Metal complex

Abstract

To provide improved metal complexes suitable as emitters for use in OLEDs.SOLUTION: There is provided a mononuclear iridium complex that exhibits oriented emission with an optical orientation anisotropy θ≤0.24, containing three ortho-metallated bidentate ligands or three ortho-metallated bidentate sub-ligands, characterized in that the angle α(μact,d) between the transition dipole moment μact and the electrical dipole moment d is ≤40°.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to iridium complexes suitable for use as emitters in organic electroluminescent devices. [Background technology]

[0002] According to the prior art, triplet emitters used in phosphorescent organic electroluminescent devices (OLEDs) are bis- and tris-ortho-metallated iridium complexes with aromatic ligands, where the ligands are bound to the metal via a negatively charged carbon atom and an uncharged nitrogen atom, or a negatively charged carbon atom and an uncharged carbene carbon atom. Examples of such complexes include tris(phenylpyridyl)iridium(III) and its derivatives, as well as many related complexes. The complexes may be homo- or heteroleptic. This type of complex is also known as a polypodal ligand, and is disclosed, for example, in WO 2016 / 124304. While complexes with polypodal ligands offer advantages over complexes with otherwise identical complex structures except for the absence of a polypodal bridge, there is still room for improvement. This is particularly true in the combination of high compound efficiency and good lifetime. Furthermore, there is still room for improvement in voltage shift. Here, voltage shift refers to the shift to higher operating voltages and therefore to higher operating voltages as the emissive concentration in the emissive layer increases. Because a certain concentration of emitter is required for good OLED lifetime (e.g., a concentration of 7% to 12% for a green phosphorescent emitter), materials with lower emitter concentrations are at a disadvantage when it comes to voltage shift. This is because a higher voltage shift results in a higher absolute operating voltage at a specific current density compared to lower emitters. Because operating voltage directly affects the power consumption of an OLED, even a slightly higher operating voltage for a material compared to a reference material can be a criterion for excluding this material. Therefore, in practice, materials with a smaller voltage shift are typically selected. A smaller voltage shift also generally leads to a longer OLED lifetime.

[0003] The external quantum efficiency of an OLED is composed of four distinct factors: the electron and hole charge carrier balance, the spin multiplicity, the photoluminescence quantum efficiency (PLQE) of the emitter, and the outcoupling factor, which indicates the proportion of internally generated photons that can be outcoupled from the OLED. The first three factors are also known as internal quantum efficiencies. The outcoupling factor is essentially determined by the orientation of the complex. Dipole emission is strongest perpendicular to the dipole alignment, and horizontal dipole alignment, i.e., alignment with the axis in the plane of the horizontal dipole, is preferred (see, for example, T.D. Schmidt et al., Phys. Rev. Applied 8, 037001 (2017)). If it is possible to align the emitter perfectly horizontally, the efficiency can be increased by at least 50% compared to isotropic emitter alignment. Therefore, one way to improve the efficiency of OLEDs is to orient the emitter in a layer with optically active, i.e., emissive, ligands, preferably perpendicular to the OLED layer direction.

[0004] In phosphorescent iridium complexes, the transition dipole moment of iridium points toward the emissive ligand of the complex. To achieve directional emission, the transition dipole moment of the emissive ligand must be aligned in the plane of the layer. This can be achieved by extending the emissive ligand with aromatic radicals linearly in the direction of the transition dipole moment and maximizing the van der Waals forces between these aromatic radicals and matrix molecules in the layer, as disclosed, for example, in US 2017 / 0294597 or WO 2018 / 178001. However, with such metal complexes, a voltage shift to higher operating voltages has been observed in some cases as the emitter concentration in the emissive layer increases, which can lead to higher operating voltages and shorter lifetimes. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2016 / 124304 [Patent Document 2] US Patent Application Publication No. 2017 / 0294597 [Patent Document 3] International Publication No. 2018 / 178001 [Non-patent literature]

[0006] [Non-Patent Document 1] T.D. Schmidt et al., Phys. Rev. Applied 8, 037001 (2017) Summary of the Invention [Problem to be solved by the invention]

