A compound containing a bisphenanthroline structure, an organic electroluminescent device and a stacked organic electroluminescent device

Abstract

The application discloses a compound containing a bisphenanthroline structure, an organic electroluminescent device and a laminated organic electroluminescent device, and belongs to the technical field of semiconductor materials. The structure of the compound is shown in general formula (1). The compound is connected between two bisphenanthroline structure units through a specific structure unit, and the formed compound has good electron injection and transmission capacity, and good electron resistance and stability. When the compound is used as a material of an organic electroluminescent device, good efficiency and service life can be achieved under low driving voltage.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor materials, in particular to an organic compound containing a biferrocenyl structure, a single-layer OLED light-emitting device and an OLED stack light-emitting device prepared therefrom. BACKGROUND

[0002] Organic electroluminescence (OLED: Organic Light Emission Diodes) device technology can be used to manufacture new display products and new lighting products, and is expected to replace existing liquid crystal displays and fluorescent lamp lighting, and has a very wide application prospect. The OLED light-emitting device has a sandwich structure, including an electrode material film layer and an organic functional material film layer sandwiched between different electrode film layers, and various different functional materials are stacked together according to the purpose to form the OLED light-emitting device. As a current device, when a voltage is applied to the electrodes of the OLED light-emitting device, positive and negative charges in the organic layer functional material film layer are further recombined in the light-emitting layer, i.e. OLED electroluminescence is generated.

[0003] At present, OLED display technology has been applied in the field of smart phones, tablet computers and other fields, and will further expand to large-size application fields such as televisions, but compared with the actual product application requirements, the performance of OLED devices such as luminous efficiency and service life needs to be further improved. The current research on improving the performance of OLED light-emitting devices includes: reducing the driving voltage of the device, improving the luminous efficiency of the device, and improving the service life of the device. In order to continuously improve the performance of OLED devices, not only the innovation of OLED device structure and manufacturing process is needed, but also the continuous research and innovation of OLED optoelectronic functional materials are needed, and higher performance OLED functional materials are created.

[0004] OLED optoelectronic functional materials applied to OLED devices can be divided into two categories in terms of use, namely charge injection and transport materials and light-emitting materials. Further, the charge injection and transport materials can be divided into electron injection and transport materials, electron blocking materials, hole injection and transport materials, and hole blocking materials. As charge transport materials, they require good carrier mobility, high glass transition temperature, etc. For OLED devices, electrons are injected from the cathode, then transmitted through the electron transport layer to the host material, and then recombined with holes in the host material to generate excitons. Therefore, improving the injection and transport capacity of the electron transport layer is beneficial to reducing the device driving voltage and obtaining high efficiency of electron-hole recombination.

[0005] In addition, in the stacked OLED, the stacked OLED is connected in series through a charge generation layer (CGL) by two or more independent light emitting units. Under the action of an applied electric field, the electrons and holes generated by the CGL are injected into the adjacent light emitting unit and recombine into excitons to emit light. Therefore, the material selection and design of the CGL are key factors affecting the photoelectric performance and service life of the stacked OLED. The CGL layer is constructed in the form of a p-n structure, in which the p-type material mainly generates holes, such as F4-TCNQ and HAT-CN materials, and the n-type doped material is doped with a low work function metal through an electron transport layer material, such as Alq3:Mg and Bphen:Li. Therefore, the performance of the electron transport material of the n-type doped material in the CGL has a very great influence on the performance of the device. It requires high efficient electron injection ability, transmission ability and high electron durability. At the same time, the heat resistance and film stability of the material are also important. Materials with low heat resistance not only decompose easily during material evaporation, but also decompose thermally when the device generates heat during operation, which causes material degradation. In the case of poor material film phase stability, the material also crystallizes in a short time, which causes the organic film layer to directly separate and causes device degradation. Therefore, the material used is required to have high heat resistance and good film stability.

[0006] With the significant progress of OLED devices, the performance requirements of the materials are also increasing, not only requiring good material stability, but also requiring good efficiency and service life at low driving voltage. SUMMARY

[0007] In view of the above problems existing in the prior art, the present application provides a compound containing a bisphenanthroline structure and an OLED light emitting device comprising the same. In the compound of the present application, the aryl or heteroaryl substituted 1,10 bisphenanthroline at a specific site is connected through a specific linking unit. The compound has good electron injection and transmission ability, and can form a coordination coupling effect with metal to achieve good electron injection and transmission, as well as excellent charge generation layer effect. When used in a stacked OLED device, it can effectively reduce the driving voltage of the device and improve the efficiency and service life of the device.

[0008] The present application provides the technical solutions as follows:

[0009] A compound containing a bisphenanthroline structure, the structure of the compound is shown as general formula (1):

[0010]

[0011] In general formula (1), L1 represents a phenyl group, a naphthyl group, a biphenyl group, a terphenyl group or a pyridyl group;

[0012] R1, R2 are independently represented by the structure of general formula (a-1), general formula (a-2) or general formula (a-3);

[0013] Ar1 is represented by phenyl, pyridyl, naphthyl or biphenyl.

[0014] Preferably, the structure of the compound is represented by any one of general formula (1-1) to general formula (1-3):

[0015] L1 has the same meaning as defined above; Ar1 has the same meaning as defined above.

[0016] Preferably, L1 is represented by any one of formula b-1 to b-7:

[0017]

[0018] Preferably, L1 is represented by any one of formula c-1 to c-9:

[0019]

[0020] Further preferably, the structure of the compound is represented by any one of the following structures:

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028] An organic electroluminescent device comprising a first electrode, a second electrode and an organic functional layer, the organic functional layer being located between the first electrode and the second electrode, the organic functional layer comprising a hole transport region, a light-emitting layer and an electron transport region, the light-emitting layer being located between the hole transport region and the electron transport region, the electron transport region comprising the compound comprising a bisphenanthroline structure.

[0029] Preferably, the hole transport region comprises a hole injection layer, a hole transport layer and an electron blocking layer, and the electron transport region comprises an electron hole blocking layer, an electron transport layer and an electron injection layer.

