relatively stable level, the molecular weight of R ⁷ is preferably 300 or more.

另一方面，從無熱分解地、安定地蒸鍍之觀點來看，一般式(1)所表示的化合物之分子量較佳為1000以下，更佳為800以下。On the other hand, the molecular weight of the compound represented by the general formula (1) is preferably 1,000 or less, and more preferably 800 or less, from the viewpoint of vapor deposition without thermal decomposition.

另外，從賦予較高的螢光量子產率、較難以熱分解的觀點來看，R⁷ 係選自芳基或雜芳基為佳，特佳為芳基。此外，R⁷ 較佳為具有分枝的取代基或9-蒽衍生物等龐大的取代基。在此所謂的分支構造係指：直接鍵結到亞甲吡咯環的芳基或雜芳基進一步具有複數的取代基之構造。因為R⁷ 的龐大可防止分子的凝集，所以更能提高發光效率及壽命。Further, from the viewpoint of imparting a high fluorescence quantum yield and being difficult to thermally decompose, R ⁷ is preferably selected from an aryl group or a heteroaryl group, and particularly preferably an aryl group. Further, R ^{7 is} preferably a bulky substituent such as a branched substituent or a 9-anthracene derivative. The term "branched structure" as used herein means a structure in which an aryl group or a heteroaryl group directly bonded to a methylene pyrrole ring further has a plurality of substituents. Since the bulk of R ⁷ prevents aggregation of molecules, it is possible to improve luminous efficiency and life.

具有分支構造的取代基之較佳例子可列舉下述一般式(2)。Preferred examples of the substituent having a branched structure include the following general formula (2).

在此，R⁸ 及R⁹ 可相同亦可相異，其係選自芳基或雜芳基。Here, R ⁸ and R ⁹ may be the same or different and are selected from an aryl group or a heteroaryl group.

芳基及雜芳基的說明與上述相同。從得到更高的螢光量子產率的觀點來看較佳可使用芳基；從熱的安定性來看，可列舉苯基及萘基作為特佳之例子。The description of the aryl group and the heteroaryl group is the same as described above. From the viewpoint of obtaining a higher fluorescence quantum yield, an aryl group is preferably used; and from the viewpoint of thermal stability, a phenyl group and a naphthyl group are exemplified as particularly preferable examples.

此外，從防止分子凝集的觀點來看，R⁸ 及R⁹ 之至少一者係以烷基取代為佳，R⁸ 及R⁹ 之至少一者有以烷基取代的芳基為特佳。烷基的說明雖與上述相同，但從熱安定性的觀點來看，可列舉甲基及第三丁基作為特佳之例子。Further, from the viewpoint of preventing aggregation of the molecule, R ⁸ and R ⁹ is at least one of an alkyl-based substituent preferably, R ⁸ and R ⁹ have the at least one alkyl-substituted aryl group is particularly preferred. Although the description of the alkyl group is the same as described above, a methyl group and a third butyl group are particularly preferable examples from the viewpoint of thermal stability.

此外，從防止分子凝集的觀點來看，因為無論烷基的取代位置在那個位置都發揮同樣的效果，所以沒有特別限定。以下顯示具有一般式(1)所表示之亞甲吡咯骨架的化合物之一例。Further, from the viewpoint of preventing aggregation of molecules, the same effect is exhibited regardless of the position at which the alkyl group is substituted at that position, and thus it is not particularly limited. An example of a compound having a methylene pyrrole skeleton represented by the general formula (1) is shown below.

一般式(1)所表示的化合物例如可利用特表平8-509471號公報或特開2000-208262號公報中記載的方法來製造。即，藉由亞甲吡咯化合物及金屬鹽在鹼基的共存下反應，以得到目的之亞甲吡咯系金屬錯合物。The compound represented by the general formula (1) can be produced, for example, by the method described in JP-A-H05-509471 or JP-A-2000-208262. That is, the methylene pyrrole compound and the metal salt are reacted in the coexistence of bases to obtain the intended methylene pyrrole metal complex.

此外，關於亞甲吡咯-氟化硼錯合物之合成可參考J. Org. Chem.,vol.64,No.21,pp.7813-7819(1999)、Angew. Chem.,Int. Ed. Engl.,vol.36,pp.1333-1335(1997).等記載的方法來製造。即，下記一般式(3)所表示的化合物及一般式(4)所表示的化合物在二氯甲烷中反應，形成亞甲吡咯骨架後，在胺的存在下添加三氟化硼***，得到亞甲吡咯-氮化硼錯合物。Further, regarding the synthesis of the methylene pyrrole-boron fluoride complex, reference is made to J. Org. Chem., vol. 64, No. 21, pp. 7813-7819 (1999), Angew. Chem., Int. Ed. Manufactured by the method described in Engl., vol. 36, pp. 1333-1335 (1997). That is, the compound represented by the general formula (3) and the compound represented by the general formula (4) are reacted in dichloromethane to form a methylene pyrrole skeleton, and then boron trifluoride etherate is added in the presence of an amine to obtain a sub- Pyrrole-boron nitride complex.

再者，關於一般式(3)所表示的化合物例如藉由在鈴木偶合(Suzuki coupling)之條件下，使溴化苯甲醛及硼酸衍生物反應(參考文獻：Chem. Rev.,vol.95(1995))，得到R⁷ 中導入各種芳基及雜芳基者。Further, the compound represented by the general formula (3) is reacted with brominated benzaldehyde and a boronic acid derivative, for example, under the conditions of Suzuki coupling (Reference: Chem. Rev., vol. 95 ( 1995)), which gives various aryl and heteroaryl groups introduced into R ⁷ .

接著舉例詳細說明有關本發明之發光元件的實施形態。本發明之發光元件具有陽極、陰極、及介於該陽極與該陰極間之有機層，該有機層至少含發光層，該發光層係藉電能發光。Next, an embodiment of the light-emitting element of the present invention will be described in detail by way of examples. The light-emitting element of the present invention has an anode, a cathode, and an organic layer interposed between the anode and the cathode. The organic layer contains at least a light-emitting layer, and the light-emitting layer emits light by electric energy.