[0007] The problem solved by the present invention is to provide improved metal complexes suitable as emitters for use in OLEDs. More specifically, the problem solved by the present invention is to provide metal complexes that, when used as emitters in OLEDs, lead to good or improved EQE. A further problem solved by the present invention is to provide metal complexes that, when used as emitters in OLEDs, result in a reduced voltage shift, thereby improving operating voltage and / or lifetime. Here, voltage shift refers to the shift to higher operating voltages, and therefore operating voltages, when the emitting layer concentration is increased, as explained above. [Means for solving the problem]

[0008] It has surprisingly been found that mononuclear iridium complexes having three ortho-metallated bidentate or ancillary ligands that exhibit directional emission simultaneously have good efficiency, particularly little, if any, voltage shift, and therefore particularly good operating voltage and lifetime, when the angle between the electronic dipole moment and the transition dipole moment of the complex is 40° or greater. The present invention therefore provides these complexes and organic electroluminescent devices comprising these complexes.

[0009] The present invention therefore provides mononuclear iridium complexes comprising three ortho-metallated bidentate ligands or three ortho-metallated bidentate ancillary ligands, which exhibit oriented emission with an optical orientation anisotropy θ≦0.24, and which have a transition dipole moment μ act and the angle α(μ act , d) is ≦40°; However, the following compounds are excluded from the present invention:

[0010] [ka]

[0011] [ka]

[0012] μ as bold and italic act The designations 'a' and 'd' indicate that these are vectors. Bold and italic type is typically used for vectors in this application.

[0013] In the sense of the present invention, an ortho-metallated bidentate ligand is a ligand that binds to iridium through two coordination sites, where at least one iridium-carbon bond is present. In the sense of the present invention, an ortho-metallated bidentate ancillary ligand is likewise bound to iridium through two coordination sites, where at least one iridium-carbon bond is present, where this ancillary ligand is covalently bonded to the other two bidentate ancillary ligands of the complex via bridging groups, forming a multipodal ligand that is hexadentate overall. When a ligand or ancillary ligand is referred to herein as being coordinated or bonded to iridium, this refers to any type of bond of the ligand or ancillary ligand to iridium, regardless of the covalent component of the bond, in the sense of the present invention.

[0014] Orientation of the complex is particularly possible in heteroleptic complexes, since this allows for the preferred arrangement of octahedral complexes. Therefore, the complexes of the present invention are preferably heteroleptic complexes, i.e., complexes containing at least two different ligands or subligands. Here, it is preferred that the complex has two identical bidentate ligands or subligands and a further bidentate ligand or subligand that is different from the two ligands or subligands.

[0015] To obtain directional emission, the transition dipole moment μ of the complex act (where "act" stands for "active", i.e. optically active transition dipole moment) must be aligned parallel, i.e. very substantially parallel, to the layer plane of the OLED. For this purpose, preferably exactly one of the three bidentate ligands or subligands is an emissive or optically active ligand or subligand, where the terms "emissive ligand" and "(optically) active ligand" and the terms "emissive subligand" and "(optically) active subligand" are used synonymously hereinafter. In the sense of the present invention, an optically active ligand or subligand is understood to mean a ligand or subligand that is responsible for the luminescence of the complex. This ligand or subligand will hereinafter be referred to as L act while the two other, optically inactive ligands or ancillary ligands are simply referred to as L. Here, the ligand Ir(L) is E T1,act The ligand Ir(L act ) with a higher triplet energy E T1,L The triplet energy ΔE=E T1,L -E T1,act >0, the emission of the complex is due to the ligand Ir(L act ) to achieve the effect that is mainly due to the (electron and spin) density of the complex, which can be inferred from the metal, but also contains the active ligand, especially in the transition. Therefore, from now on, the active ligand L actor the triplet energy of the ligand L.

[0016] Ir(L act ) and the triplet energy of Ir(L), more generally E T1,i (three ligands i=1, 2, 3) are determined by quantum chemical calculations as generally described in part 1.1 of the Examples, where the triplet energy of the ligand Ir(L) is act ), it is preferred that it is at least 0.05 eV greater, more preferably at least 0.10 eV greater, and most preferably at least 0.20 eV greater.

[0017] Those skilled in the art know that a large number of complexes with different ligands and their emission energies are known, and therefore different combinations of ligands can be selected to obtain a complex with just one optically active ligand or ancillary ligand. Thus, those skilled in the art can select a known homoleptic complex with a known emission energy, or alternatively, calculate the emission energy of the corresponding homoleptic complex. Then, the above energy difference is the Ir(L act It is possible to assemble suitable heteroleptic complexes between Ir(L) and Ir(L). The complexes thus assembled can be checked by calculating the exact energies of the optically active and inactive ligands or ancillary ligands, again as described in part 1.1 of the Examples, and thereby checking whether the emission color of the complex matches the prediction and satisfies the above energy conditions.

