Luminescent materials for OLEDs

Abstract

The invention relates to luminescent materials for OLEDs based on specific metal complexes and to the corresponding use thereof in OLEDs.

Description

Technical Field

[0001] The present invention relates to a light-emitting layer for an OLED, which emits, for example, circularly polarized light, and which has a specific metal complex. The present invention also relates to an OLED comprising such a light-emitting layer, a method for generating light, and the use of a metal complex for generating light in the light-emitting layer of an OLED. In addition, the present invention includes a ligand for the corresponding metal complex. Background Art

[0002] OLEDs are nowadays widely known for their various applications. In particular, they are advantageous in televisions or monitors and in general in display devices due to their low energy operation and good image quality with a high contrast ratio.

[0003] OLED-based displays are equipped with filters that reduce reflections from other light sources such as sunlight, thus preventing a loss of contrast. A linear polarizer in combination with a quarter-wave plate is used as a filter, but even so, only about 50% of the light emitted by the light-emitting layer is able to pass through and be detected by the user. Therefore, in order to achieve a corresponding brightness, high electrical powers are required to compensate for the light losses. In contrast, a display with a high asymmetry factor g Lum The circularly polarised luminescence (CPL) generated by the chiral luminescent material can pass 100% through the filter, thereby achieving significantly higher energy efficiency. However, these technologies have not been fully recognized in the prior art.

[0004] Currently, efficient commercial OLEDs require phosphorescent triplet emitters, usually in the form of metal complexes of the expensive elements iridium or platinum, to efficiently convert all excitons formed by electron-hole recombination into light. An alternative approach is to emit light through thermally activated delayed fluorescence (TADF), which can be achieved with complexes of the cheaper element copper or inexpensive organic compounds. While green-emitting OLEDs perform well, efficient electroluminescence in the deep red range remains a challenge. Summary of the invention

[0005] Therefore, it is an object of the present invention to at least partially overcome at least one disadvantage of the prior art. In particular, it is an object of the present invention to provide a light-emitting layer capable of efficient electroluminescence in the deep red range.

[0006] This object is at least partially solved by the compounds according to claim 1. The problem is also solved at least partially by the use according to claim 9, the metal complex according to claim 10, the use according to claim 14, a light-emitting layer for an organic light-emitting diode having the features of claim 15, an organic light-emitting diode having the features of claim 16 and a method having the features of claim 18. Preferred embodiments of the invention are described in the dependent claims, the description or the drawings, wherein the dependent claims or the further features described or shown in the description or the drawings may represent objects of the invention alone or in any combination, unless the context clearly indicates otherwise.

[0007] A p-cyclophane-carbene compound is described, characterized in that the p-cyclophane-carbene compound corresponds to the following structure (I):

[0008] in:

[0009] R 1 is selected from aryl, heteroaryl, alkyl, perfluoroalkyl, perfluoroaryl, wherein

[0010] R 2 and R 3 are the same or different and are independently selected from aryl, heteroaryl, alkyl, alkenyl, alkynyl, perfluoroalkyl, perfluoroaryl, wherein

[0011] R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 are identical or different and are independently selected from hydrogen, deuterium, halogen, silyl, alkyl, alkenyl, alkynyl, perfluoroalkyl, aryl, heteroaryl, alkoxy, wherein

[0012] R 12 , R 13 , R 14 , R 15 , R 16 , R 17 are the same or different and are independently selected from hydrogen, deuterium, halogen, alkyl, alkenyl, alkynyl, perfluoroalkyl, aryl, heteroaryl, alkoxy, COR 18 、CO2R 19 ,CONR 20 , cyano, nitro, SO3R 21 PO3R 22 2, where

[0013] R18 , R 19 , R 20 , R 21 , R 22 are identical or different and are independently selected from hydrogen, deuterium, halogen, silyl, alkyl, alkenyl, alkynyl, perfluoroalkyl, aryl, heteroaryl, alkoxy, and wherein

[0014] An - It is an anion.

[0015] The compound shown in structure (I) is shown as a salt in which the cation acts as a ligand capable of forming a bond with a metal. In this respect, it will be immediately clear to the person skilled in the art that when referring to the corresponding ligand in the context of the present invention, this refers to the paracyclophane carbene cation, which can then bond to or be bonded to the metal atom as a ligand usually does.

[0016] In principle, for example, C1-alkyl is intended to denote an alkyl radical having one carbon atom, wherein the corresponding designations of the other radicals are to be understood accordingly, so that, for example, C12-alkoxy denotes an alkoxy radical having 12 carbon atoms.

[0017] In addition, the term An - Essentially one anion is described, regardless of its valency. The paracyclophane-carbene cation and anion are intended to form neutral salts. Depending on the anion selected, therefore, there may be, for example, one, two or more cations to form a paracyclophane-carbene compound according to structure (I) that is generally a neutral salt.

[0018] The p-cyclophane-carbene compounds according to structure (I) are particularly advantageous for forming ligands for metal complexes which are used as light-emitting materials in OLEDs.

[0019] For use in OLEDs, luminescence by thermally activated delayed fluorescence (TADF) represents an alternative to prior art solutions, which can be realized with complexes of very cheap metals such as copper or with cheap organic compounds. While green-emitting OLEDs perform well, efficient electroluminescence in the deep red range remains a challenge.

[0020] Compared to existing iridium emitters, the ligands according to the invention are used to convert commercially available starting materials into racemic metal complexes, such as copper(I) complexes, which can be produced very cheaply and, due to TADF, show the highest radiative constants of molecular emitters reported to date in the red range, up to 2×10 6 s -1 , and has also been successfully used to test OLEDs.

[0021] When used as ligands for metal complexes in OLED emitters, the described ligands thus enable very high light yields and thus significantly improve the quality of the OLEDs. Furthermore, they can be operated with relatively very low energy input.

[0022] Due to their chiral properties, these compounds are also suitable for use in enantiomerically pure form in OLEDs based on circularly polarized emission (CPL) in order to pass the antireflection filters of the display with maximum efficiency. Therefore, this new class of emitters shows interesting potential for commercial energy-efficient applications. If necessary, these positive properties can be further improved by further optimizing the molecular structure and the OLED structure.

[0023] In principle, the light-emitting layer according to the invention can thus be tailored to the respective application.

[0024] Furthermore, the possible synthesis routes can lead to significantly lower production costs and / or easier production, for example, compared to the iridium or platinum complexes used in the prior art.

[0025] According to the invention, low-energy operation of OLEDs can thus be combined with a high light yield, thereby achieving high quality while keeping costs moderate, wherein in particular a high light yield in the red spectral range is possible.

[0026] As regards the p-cyclophane-carbene compounds which can be used as ligands in the metal complexes of the light-emitting layer of OLEDs, particular preference may be given to:

[0027] R 1 is selected from C5 to C18 aryl, C5 to C18 heteroaryl, C1 to C18 alkyl, C1 to C18 perfluoroalkyl, C5 to C18 perfluoroaryl, wherein

[0028] R 2 and R 3 are the same or different and are independently selected from C5 to C18 aryl, C5 to C18 perfluoroaryl, C5 to C18 heteroaryl, C1 to C12 alkyl, C1 to C12 alkenyl, C1 to C12 alkynyl, C1 to C12 perfluoroalkyl, wherein

[0029] R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11are the same or different and are independently selected from hydrogen, deuterium, halogen, silyl, C1 to C12 alkyl, C1 to C12 alkenyl, C1 to C12 alkynyl and C1 to C12 perfluoroalkyl, C5 to C18 aryl, C5 to C18 perfluoroaryl, C5 to C18 heteroaryl, C1 to C12 alkoxy, wherein

[0030] R 12 , R 13 , R 14 , R 15 , R 16 , R 17 are the same or different and are independently selected from hydrogen, C1 to C18 alkyl, C1 to C18 alkenyl, C1 to C18 alkynyl, C1 to C18 perfluoroalkyl, C5 to C18 aryl, C5 to C18 perfluoroaryl, C5 to C18 heteroaryl, C1 to C18 alkoxy, COR 18 、CO2R 19 ,CONR 20 , cyano, nitro, SO3R 21 PO3R 22 2, where

[0031] R 18 , R 19 , R 20 , R 21 , R 22 are the same or different and are independently selected from hydrogen, deuterium, halogen, silyl, C1 to C18 alkyl, C1 to C18 alkenyl, C1 to C18 alkynyl, C1 to C18 perfluoroalkyl, C5 to C18 aryl, C5 to C18 heteroaryl, C1 to C18 alkoxy, and wherein

[0032] An - is an anion selected from the group consisting of halide, trifluoromethanesulfonate, sulfate, phosphate, silicate, tetrafluoroborate, hexafluorophosphate, and tetraarylborate.