[0030] Preferably, the hole transport region comprises a hole transport layer, the electron transport region comprises an electron transport layer, and the electron transport layer comprises the compound containing the bisphenanthroline structure.

[0031] An organic electroluminescent device comprising a first electrode, a second electrode, and an organic functional layer between the first electrode and the second electrode, the organic functional layer comprising a hole transport layer, an emission layer, and an electron transport layer, the emission layer being between the hole transport layer and the electron transport layer, and the electron transport layer comprising the compound containing the bisphenanthroline structure.

[0032] A stacked organic electroluminescent device comprising a first electrode, a second electrode, a first emission unit, a second emission unit, and a charge generation layer, the first emission unit, the second emission unit, and the charge generation layer being between the first electrode and the second electrode, the charge generation layer being between the first emission unit and the second emission unit, and the charge generation layer comprising the compound containing the bisphenanthroline structure.

[0033] Preferably, the first emission unit comprises a hole transport region, an emission layer, and an electron transport region, and the second emission unit comprises a hole transport region, an emission layer, and an electron transport region.

[0034] Preferably, the charge generation layer further comprises a metal material.

[0035] Further preferably, the metal material is Li, Ca, Ag, Cs, or Yb.

[0036] Further preferably, the metal material is Yb.

[0037] The present application has the beneficial technical effects of:

[0038] (1) The 1,10-bisphenanthroline substituted by aryl or heteroaryl phenyl at a specific site in the compound of the present application is connected on both sides by a specific linking unit, has good electron injection and transport capacity, can effectively improve electron injection and transport, thereby reducing device driving voltage and improving device efficiency.

[0039] (2) Further, since the compound of the present application has good electron-withdrawing ability, film stability, and electron resistance, it is used as an n-type material of a CGL layer, can form a stable N-metal coordination bond with metals such as Yb, form a stable and flat organic-metal doped film, inhibit the oxidation of the metal, and is conducive to improving the charge generation efficiency and device stability.

[0040] (3) The compound described in the application can effectively reduce the driving voltage of the OLED device and improve the service life of the device after being applied to the OLED device as an organic electroluminescent functional layer material, has good application effect in the OLED light-emitting device, and has good industrialization prospect. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 Structure diagram of the material listed in the application applied to a single-layer OLED device;

[0042] In the figure: 1, substrate; 2, anode; 3, hole injection layer; 4, hole transport layer; 5, electron blocking layer; 6, light-emitting layer; 7, hole blocking layer; 8, electron transport layer; 9, electron injection layer; 10, cathode; 11, cover layer.

[0043] Figure 2 Structure diagram of the material listed in the application applied to a stacked OLED device;

[0044] In the figure: 1, substrate; 2, first electrode layer; 3, hole injection layer; 4, hole transport layer; 5, electron blocking layer; 6, light-emitting layer; 7, hole blocking layer; 8, electron transport layer; 9, charge generation layer (CGL layer); 10, hole transport layer; 11, electron blocking layer; 12, light-emitting layer; 13, hole blocking layer; 14, electron transport layer; 15, electron injection layer; 16, second electrode layer; 17, cover layer. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application, and the embodiments in the application and the features in the embodiments can be combined with each other without conflict. The application will be further described below with reference to the drawings and specific embodiments, but is not limited to the application.

[0046] In the application, unless otherwise specified, HOMO means the highest occupied orbital of a molecule, and LUMO means the lowest unoccupied orbital of a molecule. In addition, in the application, the HOMO and LUMO energy levels are expressed by absolute values, and the comparison between the energy levels is also the comparison of the absolute values, and the person skilled in the art knows that the greater the absolute value of the energy level is, the lower the energy of the energy level is.

[0047] In the drawings, the size of the layer and the region can be exaggerated for clarity. It will also be understood that when a layer or element is referred to as being "on" another layer or substrate, it can be directly on the other layer or substrate, or intervening layers can also be present. In addition, it will also be understood that when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers can also be present. Identical reference numerals designate the same elements throughout the specification.

[0048] In the present application, the terms "upper", "lower", "top" and "bottom" and the like used in describing the electrodes and the organic electroluminescent device, and other structures, merely indicate the orientation in a certain specific state, and do not mean that the relevant structure can only exist in the described orientation; on the contrary, if the structure can be changed in position, for example, inverted, the orientation of the structure is changed accordingly. Specifically, in the present application, the "bottom", "lower" side of the electrode refers to the side of the electrode that is close to the substrate during preparation, and the opposite side away from the substrate is the "top", "upper" side.

[0049] Organic electroluminescent device and stacked organic electroluminescent device

[0050] The present application provides an organic electroluminescent device, comprising a first electrode, a second electrode and an organic functional layer, the organic functional layer is located between the first electrode and the second electrode, the organic functional layer comprises a hole transport layer, a light-emitting layer and an electron transport layer, the light-emitting layer is located between the hole transport layer and the electron transport layer, and the electron transport layer comprises a compound described by general formula (1).

[0051] The present application provides a stacked organic electroluminescent device, comprising a first electrode, a second electrode, a first light-emitting unit, a second light-emitting unit and a charge generation layer, the first light-emitting unit, the second light-emitting unit and the charge generation layer are located between the first electrode and the second electrode, the charge generation layer is located between the first light-emitting unit and the second light-emitting unit, and the charge generation layer comprises a compound described by general formula (1).

[0052] In a preferred embodiment, the first light-emitting unit comprises a hole transport region, a light-emitting layer and an electron transport region, and the second light-emitting unit comprises a hole transport region, a light-emitting layer and an electron transport region. In a preferred embodiment, the charge generation layer further comprises a metal material. In a preferred embodiment, the metal material is Li, Ca, Ag, Cs or Yb.