[0018] In order to orient the complex in the layer so as to obtain directional emission perpendicular to the layer plane, optically active ligands or ancillary ligands L actIt is necessary that the optically active ligands or ancillary ligands are arranged very substantially parallel to the layer plane. To maximize the van der Waals interactions between the optically active ligands or ancillary ligands and the matrix material of the layer, this can be achieved by extending the optically active ligands or ancillary ligands with aromatic or heteroaromatic ring systems in the direction of the transition dipole moment. As described in a general sense in part 1.3 of the Examples, the direction of the transition dipole moment in the illuminant is determined by quantum chemical calculations.

[0019] The optical orientation anisotropy is determined by the following equation (see: T.D. Schmidt et al., Phys. Rev. Applied 8, 037001 (2017), equation (4) in chapter III.B):

[0020]

number

number

[0021] The structure of the complex and its interaction with the substrate during deposition result in optical orientation anisotropy. As described in general terms in Part 2 of the Examples, this can be determined by a combination of quantum chemical and molecular dynamics calculations. Alternatively, the optical orientation anisotropy can be determined experimentally, as described in Chapter III.B and Figure (4) of T.D. Schmidt et al., Phys. Rev. Applied 8, 037001 (2017), and in Part 4 of the Examples. In a preferred embodiment of the invention, the optical orientation anisotropy is determined computationally.

[0022] In a preferred embodiment of the present invention, the optical orientation anisotropy θ is ≦0.22, more preferably ≦0.20, even more preferably ≦0.18, and particularly preferably ≦0.16.

[0023] The electronic dipole moment d of the complex is determined from the structure of the complex. The estimation of the electronic dipole moment of the complex can be performed in advance by adding the dipole moments of each bidentate ligand, or bidentate subligand in the case of polypodal complexes, where Ir is replaced by H and the relative orientation of the three ligands in an octahedral bonding context should be taken into account. The electronic dipole moment d can be determined by quantum chemical calculations as described in the general description of part 1.1 of the Examples.

[0024] transition dipole moment μ act The angle between the transition dipole moment μ and the electronic dipole moment d is fixed by the structure of the complex. In the vast majority of known directional luminescence tris-ortho-metallated iridium complexes, the electronic dipole moments are aligned such that the overall result is to prevent the injection of holes from the adjacent hole transport layer. In this case, the transition dipole moment μ act The angle between the transition dipole moment μ and the electron dipole moment d is significantly larger than 40°, e.g., 80° for Ir(ppy)3. However, the transition dipole moment μ actWhen the angle between the α (which should be in the plane of the layers for a favorable optical orientation anisotropy) and the electronic dipole moment d is <40°, the component of the electronic dipole moment perpendicular to the plane of the layers, as seen from the sine of the angle α, is significantly reduced, so that the electronic dipole moment d interacts less with the charge injection, resulting in a smaller voltage shift.

[0025] In a preferred embodiment of the present invention, the transition dipole moment μ act The angle α between the transition dipole moment μ and the electronic dipole moment d is ≦35°, more preferably ≦30°, even more preferably ≦25°, and particularly preferably ≦20°. The lower limit of the angle α is 0°. In this case, the transition dipole moment and the electronic dipole moment are aligned parallel to each other, and the electronic dipole moment μ act When lies in the plane of the substrate, it no longer interacts with the charge injection.

[0026] The transition dipole moment μ of the active ligand of the complex that is required to have an optical orientation anisotropy θ≦0.24 is given below. act and the angle α(μ act The present invention describes a method for forming a suitable iridium complex having both an optical orientation anisotropy θ≦0.24 and an angle α(μ act The method for finding suitable complexes with α, β ...