有機層除僅具發光層之構成者外，尚有1)電洞輸送層/發光層、2)電洞輸送層/發光層/電子輸送層、3)發光層/電子輸送層、4)電洞輸送層/發光層/電洞阻止層、5)電洞輸送層/發光層/電洞阻止層/電子輸送層、6)發光層/電洞阻止層/電子輸送層、以及7)在一層中混合以上之組合物質的型態之任一者亦可。即，以元件構成來說，除上述1)～6)之多層積層構造外，亦可僅設置一層如單獨含有7)的發光材料、或含有發光材料與電洞輸送材料或電子輸送材料的層亦可。該各層可各係單一層或複數層。此外，電洞輸送層由複數層所構成時，接於電極的一側之層稱為電洞注入層；但以下之說明中，電洞注入層係含於電洞輸送層。另一方面，雖然電子輸送層由複數層所構成時，接於電極的一側之層稱為電子注入層；但以下之說明中，電子注入層係含於電子輸送層。再者，本發明中發光物質係指適用於自行發光之物、及有助於其發光之物之任一者、與發光有關之化合物、層等。In addition to the composition of the light-emitting layer, the organic layer has 1) a hole transport layer/light-emitting layer, 2) a hole transport layer/light-emitting layer/electron transport layer, 3) a light-emitting layer/electron transport layer, and 4) electricity. Hole transport layer/light-emitting layer/hole stop layer, 5) hole transport layer/light-emitting layer/hole stop layer/electron transport layer, 6) light-emitting layer/hole stop layer/electron transport layer, and 7) on one layer It is also possible to mix any of the above combinations of the above substances. That is, in the element configuration, in addition to the multilayer laminated structure of the above 1) to 6), only one layer of a luminescent material such as 7) alone or a layer containing a luminescent material and a hole transporting material or an electron transporting material may be provided. Also. The layers can each be a single layer or a plurality of layers. Further, when the hole transport layer is composed of a plurality of layers, the layer connected to one side of the electrode is referred to as a hole injection layer; however, in the following description, the hole injection layer is included in the hole transport layer. On the other hand, when the electron transport layer is composed of a plurality of layers, the layer on one side of the electrode is referred to as an electron injection layer; however, in the following description, the electron injection layer is included in the electron transport layer. Further, the luminescent material in the present invention means any one suitable for self-luminescence, a substance which contributes to luminescence, a compound related to luminescence, a layer, and the like.

若能對有機層高效率地注入電洞之材料，本發明中之陽極即無特殊限制，但以使用功函數較大之材料為佳。雖然氧化錫、氧化銦、氧化錫銦、氧化錫銦(ITO)等導電性金屬氧化物，或金、銀、鉻等金屬，碘化銅、硫化銅等無機導電性物質，聚噻吩、聚吡咯及聚苯胺等導電性聚合物等無特殊限制，但由陽極側產生發光的情況下，較佳為使用ITO玻璃。若能給元件之發光供給充分之電流者，陽極之電阻並無特別限定，但考量發光元件之耗電量，較佳為低電阻。例如，300Ω/□以下之ITO基板即具元件電極之功能，但使用100Ω/□以下之低電阻品為佳。陽極之厚度可配合電阻值任意選擇，但通常係多使用100~300nm間者。又，為保有發光元件之機械強度，以將陽極形成於基板上為佳。基板係使用鹼石灰玻璃、無鹼玻璃等，另外，由於厚度也是在維持機械強度上只要有充分的厚度即可，所以0.5mm以上已屬充分。再者，陽極若具安定功能，則基板不一定必須為玻璃，例如，亦可將陽極形成於塑膠基板上。形成陽極之膜之方法，並無特殊限制，且不特定受限於電子束法、濺鍍法及化學反應法等。The anode of the present invention is not particularly limited as long as it can efficiently inject the material of the hole into the organic layer, but it is preferable to use a material having a large work function. Conductive metal oxides such as tin oxide, indium oxide, indium tin oxide, and indium tin oxide (ITO), or metals such as gold, silver, and chromium, inorganic conductive materials such as copper iodide and copper sulfide, and polythiophene and polypyrrole. The conductive polymer such as polyaniline is not particularly limited. However, when light is generated from the anode side, ITO glass is preferably used. If a sufficient current can be supplied to the light emission of the element, the resistance of the anode is not particularly limited, but the power consumption of the light-emitting element is preferably low resistance. For example, an ITO substrate of 300 Ω/□ or less has a function as an element electrode, but a low resistance product of 100 Ω/□ or less is preferably used. The thickness of the anode can be arbitrarily selected in accordance with the resistance value, but usually it is used between 100 and 300 nm. Further, in order to maintain the mechanical strength of the light-emitting element, it is preferable to form the anode on the substrate. The substrate is made of soda-lime glass, alkali-free glass, or the like, and the thickness is also sufficient to maintain the mechanical strength as long as it has a sufficient thickness. Therefore, 0.5 mm or more is sufficient. Furthermore, if the anode has a stable function, the substrate does not have to be glass. For example, the anode can be formed on the plastic substrate. The method of forming the film of the anode is not particularly limited, and is not particularly limited by the electron beam method, the sputtering method, the chemical reaction method, and the like.

若能將電子高效率注入此有機層之物質，陰極即無特殊限制，一般可列舉鉑、金、銀、銅、鐵、錫、鋅、鋁、銦、鉻、鋰、鈉、鉀、鈣、鎂、銫，以及這些之合金等。為提高電子注入效率以提升元件特性，鋰、鈉、鉀、鈣、鎂、銫、或含這些低功函數金屬之合金即有效。然而，這些低功函數金屬在大氣中一般大多不安定，故較佳者可列舉例如使用在有機層中摻雜微量的鋰、鎂(真空蒸鍍之膜厚計顯示1nm以下)之高安定性電極之方法，但亦可使用如氟化鋰之無機鹽，但不限定於此。並且，為保護電極，較佳為積層列舉之鉑、金、銀、銅、鐵、錫、鋁及銦等金屬，或使用這些金屬之合金，氧化矽、二氧化鈦及氮化矽等無機物，聚乙烯醇、氯乙烯、烴系高分子物等有機高分子化合物。此等電極之製作方法係電阻加熱、電子束、濺鍍、離子電鍍及塗布等，可取得導通者即無特殊限制。If the electron can be efficiently injected into the organic layer, the cathode is not particularly limited, and generally, platinum, gold, silver, copper, iron, tin, zinc, aluminum, indium, chromium, lithium, sodium, potassium, calcium, Magnesium, bismuth, and alloys of these. In order to improve the electron injection efficiency to enhance the characteristics of the element, lithium, sodium, potassium, calcium, magnesium, barium, or an alloy containing these low work function metals is effective. However, these low work function metals are generally unstable in the atmosphere, and therefore, for example, high stability in which a small amount of lithium or magnesium is doped in the organic layer (the thickness of the vacuum vapor deposition film is 1 nm or less) is preferably used. The method of the electrode, but an inorganic salt such as lithium fluoride may be used, but is not limited thereto. Further, as the protective electrode, a metal such as platinum, gold, silver, copper, iron, tin, aluminum or indium, or an alloy of these metals, an inorganic substance such as cerium oxide, titanium oxide or tantalum nitride, or polyethylene is preferably used. An organic polymer compound such as an alcohol, a vinyl chloride or a hydrocarbon-based polymer. These electrodes are produced by resistance heating, electron beam, sputtering, ion plating, coating, etc., and there is no particular limitation on the conductive person.