[0033] More preferably, R 1 It can be selected from C9 to C18 aryl, C9 to C18 heteroaryl, C1 to C12 alkyl, C1 to C12 perfluoroalkyl, C9 to C18 perfluoroaryl, wherein

[0034] R 2 and R 3 are identical or different and are independently selected from C5 to C6 aryl and C5 to C6 heteroaryl,

[0035] R 4 , R 5 , R 6 , R 7 , R 8 , R 9, R 10 , R 11 are identical or different and are independently selected from hydrogen, deuterium, halogen and silyl, C1 to C4 alkyl, C1 to C4 alkenyl, C1 to C4 alkynyl and C1 to C4 perfluoroalkyl, C5 to C6 aryl, C5 to C6 heteroaryl, C5 to C6 perfluoroaryl, C1 to C4 alkoxy, wherein

[0036] R 12 , R 13 , R 14 , R 15 , R 16 , R 17 are the same or different and are independently selected from hydrogen, C1 to C4 alkyl, C1 to C4 alkenyl, C1 to C4 alkynyl, and C1 to C4 perfluoroalkyl, C5 to C6 aryl, C5 to C6 perfluoroaryl, C5 to C6 heteroaryl, C1 to C4 alkoxy, COR 18 、CO2R 19 ,CONR 20 , cyano, nitro, SO3R 21 PO3R 22 2, where

[0037] R 18 , R 19 , R 20 , R 21 , R 22 are the same or different and are independently selected from hydrogen, deuterium, halogen, silyl, C1 to C4 alkyl, C1 to C4 alkenyl, C1 to C4 alkynyl, C1 to C4 perfluoroalkyl, C5 to C12 aryl, C5 to C12 heteroaryl, C1 to C4 alkoxy, and wherein

[0038] An - is an anion selected from the group consisting of halide, trifluoromethanesulfonate, sulfate, phosphate, silicate, tetrafluoroborate, hexafluorophosphate, and tetraarylborate.

[0039] In particular, R 1 It may be a dialkylphenyl group. For example, the dialkylphenyl group may be 2,6-diisopropylphenyl group.

[0040] It is also preferred that R 2 and R 3 In principle, the benzene ring can be substituted, but it is also possible for the benzene ring to be unsubstituted.

[0041] It is further preferred that R 4 , R 5 , R 6 , R 7 , R 8 , R 9, R 10 and R 11 For hydrogen.

[0042] Additionally or alternatively, R 12 , R 13 , R 14 , R 15 , R 16 and R 17 Hydrogen may be advantageous.

[0043] In a specific embodiment of the present invention, it can be provided that the para-cyclophane-carbene compound has the following structure (II):

[0044]

[0045] In this structure, the group 'dipp' refers to 2,6-diisopropylphenyl, and the anion OTF - Refers to the trifluoromethanesulfonic acid group, which can also be called a triflate group.

[0046] According to the above content, the present invention also relates to the use of the above-mentioned p-cyclophane-carbene compound in producing a metal complex of a light-emitting material of a light-emitting layer of an organic light-emitting diode.

[0047] In summary, as described in detail above for cyclophane-carbene compounds, low-energy operation of OLEDs can be combined with high light yields, thereby achieving high quality while keeping costs moderate, wherein in particular high light yields in the red spectral range are possible.

[0048] With regard to further advantages and technical features of the cyclophane-carbene compounds and their use, reference is made to the description of the metal complexes, their use as luminescent materials in luminescent layers, the luminescent layers, the organic light-emitting diodes, the methods, the drawings and the legends to the drawings.

[0049] Furthermore, a metal complex is described. The metal complex is characterized by having the following structure (III):

[0050] L 1 Me[L 2 ] m [L 3 ] m (III)

[0051] Among them, L 1 is a para-cyclophane-carbene ligand as described above, wherein

[0052] L 2 and L 3 The same or different and independently selected from NR 23 2. NR 243.PR 25 2. PR 26 3. OR 27 2. OR 28 , SR 29 , SR 30 2. SR 31 , SeR 32 2. SeR 34 、TeR 35 2.TeR 36 , silyl, aryl, heteroaryl, alkenyl, alkynyl, isonitrile, cyclopentadienyl, halogen, wherein

[0053] m is a number selected from 0, 1 or 2, provided that at least one m is not equal to zero, wherein

[0054] R 23 , R 24 , R 25 , R 26 , R 27 , R 28 , R 29 , R 30 , R 31 , R 32 , R 33 , R 34 , R 35 , R 36 are the same or different and are independently selected from aryl, heteroaryl, alkenyl, alkynyl, alkyl, perfluoroalkyl, perfluoroaryl, and wherein

[0055] Me is a metal selected from copper, silver and gold.

[0056] About Ligand L 1 As a description of the paracyclophane-carbene ligand, the following should be noted. As is well known and well-known in the literature, the paracyclophane-carbene salt reacts with a base to form a neutral carbene ligand that binds to a metal. In other words, the paracyclophane-carbene compound can also be described as a corresponding ligand salt having a paracyclophane-carbene structural unit as a ligand.

[0057] In principle, in addition to the ligand L 1 In addition, the metal of the metal complex can also have only one ligand L 2 Without ligand L 3 , or there is only one ligand L 3 Without ligand L 2 , or ligand L 2 and L 3 Both exist. In addition, the ligand L 2 and L 3 may be separated from each other, or ligand L may be present2 , which binds to the metal with two bonds and can therefore be referred to as a bridging ligand or a chelating ligand.

[0058] Such metal complexes are used in particular as emitting materials in the emitting layer of organic light-emitting diodes. This has particular advantages for achieving efficient electroluminescence, especially in the deep red range. This has often remained a challenge for solutions from the prior art.

[0059] Compared to existing iridium emitters, the metal complexes according to the invention describe racemic metal complexes which can be produced very inexpensively from commercial starting materials and which, due to TADF, have the highest radiative constants reported to date for molecular emitters in the red range, up to 2×10 6 s -1 , and has also been successfully used to test OLEDs.

[0060] Overall, very high light yields can be achieved, which can significantly improve the quality of OLEDs. In addition, they can be operated with relatively low energy input.

[0061] According to the invention, low-energy operation of OLEDs can thus be combined with a high light yield, thereby achieving high quality while keeping costs moderate, wherein in particular a high light yield in the red spectral range is possible.

[0062] It may be preferred to:

[0063] L 1 is the above-mentioned cyclophane-carbene ligand, wherein

[0064] Me is a metal selected from copper, silver and gold, and wherein

[0065] L 2 is a ligand selected from heteroaryl and halogen.

[0066] For example, it may be preferred that:

[0067] L 1 is the above-mentioned cyclophane-carbene ligand, wherein

[0068] Me is copper, and wherein

[0069] L 2 is a ligand selected from carbazole ligands and halogens.

[0070] In particular, the use of copper complexes, for example, allows for the formation of more cost-effective complexes than the iridium complexes of the prior art. Advantages in this respect may therefore be particularly significant.

[0071] In certain embodiments, the metal complex may be selected from structures (IV), (V), (VI), (VII), (VIII) and (IX) shown below:

[0072]

[0073]

[0074]

[0075] According to the above content, the present invention also relates to the use of the above metal complex as a light-emitting material in a light-emitting layer of an organic light-emitting diode.

[0076] In summary, as described above with respect to cyclophane-carbene compounds and the corresponding metal complexes, low-energy operation of OLEDs can be combined with high light yields, thereby achieving high quality while keeping costs moderate, wherein, in particular, high light yields in the red spectral range are possible.

[0077] With regard to further advantages and technical features of the metal complexes and their use as luminescent materials in the luminescent layer, reference is made to the description of the cycloarene-carbene compounds and their use, the luminescent layer, the organic light-emitting diode, the method, the drawings and the legends to the drawings.

[0078] Furthermore, a light-emitting layer for an organic light-emitting diode is described, comprising a metal complex for emitting light, characterized in that the metal complex is formed as described above.

[0079] Thus, a light-emitting layer for an organic light-emitting diode (OLED) is described. In principle, the OLED can be constructed in a manner known from the prior art. Therefore, no special requirements need to be met in order to implement the above-described light-emitting layer in an OLED.

[0080] As mentioned above, the light-emitting layer is characterized in that it contains a metal complex as the active light-emitting material. In general form, the light-emitting layer comprises a metal complex corresponding to the following structure (III):

[0081] L 1 Me[L 2 ] m [L 3 ] m (III)

[0082] Among them, L 1 is a para-cyclophane-carbene ligand as described above, wherein

[0083] L 2 and L 3 The same or different and independently selected from NR 23 2. NR24 3.PR 25 2. PR 26 3. OR 27 2. OR 28 , SR 29 , SR 30 2. SR 31 , SeR 32 2. SeR 34 、TeR 35 2.TeR 36 , silyl, aryl, heteroaryl, alkenyl, alkynyl, isonitrile, cyclopentadienyl, halogen, wherein

[0084] m is a number selected from 0, 1 or 2, provided that at least one m is not equal to zero, wherein

[0085] R 23 , R 24 , R 25 , R 26 , R 27 , R 28 , R 29 , R 30 , R 31 , R 32 , R 33 , R 34 , R 35 , R 36 are the same or different and are independently selected from aryl, heteroaryl, alkenyl, alkynyl, alkyl, perfluoroalkyl, perfluoroaryl, and wherein

[0086] Me is a metal selected from copper, silver and gold.