[0053] As the substrate of the organic electroluminescent device of the present application, any substrate commonly used for organic electroluminescent devices can be used. Examples are transparent substrates such as glass or transparent plastic substrates; opaque substrates such as silicon substrates; flexible PI film substrates. Different substrates have different mechanical strength, thermal stability, transparency, surface smoothness, water resistance. Depending on the properties of the substrate, its use direction is different. In the present application, it is preferred to use a transparent substrate. The thickness of the substrate is not particularly limited.

[0054] A first electrode is formed on a substrate, and the first electrode and a second electrode can be opposite to each other. The first electrode can be an anode. The first electrode can be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode. When the first electrode is a transmissive electrode, it can be formed using a transparent metal oxide, such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or indium tin zinc oxide (ITZO), etc. When the first electrode is a semi-transmissive electrode or a reflective electrode, it can include Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or a mixture of metals. The thickness of the first electrode layer depends on the material used, and is typically 50-500 nm, preferably 70-300 nm, and more preferably 100-200 nm.

[0055] The organic functional material layer disposed between the first electrode and the second electrode includes, from bottom to top, a hole transport region, a light emitting layer, and an electron transport region.

[0056] In this context, the hole transport region constituting the organic electroluminescent device can include a hole injection layer, a hole transport layer, an electron blocking layer, etc.

[0057] As a material for the hole injection layer, the hole transport layer, and the electron blocking layer, any material can be used from among known materials related to OLED devices.

[0058] Examples of the above-described material can be a phthalocyanine derivative, a triazole derivative, a triarylmethane derivative, a triarylamine derivative, an oxazole derivative, an oxadiazole derivative, a hydrazone derivative, a stilbene derivative, a pyridinoline derivative, a polysilane derivative, an imidazole derivative, a phenylenediamine derivative, an amino-substituted quinone derivative, a styryl anthracene derivative, a styryl amine derivative, etc. styrenic compound, a fluorene derivative, a spirofluorene derivative, a silazane derivative, an aniline-based copolymer, a porphyrin compound, a carbazole derivative, a polyarylalkane derivative, a polyphenylenevinylene and a derivative thereof, a polythiophene and a derivative thereof, a poly-N-vinylcarbazole derivative, a conductive polymer oligomer such as a thiophene oligomer, an aromatic tertiary amine compound, a styryl amine compound, a triamine, a tetraamine, a benzidine, a propargyl diamine derivative, a p-phenylenediamine derivative, a m-phenylenediamine derivative, 1,1'-bis(4-diarylamino phenyl)cyclohexane, 4,4'-bis(diarylamine-based) biphenyl, bis[4-(diarylamine) phenyl] methane, 4,4"-bis(diarylamine) terphenyl, 4,4"'-bis(diarylamine) quaterphenyl, 4,4'-bis(diarylamine) diphenyl ether, 4,4'-bis(diarylamine) diphenyl sulfane, bis[4-(diarylamine) phenyl] dimethyl methane, bis[4-(diarylamine) phenyl]-di(trifluoromethyl) methane, or a 2,2-diphenylethene compound, etc.

[0059] Further, according to the device matching requirement, the hole transport film layer between the hole transport auxiliary layer and the hole injection layer of the organic electroluminescent device can be a single film layer or a superimposed structure of multiple hole transport materials. In this regard, the film thickness of the hole carrier conductive film layer of the above-mentioned various different functions is not particularly limited.

[0060] The hole injection layer comprises a hole-conducting host organic material and a P-doped material having a deep HOMO level (and a deep LUMO level accordingly). Based on the empirical summary, in order to achieve smooth injection of holes from the anode to the organic film layer, the HOMO level of the hole-conducting host organic material used in the anode interface buffer layer must have certain characteristics with the P-doped material, so as to achieve the occurrence of charge transfer state between the host material and the doped material, to achieve the ohmic contact between the buffer layer and the anode, and to achieve efficient injection of holes from the electrode to the hole injection.

[0061] In view of the above-mentioned empirical summary, for different hole-conducting host materials with different HOMO levels, different P-doped materials need to be selected to match them, so as to achieve ohmic contact at the interface and improve the hole injection effect.

[0062] Therefore, in one embodiment of the present application, in order to better inject holes, the hole injection layer further comprises a P-doped material having charge conductivity selected from the following: a quinone derivative, such as tetracyanoquinodimethane (TCNQ) and 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinone dimethane (F4-TCNQ); or a hexaazatriphenylene derivative, such as 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HAT-CN); or a cyclopropane derivative, such as 4,4',4"-((1E,1'E,1"E)-cyclopropane-1,2,3-trimethylene tricyanocarbonyl)) tris(2,3,5,6-tetrafluorobenzyl); or a metal oxide, such as tungsten oxide and molybdenum oxide, but not limited thereto.

[0063] In the hole injection layer of the present application, the ratio of the hole transport material to the P-doped material is 99:1-95:5, preferably 99:1-97:3, based on mass.

[0064] The thickness of the hole injection layer of the present application can be 5-100 nm, preferably 5-50 nm and more preferably 5-20 nm, but the thickness is not limited to this range.

[0065] The thickness of the hole transport layer of the present application can be 5-200 nm, preferably 10-150 nm and more preferably 20-100 nm, but the thickness is not limited to this range.

[0066] The thickness of the electron blocking layer of the present application can be 1-20 nm, preferably 5-10 nm, but the thickness is not limited to this range.

[0067] After the hole injection layer, the hole transport layer and the electron blocking layer are formed, the corresponding light emitting layer is formed on the electron blocking layer.

[0068] The light emitting layer can contain a host material and a dopant material, the host material can be used from any material selected from the known related materials for OLED devices, and the dopant material can be used from any material selected from the known related materials for OLED devices.

[0069] In the light emitting layer of the present application, the ratio of the host material to the guest material used is 99:1-70:30, preferably 99:1-85:15 and more preferably 97:3-87:13, based on mass.

[0070] The thickness of the light emitting layer can be adjusted to optimize the light emitting efficiency and the driving voltage. The preferred thickness range is 5 nm to 50 nm, further preferably 10-50 nm, more preferably 15-30 nm, but the thickness is not limited to this range.