電洞輸送層係藉由積層、混合單獨一種電洞輸送性物質或二種以上之物質的方法、或使用電洞輸送性物質與高分子黏結劑之混合物的方法來形成，對電洞輸送性物質來說以N,N’-二萘-N,N’-聯苯-4,4’-聯苯-1,1’-二胺等之三苯胺類、雙(N-烯丙基咔唑)等之咔唑類、吡唑啉衍生物、二苯乙烯系化合物、腙系化合物、酞青素衍生物、代表卟啉衍生物的雜環化合物、就聚合物系來說在側鏈上具有該單體之聚碳酸酯或苯乙烯衍生物、聚乙烯咔唑、聚矽烷等為佳，但只要形成製造元件所需之薄膜，可從陽極注入電洞，並有可輸送電洞的化合物的話，並沒有特別限定。The hole transport layer is formed by laminating, mixing a single hole transporting substance or two or more substances, or using a mixture of a hole transporting substance and a polymer binder, and transporting holes. For the substance, triphenylamines such as N,N'-dinaphthyl-N,N'-biphenyl-4,4'-biphenyl-1,1'-diamine, bis(N-allylcarbazole) a carbazole, a pyrazoline derivative, a stilbene compound, an anthraquinone compound, an anthraquinone derivative, a heterocyclic compound representing a porphyrin derivative, etc., and having a side chain in the polymer chain The monomer polycarbonate or styrene derivative, polyvinyl carbazole, polydecane, etc. are preferred, but as long as a film for fabricating the component is formed, a hole can be injected from the anode, and a compound capable of transporting a hole can be used. It is not particularly limited.

再者，在連接電極的洞注入層的情況下，在上述電洞輸送材料中添加如氯化鐵(III)之無機鹽，形成電洞注入層亦可。再者，添加氧化鉬或氧化釩這樣的金屬氧化物，形成電洞注入層亦可。更進一步地，添加具有如氰基取代的芳香族吖化合物強的受體性的化合物，或積層亦可形成電洞注入層者。Further, in the case of connecting the hole injection layer of the electrode, an inorganic salt such as iron (III) chloride may be added to the hole transporting material to form a hole injection layer. Further, a metal oxide such as molybdenum oxide or vanadium oxide may be added to form a hole injection layer. Further, a compound having a strong acceptability such as a cyano substituted aromatic fluorene compound may be added, or a layer may be formed to form a hole injection layer.

發光層為單一層，複數層之任一者均可，不論是主要材料和摻雜材料之混合物、單獨的主要材料，任一者均可。主要材料與摻雜材料係可各自為一種類，亦可為複數之組合。不論摻雜材料是含於主要材料全體、含於部份，任一者均可。不論摻雜材料是與主要材料積層、分散於主要材料中，任一者均可。因為摻雜材料之量過多則起濃度消光現象，因此相對於主要材料與摻雜材料的合計以10重量%以下為佳，更佳為2重量%以下。摻雜方法可藉由摻雜材料與主要材料之共蒸鍍法來形成，亦可預先混合摻雜材料與主材料之後蒸鍍。The luminescent layer is a single layer, and any of the plurality of layers may be used, either as a mixture of the main material and the doping material, or as a separate main material. The main material and the doping material may each be one type or a combination of plural numbers. Either the doping material is contained in the entire material and in the part, either. Either the doping material is laminated with the main material and dispersed in the main material, either. When the amount of the dopant material is too large, the concentration extinction phenomenon is exhibited. Therefore, the total amount of the main material and the dopant material is preferably 10% by weight or less, more preferably 2% by weight or less. The doping method may be formed by a co-evaporation method of a doping material and a main material, or may be performed after pre-mixing the doping material and the main material.

雖然本發明之發光元件材料亦可用來作為主要材料，從高的螢光量子產率及小的發光光譜半值幅的觀點來看，可適用作摻雜材料。使用本發明的發光元件材料作為摻雜材料的情況下，在綠色範圍顯示強發光。從亞甲吡咯系摻雜劑即使極微量也可發光的觀點來看，可將微量的該化合物以夾層狀包夾於主要材料中。此情況下，可積層一層、或兩層以上的主要材料。Although the light-emitting element material of the present invention can also be used as a main material, it can be suitably used as a doping material from the viewpoint of high fluorescence quantum yield and a small half-value of the emission spectrum. When the light-emitting device material of the present invention is used as a dopant material, strong light emission is exhibited in the green range. From the viewpoint that the methylene pyrrole-based dopant can emit light even in a very small amount, a trace amount of the compound can be sandwiched in the main material in a sandwich form. In this case, one or more layers of the main material may be laminated.