[0087] Normally, it may be preferred to:

[0088] L 1 is a para-cyclophane-carbene ligand as described above, wherein

[0089] Me is a metal selected from copper, silver and gold, and wherein

[0090] L 2 is a ligand selected from heteroaryl and halogen.

[0091] For example, it may be preferred that:

[0092] L 1 is a para-cyclophane-carbene ligand as described above, wherein

[0093] Me is copper, and wherein

[0094] L 2 is a ligand selected from carbazole ligands and halogens.

[0095] In particular, the use of, for example, copper complexes, for example, allows for the formation of more cost-effective complexes compared to the iridium complexes of the prior art. Advantages in this respect may therefore be particularly significant.

[0096] In a particular embodiment, the metal complex may be selected from structures (IV), (V), (VI), (VII), (VIII) and (IX) shown below:

[0097]

[0098]

[0099]

[0100] In summary, the present invention describes ligands that can be used to produce racemic metal complexes, such as copper(I) complexes, very cheaply from commercial starting materials and that, compared to existing iridium emitters, show, due to TADF, the highest radiative constants of molecular emitters reported to date in the red range, up to 2×10 6 s -1 , and has also been successfully used to test OLEDs.

[0101] When used as ligands for metal complexes in OLED emitters, the ligands thus enable very high light yields, thus significantly improving the quality of the OLEDs. In addition, they can be operated at relatively very low energy inputs.

[0102] According to the invention, low-energy operation of OLEDs can thus be combined with a high light yield, thereby achieving a high quality while keeping costs moderate, wherein in particular a high light yield in the red spectral range is possible.

[0103] For further advantages and technical features of the light-emitting layer, reference is made to the description of the cyclophane-carbene compounds and their uses, the metal complexes and their uses as light-emitting materials in the light-emitting layer, the organic light-emitting diodes, the methods, the drawings and the description of the drawings.

[0104] Furthermore, an organic light emitting diode (OLED) is described, comprising a cathode, a light emitting layer, a hole transport layer and an anode, characterized in that the light emitting layer is formed as described above.

[0105] Therefore, the metal complex forming the light-emitting material and located in the light-emitting layer may correspond to the following structure (III):

[0106] L 1 Me[L 2 ] m [L 3 ] m(III)

[0107] Among them, L 1 is a para-cyclophane-carbene ligand as described above, wherein

[0108] L 2 and L 3 The same or different and independently selected from NR 23 2. NR 24 3.PR 25 2. PR 26 3. OR 27 2. OR 28 , SR 29 , SR 30 2. SR 31 , SeR 32 2. SeR 34 、TeR 35 2.TeR 36 , silyl, aryl, heteroaryl, alkenyl, alkynyl, isonitrile, cyclopentadienyl, halogen, wherein

[0109] m is a number selected from 0, 1 or 2, provided that at least one m is not equal to zero, wherein

[0110] R 23 , R 24 , R 25 , R 26 , R 27 , R 28 , R 29 , R 30 , R 31 , R 32 , R 33 , R 34 , R 35 , R 36 are the same or different and are independently selected from aryl, heteroaryl, alkenyl, alkynyl, alkyl, perfluoroalkyl, perfluoroaryl, and wherein

[0111] Me is a metal selected from copper, silver and gold.

[0112] As described in detail above with reference to the description of the metal complexes, the metal complexes of the light-emitting layer can be further developed.

[0113] As described in more detail above with respect to the light-emitting layer, the use of copper complexes as emitting materials in the light-emitting layer offers the advantages of low-energy operation of appropriately equipped OLEDs combined with high luminous efficiency, in particular in the red spectral range, wherein cost-effective production is also possible.

[0114] In principle, the structure of an OLED comprising cathode layer, light-emitting layer, hole-transport layer and anode layer can be formed in a manner known from the prior art.

[0115] For example, the cathode may have or consist of a metal or metal alloy such that the cathode or its material has a low electron work function. Examples include calcium, aluminum, barium, ruthenium or magnesium-silver alloys.

[0116] The anode may be, for example, a metal oxide such as indium tin oxide (ITO).

[0117] The hole transport layer (HTL) can be a molecular or polymeric material, such as poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS).

[0118] The luminescent layer has, in particular, the above-mentioned copper complex as a luminescent material. Preferably, this copper complex is diluted in a suitable matrix, for example, in a concentration of 1 wt.% to 10 wt.%, preferably 1 wt.% to 5 wt.%, wherein the above-mentioned proportions are related to the entire luminescent layer. A suitable matrix material can be, for example, 1,3-bis(N-carbazolyl)benzene (mCP).

[0119] As regards the matrix material, this can generally be selected from a wide range as long as the energy level enables energy transfer or direct complexation on the emitter. The choice of a specific material depends inter alia on the energy of the selected Cu complex, ie the specifically selected ligand.

[0120] Furthermore, the above-described layer structure may be applied to a substrate, for example a glass substrate.

[0121] The production and construction of the OLEDs can correspond essentially to those according to the prior art.

[0122] In principle, an OLED consists only of the above-mentioned layers, but this does not exclude the possibility of further layers which should be covered by the invention. For example, optimized doped charge transport layers or charge / exciton blocking layers can be envisaged. Additional layers can be used, for example, for energetic tuning of subsequent functional layers, such as balancing carrier injection asymmetries, creating targeted energy cascades to optimize energy transfer to the emitter, etc.

[0123] It may be preferred that the organic light emitting diode further comprises a filter for reducing reflection of an external light source, the filter being at least partially opaque to linearly polarized light.

[0124] In addition to the above-mentioned layers, the layer structure or the OLED therefore preferably comprises a filter or a filter combination for reducing reflections of external light sources. In particular, the filter combination consists of a linear polarizer and a λ / 4 wave plate. This filter combination is characterized in that it can filter out at least a portion of the linearly polarized light in the beam path, thereby filtering out sunlight from the beam path. While in the emission of a standard OLED, part of the generated linearly polarized light is also blocked by this filter arrangement and does not contribute to the generation of light, for the proposed light emitter, in particular a light emitter that emits circularly polarized light, in principle each light particle generated can be decoupled and contribute to the generation of light. This significantly reduces the reflection of sunlight, while the internally generated light can completely pass through the filter arrangement, thereby significantly improving the contrast of the image emitted by the OLED, especially under traditionally difficult conditions, such as strong sunlight outdoors.

[0125] In particular, such a filter can offer advantages for the above-mentioned OLEDs, since an OLED with a linear polarizer as filter does not reduce the light yield of circularly polarized light. Thus, in particular with the OLED according to the invention, high-quality images can be achieved.

[0126] For further advantages and technical features of the organic light-emitting diode, reference is made to the description of the cyclophane-carbene compounds and their uses, the metal complexes and their uses as luminescent materials in the luminescent layer, the luminescent layer, the method, the drawings and the description of the drawings.

[0127] Furthermore, a method for generating, in particular circularly polarized light by means of an organic light-emitting diode is described, the method comprising:

[0128] Step a) providing an organic light emitting diode as described above, and

[0129] Step b) applies a voltage between the anode and the cathode to inject charge carriers and generate, in particular, circularly polarized light.

[0130] With regard to method step a), in particular with regard to the formation and further development of the OLED and in particular the formation and further development of the emitting material in the emitting layer, reference is made in its entirety to the corresponding description of the OLED and the emitting layer.

[0131] By applying a voltage between the anode and cathode, which is possible within the scope known to those skilled in the art of OLEDs, the luminescent material in the luminescent layer can be excited to emit circularly polarized light. This can be achieved in a surprising manner with the above-mentioned copper complexes and with a high light yield, which brings significant advantages.

[0132] OLEDs can operate at voltages in the range of a few volts and up to 1A / cm 2 The current density range is 10 mA / cm 2This is common to known OLED structures. This means that in particular OLEDs with a circular emitting active layer can be controlled by known circuits and implemented in existing structures (eg display units).

[0133] Overall, it is possible to use the above-mentioned metal complexes as luminescent materials to produce images with high luminous efficacy (especially in the red spectral range) and good contrast, whereby energy-saving operation is also possible.

[0134] With regard to further advantages and technical features of the method, reference is made to the description of the cyclophane-carbene compounds and their use, the metal complexes and their use as luminescent materials in luminescent layers, the luminescent layers, the organic light-emitting diodes, the drawings and the description of the drawings.