[0071] In the present application, the electron transport region can include, from bottom to top, a hole blocking layer, an electron transport layer and an electron injection layer disposed on the light emitting layer, but is not limited thereto.

[0072] The hole blocking layer is a layer that blocks the holes injected from the anode from passing through the light emitting layer into the cathode, thereby prolonging the life of the device and improving the efficiency of the device. The hole blocking layer of the present application can be disposed on the light emitting layer. As the hole blocking layer material of the organic electroluminescent device of the present application, a compound having a hole blocking effect known in the prior art can be used, for example, a phenanthroline derivative such as bathocuproin (referred to as BCP), a metal complex of a hydroxyquinoline derivative such as aluminum(III) bis(2-methyl-8-quinolinolato)-4-phenylphenolate (BAlq), various rare earth complexes, an oxazole derivative, a triazole derivative, a triazine derivative, a pyrimidine derivative such as 9,9'-(5-(6-([1,1'-biphenyl]-4-yl)-2-phenylpyrimidin-4-yl)-1,3-phenylene)bis(9H-carbazole) (CAS No.: 1345338-69-3), etc. The thickness of the hole blocking layer of the present application can be 2-200 nm, preferably 5-150 nm and more preferably 10-100 nm, but the thickness is not limited to this range.

[0073] The electron transport layer can be disposed on the light emitting layer or the hole blocking layer, if present.

[0074] The thickness of the electron transport layer of the present application can be 10 to 80 nm, preferably 20 to 60 nm, and more preferably 25 to 45 nm, but the thickness is not limited to this range.

[0075] An electron injection layer can be disposed on the electron transport layer. The electron injection layer material is generally a material preferably having a low work function so that electrons are easily injected into the organic functional material layer. As the electron injection layer material of the organic electroluminescent device of the present application, an electron injection layer material for an organic electroluminescent device known in the art can be used, for example, lithium; a lithium salt such as lithium 8-hydroxyquinolinate, lithium fluoride, lithium carbonate, or lithium azide; or a cesium salt, cesium fluoride, cesium carbonate, or cesium azide. The thickness of the electron injection layer of the present application can be 0.1 to 5 nm, preferably 0.5 to 3 nm, and more preferably 0.8 to 1.5 nm, but the thickness is not limited to this range.

[0076] A second electrode can be disposed on the electron transport region. The second electrode can be a cathode. The second electrode can be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode. When the second electrode is a transmissive electrode, the second electrode can include, for example, Li, Yb, Ca, LiF / Ca, LiF / Al, Al, Mg, BaF, Ba, Ag, or a compound or mixture thereof; when the second electrode is a semi-transmissive electrode or a reflective electrode, the second electrode can include Ag, Mg, Yb, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or a compound or mixture thereof, but is not limited thereto. The thickness of the cathode depends on the material used, and is generally 10 to 50 nm, preferably 15 to 20 nm.

[0077] The organic electroluminescent device of the present application can further include an encapsulation structure. The encapsulation structure can be a protective structure that prevents external substances such as moisture and oxygen from entering the organic layer of the organic electroluminescent device. The encapsulation structure can be, for example, a can such as a glass can or a metal can; or a thin film covering the entire surface of the organic layer.

[0078] A method of manufacturing the organic electroluminescent device of the present application includes sequentially laminating an anode, a hole injection layer, a hole transport layer, an electron blocking layer, an organic film layer, an electron transport layer, an electron injection layer, and a cathode on a substrate, and optionally a cover layer. In this regard, a method such as vacuum deposition, vacuum evaporation, spin coating, casting, an LB method, inkjet printing, laser printing, or LITI can be used, but is not limited thereto. In the present application, it is preferable to use a vacuum evaporation method to form the respective layers. A person skilled in the art can routinely select the respective process conditions in the vacuum evaporation method as necessary.

[0079] The raw materials involved in the synthesis examples of the present application can be purchased from the market or prepared by conventional preparation methods in the art;

[0080] Synthesis of intermediate B-1:

[0081]

[0082] In a 500 ml round-bottom flask, under nitrogen protection, raw material A-1 (20 mmol), bis(pinacolato)diboron (44 mmol, CAS: 73183-34-3), KOAC (80 mmol), dioxane (150 mL) were added in turn, the air was replaced by nitrogen for 30 min, Pd(PPh3)4 (0.4 mmol) was added, and it was heated to reflux under nitrogen protection for 16 h. TLC detection of the reaction liquid showed that the raw material A-1 was completely reacted, after the reaction was completed, the reaction system was naturally cooled to room temperature, and then poured into a separatory funnel and shaken to separate the layers. The aqueous phase was extracted with dichloromethane (50 ml*3), the organic phase was combined and dried with anhydrous magnesium sulfate, filtered, and the filtrate was rotary evaporated to remove dichloromethane to obtain intermediate B-1. LC-MS: measured value: 331.29 ([M+H] + ); accurate mass: 330.22.

[0083] Intermediate B was prepared by a similar method to the synthesis of intermediate B-1, and the raw materials used are shown in Table 1;

[0084] Table 1

[0085]

[0086]

[0087] Example 1: Synthesis of compound 2

[0088]

[0089] In a 200 ml round-bottom flask, under nitrogen protection, raw material C-1 (22 mmol), intermediate B-1 (10 mmol), K2CO3 (30 mmol), tetrahydrofuran (900 mL), water (30 mL) were added in turn, the air was replaced by nitrogen for 30 min, Pd(PPh3)4 (0.2 mmol) was added, and it was heated to reflux under nitrogen protection for 24 h. TLC detection of the reaction liquid showed that the raw material C-1 was completely reacted, after the reaction was completed, the reaction system was naturally cooled to room temperature, and then rotary evaporated to remove the solvent, the residue was dissolved in dichloromethane 100 ml, washed with water 50 ml, poured into a separatory funnel and shaken to separate the layers. The aqueous phase was extracted with dichloromethane (50 ml*3), the organic phase was combined and dried with anhydrous magnesium sulfate, filtered, and the filtrate was rotary evaporated to remove dichloromethane to obtain a crude product, which was purified by silica gel column chromatography to obtain compound 2. Elemental analysis: C 42 H 26N4, Theory: C, 85.98; H, 4.47; N, 9.55; Found: C, 85.88; H, 4.45; N, 9.65. LC-MS: Found: 587.45 ([M+H] + ), Exact Mass: 586.22.