[0027] Step 1:A bidentate ligand L is selected that forms an ortho-metallated complex, from which the homoleptic Ir complex Ir(L)3 is formed. The 3D configurations of the singlet ground state and one of the three (identical) triplet states of the homoleptic complex Ir(L)3 are calculated as described in general terms in Part 1 of the Examples. Based on the triplet configurations, the transition dipole moment μ L and triplet energy E T1,L Calculate the direction of μ based on the metal-ligand charge transport (MLCT) properties of the transition. L The plane of the ligands usually points away from the iridium. This is shown in Figure 2 for the example of Ir(ppy)3, where μ L points in the Ir → C5 direction. Figure 2 shows the transition dipole moment μ of one of the three ppy ligands. L , and the electronic dipole moment d of the singlet ground state of Ir(ppy)3. In homoleptic complexes, the electronic dipole moment d indicates the C3 symmetry axis for symmetry reasons.

[0028] Step 2: To keep the transition dipole moment as close as possible to the plane of the substrate during the deposition process, thereby maximizing light outcoupling from the OLED, one of the three ligands is extended with an aromatic ring system to increase the van der Waals interaction between this ligand and the substrate, which is primarily formed by the triplet matrix material, compared to the other two ligands. The extension requires triplet energies >E T1,L An aromatic system having more than six carbon atoms is selected, having a triplet energy greater than that of the homoleptic complex (see part 1.1 of the Examples), thereby increasing the molecular weight of the entire complex to preferably 1500 g / mol or less, more preferably 1200 g / mol or less, even more preferably 1000 g / mol or less, and especially preferably 800 g / mol or less, to ensure volatility of the complex after expansion. Useful aromatic systems are very substantially flat units with or without heteroatoms that have strong van der Waals interactions, such as triphenylene, biphenyl, terphenyl, dibenzofuran, and dibenzothiophene. Examples are shown in Figure 3.

[0029] The suitability of these systems, hereafter referred to as "extended units", is determined by the calculated eigenvalues ​​of the rotation tensor, hereafter

number

[0030] Thanks to suitable extender units, such as Ir(ppy-CN)2(ppy), the optical orientation anisotropy can be reduced from the virtually isotropic value of θ = 0.31 (without extension) to θ = 0.19 by extending the active ligand with triphenylene or para-terphenyl (Figure 3b). This corresponds to a possible increase in the absolute EQE of approximately 20% for the unextended complex to approximately 30% with triphenylene or para-terphenyl, i.e., a relative increase in the EQE by a factor of 1.5. A perfectly aligned emitter has θ = 0, a totally unoriented one has θ = 1, and a precisely isotropic one has θ = 1 / 3.

[0031] Eigenvector of the largest eigenvalue

number

[0032] Step 3:The connection point to the single bond of the extender unit on the ligand side is μ in step 1. L or the reflection point of the transition dipole moment in the iridium atom -μ L and step 2 p z The angle β formed between cn is selected so that the minimum value of is obtained (Fig. 4). z and the definition of the connection point of the extension unit. Figure 4b) shows the transition dipole moment μ L and p z The angle β between cn For visualization, we show how the attachment points to the ligand are found by L is transferred to each possible attachment point of the ligand (C1-C11 in Figure 4b). In the case of Ir(ppy)3 with biphenyl as the extender unit, β c3 is β c10 The carbon atom C3 is the most suitable point of attachment because it is smallest with μ L or -μ L The goal is to have as many atoms of the active ligand as possible lined up in a linear fashion in the direction of the nucleus, and C3 with its seven atoms (Ir, N, C, C, C, C, C) is more preferable than the connection point C10. The Ir → C11 bond is the latter μ L The newly formed extended ligand, due to its somewhat elongated π-electron system, has a smaller triplet energy than the two other ligands L, and is therefore more optically active. act and the two other ligands are called co-ligands L.

[0033] Step 4: Then, two existing ligands L and a new extended ligand L act A newly formed heteroleptic complex consisting of Ir(L)L act In the 3D geometry, the singlet ground state electronic dipole moment d, and the transition dipole moment μ act , and the triplet state energy of the active ligand, E T1,act is calculated, and μact The angle between α(μ act ,d).

[0034] μ act is the extension unit p z If the extension axis of μ is significantly deviated from the axis, the next best connection point in step 3 is selected. Otherwise, μ act This is because it is not guaranteed that μ will be present in the plane of the substrate during deposition. In the sense of the present invention, a large deviation is a deviation of more than 20°. This would occur in the selection of C10 instead of C3 in step 3. act In the case of C10, it is pulled in the direction of Ir → C10. In this respect, C3 is more suitable for connection than C10. μ act But further p z direction, the triplet energy E in the heteroleptic complex T1,L and their transition dipole moments μ L is similarly calculated for the two co-ligands, since these are needed later for the calculation of the optical orientational anisotropy.