另外，發光層中所添加的摻雜材料不必要限定於只有前述亞甲吡咯系摻雜劑一種，使用混合複數的亞甲吡咯系摻雜劑或混合已知之摻雜材料一種以上與亞甲吡咯系摻雜劑亦可。此種情況下，以組合顯示不同的波長範圍之發光的摻雜劑可得到白色發光等所期望之發光。具體來說從習知可知，可使雙(二異丙基苯基)苝四羧酸亞胺等的萘亞甲基亞胺衍生物、紫環酮衍生物、Eu錯合物等的稀土錯合物、4-(二氰基亞甲基)-2-甲基-6-(p-二甲基胺苯乙烯)-4H-吡喃或其相似物、鎂酞青素等的金屬酞青素衍生物、去吖黃素衍生物(deazaflavin deviation)、蒽、芘、稠四苯、、聯三伸苯、有苝及茚等的縮合多環芳香族烴的化合物或其衍生物、呋喃、吡咯、噻吩、苯并噻吩、苯并呋喃、吲哚、二苯并噻吩、二苯并呋喃、咪唑吡啶、有吡及硫等的雜芳環的化合物或其衍生物、二苯乙烯苯衍生物、4,4’-雙(2-(4-聯苯胺苯基)乙烯基)二苯基等的胺苯乙烯衍生物、二側氧吡咯(3,4-c]吡咯衍生物、2,3,5,6-1H，4H-四氫化-9-(2’-苯并噻唑)喹并(9,9a,1-gh]香豆素等的香豆素衍生物、及N,N’-聯苯-N,N’-二(3-甲苯基)-4,4’-聯苯-1,1’-二胺所代表的芳香族胺衍生物等共存，然而並不特別限定於此。In addition, the doping material added to the light-emitting layer is not necessarily limited to only one type of the above-mentioned methylene pyrrole-based dopant, and a mixed plurality of methylene pyrrole-based dopants or a mixture of known one or more kinds of doping materials and methylene pyrrole are used. A dopant can also be used. In this case, a desired light emission such as white light emission can be obtained by combining dopants that display light emission in different wavelength ranges. Specifically, it is known that rare earths such as a naphthaleneimine derivative such as bis(diisopropylphenyl)phosphonium tetracarboxyimide, a purple ring ketone derivative, and an Eu complex can be obtained. Compound, 4-(dicyanomethylidene)-2-methyl-6-(p-dimethylaminostyrene)-4H-pyran or the like, metal indigo such as magnesium phthalocyanine Derivatives, deazaflavin derivatives, hydrazine, hydrazine, thick tetracene, a compound of a condensed polycyclic aromatic hydrocarbon having a benzene, a hydrazine or a hydrazine, or a derivative thereof, furan, pyrrole, thiophene, benzothiophene, benzofuran, anthracene, dibenzothiophene, dibenzo Furan, imidazolium, pyridinium Sulfur a heterocyclic ring compound or a derivative thereof, a stilbene benzene derivative, an amine styrene derivative such as 4,4'-bis(2-(4-benzidinephenyl)vinyl)diphenyl, or the like, Bis-oxopyrrole (3,4-c)pyrrole derivative, 2,3,5,6-1H,4H-tetrahydro-9-(2'-benzothiazole)quine And (9,9a,1-gh] coumarin derivatives such as coumarin, and N,N'-biphenyl-N,N'-bis(3-tolyl)-4,4'-biphenyl The aromatic amine derivative represented by the -1,1'-diamine or the like coexists, but is not particularly limited thereto.

主要材料並沒有特別限定，但可使用習知作為發光體使用的具有蒽或芘等之縮合芳香族作為基本骨架的衍生物、參(8-喹啉酸根)鋁(III)為起源的金屬螯合化氧型(oxinoid)化合物、雙苯乙烯蒽衍生物或二苯乙烯苯衍生物等的雙苯乙烯衍生物、二唑衍生物、二唑衍生物、吡咯并吡咯衍生物、咔唑衍生物、聚合物系可使用聚苯乙炔衍生物、聚對苯衍生物、聚茀衍生物、聚乙烯咔唑衍生物以及聚噻吩衍生物等。The main material is not particularly limited, but a metal chelate derived from a derivative having a condensed aromatic group such as ruthenium or osmium as a basic skeleton and ginseng (8-quinolinate) aluminum (III), which is conventionally used as an illuminant, may be used. a bisstyrene derivative such as an oxinoid compound, a bisstyrene hydrazine derivative or a stilbene benzene derivative, Diazole derivatives, As the oxadiazole derivative, the pyrrolopyrrole derivative, the carbazole derivative, and the polymer, a polyphenylacetylene derivative, a polyparaphenylene derivative, a polyfluorene derivative, a polyvinylcarbazole derivative, a polythiophene derivative, or the like can be used. .

其中，使用具有蒽或芘等之縮合芳香族作為基本骨架的衍生物作為主要材料時，因具有含本發明之亞甲吡咯骨架的化合物之高發光效率效果更為顯著，故較佳。具體而言，使用選自蒽化合物、芘化合物及二苯乙烯亞芳香基衍生物的化合物作為主要材料時，有較高效率較佳。此外，具有高耐熱性及載體輸送能力的觀點來看，因使用蒽化合物、或芘化合物作為主要材料時，可得到高效率、長壽命的發光元件，故較佳。Among them, when a derivative having a condensed aromatic group such as ruthenium or osmium as a basic skeleton is used as a main material, since a compound having a propylene pyrrole skeleton of the present invention has a high luminous efficiency effect, it is more preferable. Specifically, when a compound selected from the group consisting of an anthracene compound, an anthracene compound, and a stilbene arylene derivative is used as a main material, higher efficiency is preferred. Further, from the viewpoint of high heat resistance and carrier transport ability, when a ruthenium compound or a ruthenium compound is used as a main material, a light-emitting element having high efficiency and long life can be obtained, which is preferable.

電子輸送層係在具賦予電場的電極間中能有效地輸送來自陰極的電子為必要，其係期望能由電子注入效率高、且有效地輸送被注入的電子之電子輸送材料來形成。因此，要求電子親和力大，且電子移動度大，以及安定性優異，於製造時及使用時不易產生形成阱之雜質的物質。滿足此種條件的物質可列舉8-羥喹啉鋁所代表的喹啉醇衍生物金屬錯合物、羥苯基唑錯合物等的羥唑錯合物、苝衍生物、紫環酮衍生物、有萘及蒽等的縮合芳環的化合物或其衍生物、二唑衍生物、雙苯乙烯衍生物、啡啉衍生物、氧化磷衍生物、苯咪唑衍生物、矽咯(silole)衍生物、三衍生物等。The electron transport layer is necessary to efficiently transport electrons from the cathode between the electrodes having the electric field, and is desirably formed by an electron transport material having high electron injection efficiency and efficiently transporting the injected electrons. Therefore, it is required to have a large electron affinity, a large electron mobility, and excellent stability, and it is difficult to generate a substance which forms impurities of a well at the time of manufacture and use. Examples of the substance satisfying such a condition include a quinolol derivative metal complex represented by 8-hydroxyquinoline aluminum, and a hydroxyphenyl group. a hydroxyzole complex such as a azole complex, an anthracene derivative, a benzalkonone derivative, a compound having a condensed aromatic ring such as naphthalene or an anthracene, or a derivative thereof, Diazole derivatives, bisstyrene derivatives, phenanthroline derivatives, phosphorus oxide derivatives, benzimidazole derivatives, silole derivatives, three Derivatives, etc.