[0135] The invention is explained below with reference to the drawings and embodiments, wherein the features presented below may each represent an aspect of the invention both individually and in combination, and wherein the invention is not limited to the following drawings, the following description and the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0136] As shown below:

[0137] Figure 1 A schematic diagram of the structure of an OLED in a configuration according to the present invention;

[0138] Figure 2 A schematic diagram of the structure of an OLED in another configuration according to the present invention;

[0139] Figure 3 is a reaction scheme for producing a p-cyclophane-carbene compound according to the present invention;

[0140] Figure 4 For compound 6 1 H-NMR spectroscopy;

[0141] Figure 5 For compound 6 13 C-NMR spectroscopy;

[0142] Figure 6 For compound 7 1 H-NMR spectroscopy;

[0143] Figure 7 For compound 7 13 C-NMR spectroscopy;

[0144] Figure 8 For compound 9 1 H-NMR spectroscopy;

[0145] Fig. 9 For compound 9 13 C-NMR spectroscopy;

[0146] Fig.10 For compound 10 1 H-NMR spectroscopy;

[0147] Fig.11 For compound 10 13 C-NMR spectroscopy;

[0148] Fig.12 For compound 11 1 H-NMR spectroscopy;

[0149] Fig.13 For compound 11 13 C-NMR spectroscopy;

[0150] Fig.14 For compound 12 1 H-NMR spectroscopy;

[0151] Fig.15 For compound 12 13 C-NMR spectroscopy;

[0152] Fig.16 are the normalized excitation and emission spectra of compounds 6, 7, and 8;

[0153] Fig.17 are the normalized excitation and emission spectra of compounds 9, 10, 11, and 12;

[0154] Fig.18 are the normalized excitation and emission spectra of compounds 9, 10, 11, and 12;

[0155] Fig.19 is the EL spectrum of an example OLED; and

[0156] Fig. 20 The current-voltage characteristics of an OLED under a positive voltage are shown in FIG. Specific implementation plan

[0157] Figure 1 The configuration of a layer structure 10 for an OLED according to the configuration of the present invention is shown. The layer structure 10 includes an anode 14, a cathode 16 and a light-emitting layer 18. The anode 14 may include, for example, be composed of a material with a medium work function (such as ITO), while the cathode 16 may include, for example, be composed of a material with a low work function (such as calcium). The light-emitting layer 18 includes a metal complex as described below.

[0158] Furthermore, a layer 20 is shown, which is a hole transport layer. This can be achieved, for example, by means of the hole transport polymer poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS).

[0159] In principle, further layers may be present without departing from the scope of the present invention. For example, a hole transport layer may be provided between the light-emitting layer 18 and the hole-conducting layer 20, and / or an electron transport layer may be present between the light-emitting layer 18 and the cathode 16. In principle, the transport layers may also serve as exciton and charge carrier blocking layers, or, due to their energetics, realize multiple functions within the same layer.

[0160] Figure 2 Also shown is a cover layer 22, such as a cover glass, which defines the layer structure 10 on top, and a seal 24 is shown between the cover layer 22 and the substrate 12, which seal can be formed with an adhesive such as an epoxy adhesive. Thus, the substrate 12, the cover layer 22 and the seal can encapsulate the layer structure 10, thereby protecting it from external influences. This can, for example, minimize the degradation of calcium and organic materials. The encapsulation can, for example, contain a protective gas such as nitrogen.

[0161] Figure 1 and Figure 2 The embodiments of the present invention are common in that the light-emitting layer 18 comprises a defined copper complex as the light-emitting material. It is assumed that the metal complex corresponds to the following structure (III):

[0162] L 1 Me[L 2 ] m [L 3 ] m (III)

[0163] Among them, L 1 is a para-cyclophane-carbene ligand according to any one of claims 1 to 8, wherein

[0164] L 2 and L 3 The same or different and independently selected from NR 23 2. NR 24 3.PR 25 2. PR 26 3. OR 27 2. OR 28 , SR 29 , SR 30 2. SR 31 , SeR 32 2. SeR 34 、TeR 35 2.TeR 36 , silyl, aryl, heteroaryl, alkenyl, alkynyl, isonitrile, cyclopentadienyl, halogen, wherein

[0165] m is a number selected from 0, 1 or 2, provided that at least one m is not equal to zero, wherein

[0166] R 23 , R 24 , R 25 , R 26 , R 27 , R 28 , R 29 , R 30 , R 31 , R 32 , R 33 , R 34 , R 35 , R 36 are the same or different and are independently selected from aryl, heteroaryl, alkenyl, alkynyl, alkyl, perfluoroalkyl, perfluoroaryl, and wherein

[0167] Me is a metal selected from copper, silver and gold.

[0168] For example, the metal complex can be selected from structures (IV), (V), (VI), (VII), (VIII) and (IX) shown below:

[0169]

[0170]

[0171] In the following, the synthesis examples of the above-defined luminescent materials present in the luminescent layer 18 are shown. First, the ligands, especially the ligand L, are discussed. 1 Subsequently, the synthesis of various metal complexes is described.

[0172] As shown below, structure (II) corresponds to compound 6, structure (IV) corresponds to compound 7, structure (VI) corresponds to compound 9, structure (VII) corresponds to compound 10, structure (VIII) corresponds to compound 11, structure (IX) corresponds to compound 12, structure (IV) corresponds to compound 7, and structure (IV) corresponds to compound 7.

[0173] Examples of the synthesis of ligands included in copper complexes

[0174] like Figure 3 As shown, the p-cyclophane-carbene ligand or p-cyclophane-carbene compound can be synthesized according to Scheme 1.

[0175] Specifically, the synthesis is carried out as follows:

[0176] Racemic-4-formyl[2.2]p-cyclophane (Compound 1)

[0177]

[0178] In a 500mL Schlenk flask, 2.00g (9.60mmol, 1.0eq) -[2.2] paracyclophane in 150mL of DCM was cooled to 0°C. 0.90ml (10mmol, 1.05eq) of titanium tetrachloride and 2.1ml (19mmol, 2eq) of dichloromethoxymethane were carefully added and stirred overnight. The black reaction solution was added to 200ml of ice. The turquoise suspension was stirred for 2 hours. The colorless organic phase was separated and the colorless aqueous phase was extracted twice with 50ml of DCM. The combined organic phases were dried with Na2SO4, filtered, and all volatile components were removed under reduced pressure. After washing with pentane, a colorless solid product (2.10g, 8.89mmol, 93%) was obtained.

[0179] Spectral data were obtained from literature.

[0180] Racemic-4-formyl[2.2]-p-cyclophane-O-methylaldoxime (Compound 3)

[0181]

[0182] In a 100 mL Schlenk flask, 424 mg (5.08 mmol, 1.2 eq) of methoxyamine hydrochloride, 0.67 mL (8.4 mmol, 2 eq) of pyridine and 0.5 g of molecular sieves were added. Stir in 12 mL of DCM for 5 minutes. Add 1.00 g (4.23 mmol, 1 eq) of racemic-4-formyl[2.2]paracyclophane and stir overnight. The yellow reaction mixture is extracted three times with 20 ml of DCM, filtered through silica, and all volatile components are removed under reduced pressure. The product (660 mg, 2.49 mmol, 59%) is obtained as a colorless solid by column chromatography (silica; pentane:ethyl acetate 100:0→50:1).

[0183] Spectral data were obtained from literature.

[0184] Racemic-4-bromo-5-formyl[2.2]-p-cyclophane-O-methylaldoxime (Compound xx)

[0185]

[0186] In a 100 mL Young tube, 200 mg (754 μmol, 1 eq) of rac-4-formyl [2.2] paracyclophane-O-methylaldehyde oxime, 34 mg (0.15 mmol, 0.2 eq) of palladium (II) acetate, 33 mg (0.15 mmol, 0.2 eq) of silver (I) trifluoroacetate and 161 mg (905 μmol, 1.2 eq.) of N-bromosuccinimide were stirred in 25 ml of DCE at 100 ° C for 6 hours. The reaction mixture was cooled to room temperature, 25 ml of DCM and 20 ml of distilled water were added. The aqueous phase was extracted twice with 20 ml of DCM. The organic phase was dried over magnesium sulfate, filtered through celite, and all volatile components were removed under reduced pressure. The crude product was used without further treatment.

[0187] Spectral data were obtained from literature.