[0035] Figure 5 shows an example of Ir(L)2L act = Ir(ppy)2(ppy-C3-biphenyl), where μ of the extended ligand act is the "old" μ of Ir(ppy)3 L Compared with the homoleptic Ir(ppy)3 complex (the "old" μ L ) predicted expansion axis p z and β' c3 However, the β of step 3 has excellent optical alignment. c3 At this point, the attachment point at C3 is preserved, while the extension at C10 is likely to be compromised. In aromatic extended ppy ligands, μ act is always close to the Ir→N direction, and extension in the para position to Ir→N (C3 in Figure 5) is often the best choice.

[0036] As shown in Figure 5c), due to the loss of symmetry between the ligands, the electronic dipole moment d of the whole molecule is no longer just on the pseudo-C3 symmetry axis, but is shifted more towards the active ligand, which results in an angle α(μ act ,d) decreases. active ligand μ act The angle between the electron dipole moment of the molecule and the electron dipole moment of the molecule is α(μ act ,d)=55°, that is, still α(μ act , d)>40°. Therefore, Ir(ppy)2 (ppy-C3-biphenyl) is not according to the invention.

[0037] Step 5: α(μ act ,d)≦40°are not satisfied, the introduction of electronically active groups such as CN, F, N, O, etc. in the two co-ligands significantly changes the electronic dipole moments of the two co-ligands (Ir is nominally replaced by H) in terms of either their contribution or their direction in the co-ligand plane. Thus, as a result of these electronically active groups, the electronic dipole moment of the whole molecule (in each case Ir is nominally replaced by H), which is roughly the result of the vector addition of the three electronic dipole moments of the ligands, deviates from the pseudo-C3-axial symmetry and becomes μ act approaches α(μ act , d) is significantly reduced, whereby the change in co-ligand usually does not result in a significant change in the transition dipole moment of the active ligand.

[0038] In the case of Ir(ppy)2(ppy-C3-biphenyl) with a fixed activating ligand (ppy-C3-biphenyl), the electronic dipole moment of the activating ligand (Ir is nominally replaced by H) is close to the transition dipole moment of the activating ligand, i.e., parallel to Ir → N. The electronic dipole moment of the ppy co-ligand (Ir is nominally replaced by H) initially points in a similar direction in the plane of the ligand (parallel to Ir → N) and is slightly smaller in magnitude than the electronic dipole moment of the activating ligand. The overall electronic dipole moment of the Ir(ppy)2(ppy-C3-biphenyl) complex deviates slightly from the pseudo-C3 axial symmetry of the activating ligand direction due to the vector addition of the three electronic dipole moments of the ligand in the octahedral bonding state of the facial complex, thereby forming a very large angle α(μ) with the transition dipole moment of the activating ligand. act , d) = 55°. Therefore, the angle is reduced compared to the homoleptic Ir(ppy)3, as shown in Figure 6. After the expansion, μ act is no longer parallel to Ir→C5 but points in the Ir→N direction, and d is parallel to μ act This is because the direction is slightly away from the C3 axis of symmetry.

[0039] To move the overall molecular electronic dipole moment further away from the pseudo-C3 axial symmetry, electronically modified ppy-based co-ligands along the C7, C8, and / or C9 positions are preferred over L = ppy. These have a smaller angle α(μ) due to two effects: act ,d), which is shown by a three-dimensional vector model of the electronic dipole moments of the three ligands.

[0040] First, the electronic symmetry between the Ir-bonded N and C of phenylpyridine is compensated, minimizing the magnitude of the co-ligand electronic dipole, thereby necessarily reducing the angle α(μ act, d) is reduced because the electronic dipole moment of the active ligand points in the same direction as the transition dipole moment of the active ligand. Then, the direction of the electronic dipole moment of the co-ligand changes significantly, and the vector addition of the three electronic dipole moments of the ligands causes the total electronic dipole moment of the resulting complex to move far away from the C3 axial symmetry and approach the transition dipole moment of the active ligand. This is the case when, in Ir(ppy)2 (ppy-C3-biphenyl), one cyano group is introduced into each of the two co-ligands at the C8 position, or even better, at C7, causing a significant change in the direction of the electronic co-ligand dipole compared to ppy, and in the case of C8, α(μ act ,d)=45°, or better α(μ act , d) = 25°. For example, in the case of Ir(ppy-C7-CN)2 (ppy-C3-biphenyl), the first of the two criteria of the present invention is α(μ act ,d)≦40°, so it is satisfied.