[0090] Example 2: Synthesis of compound 3

[0091]

[0092] Compound 3 was prepared according to the procedure for the synthesis of compound 2 in Example 1, except that intermediate B-3 was used instead of intermediate B-1. Elemental Analysis: C 42 H 26 N4, Theory: C, 85.98; H, 4.47; N, 9.55; Found: C, 86.07; H, 4.40; N, 9.54. LC-MS: Found: 587.40 ([M+H] + ), Exact Mass: 586.22.

[0093] Example 3: Synthesis of compound 11

[0094]

[0095] Compound 11 was prepared according to the procedure for the synthesis of compound 2 in Example 1, except that starting material C-2 was used instead of starting material C-1. Elemental Analysis: C 42 H 26 N4, Theory: C, 85.98; H, 4.47; N, 9.55; Found: C, 85.89; H, 4.50; N, 9.62. LC-MS: Found: 587.39 ([M+H] + ), Exact Mass: 586.22.

[0096] Example 4: Synthesis of compound 12

[0097]

[0098] Compound 12 was prepared according to the procedure for the synthesis of compound 2 in Example 1, except that starting material C-2 was used instead of starting material C-1, and intermediate B-3 was used instead of intermediate B-1. Elemental Analysis: C 42 H 26 N4, Theory: C, 85.98; H, 4.47; N, 9.55; Found: C, 86.03; H, 4.51; N, 9.50. LC-MS: Found: 587.29 ([M+H] + ), Exact Mass: 586.22.

[0099] Example 5: Synthesis of compound 17

[0100]

[0101] Compound 17 was prepared according to the procedure for the synthesis of compound 2 in Example 1, except that starting material C-3 was used instead of starting material C-1. Elemental Analysis: C 42 H 26 N4, Theoretical value: C, 85.98; H, 4.47; N, 9.55; Test value: C, 85.89; H, 4.52; N, 9.58. LC-MS: measured value: 587.35 ([M+H] + ), accurate mass: 586.22.

[0102] Example 6: Synthesis of compound 19

[0103]

[0104] Compound 19 was prepared according to the procedure for the synthesis of compound 2 in Example 1, except that intermediate B-4 was used instead of intermediate B-1. Elemental Analysis: C 46 H 28 N4, Theoretical value: C, 86.77; H, 4.43; N, 8.80; Test value: C, 86.78; H, 4.52; N, 8.76. LC-MS: measured value: 637.29 ([M+H] + ), accurate mass: 636.23.

[0105] Example 7: Synthesis of compound 20

[0106]

[0107] Compound 20 was prepared according to the procedure for the synthesis of compound 2 in Example 1, except that intermediate B-5 was used instead of intermediate B-1. Elemental Analysis: C 46 H 28 N4, Theoretical value: C, 86.77; H, 4.43; N, 8.80; Test value: C, 86.73; H, 4.38; N, 8.88. LC-MS: measured value: 637.27 ([M+H] + ), accurate mass: 636.23.

[0108] Example 8: Synthesis of compound 25

[0109]

[0110] Compound 25 was prepared according to the procedure for the synthesis of compound 2 in Example 1, except that starting material C-2 was used instead of starting material C-1, and intermediate B-4 was used instead of intermediate B-1. Elemental Analysis: C46 H 28 N4, Theor. : C, 86.77; H, 4.43; N, 8.80; Found: C, 86.74; H, 4.37; N, 8.90. LC-MS: Measured: 637.38 ([M+H] + ), Exact mass: 636.23.

[0111] Example 9: Synthesis of compound 26

[0112]

[0113] Compound 26 was prepared according to the procedure for the synthesis of compound 2 in Example 1, except that starting material C-2 was used instead of starting material C-1, and intermediate B-5 was used instead of intermediate B-1. Elemental Analysis: C 46 H 28 N4, Theor. : C, 86.77; H, 4.43; N, 8.80; Found: C, 86.84; H, 4.40; N, 8.77. LC-MS: Measured: 637.41 ([M+H] + ), Exact mass: 636.23.

[0114] Example 10: Synthesis of compound 29

[0115]

[0116] Compound 29 was prepared according to the procedure for the synthesis of compound 2 in Example 1, except that starting material C-3 was used instead of starting material C-1, and intermediate B-4 was used instead of intermediate B-1. Elemental Analysis: C 46 H 28 N4, Theor. : C, 86.77; H, 4.43; N, 8.80; Found: C, 86.75; H, 4.50; N, 8.73. LC-MS: Measured: 637.42 ([M+H] + ), Exact mass: 636.23.

[0117] Example 11: Synthesis of compound 30

[0118]

[0119] Compound 30 was prepared according to the procedure for the synthesis of compound 2 in Example 1, except that starting material C-3 was used instead of starting material C-1, and intermediate B-5 was used instead of intermediate B-1. Elemental Analysis: C 46 H 28 N4, Theor. : C, 86.77; H, 4.43; N, 8.80; Found: C, 86.66; H, 4.50; N, 8.88. LC-MS: Measured: 637.66 ([M+H]+ Exact mass: 636.23.

[0120] Example 12: Synthesis of compound 31

[0121]

[0122] Compound 31 was prepared according to the procedure for synthesis of compound 2 in Example 1, except that intermediate B-6 was used instead of intermediate B-1. Elemental analysis: C 46 H 28 N4, Theoretical value: C, 86.77; H, 4.43; N, 8.80; Test value: C, 86.83; H, 4.32; N, 8.92. LC-MS: measured value: 637.45 ([M+H] + ), exact mass: 636.23.