[0188] Racemic-4-bromo-5-formyl[2.2]p-cyclophane (Compound 4)

[0189]

[0190] In a 10ml microwave vial, 160mg (465μmol, 1eq.) racemic-4-bromo-5-formyl [2.2] p-cyclophane-O-methylaldoxime, 180mg (946μmol, 2.0eq.) p-toluenesulfonic acid monohydrate and 0.35ml (4.7mmol, 10eq., 37% in water) of formaldehyde were irradiated with 70W (120°C) microwaves for 4 hours in 5ml of THF and 1ml of water. The reaction mixture was cooled to room temperature and all volatile components were removed under reduced pressure. A colorless solid product (140mg, 0.444mmol, 96%) was obtained by column chromatography (silicon dioxide; cyclohexane: ethyl acetate 100:0→50:1).

[0191] Spectral data were obtained from literature.

[0192] Racemic-4-bromo-5-formyl[2.2]-p-cyclophane-N-(2,6-diisopropylphenyl)methanimine (Compound 5)

[0193]

[0194] At 0°C, to a 1 ml toluene solution containing 100 mg (317 μmol, 1.0 eq) of racemic-4-bromo-5-formyl[2.2]paracyclophane and 0.60 mg (0.34 mmol, 1.1 eq) of N-(2,6-diisopropylphenyl)amine, 0.07 ml (0.6 mmol, 2 eq.) of titanium tetrachloride was carefully added, and the mixture was heated under reflux for 2 hours. The orange reaction mixture was added to 3 ml of isopropanol. 3 ml of distilled water and 4 ml of ether were added. The aqueous phase was extracted twice with 5 ml of ether. The combined organic phases were dried over Na2SO4, decanted, and all volatile components were removed under reduced pressure. The product (100 mg, 0.211 mmol, 66%) was obtained as a yellow oil by column chromatography (silicon dioxide; cyclohexane: ethyl acetate 100:0→50:1).

[0195] 1 H-NMR data are as follows: (500 MHz, CDCl3) δ8.26 (s, 1H), 7.21 (m, 2H), 7.15 m, 1H), 6.98 (m, 1H), 6.67 (m, 2H), 6.58 (m, 3H), 4.26 (m, 1H), 3.56 (m, 1H), 3.19 (m, 5H), 3.10 (m, 1H), 2.93 (m, 2H), 1.28 (d, J = 6.8 Hz, 6H), 1.24 (d, J = 6.9 Hz, 6H).

[0196] (HiPC)(OTf)(Compound 6)

[0197]

[0198] At -80°C, 4.8 ml (2.5 M, 12 mmol, 1.05 eq) of n-butyl lithium was slowly added to 15 ml of ether containing 5.40 g (11.4 mmol, 1.0 eq) of racemic-4-bromo-5-formyl[2.2]-cyclophane-N-(2,6-diisopropylphenyl)methanimine. The red solution was stirred at -80°C for 1 hour. At -80°C, a solution of 2.20 g (12.1 mmol, 1.05 eq) of benzophenone in 10 ml of Et2O was added, causing the solution color to change from green to violet. The mixture was stirred at -80°C for another 30 minutes and then at room temperature for 30 minutes. 2.0 ml (12 mmol, 1.05 eq.) of trifluoromethanesulfonic anhydride was added to the yellow-orange solution at -80°C and then warmed to room temperature overnight. The yellow precipitate was filtered off and washed three times with 5 ml of ether. The ether was sublimed into THF solution to obtain a yellow crystalline product (3.60 g, 5.07 mmol, 45%).

[0199] The spectral data are as follows and are Figure 4 ( 1 H-NMR) and Figure 5 ( 13 C-NMR) are shown as follows:

[0200] 1 H-NMR (600 MHz, CD2Cl2) δ 9.65 (s, 1H), 8.10 (bs, 1H), 7.71 (bs, 1H), 7.56 (m, 1H), 7.45 (bs, 1H), 7.37 (m, 1H), 7.33 (m, 1H), 7.30 (m, 1H), 7.17 (bs, 1H), 7.05 (bs, 1H), 6.93 (m, 1H), 6.85 (m, 1H), 6.82 (m, 1H), 6.80 (m, 1H), 6.78 (m, 1H), 6.61 (m, 1H), 5.29 (m, 1H), 3.99 (m, 1H), 3.75 (m, 1H), 3.56 (m, 1H), 3.31 (sept, J = 6.7 Hz, 1H), 3.17 (m, 1H), 2.97 (m, 1H), 2.78 (m, 1H), 2.60 (m, 1H), 2.40 (m, 1H), 1.31 (d, J = 6.7 Hz, 3H), 0.86 (sept., J = 6.7 Hz, 1H), 0.70 (d, J = 6.8 Hz, 3H), 0.49 (d, J = 6.7 Hz, 3H), -0.12 (d, J = 6.6 Hz, 3H).

[0201] 13 C-NMR (151 MHz, CD2Cl2) δ 174.0 (s), 148.6 (s), 147.2 (s), 146.8 (s), 146.7 (s), 143.3 (s), 140.6 (s), 138.9 (s), 137.9 (s), 137.1 (s), 133.6 (s), 133.0 (s), 132.7 (s), 132.0 (s), 131.9 (s), 131.6 (s), 131.2 (s), 130.8 (s), 130.54 (d, J = 1.5 Hz), 130.2 (s), 130.1 (s), 128.8 (s), 126.6 (s), 124.8 (s), 95.7 (s), 35.1 (s), 34.5 (s), 32.8 (s), 31.1 (s), 29.8 (s), 26.2 (s), 25.4 (s), 22.9 (s), 21.7 (s).

[0202] 15 N-NMR (60.8 MHz, CD2Cl2) δ -163.4.

[0203] 19F-NMR (565 MHz, THF) δ-78.55.

[0204] Elemental analysis: Calculated: C, 72.76; H, 5.96; N, 1.97; Measured: C, 72.8; H, 6.2; N, 1.9.

[0205] Examples of the synthesis of various copper complexes useful as luminescent materials

[0206] [CuCl(iPC)](Compound 7)

[0207]

[0208] At -85 ° C, to 300mg (423 μ mol, 1.0 eq.) [iPCH] (OTf) and 70mg cuprous chloride (I) dimethyl sulfide (0.44mmol, 1.05eq.) in the suspension formed in 20ml of THF, slowly add 69mg (0.43mmol, 1.0eq) KHMDS solution formed in 2mL of THF. The yellow-orange suspension is warmed to room temperature overnight. All volatile components of the yellow-green suspension are removed under reduced pressure. After extraction with DCM and filtering through basic alumina, the crude product is precipitated by adding pentane, and washed twice with 2ml of pentane. By subliming pentane in THF / cyclohexane solution, an orange crystal product is obtained, which is a 1:1 adduct (112mg, 170 μ mol, 40%) with THF.

[0209] The spectral data are as follows and are Figure 6 ( 1 H-NMR) and Figure 7 ( 13 C-NMR) showed:

[0210] 1H-NMR(600MHz,THF)δ7.82(m,1H),7.67(m,1H),7.43(m,1H),7.34(m,1H),7.24(m,3H),7.11(bs,2H),6.95(m,1 H),6.90(m,1H),6.79(m,1H),6.74(m,1H),6.67(m,1H),6.58(m,1H),6.38(m,1H),5.00(m,1H),4.81(m,1H),3. 54(sept.,J=6.7Hz,1H),3.48(m,1H),3.23(m,1H),2.94(m,1H),2.71(m,1H),2.54(m,1H),2.41(m,1H),1.35(d , J=6.8Hz, 3H), 1.10 (sept., J=6.8Hz, 1H), 0.81 (d, J=6.7Hz, 3H), 0.49 (d, J=6.7Hz, 3H), -0.20 (d, J=6.7Hz, 3H).

[0211] 13 C-NMR(151MHz,THF)δ229.4(s),149.6(s),145.9(s),144.8(s),143.1(s),143.1(s),140.4(s),139. 6(s),139.3(s),138.9(s),136.4(s),136.1(s),134.7(s),133.5(s),132.9(s),132.8(s),132.7(s) ,132.6(s),131.6(s),131.0(s),130.3(s),129.5(s),129.2(s),129.1(s),128.3(s),125.9(s),124 .4(s),95.8(s),35.6(s),34.8(s),34.4(s),30.6(s),30.3(s),29.9(s),27.1(s),23.2(s),21.3(s).

[0212] Elemental analysis: Calculated: C, 75.17; H, 6.97; N, 1.83; Measured: C, 75.1; H, 6.9; N, 1.9.

[0213] [CuBr(iPC)](Compound 8)

[0214]

[0215] At-85 ℃, to 300mg (423 μ mol, 1.0eq) [iPCH] (OTf) and 87mg cuprous bromide (I) dimethyl sulfide (0.42mmol, 1.05eq.) in the suspension formed in 20mL THF, slowly add 69mg (0.43mmol, 1.0eq) KHMDS solution formed in 2mL THF. The yellow-orange suspension is warmed to room temperature overnight. All volatile components of the yellow-orange suspension are removed under reduced pressure. After DCM extraction and filtering through basic alumina, the crude product is precipitated by adding pentane, and washed twice with the pentane of 2ml. By subliming pentane in THF / cyclohexane solution, obtain orange crystal product (21mg, 30 μ mol, 7%).