[0041] Figure 6 shows that in the homoleptic complex Ir(ppy)3, the electron dipole moment d is C3 axially symmetric and α(μ act ,d) = 80°. The electronic dipole moments of all three ligands point in the same direction in the plane of the ligands (Ir → N). Extension of the active ligand breaks the symmetry, and d becomes somewhat more aligned with the active ligand, as the electronic dipole of the extended ligand grows in magnitude. At the same time, compared to Ir(ppy)3, μ act There is also a change in the direction of α(μ act ,d) = 55°. The electronically active cyano groups on the two co-ligands at C8 or C7 positions can further move d away from the C3 axial symmetry, because in the co-ligand plane the direction of the electronic dipole moment of the co-ligand changes significantly compared to ppy, and finally α(μ act ,d) = 25°, i.e., α ≦ 40° in Ir(ppy-C7-CN)2(ppy-C3-biphenyl).

[0042] Ir(ppy-C7-CN)2(ppy-C3-biphenyl) and similarly active ppy-C3-biphenyl ligands with small angles α(μ act Further examples of electronically modified ppy co-ligands leading to ,d) are shown in Figure 7. In Figure 7a) an electronically modified ppy ligand is shown to have a transition dipole moment μ act and Ir(L)2L bearing the active ppy-C3-terphenyl ligand act The small angle α(μ) between the electron dipole moment d of the entire complex act ,d), which can lead to a smaller electronic dipole of the co-ligand (the length of the vector written corresponds to the magnitude), as in the case of co-ligand 55, or to a larger change in the direction of the electronic dipole moment of the co-ligand compared to ppy, as in the case of co-ligand 14 (which is the co-ligand of Ir(ppy-C7-CN)2(ppy-C3-biphenyl)).

[0043] Figure 7b) shows the optical orientation anisotropy θ and angle α (μ) in combination with the active co-ligand L (ppy-C3-terphenyl) of Figure 7a). act ,d), one without a multipodal bridge and one with a multipodal bridge (the latter is identified in the nomenclature by the addition "poly"). The homoleptic reference complex Ir(ppy)3 exhibits a virtually isotropic optical orientation θ = 0.31 and a very large angle α (μ act , d) = 80° (see Figure 6), i.e., optically and electronically unfavorable. Extension with para-terphenyl groups leads to better optical and electronic properties. Introduction of multi-legged caps leads to an improvement in optical alignment at the expense of a slightly higher angle, since the overhead linkage has the effect of keeping the electronic dipole moment somewhat closer to pseudo-axial symmetry. Modification of the co-ligands with electronically active groups leads to an even smaller angle α(μ act ,d), which leads to α(μ act,d) Both θ≦40° and θ≦0.24 are possible, and all compounds in the upper left quadrant are suitable. The introduction of a multi-legged cap for bridging three ligands is act , but affects the optical alignment parameter θ. act , d) and θ are always combined with the same active ligand (ppy-C3-biphenyl), one with a multipodal cap and one without.

[0044] Step 6: Ir(L)2L act In α(μ act ,d) ≦40°, a second criterion must be satisfied: an optical orientation anisotropy θ≦0.24, to allow for good outcoupling properties and thus high efficiency. Following the rule construction described in steps 1 to 5, this is usually the case (see step 7 below for an exception).

[0045] Here, the optical orientation anisotropy θ of a mixed film of the synthesized complex in a proportion of 10% by volume in a triplet matrix material as a reference material by angle-dependent photoluminescence can be measured (see Example Part 3 "Measurement of the emitter orientation in evaporated films"). However, θ is preferably determined by the angle-dependent photoluminescence of Ir(L)L. act are calculated by molecular dynamics simulation of the deposition process based on the geometry, energy, and transition dipole moment of the three triplet states of θ, determined by quantum chemical means in step 4 (see part 2 of the Examples). Furthermore, this calculation yields an overall value θ by averaging by energetics (Boltzmann distribution) and kinetics of the three respective optical orientational anisotropies θ of the three ligands in the heteroleptic complex. 1=act , θ 2=L、 θ 3=L The calculated θ has good correlation with the procedure (correlation coefficient R for 30 test illuminants). 2 =0.70).