[0123] Example 13: Synthesis of compound 32

[0124]

[0125] Compound 32 was prepared according to the procedure for synthesis of compound 2 in Example 1, except that intermediate B-7 was used instead of intermediate B-1. Elemental analysis: C 46 H 28 N4, Theoretical value: C, 86.77; H, 4.43; N, 8.80; Test value: C, 86.81; H, 4.39; N, 8.84. LC-MS: measured value: 637.32 ([M+H] + ), exact mass: 636.23.

[0126] Example 14: Synthesis of compound 37

[0127]

[0128] Compound 37 was prepared according to the procedure for synthesis of compound 2 in Example 1, except that raw material C-2 was used instead of raw material C-1, and intermediate B-6 was used instead of intermediate B-1. Elemental analysis: C 46 H 28 N4, Theoretical value: C, 86.77; H, 4.43; N, 8.80; Test value: C, 86.95; H, 4.27; N, 8.72. LC-MS: measured value: 637.65 ([M+H] + ), exact mass: 636.23.

[0129] Example 15: Synthesis of compound 38

[0130]

[0131] Compound 38 was prepared according to the procedure for the synthesis of Compound 2 in Example 1, except that starting material C-2 was used instead of starting material C-1, and intermediate B-7 was used instead of intermediate B-1. Elemental Analysis: C 46 H 28 N4, Theoretical value: C, 86.77; H, 4.43; N, 8.80; Test value: C, 86.57; H, 4.40; N, 8.95. LC-MS: measured value: 637.16 ([M+H] + ), accurate mass: 636.23.

[0132] Example 16: Synthesis of Compound 42

[0133]

[0134] Compound 42 was prepared according to the procedure for the synthesis of Compound 2 in Example 1, except that starting material C-3 was used instead of starting material C-1, and intermediate B-7 was used instead of intermediate B-1. Elemental Analysis: C 46 H 28 N4, Theoretical value: C, 86.77; H, 4.43; N, 8.80; Test value: C, 86.57; H, 4.40; N, 8.95. LC-MS: measured value: 637.16 ([M+H] + ), accurate mass: 636.23.

[0135] Example 17: Synthesis of Compound 48

[0136]

[0137] Compound 48 was prepared according to the procedure for the synthesis of Compound 2 in Example 1, except that intermediate B-2 was used instead of intermediate B-1. Elemental Analysis: C 48 H 30 N4, Theoretical value: C, 86.98; H, 4.56; N, 8.45; Test value: C, 87.07; H, 4.50; N, 8.40. LC-MS: measured value: 663.35 ([M+H] + ), accurate mass: 662.25.

[0138] Example 18: Synthesis of Compound 89

[0139]

[0140] Compound 89 was prepared according to the procedure for the synthesis of Compound 2 in Example 1, except that intermediate B-9 was used instead of intermediate B-1. Elemental Analysis: C 54 H 34N4, Theory: C, 87.78; H, 4.64; N, 7.58; Found: C, 87.86; H, 4.60; N, 7.55. LC-MS: Obs. 739.34 ([M+H] + ), Accurate Mass: 738.28.

[0141] Example 19: Synthesis of compound 116

[0142]

[0143] Compound 116 was prepared according to the procedure for synthesis of compound 2 in Example 1, except that intermediate B-10 was used to replace intermediate B-1. Elemental Analysis: C 54 H 34 N4, Theory: C, 87.78; H, 4.64; N, 7.58; Found: C, 87.86; H, 4.60; N, 7.55. LC-MS: Obs. 739.34 ([M+H] + ), Accurate Mass: 738.28.

[0144] Example 20: Synthesis of compound 142

[0145]

[0146] Compound 142 was prepared according to the procedure for synthesis of compound 2 in Example 1, except that intermediate B-8 was used to replace intermediate B-1. Elemental Analysis: C 41 H 25 N5, Theory: C, 83.79; H, 4.29; N, 11.92; Found: C, 83.90; H, 4.37; N, 11.86. LC-MS: Obs. 588.55 ([M+H] + ), Accurate Mass: 587.21.

[0147] Example 21: Synthesis of compound 164

[0148]

[0149] Compound 164 was prepared according to the procedure for synthesis of compound 2 in Example 1, except that starting material C-4 was used to replace starting material C-1. Elemental Analysis: C 50 H 30 N4, Theory: C, 87.44; H, 4.40; N, 8.16; Found: C, 87.50; H, 4.37; N, 8.11. LC-MS: Obs. 687.33 ([M+H] + ), Accurate Mass: 686.25.

[0150] Example 22: Synthesis of compound 166

[0151]

[0152] Compound 166 was prepared according to the method for synthesizing compound 2 in Example 1, except that the starting material C-5 was used to replace the starting material C-1. Elemental analysis: C 40 H 24 N6, Theoretical value: C, 81.61; H, 4.11; N, 14.28; Test value: C, 81.55; H, 4.08; N, 14.32. LC-MS: measured value: 589.25 ([M+H] + ), accurate mass: 588.21.

[0153] Example 23: Synthesis of compound 168

[0154]

[0155] Compound 168 was prepared according to the method for synthesizing compound 2 in Example 1, except that the starting material C-6 was used to replace the starting material C-1. Elemental analysis: C 54 H 34 N4, Theoretical value: C, 87.78; H, 4.64; N, 7.58; Test value: C, 87.81; H, 4.58; N, 7.60. LC-MS: measured value: 739.40 ([M+H] + ), accurate mass: 738.28.

[0156] The application effects of the compounds synthesized according to the present application as the electron transport layer in devices are illustrated in detail below by means of device examples 1-23 and device comparison examples 1-10. Device examples 2-23 and device comparison examples 1-10 are compared with device example 1, the manufacturing process of the devices is completely the same, and the same substrate material and electrode material are used, and the film thickness of the electrode material is also kept consistent, the only difference is that the electron transport material in the devices is changed. The device structure is shown in Table 2, and the performance test results of each device are shown in Table 3.

[0157] The molecular structural formula of the related material is as follows:

[0158]

[0159] The structures of comparative compounds ET-1, ET-2, ET-3, ET-4, ET-5, ET-6, ET-7, ET-8, ET-9 and ET-10 are shown above. The above materials are all commercially available.