其中，具有本發明之亞甲吡咯骨架的化合物係具有強電子接受性，從藉由與電子輸送能力優異的電子輸送層組合，而可得到高效率‧長壽命的發光來看，電子輸送材料較佳為使用選自碳、氫、氮、氧、矽及磷之元素構成，以使用具有含電子接受性氮的雜芳環構造的化合物為佳。Among them, the compound having the methylene pyrrole skeleton of the present invention has strong electron acceptability, and can be obtained by combining an electron transport layer excellent in electron transporting ability to obtain high efficiency and long life. It is preferred to use an element selected from the group consisting of carbon, hydrogen, nitrogen, oxygen, helium and phosphorus to preferably use a compound having a heteroaryl ring structure containing electron-accepting nitrogen.

電子接受性氮係表示與相鄰原子之間形成複鍵之氮原子。因氮原子具高度陰電性，該複鍵具接受電子的性質，電子輸送能力優異，在電子輸送層中使用可降低發光元件的驅動電壓。因此，含電子接受性氮之雜芳環具有高電子親合性。作為含電子接受性氮之雜芳環可列舉例如吡啶環、吡環、嘧啶環、喹啉環、喹啉環、萘啶環、嘧啶并嘧啶環、苯并喹啉環、啡啉環、咪唑環、唑環、二唑環、***環、噻唑環、噻二唑環、苯并唑環、苯并噻唑環、苯咪唑環及菲并咪唑環等。The electron accepting nitrogen system represents a nitrogen atom which forms a complex bond with an adjacent atom. Since the nitrogen atom has a high degree of electro-negative property, the complex bond has the property of accepting electrons and has excellent electron transporting ability, and the use in the electron transport layer can lower the driving voltage of the light-emitting element. Therefore, the heteroaryl ring containing electron-accepting nitrogen has high electron affinity. Examples of the heteroaryl ring containing electron-accepting nitrogen include a pyridine ring and a pyridyl group. Ring, pyrimidine ring, quinoline ring, quin a porphyrin ring, a naphthyridine ring, a pyrimidopyrimidine ring, a benzoquinoline ring, a phenanthroline ring, an imidazole ring, Oxazole ring, Diazole ring, triazole ring, thiazole ring, thiadiazole ring, benzo An azole ring, a benzothiazole ring, a benzimidazole ring, and a phenimidazole ring.

作為具有此等雜芳環構造的化合物，作為較佳化合物可列舉例如苯咪唑衍生物、苯唑衍生物、苯噻唑衍生物、二唑衍生物、噻二唑衍生物、***衍生物、吡衍生物、啡啉衍生物、喹啉衍生物、喹啉衍生物、苯并喹啉衍生物、二吡啶或三吡啶等的寡吡啶衍生物、喹啉衍生物及萘啶衍生物等。其中，從電子輸送能力的觀點來看，較佳係使用參(N-苯基苯咪唑-2-基)苯等的咪唑衍生物、1,3-雙[(4-第三丁基苯基)1,3,4-二唑]伸苯等的二唑衍生物、N-萘-2,5-聯苯-1,3,4-***等的***衍生物、1,3-雙(1,10-啡啉-9-基)苯等的啡啉衍生物、2,2’-雙(苯并[H]喹啉-2-基)-9,9’-螺二茀等的苯并喹啉衍生物、2,5-雙(6’-(2’,2”-二吡啶基))-1,1-二甲基-3,4-聯苯矽咯等的二吡啶衍生物、1,3-雙(4’-(2,2’:6’2”-三吡啶))苯等的三吡啶衍生物、雙(1-萘)-4-(1,8-萘啶-2-基)苯基氧化膦等的萘啶衍生物。As a compound having such a heteroaromatic ring structure, preferred examples of the compound include a benzimidazole derivative and benzene. An azole derivative, a benzothiazole derivative, Diazole derivatives, thiadiazole derivatives, triazole derivatives, pyridyl Derivatives, phenanthroline derivatives, quinolin Oligopyridine derivatives such as porphyrin derivatives, quinoline derivatives, benzoquinoline derivatives, dipyridine or tripyridine, and quinolin A morphine derivative, a naphthyridine derivative, and the like. Among them, from the viewpoint of electron transporting ability, it is preferred to use an imidazole derivative of ginseng (N-phenylbenzimidazole-2-yl)benzene or the like, 1,3-bis[(4-tert-butylphenyl) ) 1,3,4- Diazole Diazole derivatives, triazole derivatives such as N-naphthalene-2,5-biphenyl-1,3,4-triazole, 1,3-bis(1,10-morpholin-9-yl)benzene, etc. a phenanthroline derivative, a benzoquinoline derivative such as 2,2'-bis(benzo[H]quinolin-2-yl)-9,9'-spirobifluorene, 2,5-bis (6) a dipyridine derivative of '-(2',2"-dipyridyl))-1,1-dimethyl-3,4-biphenylfluorene, 1,3-bis(4'-(2, 2':6'2"-tripyridine)) a naphthyridine derivative such as a tripyridine derivative such as benzene or a bis(1-naphthalene)-4-(1,8-naphthyridin-2-yl)phenylphosphine oxide Things.

該電子輸送材料係可單獨使用，而亦可與不同電子輸送材料積層或混合使用，或混合一種以上之其它電子輸送材料於該電子輸送材料使用。另外，亦可與鹼金屬或鹼土金屬等的金屬或與其金屬錯合物等混合使用。雖然電子輸送層的游離電位無特殊限制，但較佳為5.8eV以上8.0eV以下，更佳為6.0eV以上7.5eV以下。The electron transporting material may be used alone, or may be laminated or mixed with different electron transporting materials, or may be used in combination with one or more other electron transporting materials. Further, it may be used in combination with a metal such as an alkali metal or an alkaline earth metal or a metal complex or the like. Although the free potential of the electron transport layer is not particularly limited, it is preferably 5.8 eV or more and 8.0 eV or less, more preferably 6.0 eV or more and 7.5 eV or less.

電洞阻止層係在賦予電場的電極間中，為防止來自陽極的電洞與來自陰極的電子無再結合的移動之層，根據構成各層之材料的種料，藉由***此層使電洞和電子的再結合機率增加，有增加發光校率的情況。所以，電洞阻止性材料係期望藉由電洞輸送性材料來降低最高占有分子軌道能級，使難以與構成相鄰的層之材料生成激發錯合物。具體而言，可列舉啡啉衍生物或***衍生物等，但只要形成製造元件所需之薄膜，可有效率的阻止來自陽極之電洞的移動之化合物的話，並無特別限制。The hole blocking layer is a layer that prevents the holes from the anode and the electrons from the cathode from moving back in the electrode between the electric field, and the hole is formed by inserting the layer according to the material constituting the material of each layer. The probability of recombination with electrons increases, and there is a case where the illuminance rate is increased. Therefore, the hole-blocking material is expected to reduce the highest occupied molecular orbital energy level by the hole transporting material, making it difficult to form an excitation complex with the material constituting the adjacent layer. Specifically, a phenanthroline derivative or a triazole derivative may be mentioned, but it is not particularly limited as long as it forms a film which is required for the production of the element and can effectively prevent the movement of the hole from the anode.