[0216] The spectral data are as follows:

[0217] 1 H-NMR(600MHz,THF)δ7.82(m,1H),7.67(m,1H),7.43(m,1H),7.34(m,1H),7.24(m,3H),7.11(bs,2H),6.95(m,1 H),6.90(m,1H),6.79(m,1H),6.74(m,1H),6.67(m,1H),6.58(m,1H),6.38(m,1H),5.00(m,1H),4.81(m,1H),3. 54(sept.,J=6.7Hz,1H),3.48(m,1H),3.23(m,1H),2.94(m,1H),2.71(m,1H),2.54(m,1H),2.41(m,1H),1.35(d , J=6.8Hz, 3H), 1.10 (sept., J=6.8Hz, 1H), 0.81 (d, J=6.7Hz, 3H), 0.49 (d, J=6.7Hz, 3H), -0.20 (d, J=6.7Hz, 3H).

[0218] Elemental analysis: Calculated: C, 71.73; H, 5.88; N, 1.99; Measured: C, 71.4; H, 6.0; N, 1.8.

[0219] [Cu(Cbz)(iPC)](Compound 9)

[0220]

[0221] In a 20mL screw cap vial, 16mg (78μmol, 1.03eq) KCbz was added to a solution of 50mg (76μmol, 1.0eq) [CuCl (iPC)] in 4mL of THF, and stirred overnight. The dark red suspension was mixed with 2ml of ether, filtered through basic alumina, and evaporated to a quarter of the volume under reduced pressure. A mixture of cyclohexane and pentane was sublimed into the solution to obtain a yellow crystalline product, which was a 2:3 adduct (45mg, 57μmol, 75%) with THF.

[0222] The spectral data are as follows and are Figure 8 ( 1 H-NMR) and Fig. 9 ( 13 C-NMR) showed:

[0223] 1 H-NMR(600MHz,THF)δ7.96m,1H),7.83m,2H),7.67(m,1H),7.49(m,1H),7.45(m,1H),7.38(m,2H),7.29(m,1H) ,7.17(bs,21H),7.01(m,1H),6.97(m,4H),6.80(m,3H),6.73(m,3H),6.62(m,1H),6.50(m,1H),5.13(m,2H),3. 90(m,1H),3.72(m,1H),3.64(sept.,J=6.8Hz,1H),3.37(m,1H),2.98(m,1H),2.74(m,1H),2.61(m,1H),2.43(m ,1H),1.26(m,1H),1.13(d,J=6.7Hz,3H),0.87(d,J=6.8Hz,3H),0.51(d,J=6.7Hz,3H),-0.16(d,J=6.7Hz,3H).

[0224] 13C-NMR(151MHz,THF)δ230.9(s),151.0(s),150.3(s),146.4(s),144.7(s),143.3(s),143.3(s),140.2(s),139.9(s) ,139.4(s),136.4(s),136.3(s),134.9(s),133.6(s),133.1(s),132.9(s),132.8(s),132.6(s),131.6(s),131.1(s) ,130.5(s),129.6(s),129.3(s),129.2(s),128.2(s),126.5(s),125.4(s),125.1(s),123.5(s),119.4(s),115.6(s) ),115.0(s),96.0(s),35.7(s),35.1(s),30.8(s),30.4(s),30.1(s),26.8(s),26.2(s),25.5(s),23.2(s),21.7(s).

[0225] Elemental analysis: Calculated: C, 80.28; H, 6.85; N, 3.12; Measured: C, 79.9; H, 6.9; N, 3.3.

[0226] [Cu(Cbz tBu )(iPC)](Compound 10)

[0227]

[0228] In a 20 mL screw cap vial, 28 mg (77 μmol, 1 eq.) [KCbz tBu ·(Et2O) 2 / 3 ] Add 50mg (76μmol, 1.0eq.) [CuCl (iPC)] in the solution formed by 4mL THF, and stir overnight. The dark red suspension is mixed with 2ml of ether, filtered through basic alumina, and evaporated to a quarter of the volume under reduced pressure. By subliming a mixture of cyclohexane and pentane into the solution, a yellow crystalline product is obtained, which is a 4:5 adduct with THF (51mg, 57μmol, 75%).

[0229] The spectral data are as follows and are Fig.10 ( 1 H-NMR) and Fig.11 ( 13 C-NMR) showed:

[0230] 1H-NMR(600MHz,THF)δ7.94(m,1H),7.91(m,2H),7.66(m,1H),7.50(m,1H),7.44(m,1H),7.39(m,1H),7.36(m,1H),7.28(m ,1H),7.16(bs,2H),7.08(m,2H),6.99(m,1H),6.97(m,1H),6.91(m,1H),6.76(m,1H),6.68(m,2H),6.61(m,1H),6.53(m, 1H),5.12(m,1H),5.09(m,1H),3.82(m,1H),3.67(m,1H),3.29(m,1H),2.94(m,1H),2.70(m,1H),2.58(m,1H),2.41(m,1H ), 1.41 (s, 18H), 1.26 (m, 1H), 1.12 (d, J = 6.7Hz, 3H), 0.84 (d, J = 6.7Hz, 3H), 0.50 (d, J = 6.7Hz, 3H), -0.17 (d, J = 6.7Hz, 3H).

[0231] 13 C-NMR(151MHz,THF)δ231.0(s),150.3(s),149.6(s),146.3(s),144.7(s),143.3(s),143.2(s),140.2(s),139.8(s),1 39.8(s),139.4(s),137.6(s),136.4(s),136.2(s),135.0(s),133.7(s),133.0(s),132.9(s),132.8(s),132.6(s),131 .5(s),131.0(s),130.4(s),129.5(s),129.3(s),129.1(s),128.2(s),126.4(s),125.3(s),125.0(s),121.1(s),115.3 (s),114.5(s),95.9(s),35.6(s),35.0(s),34.9(s),32.6(s),30.8(s),30.4(s),30.1(s),26.9(s),23.2(s),21.7(s).

[0232] Elemental analysis: Calculated value: 81.13; H, 7.62; N, 2.82; Measured value: C, 81.0; H, 7.3; N, 3.1.

[0233] [Cu( Me Cbz)(iPC)](Compound 11)

[0234]

[0235] In a 20 mL screw cap vial, 17 mg (78 μmol, 1 eq) of K Me Cbz was added to a solution of 50 mg (76 μmol, 1.0 eq.) [CuCl (iPC)] formed in 4 ml THF, and stirred overnight. The dark red suspension was mixed with 2 ml of ether, filtered with basic alumina, and evaporated to a quarter of the volume under reduced pressure. A mixture of cyclohexane and pentane was sublimed into the solution to obtain a yellow crystalline product, which was a 2:3 adduct with THF (48 mg, 60 μmol, 79%).

[0236] The spectral data are as follows and are Fig.12 ( 1 H-NMR) and Fig.13 ( 13 C-NMR) showed:

[0237] 1 H-NMR(600MHz,THF)δ7.95(m,1H),7.87(m,1H),7.78(m,1H),7.74(m,1H),7.60(bs,1H),7.48(m,1H),7.39(m,1H),7.29(m,3H), 7.22(m,2H),7.02(m,3H),6.93(m,1H),6.90(m,1H),6.86(m,1H),6.82(m,1H),6.79(m,1H),6.78(m,1H),6.69(m,1H),6.61(m,1 H),6.40(m,1H),5.06(m,1H),4.97(m,1H),3.64(sept.,J=6.7Hz,1H),3.60(m,1H),3.53(m,1H),3.18(m,1H),2.99(m,1H),2.74 (m,1H),2.65(m,1H),2.61(s,3H),2.42(m,1H),1.25(m,1H),1.09(d,J=6.8Hz,3H),0.94(d,J=6.7Hz,3H),0.47(d,J=6.7Hz,3H).

[0238] 13C-NMR(151MHz,THF)δ231.4(s),151.2(s),149.8(s),149.6(s),145.9(s),144.8(s),143.5(s),143.0(s),140.3(s),140.0(s),139.7( s),139.5(s),136.5(s),136.4(s),135.1(s),133.7(s),133.0(s),132.7(s),132.7(s),132.5(s),131.8(s),131.0(s),130.6(s),129 .6(s),129.4(s),129.3(s),128.2(s),126.3(s),125.9(s),125.3(s),124.8(s),124.6(s),123.2(s),121.5(s),119.5(s),117.6(s), 115.8(s),115.8(s),115.7(s),96.1(s),35.7(s),34.6(s),30.8(s),30.5(s),30.2(s),27.0(s),26.2(s),23.5(s),21.7(s),20.9(s).

[0239] Elemental analysis: Calculated: C, 80.36; H, 6.97; N, 3.07; Measured: C, 80.4; H, 6.9; N, 3.3.