[0160] Device example 1

[0161] The specific preparation process is as follows:

[0162] As shown in Figure 1 Figure 1, the transparent substrate layer 1 is transparent glass, the anode layer 2 is Ag (100 nm), the anode layer 2 is washed, i.e. sequentially washed with alkali, pure water, dried, and then washed with ultraviolet-ozone to remove organic residues on the surface of the anode layer. After the above washing, on the anode layer 2, a vacuum evaporation device is used to evaporate HT-1 and P-1 with a film thickness of 10 nm as a hole injection layer 3, the mass ratio of HT-1 and P-1 being 97:3. Then HT-1 with a thickness of 117 nm is evaporated as a hole transport layer 4. Subsequently, EB-1 with a thickness of 10 nm is evaporated as an electron blocking layer 5. After the above electron blocking material is evaporated, an OLED light-emitting device is prepared, and the light-emitting layer 6 has a structure including BH-1 used as a host material in the OLED light-emitting layer 6, and BD-1 used as a dopant material, the doping ratio of the dopant material being 3% by weight, and the film thickness of the light-emitting layer being 20 nm. After the above light-emitting layer 6, HB-1 is continuously evaporated, the film thickness of the evaporated HB-1 being 8 nm, and the evaporated HB-1 is used as a hole blocking layer 7. On the above hole blocking layer 7, compound 2 and Liq are continuously evaporated, the mass ratio of compound 2 and Liq being 1:1, the vacuum evaporation film thickness of the material being 30 nm, and the material is used as an electron transport layer 8. On the electron transport layer 8, a LiF layer with a film thickness of 1 nm is prepared by a vacuum evaporation device, and the LiF layer is used as an electron injection layer 9. On the electron injection layer 9, an Mg:Ag electrode layer with a film thickness of 16 nm is prepared by a vacuum evaporation device, the mass ratio of Mg and Ag being 1:9, and the Mg:Ag electrode layer is used as a cathode layer 10. On the cathode layer 10, CP-1 with a thickness of 65 nm is vacuum evaporated as a cover layer 11.

[0163] Device Examples 2-20 and Device Comparative Examples 1-10 are prepared in a similar manner to Device Example 1, and the substrate is transparent glass, and the anode is Ag (100 nm), and the difference is that the parameters in Table 2 below are used.

[0164] Table 2

[0165]

[0166]

[0167] The devices are tested, and the driving voltage, current efficiency, CIEx, CIEy, and LT95 lifetime of the devices are tested. The driving voltage, current efficiency, CIEx, and CIEy are tested by using an IVL (current-voltage-luminance) test system (Suzhou Fudashan Scientific Instrument Co., Ltd.), and the current density during the test is 10 mA / cm 2 . LT95 refers to the time taken for the luminance of the device to decay to 95% of the initial luminance, and the current density during the test is 50 mA / cm 2; the lifetime test system is EAS-62C OLED device lifetime tester from Japan System Techno Co. Ltd. The efficiency and lifetime data of each device example and device comparative example are shown in Table 3.

[0168] Table 3

[0169]

[0170]

[0171] From the device data results in Table 3, it can be seen that the organic light-emitting device of the present application has obtained great improvement in driving voltage and lifetime relative to the OLED device of the comparative material.

[0172] Further, in order to illustrate the application of the compound of the present application as a charge generation layer in an organic electroluminescent device, the performance of the material of the present application is researched by constructing a stacked device (2-layer blue light device). It should be noted that, since the stacked device needs to consider the optical design of the device, compared with the single-layer device structure, the film thickness and structure of the device need to be redesigned and adjusted, and it is not simply to stack the single-layer device.

[0173] The application effect of the compound synthesized in the device as a charge generation layer (CGL) material in the stacked OLED device is illustrated in detail below by device examples 24-46 and device comparative examples 11-20. Device examples 25-46 and device comparative examples 11-20 are compared with device example 24, the manufacturing process of the device is completely the same, and the same substrate material and electrode material are used, and the film thickness of the electrode material is also consistent, the difference is that the CGL material in the device is changed. The specific device structure is shown in Table 4. In Table 4, the device structure is only listed for the material structure of the CGL layer for convenience, and the other layer structure and film thickness are omitted because they are consistent.

[0174] Table 4

[0175]

[0176]

[0177] Device example 24

[0178] The specific preparation process is as follows:

[0179] As Figure 2As shown, the transparent substrate layer 1 is transparent glass, the anode layer 2 is Ag (100 nm), the anode layer 2 is washed, i.e. sequentially washed with alkali, pure water, dried, and then washed with ultraviolet-ozone to remove organic residues on the surface of the anode layer. After the above washing, on the anode layer 2, a vacuum evaporation device is used to evaporate HT-1 and P-1 with a film thickness of 10 nm as the hole injection layer 3, the mass ratio of HT-1 and P-1 is 97:3. Then HT-1 with a thickness of 117 nm is evaporated as the hole transport layer 4. Then EB-1 with a thickness of 10 nm is evaporated as the electron blocking layer 5. After the above electron blocking material is evaporated, the light-emitting layer 6 of the OLED light-emitting device is prepared, which includes BH-1 as the host material and BD-1 as the dopant material used in the OLED light-emitting layer 6, the doping ratio of the dopant material is 3% by weight, and the film thickness of the light-emitting layer is 20 nm. After the above light-emitting layer 6, HB-1 is continuously evaporated with a film thickness of 8 nm as the hole blocking layer 7. On the above hole blocking layer 7, ET-A and Liq are continuously evaporated, the mass ratio of ET-A and Liq is 1:1. The vacuum evaporation film thickness of the material is 20 nm, which is the electron transport layer 8. On the electron transport layer 8, a vacuum evaporation device is used to evaporate the charge generation layer 9 (CGL layer) with a structure of Yb: compound 2 (the doping ratio of Yb is 5% by weight) and a film thickness of 10 nm. Then, HT-1 and P-1 with a film thickness of 10 nm are continuously evaporated as the hole injection layer 3, the mass ratio of HT-1 and P-1 is 97:3. Then HT-1 with a thickness of 117 nm is evaporated as the hole transport layer 10. Then EB-1 with a thickness of 10 nm is evaporated as the electron blocking layer 11. After the above electron blocking material is evaporated, the light-emitting layer 12 of the OLED light-emitting device is prepared, which includes BH-1 as the host material and BD-1 as the dopant material used in the OLED light-emitting layer 6, the doping ratio of the dopant material is 3% by weight, and the film thickness of the light-emitting layer is 20 nm. After the above light-emitting layer 12, HB-1 is continuously evaporated with a film thickness of 8 nm as the hole blocking layer 13. On the above hole blocking layer 13, ET-A and Liq are continuously evaporated, the mass ratio of ET-A and Liq is 1:1, and the film thickness is 30 nm, which is the electron transport layer 14. On the electron transport layer 14, a LiF layer with a film thickness of 1 nm is prepared by a vacuum evaporation device, which is the electron injection layer 15. On the electron injection layer 15, a Mg:Ag electrode layer with a film thickness of 16 nm is prepared by a vacuum evaporation device, the mass ratio of Mg and Ag is 1:9, which is the cathode layer 16. On the cathode layer 16, CP-1 with a film thickness of 65 nm is vacuum evaporated as the cover layer 17.