以上電洞輸送層、發光層、電子輸送層、電洞阻止層係可積層、混合單獨或兩種以上之材料，或可使高分子黏結劑、聚碳酸酯、聚苯乙烯、聚(N-乙烯咔唑)、聚甲基丙烯酸甲酯等分散而使用。The above hole transport layer, the light emitting layer, the electron transport layer, and the hole blocking layer may be laminated, mixed with two or more materials alone, or may be a polymer binder, polycarbonate, polystyrene, poly (N- Ethylene carbazole, polymethyl methacrylate or the like is dispersed and used.

形成發光層的上述各層之形成方法係電阻加熱蒸鍍、電子束蒸鍍、濺鍍、分子積層法、塗布法、噴墨法、印刷法、雷射引發熱轉印法等，並沒有特別的限定，通常，電阻加熱蒸鍍或電子束蒸鍍在特性方面較佳的。層的厚度係根據於掌管發光的物質之電阻值而定，而無法限定，但可在1～1000nm之間選擇。The formation method of the above-mentioned respective layers forming the light-emitting layer is resistance heating vapor deposition, electron beam evaporation, sputtering, molecular layering, coating, inkjet, printing, laser-induced thermal transfer, etc., and there is no particular In general, resistance heating evaporation or electron beam evaporation is preferred in terms of characteristics. The thickness of the layer is determined according to the resistance value of the substance that emits light, and is not limited, but may be selected between 1 and 1000 nm.

本發明的發光元件係具有將電能轉換成光的功能。在此，主要使用直流電流當作電能，但亦可使用脈衝電流或交流電流。電流值及電壓值係沒有特別的限制，但若考慮元件的消耗電力或壽命，較佳應以盡可能低的能量可得到最大的亮度的方式為之。The light-emitting element of the present invention has a function of converting electrical energy into light. Here, a direct current is mainly used as the electric energy, but a pulse current or an alternating current can also be used. The current value and the voltage value are not particularly limited, but in consideration of the power consumption or life of the element, it is preferable to obtain the maximum brightness with the lowest possible energy.

本發明的發光元件，例如可適用作為以矩陣及/或節段方式顯示的顯示器。本發明中矩陣方式係指用於顯示的畫素配置成格子狀，以畫素的集合來顯示文字或影像。本發明中節段方式係以顯示預先決定的資訊之方式來形成圖案，並使所決定的範圍發光之方式，而且，前述矩陣顯示與節段顯示亦可共存於同一面板之中。The light-emitting element of the present invention can be applied, for example, as a display that is displayed in a matrix and/or a segment. In the matrix method of the present invention, the pixels for display are arranged in a lattice shape, and characters or images are displayed in a set of pixels. In the present invention, the segment method is a method of forming a pattern by displaying predetermined information and causing the determined range to emit light, and the matrix display and the segment display may coexist in the same panel.

實施例Example

以下舉出實施例來說明本發明，惟本發明不受此等實施例所限定。The invention is illustrated by the following examples, but the invention is not limited by the examples.

¹ H-NMR係使用超傳導FT-NMR EX-270(日本電子(股)製)，在重氯仿溶液中進行測定。 ¹ H-NMR was measured by a superconducting FT-NMR EX-270 (manufactured by JEOL Ltd.) in a heavy chloroform solution.

合成例1化合物[1]之合成方法Synthesis method of compound 1 [1]

將3,5-二溴苯甲醛(3.0g)、4-第三丁基苯基硼酸(5.3g)、肆(三苯基膦)鈀(0)(0.4g)、碳酸鉀(2.0g)置入燒瓶內以氮氣置換。加入經除氣的甲苯(30ml)、經除氣的水(10ml)回流4小時。將反應溶液冷却到室溫，分離有機層後以飽和食鹽水洗淨。以硫酸鎂乾燥此有機層，餾出過濾後之溶劑。得到的反應生成物藉由矽凝膠層析來精製，得到3,5-雙(p-第三丁基苯基)苯甲醛(3.5g)白色固體。3,5-Dibromobenzaldehyde (3.0 g), 4-t-butylphenylboronic acid (5.3 g), hydrazine (triphenylphosphine) palladium (0) (0.4 g), potassium carbonate (2.0 g) It was placed in a flask and replaced with nitrogen. Degassed toluene (30 ml) and degassed water (10 ml) were added and refluxed for 4 hours. The reaction solution was cooled to room temperature, and the organic layer was separated and washed with saturated brine. The organic layer was dried over magnesium sulfate, and the filtered solvent was evaporated. The obtained reaction product was purified by hydrazine gel chromatography to give 3,5-bis(p-t-butylphenyl)benzaldehyde (3.5 g) as a white solid.

將3,5-雙(4-第三丁基苯基)苯甲醛(1.5g)與2,4-二甲基吡咯(0.7g)加入反應溶液中，將脫水二氯甲烷(200ml)、三氟醋酸(1滴)加入攪拌4小時。將2,3-二氯-5,6-二氰基-1,4-苯醌(0.85g)之脫水二氯甲烷溶液加入後攪拌1小時。反應終了後，將三氟化硼二***錯合物(7.0ml)、二異丙基乙胺(7.0ml)加入攪拌4小時間後，將水(100ml)加入攪拌，分離有機層。以硫酸鎂乾燥此有機層，餾出過濾後之溶劑。得到的反應生成物藉由矽凝膠層析來精製，得到下示之化合物[1]0.4g(產率18%)。3,5-bis(4-t-butylphenyl)benzaldehyde (1.5 g) and 2,4-dimethylpyrrole (0.7 g) were added to the reaction solution to dehydrate dichloromethane (200 ml), three Fluorineacetic acid (1 drop) was added and stirred for 4 hours. A solution of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (0.85 g) in dehydrated dichloromethane was added and stirred for 1 hour. After the completion of the reaction, boron trifluoride diethyl ether complex (7.0 ml) and diisopropylethylamine (7.0 ml) were added and stirred for 4 hours, and then water (100 ml) was added to the mixture, and the organic layer was separated. The organic layer was dried over magnesium sulfate, and the filtered solvent was evaporated. The obtained reaction product was purified by hydrazine gel chromatography to give 0.4 g (yield: 18%) of the compound [1] shown below.