[0240] [Cu( OMe Cbz)(iPC)](Compound 12)

[0241]

[0242] In a 20 mL screw cap vial, 20 mg (76 μmol, 1 eq) [K OMe CBz(Et2O) 1 / 3 ] Add 50mg (76μmol, 1.0eq) [CuCl (iPC)] in the solution formed by 4mL THF, and stir overnight. The dark red suspension is mixed with 2ml of ether, filtered with basic alumina, and evaporated to a quarter of the volume under reduced pressure. By subliming a mixture of cyclohexane and pentane into the solution, a yellow crystalline product is obtained, which is a 2:3 adduct with THF (46mg, 56μmol, 74%).

[0243] The spectral data are as follows and are Fig.14 ( 1 H-NMR) and Fig.15 ( 13 C-NMR) showed:

[0244] 1 H-NMR(600MHz,THF)δ8.01(m,1H),7.81(m,1H),7.73(m,1H),7.55(m,1H),7.47(m,1H),7.38(m,1H),7.28(m,1H),7.26(m,1H),7.24(d,J=2.8Hz,1H),7.23(m,1H),7.01(m,1H),6.89(m,2H),6.84(m,1H),6.80(m,3H),6.75(m,2H),6.68(m,1H),6.59(m,1H),6.40(m,1H),5.03(m,1H),4.94(m,1H),4.05(s,3H),3.71(sept.,J=6.7Hz,1H),3.55(m,1H),3.45(m,1H),3.14(m,1H),2.98(m,1H),2.73(m,1H),2.63(m,1H),2.45(m,1H),1.30(sept.,J=6.7Hz,1H),1.28(d,J=6.8Hz,3H),0.98(d,J=6.7Hz,3H),0.52(d,J=6.7Hz,3H),-0.13(d,J=6.7Hz,3H)。

[0245] 13 C-NMR(151MHz,THF)δ232.0(s),150.5(s),149.8(s),148.2(s),146.0(s),145.4(s),143.8(s),143.2(s),141.1(s),140.4(s),139.6(s),139.5(s),139.4(s),136.4(s),135.9(s),135.2(s),133.7(s),132.9(s),132.7(s),132.6(s),131.7(s),130.9(s),130.3(s),129.5(s),129.2(s),128.1(s),126.6(s),126.0(s),125.5(s),124.6(s),123.1(s),119.4(s),116.2(s),115.5(s),115.4(s),113.1(s),103.7(s),96.0(s),55.5(s),35.8(s),34.9(s),34.8(s),30.8(s),30.5(s),30.1(s),26.9(s),23.4(s),21.7(s)。

[0246] Elemental analysis: Calculated: C, 79.47; H, 6.67; N, 3.14; Measured: C, 79.4; H, 6.3; N, 3.4.

[0247] The photophysical properties of the compounds according to the present invention are shown below. TM UV-Vis spectra were recorded on a PerkinElmer apparatus at 265°. Lifetime determinations were performed using a FLSP920 spectrometer from Edinburgh Instruments, recording excitation and emission spectra. The emission radiation was recorded at an angle of 90° to the excitation radiation. Quantum yields were recorded using a FLSP920 spectrometer from Edinburgh Instruments. All measurements were performed in 1 cm quartz cuvettes.

[0248] Fig.16 The normalized excitation and emission spectra of compounds 6, 7 and 8 are shown, and the corresponding curves are marked with the number of each compound. The normalized excitation and emission spectra in powdered solid (solid line) or PMMA matrix (dashed line) are shown. The band at 425nm in the emission spectrum is due to the scattering of the light used when exciting the sample.

[0249] Selected photophysical data of compounds 6, 7 and 8 under argon atmosphere at room temperature are also shown in Table 1.

[0250] Table 1

[0251]

[0252] a) For lifetimes fitted with two exponentials, the pre-exponential factor B is given in brackets. b) Using the mean lifetime τ weighted by the amplitude av Calculate k r .

[0253] Fig.17 Normalized excitation (left) and emission (right) spectra of compounds 9, 10, 11 and 12 in THF solution (bottom) or in a PMMA matrix (top) are shown, wherein the corresponding curves are labeled with the number of the respective compound.

[0254] Fig.18 Normalized excitation (left) and emission (right) spectra of compounds 9, 10, 11 and 12 in the ground state (bottom) or microcrystalline state (top) are shown, wherein the corresponding curves are labeled with the number of the respective compound.

[0255] Selected photophysical data of compounds 9, 10, 11 and 12 at room temperature under argon atmosphere, 77K under helium atmosphere and 6K under vacuum atmosphere are also shown in Table 2.

[0256] Table 2

[0257]

[0258]

[0259] a) For lifetimes fitted with two exponentials, the pre-exponential factor B is given in brackets. b) Using the mean lifetime τ weighted by the amplitude av Calculate k r nd = not detected.

[0260] λ max represents the maximum of the photoluminescence (PL) and is therefore an important parameter for the color that appears to the eye. The maximum found here is in the near-infrared region up to 785 nm, making it attractive for various luminescence applications.

[0261] Quantum yield Φ PL is a measure of the efficiency of a light emitter. It represents the proportion of excited state radiative transitions to the ground state and can be understood as the ratio of emitted photons to absorbed photons. Although the Φ given here is PL refers to PL, but this value is also an attractive measure of the efficiency of electroluminescence in electrically operated components. The lifetime τ is a measure of how quickly the emitters return to their ground state after excitation (during which they are in the Φ PL = 1). To avoid the "efficiency roll-off" effect in OLEDs, τ should be as small as possible. The radiation rate constant k R =Φ PL / τ can be expressed by Φ PL and τ are calculated. This can be used to compare the complex with other luminophores. The k determined here is R =19×10 5 s -1 The highest value of has exceeded many currently used Ir or Pt emitters. Generally, there are almost no luminescent materials with such a high radiation rate constant.

[0262] In the following, the chiro-optical properties of the compounds according to the present invention are described.

[0263] Anisotropy factor g abs and g lum is a measure of the degree to which left-handed and right-handed photons dominate relative to other photons during absorption and emission, respectively. The following equations apply: Among them I L and I R represents the intensity of left-handed and right-handed photons, respectively. According to the equation, the maximum value of pure left-handed emission is +2, and the maximum value of pure right-handed emission is -2. For octahedral transition metal complexes (such as Ir(III)) and similar known copper complexes, these values ​​are rarely higher than 10 -3 .

[0264] Similarly, The extinction coefficient ∈ of each absorbed photon L and ∈ R Derive. abs For us, it is not that important. For the lowest energy absorption, the anisotropy factor g is calculated. abs ≈2×10 -3 The lowest energy band g abs Should be with g lum The values ​​are of the same order of magnitude, since the electronic states involved in the TADF emission mechanism should be the same as in the lowest energy absorption (see Einstein coefficient). According to the present invention, it is expected that g lum ≈2×10 -3 This is comparable to the values ​​of phosphorescent or TADF emitters.

[0265] Regarding the application in organic light emitting diodes, the following should be noted.

[0266] By integrating molecular emitters into organic light emitting diodes (OLEDs), the molecules can be electrically excited by electric fields, similar to optical excitation (PL), which is called electroluminescence (EL). OLEDs are particularly suitable for display / screen applications. The TADF emission behavior of the emitters described according to the present invention is combined with a high quantum yield Φ PL This combination makes these materials particularly attractive for use in OLED components, as they can theoretically achieve high external quantum efficiencies (EQE). EQE is defined by the number of photons coupled out of the OLED per injected charge carrier. An important factor is the internal quantum efficiency (IQE), which can be as high as 100% for phosphorescent and TADF emitters.

[0267] To test the electroluminescent operation of the iPC emitter, compound 10 was integrated into a simple proof-of-concept OLED. Figure 1 The device architecture is described in Figure 1. Indium tin oxide (ITO) is used as a transparent anode 14 (hole injection contact), PEDOT:PSS is used as a hole injection / transport material, and calcium / aluminum is used as an electron injection top contact. The emitter is embedded in the matrix material (mCP) in an amount of 10 wt.% based on the layer by solution processing. The light-emitting layer (consisting of the emitter and the matrix) is located between the PEDOT:PSS layer and the top contact. When bipolar charge carriers are injected into the light-emitting layer, excitons (excited states) are generated on the emitter, which can undergo radiative decay (EL) and lead to coupling out through the transparent ITO anode.

[0268] Fig.19It is also shown that the measured EL spectrum corresponds to the PL spectrum in terms of spectral position and shape, which shows that the emitter according to the present invention can be electrically driven in an OLED assembly according to compound 10. The current density here is of a typical magnitude for OLEDs. The intensity of the EL changes as expected with increasing current density. Here, curve A shows a current density j of 33 mA / cm 2 Curve B shows that the current density is 17 mA / cm 2 .