[0180] After the OLED light-emitting device is prepared according to the above steps, the efficiency data and light decay life of the device are measured, and the results are shown in Table 5. The molecular structure of the related materials is shown below.

[0181]

[0182] The devices were tested for driving voltage, current efficiency, CIEx, CIEy and LT95 lifetime. The driving voltage, current efficiency, CIEx and CIEy were tested by IVL (current-voltage-luminance) test system (Suzhou Fudashan Scientific Instrument Co., Ltd.), and the current density during the test was 10 mA / cm 2 . LT95 refers to the time for the luminance of the device to decay to 95% of the initial luminance, and the current density during the test was 50 mA / cm 2 ; and the lifetime test system was EAS-62C type OLED device lifetime tester of Japan System Technique Co., Ltd. The efficiency and lifetime data of each device example and device comparative example are shown in Table 5.

[0183] Table 5

[0184]

[0185]

[0186] From the above Tables 3 and 5, it can be seen that, when the compound of the present application is applied as an electron transport material in a single-layer device, the device voltage is reduced, and the device efficiency and device lifetime are obviously improved compared with the comparative material, which indicates that the compound of the present application has good technical effects when applied as an electron transport material in a single-layer OLED. Further, when the compound of the present application is applied as a CGL material in a stacked device, the device voltage is reduced, and the device efficiency and device lifetime are improved compared with the comparative material, which further indicates that the compound of the present application has good technical effects when applied as a CGL material in a stacked OLED device.

[0187] Therefore, it can be seen that the compound of the present application achieves good technical effects by limiting the 1,10-bisphenanthroline group substituted by a specific site aryl or heteroaryl group, and bridged by a specific aromatic or heteroaromatic group. The reasons are mainly as follows: due to the introduction of the 1,10-bisphenanthroline group substituted by a specific site phenyl group, the molecular planar stacking ability can be effectively improved, and the intermolecular interaction is increased. At the same time, the group has strong electron-withdrawing ability, which can effectively improve the electron injection and transport ability, improve the electron injection and transport ability, thereby reducing the device driving voltage. Further, by adding a specific bridging group, the symmetry of the molecule is effectively destroyed, the stereostructure of the molecule is increased, the film crystallinity of the molecule is inhibited, the stability and durability of the material are improved, which is beneficial to improve the device efficiency and service life. And because the compound of the present application has good electron-withdrawing ability, stability and electron resistance, it is used as an n-type material of the CGL layer, can form a stable N-metal coordination bond with metals such as Yb, form a stable and flat organic-metal doped film, inhibit the oxidation of the metal, and is beneficial to improve the charge generation and device stability.

[0188] The above only describes the preferred embodiments of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A compound having a bisphen diol structure, characterized in that, The structure of the compound is represented by any one of General Formula (1-1) to General Formula (1-3): In General Formula (1), L1represents a phenyl group, a naphthyl group, a biphenyl group, a terphenyl group, or a pyridyl group; Ar1represents a phenyl group, a pyridyl group, a naphthyl group, or a biphenyl group.

2. The compound of claim 1, wherein The L1is represented by any one of formulae b-1 to b-7; 3. The compound of claim 1, wherein The L1is represented by any one of formulae c-1 to c-9; 4. The compound of claim 1, wherein The specific structure of the compound is represented by any one of the following structures:

5. An organic electroluminescent device comprising a first electrode, a second electrode and an organic functional layer, the organic functional layer being located between the first electrode and the second electrode, the organic functional layer comprising a hole transport region, a light-emitting layer and an electron transport region, the light-emitting layer being located between the hole transport region and the electron transport region, characterized in that, The electron transport region contains the compound containing a bisphenanthroline structure according to any one of claims 1 to 4.

6. A stacked organic electroluminescent device comprising a first electrode, a second electrode, a first light-emitting unit, a second light-emitting unit, and a charge generation layer, the first light-emitting unit, the second light-emitting unit, and the charge generation layer being located between the first electrode and the second electrode, the charge generation layer being located between the first light-emitting unit and the second light-emitting unit, characterized in that, The charge generation layer contains the compound containing a bisphenanthroline structure according to any one of claims 1 to 4.

7. The stacked organic electroluminescent device according to claim 6, wherein The first light emitting unit contains a hole transport region, a light emitting layer, and an electron transport region, and the second light emitting unit contains a hole transport region, a light emitting layer, and an electron transport region.

8. The stacked organic electroluminescent device according to claim 6, wherein The charge generation layer further contains a metal material.

9. The stacked organic electroluminescent device according to claim 8, wherein The metal material is Li, Ca, Ag, Cs, or Yb.

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