¹ H-NMR(CDCl₃ ,ppm)：7.95(s,1H)、7.63-7.48(m,10H)、6.00(s,2H)、2.58(s,6H)、1.50(s,6H)、1.37(s,18H)。 ¹ H-NMR (CDCl ₃ , ppm): 7.95 (s, 1H), 7.63-7.48 (m, 10H), 6.00 (s, 2H), 2.58 (s, 6H), 1.50 (s, 6H), 1.37 ( s, 18H).

實施例1Example 1

以如下所示之方式製作使用化合物[1]的發光元件。將ITO透明導電膜堆積成150nm的玻璃基板(旭硝子(股)製、15Ω/□、電子束蒸鍍物)切成30×40mm，進行蝕刻。將得到的基板以丙酮、SEMIKOKURIN(註冊商標)56”(Furuchi Chemical Co.製)超音波洗淨各15分鐘，再以超純水洗淨。接著以異丙醇超音波洗淨15分鐘，再於熱甲醇中浸漬15分鐘後乾燥。即將製作元件之前以UV-臭氧處理該基板1小時，設置於真空蒸鍍裝置內，排氣至裝置內真空度達5×10^-5 Pa以下。以電阻加熱法先蒸鍍銅酞青素10nm為電洞注入材料，再蒸鍍4,4’-雙(N-(1-萘)-N-苯胺)聯苯50nm為電洞輸送材料。其次，以參(8-喹啉酸根)鋁(Alq₃ )為主要材料，另以化合物[1]為摻質材料，使摻雜濃度為1重量%蒸鍍至40nm厚度作為發光材料。其次，積層1,3-雙(1,10-啡啉-2-基)苯至25nm厚度，作為電子輸送材料。接著，於有機層上摻雜0.5nm厚度之鋰後，蒸鍍鋁1μm作為陰極，製作5×5mm見方的元件。此所謂膜厚為水晶震盪式膜厚計之顯示值。由該發光元件能得到C.I.E色度座標(0.24,0.67)，發光效率10cd/A之高效率‧高色純度綠色發光(ELpeak波長524nm)。此發光元件以5mA/cm² 的直流電連續驅動時，亮度減半時間為3700小時。A light-emitting device using the compound [1] was produced in the following manner. The ITO transparent conductive film was deposited into a 150 nm glass substrate (manufactured by Asahi Glass Co., Ltd., 15 Ω/□, electron beam vapor-deposited material) and cut into 30×40 mm, and etched. The obtained substrate was washed with acetone, SEMIKOKURIN (registered trademark) 56" (manufactured by Furuchi Chemical Co.) for 15 minutes, and then washed with ultrapure water, followed by ultrasonic cleaning with isopropyl alcohol for 15 minutes. After immersing in hot methanol for 15 minutes, it is dried. The substrate is treated with UV-ozone for 1 hour immediately before the device is fabricated, and placed in a vacuum evaporation apparatus, and evacuated to a vacuum of 5 × 10 ^-5 Pa or less in the apparatus. The heating method first vaporizes the copper anthraquinone 10 nm into a hole injecting material, and then vapor-deposits 4,4'-bis(N-(1-naphthalene)-N-aniline)biphenyl 50 nm as a hole transporting material. Secondly, The ginseng (8-quinolinate) aluminum (Alq ₃ ) is the main material, and the compound [1] is used as the dopant material, and the doping concentration is 1% by weight to be evaporated to a thickness of 40 nm as a luminescent material. Secondly, the layer 1 is 3-bis(1,10-morpholin-2-yl)benzene to a thickness of 25 nm as an electron transporting material. Next, after doping lithium with a thickness of 0.5 nm on the organic layer, 1 μm of aluminum was vapor-deposited as a cathode to prepare 5×. 5mm square element. The film thickness is the display value of the crystal oscillation film thickness meter. The CIE chromaticity coordinates (0.24, 0.67) can be obtained from the light-emitting element, and the luminous efficiency is 10 cd/A. ‧ high efficiency high color purity of green light emission (ELpeak wavelength 524 nm). When the light-emitting element to a direct current 5mA / cm ² of continuous driving, luminance half time was 3700 hours.

實施例2Example 2

除使用下示化合物作為主材料以外，如同實施例1製作發光元件。由該發光元件能得到C.I.E色度座標(0.22,0.72)，發光效率12cd/A之高效率綠色發光(ELpeak波長524nm)。此發光元件以5mA/cm² 的直流電連續驅動時，亮度減半時間為3900小時。A light-emitting element was produced as in Example 1 except that the compound shown below was used as the main material. From the light-emitting element, CIE chromaticity coordinates (0.22, 0.72) and high-efficiency green light emission (ELpeak wavelength 524 nm) having an emission efficiency of 12 cd/A were obtained. When the light-emitting element was continuously driven with a direct current of 5 mA/cm ² , the luminance halving time was 3,900 hours.

比較例1Comparative example 1

除使用下示化合物[2]作為摻雜劑以外，如同實施例1製作發光元件。由該發光元件雖可得到C.I.E色度座標(0.24,0.68)之高色純度綠色發光，但發光效率降低成3cd/A(ELpeak波長520nm)。此發光元件以5mA/cm² 的直流電連續驅動時，亮度減半時間為300小時。A light-emitting element was produced as in Example 1 except that the compound [2] shown below was used as a dopant. Although high-color purity green light emission of CIE chromaticity coordinates (0.24, 0.68) was obtained from this light-emitting element, the light-emitting efficiency was lowered to 3 cd/A (ELpeak wavelength 520 nm). When the light-emitting element was continuously driven with a direct current of 5 mA/cm ² , the luminance halving time was 300 hours.

比較例2Comparative example 2

除使用下示化合物[3]作為摻雜劑以外，如同實施例1製作發光元件。此發光元件雖可得到C.I.E色度座標(0.25,0.67)之高色純度綠色發光，但低發光效率4cd/A(ELpeak波長523nm)。此發光元件以5mA/cm² 的直流電連續驅動時，亮度減半時間為330小時。A light-emitting element was fabricated as in Example 1 except that the compound [3] shown below was used as a dopant. This light-emitting element has high color purity green light emission of CIE chromaticity coordinates (0.25, 0.67), but low light emission efficiency of 4 cd/A (ELpeak wavelength 523 nm). When the light-emitting element was continuously driven with a direct current of 5 mA/cm ² , the luminance halving time was 330 hours.