[0269] Fig. 20 The current-voltage characteristics under positive voltage (forward) are shown and show typical diode behavior. It can be seen that the current in the OLED is mainly injected through the contact interface.

Claims

1. A para-cyclophane-carbene compound, characterized in that The p-cyclophane-carbene compound corresponds to the following structure (I): in: R 1 is selected from aryl, heteroaryl, alkyl, perfluoroalkyl, perfluoroaryl, wherein R 2 and R 3 are the same or different and are independently selected from aryl, heteroaryl, alkyl, alkenyl, alkynyl, perfluoroalkyl, perfluoroaryl, wherein R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 are identical or different and are independently selected from hydrogen, deuterium, halogen, silyl, alkyl, alkenyl, alkynyl, perfluoroalkyl, aryl, heteroaryl, alkoxy, wherein R 12 , R 13 , R 14 , R 15 , R 16 , R 17 are the same or different and are independently selected from hydrogen, deuterium, halogen, alkyl, alkenyl, alkynyl, perfluoroalkyl, aryl, heteroaryl, alkoxy, COR 18 、CO2R 19 ,CONR 20 , cyano, nitro, SO3R 21 PO3R 22 2, where R 18 , R 19 , R 20 , R 21 , R 22 are identical or different and are independently selected from hydrogen, deuterium, halogen, silyl, alkyl, alkenyl, alkynyl, perfluoroalkyl, aryl, heteroaryl, alkoxy, and wherein An - It is an anion.

2. The para-cyclophane-carbene compound according to claim 1, characterized in that R 1 is selected from C5 to C18 aryl, C5 to C18 heteroaryl, C1 to C18 alkyl, C1 to C18 perfluoroalkyl, C5 to C18 perfluoroaryl, wherein R 2 and R 3 are the same or different and are independently selected from C5 to C18 aryl, C5 to C18 perfluoroaryl, C5 to C18 heteroaryl, C1 to C12 alkyl, C1 to C12 alkenyl, C1 to C12 alkynyl, C1 to C12 perfluoroalkyl, wherein R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 are the same or different and are independently selected from hydrogen, deuterium, halogen, silyl, C1 to C12 alkyl, C1 to C12 alkenyl, C1 to C12 alkynyl, C1 to C12 perfluoroalkyl, C5 to C18 aryl, C5 to C18 perfluoroaryl, C5 to C18 heteroaryl, C1 to C12 alkoxy, wherein R 12 , R 13 , R 14 , R 15 , R 16 , R 17 are the same or different and are independently selected from hydrogen, C1 to C18 alkyl, C1 to C18 alkenyl, C1 to C18 alkynyl, C1 to C18 perfluoroalkyl, C5 to C18 aryl, C5 to C18 perfluoroaryl, C5 to C18 heteroaryl, C1 to C18 alkoxy, COR 18 、CO2R 19 ,CONR 20 , cyano, nitro, SO3R 21 PO3R 22 2, where R 18 , R 19 , R 20 , R 21 , R 22 are the same or different and are independently selected from hydrogen, deuterium, halogen, silyl, C1 to C18 alkyl, C1 to C18 alkenyl, C1 to C18 alkynyl, C1 to C18 perfluoroalkyl, C5 to C18 aryl, C5 to C18 heteroaryl, C1 to C18 alkoxy, and wherein An - is an anion selected from the group consisting of halide, trifluoromethanesulfonate, sulfate, phosphate, silicate, tetrafluoroborate, hexafluorophosphate, and tetraarylborate.

3. The para-cyclophane-carbene compound according to claim 1 or 2, characterized in that R 1 is selected from C9 to C18 aryl, C9 to C18 heteroaryl, C1 to C12 alkyl, C1 to C12 perfluoroalkyl, C9 to C18 perfluoroaryl, wherein, R 2 and R 3 are identical or different and are independently selected from C5 to C6 aryl and C5 to C6 heteroaryl, R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 are identical or different and are independently selected from hydrogen, deuterium, halogen and silyl, C1 to C4 alkyl, C1 to C4 alkenyl, C1 to C4 alkynyl and C1 to C4 perfluoroalkyl, C5 to C6 aryl, C5 to C6 heteroaryl, C5 to C6 perfluoroaryl, C1 to C4 alkoxy, wherein R 12 , R 13 , R 14 , R 15 , R 16 , R 17 are the same or different and are independently selected from hydrogen, C1 to C4 alkyl, C1 to C4 alkenyl, C1 to C4 alkynyl, and C1 to C4 perfluoroalkyl, C5 to C6 aryl, C5 to C6 perfluoroaryl, C5 to C6 heteroaryl, C1 to C4 alkoxy, COR 18 、CO2R 19 ,CONR 20 , cyano, nitro, SO3R 21 PO3R 22 2, where R 18 , R 19 , R 20 , R 21 , R 22 are the same or different and are independently selected from hydrogen, deuterium, halogen, silyl, C1 to C4 alkyl, C1 to C4 alkenyl, C1 to C4 alkynyl, C1 to C4 perfluoroalkyl, C5 to C12 aryl, C5 to C12 heteroaryl, C1 to C4 alkoxy, and wherein An - is an anion selected from the group consisting of halide, trifluoromethanesulfonate, sulfate, phosphate, silicate, tetrafluoroborate, hexafluorophosphate, and tetraarylborate.

4. The para-cyclophane-carbene compound according to any one of claims 1 to 3, characterized in that R 1 It is a dialkylphenyl group.

5. The para-cyclophane-carbene compound according to any one of claims 1 to 4, characterized in that R 2 and R 3 It is phenyl.

6. The para-cyclophane-carbene compound according to any one of claims 1 to 5, characterized in that R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 and R 11 For hydrogen.

7. The para-cyclophane-carbene compound according to claim 1, characterized in that R 12 , R 13 , R 14 , R 15 , R 16 and R 17 For hydrogen.

8. The para-cyclophane-carbene compound according to claim 1, characterized in that The paracyclophane-carbene compound has the following structure (II): 9 . Use of the p-cyclophane-carbene compound according to claim 1 in a metal complex of a light-emitting material for preparing a light-emitting layer of an organic light-emitting diode.

10. A metal complex, characterized in that The metal complex corresponds to the following structure (III): 50 1 Me[L 2 ] m [L 3 ] m (III), Among them, L 1 is a para-cyclophane-carbene ligand according to any one of claims 1 to 8, wherein L 2 and L 3 The same or different and independently selected from NR 23 2. NR 24 3.PR 25 2. PR 26 3. OR 27 2. OR 28 , SR 29 , SR 30 2. SR 31 , SeR 32 2. SeR 34 、TeR 35 2.TeR 36 , silyl, aryl, heteroaryl, alkenyl, alkynyl, isonitrile, cyclopentadienyl, halogen, wherein m is a number selected from 0, 1 or 2, provided that at least one m is not equal to zero, wherein R 23 , R 24 , R 25 , R 26 , R 27 , R 28 , R 29 , R 30 , R 31 , R 32 , R 33 , R 34 , R 35 , R 36 are the same or different and are independently selected from aryl, heteroaryl, alkenyl, alkynyl, alkyl, perfluoroalkyl, perfluoroaryl, and wherein Me is a metal selected from copper, silver and gold.

11. The metal complex according to claim 10, characterized in that L 1 is a para-cyclophane-carbene ligand according to any one of claims 1 to 8, wherein Me is a metal selected from copper, silver and gold, and wherein L 2 is a ligand selected from heteroaryl and halogen.

12. The metal complex according to claim 10 or 11, characterized in that L 1 is a para-cyclophane-carbene ligand according to any one of claims 1 to 8, wherein Me is copper, and wherein L 2 is a ligand selected from carbazole ligands and halogens.

13. The metal complex according to any one of claims 10 to 12, characterized in that The metal complex is selected from the following structures (IV), (V), (VI), (VII), (VIII) and (IX):

14. Use of a metal complex as a light-emitting material in a light-emitting layer of an organic light-emitting diode, characterized in that: The metal complex is formed according to any one of claims 10 to 13.

15. A light-emitting layer for an organic light-emitting diode, comprising a metal complex for emitting light, characterized in that: The metal complex is formed according to any one of claims 10 to 13.

16. An organic light emitting diode comprising a cathode, a light emitting layer, a hole transport layer and an anode, characterized in that: The light emitting layer is formed according to claim 15 .

17. The organic light emitting diode according to claim 16, characterized in that: The organic light emitting diode also has a filter for reducing reflections of external light sources, the filter being at least partially opaque to linearly polarized light.

18. A method of generating light by an organic light emitting diode, comprising: Step a) providing an organic light emitting diode according to any one of claims 16 or 17, and Step b) applying a voltage between the anode and the cathode to inject charge carriers and generate light.

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