實施例3～6Examples 3 to 6

除使用下示化合物作為主材料以外，如同實施例1製作發光元件。由此等發光元件所得到的C.I.E色度座標、發光效率及以5mA/cm² 的直流電連續驅動之際的亮度減半時間係顯示於表1。A light-emitting element was produced as in Example 1 except that the compound shown below was used as the main material. The CIE chromaticity coordinates obtained by the light-emitting elements, the luminous efficiency, and the luminance halving time when the direct current is continuously driven at 5 mA/cm ² are shown in Table 1.

實施例7～11Examples 7 to 11

除使用H-6作為主要材料，使用下示化合物或Alq₃ 作為電子輸送層外，如同實施例1製作發光元件。由此等發光元件所得到的C.I.E色度座標、發光效率及以5mA/cm² 的直流電連續驅動之際的亮度減半時間係顯示於表2。A light-emitting element was fabricated as in Example 1 except that H-6 was used as a main material, and the compound shown below or Alq _{3 was} used as the electron transport layer. The CIE chromaticity coordinates obtained by the light-emitting elements, the luminous efficiency, and the luminance halving time when the direct current is continuously driven at 5 mA/cm ² are shown in Table 2.

實施例12～18、比較例3Examples 12 to 18 and Comparative Example 3

除使用H-5作為主要材料，使用下示化合物作為摻雜材料外，如同實施例1製作發光元件。由此等發光元件所得到的C.I.E色度座標、發光效率及以5mA/cm² 的直流電連續驅動之際的亮度減半時間係顯示於表3。A light-emitting element was fabricated as in Example 1 except that H-5 was used as the main material, and the compound shown below was used as the dopant material. The CIE chromaticity coordinates obtained by the light-emitting elements, the luminous efficiency, and the luminance halving time when the direct current is continuously driven at 5 mA/cm ² are shown in Table 3.

產業利用性Industrial utilization

本發明的發光元件材料係可提供能利用於發光元件等，且薄膜安定性優異的發光元件材料。本發明的發光元件係可利用於顯示元件、平面顯示器、背光、照明、內裝、標示、看板、電子照相機及光信號產生器等的領域。The light-emitting device material of the present invention can provide a light-emitting device material which can be used for a light-emitting element or the like and which is excellent in film stability. The light-emitting element of the present invention can be utilized in the fields of display elements, flat displays, backlights, illumination, interiors, signs, billboards, electronic cameras, and optical signal generators.

Claims (9)

一種發光元件材料，其係具有一般式(1)所示之亞甲吡咯骨架，且分子量為450以上之化合物， (其中，R¹ ~R⁴ 為烷基、環烷基、烷氧基或芳醚基，其可各自相同或不同；R⁵ 及R⁶ 為鹵素、氫或烷基，其可各自相同或不同；R⁷ 為芳基、雜芳基或烯基中任一者，分子量為200以上；M係選自於由硼、鈹、鎂、鋁、鉻、鐵、鈷、鎳、銅、鋅及鉑所形成之群組中之至少一種；n為0~4的整數；m為1~3的整數；L係以選自鹵素、氫、烷基、芳基或雜芳基之1價或0價之基，通過分子内的1或2個原子與M鍵結；n為2~4的情況下，各L可彼此相同或不同；m為2或3的情況下，各亞甲吡咯骨架之R¹ ~R⁷ 可彼此相同或不同)。A light-emitting device material having a methylene pyrrole skeleton represented by the general formula (1) and having a molecular weight of 450 or more. (wherein R ¹ to R ⁴ are alkyl, cycloalkyl, alkoxy or aryl ether groups, which may each be the same or different; and R ⁵ and R ⁶ are halogen, hydrogen or alkyl, which may each be the same or different R ⁷ is any of an aryl group, a heteroaryl group or an alkenyl group having a molecular weight of 200 or more; and M is selected from the group consisting of boron, bismuth, magnesium, aluminum, chromium, iron, cobalt, nickel, copper, zinc and platinum. At least one of the group formed; n is an integer from 0 to 4; m is an integer from 1 to 3; and L is a monovalent or zero valent selected from halogen, hydrogen, alkyl, aryl or heteroaryl The base is bonded to M through 1 or 2 atoms in the molecule; in the case where n is 2 to 4, each L may be the same or different from each other; and in the case where m is 2 or 3, R of each methylene pyrrole skeleton ¹ to R ⁷ may be the same or different from each other). 如申請專利範圍第1項之發光元件材料，其中一般式(1)的M為硼，L為氟，n為2。The light-emitting device material according to claim 1, wherein M of the general formula (1) is boron, L is fluorine, and n is 2. 如申請專利範圍第2項之發光元件材料，其中一般式(1)的R⁷ 為芳基或雜芳基。A light-emitting device material according to claim 2, wherein R ⁷ of the general formula (1) is an aryl group or a heteroaryl group. 如申請專利範圍第2項之發光元件材料，其中一般式(1)的R⁷ 為下述一般式(2)所表示， (其中，R⁸ 及R⁹ 可為相同或不同，選自芳基或雜芳基)。The light-emitting element material of claim 2, wherein R ⁷ of the general formula (1) is represented by the following general formula (2), (wherein R ⁸ and R ⁹ may be the same or different and are selected from aryl or heteroaryl). 如申請專利範圍第4項之發光元件材料，其中R⁸ 及R⁹ 為芳基。The luminescent element material of claim 4, wherein R ⁸ and R ⁹ are aryl groups. 如申請專利範圍第5項之發光元件材料，其中R⁸ 及R⁹ 為至少一者為以烷基所取代的芳基。The light-emitting device material according to claim 5, wherein at least one of R ⁸ and R ⁹ is an aryl group substituted with an alkyl group. 如申請專利範圍第5或6項之發光元件材料，其中一般式(2)所表示的構造之分子量為300以上。The light-emitting device material according to claim 5 or 6, wherein the molecular weight of the structure represented by the general formula (2) is 300 or more. 一種發光元件，其特徵係在陽極與陰極之間有發光物質存在，且藉由電能發光之元件，該元件係含有如申請專利範圍第1~7項中任一項之發光元件材料。A light-emitting element characterized by having a light-emitting substance between an anode and a cathode, and an element that emits light by electric energy, the element containing the light-emitting element material according to any one of claims 1 to 7. 如申請專利範圍第8項之發光元件，其中發光層具有主要材料與摻雜材料，一般式(1)所表示之化合物為摻雜材料。The light-emitting element of claim 8, wherein the light-emitting layer has a main material and a dopant material, and the compound represented by the general formula (1) is a dopant material.