[0046] Step 7:In this calculation, the optically active ligand is 1=act lies in the plane of the substrate when θ ≦0.24, but at least one of the two co-ligands is less oriented (θ 2=L , θ 3=L >0.24), then the overall possible outcome of the average of the three contributions is θ>0.24.

[0047] In this case, the triplet energy difference between the active ligand and the two co-ligands is ΔE = E T1,L -E T1,act By increasing the angle α (μ), the effect of suppressing the emission of the two co-ligands θ ≦ 0.24 can be achieved. To achieve this, the co-ligands can be blue-shifted by introducing heteroatoms such as F, CN, N, or O, or the active ligands can be red-shifted by extending the π system. However, such modifications require a large change in the angle α (μ act ,d) also brings about changes, but it is necessary to restart at step 4.

[0048] The energy difference ΔE≒0.1 eV (which is about 4 kJ at room temperature) B T(Boltzmann constant k B and temperature T), this is not necessary in the case of Ir(ppy-C7-CN)2(ppy-C3-biphenyl) in Figure 6; the emission of the co-ligand is at least exp(4) = 50 times weaker than that of the active ligand, and only the active ligand has any relevant emission.

[0049] In rare cases, as described in steps 1-5 of the formation method, μ act Ga p z Even if it is parallel to θ 1=act >0.24. This means that the extension of the active ligand is insufficient, for example, due to excessively strong van der Waals interactions between the co-ligand and the substrate. In this case, for example, the active ligand can be extended with terphenyl or triphenylene instead of biphenyl (see Figure 3b). The sterically bulky alkyl group substituents are 1=act>0.24. In such cases, even longer extension units on the active ligand are useless; the iterative process should be restarted at step 5, step 2, or even step 1.

[0050] Preferred complexes Ir(L)L act is α(μ act ,d)≦40° and θ≦0.24 are both satisfied. Because θ≦0.24, this complex allows good light outcoupling and thus high efficiency, while at the same time not showing any shift in voltage. The electronic dipole moment d of the complex is μ act This is because they tend to exist in the substrate plane together with the electrons, and are unable to generate a strong electric field in the direction of movement.

[0051] In a preferred embodiment of the invention, the complexes of the invention have a photoluminescence quantum efficiency greater than 0.85, preferably greater than 0.9, more preferably greater than 0.95. Photoluminescence quantum efficiency is measured as described in general terms in the Examples below.

[0052] Structurally, the iridium complexes of the present invention are represented by formulas (1) and (2). [ka]

[0053] L act is an optically active ortho-metallated bidentate ligand in formula (1) and an optically active ortho-metallated ancillary ligand in formula (2). L is the same or different in each occurrence and is an optically inactive ortho-metallated bidentate ligand in formula (1) and an optically inactive ortho-metallated bidentate ancillary ligand in formula (2). V in formula (2) is an ancillary ligand L act and L via a covalent bond, forming a tripodal hexadentate ligand. Preferably, the tripodal complex is represented by formula (2).

[0054] The ligand of formula (2) contains one bidentate ancillary ligand L act and two bidentate sub-ligands L. "Bidentate" means that the particular sub-ligand in the complex coordinates or bonds to iridium via two coordination sites. "Tripodal" means that the ligand has three sub-ligands attached to a bridge V. Since the ligand has three bidentate sub-ligands, overall it is a hexadentate ligand, i.e., a ligand that coordinates or bonds to iridium via six coordination sites. In the sense of the present invention, the expression "bidentate sub-ligand" refers to the ligand that coordinates or bonds to iridium via L when the bridge V is not present. act and L is a bidentate ligand in each case. However, with the hydrogen atom formally removed from this bidentate ligand and connected to the bridge, it is no longer a separate ligand but is part of a hexadentate ligand, hence the term "ancillary ligand."

[0055] Bidentate ortho-metallated ligand or ancillary ligand L act and L are described below. The ligand or ancillary ligand L act and L coordinates to iridium via one carbon atom and one nitrogen atom, or via two carbon atoms. act Alternatively, when L is coordinated to iridium via two carbon atoms, one of the two carbon atoms is a carbene carbon atom. act is an optically active ligand or ancillary ligand, so L is L act In a preferred embodiment of the invention, the two ligands or ancillary ligands L are identical.

[0056] More preferably, each ligand or subligand L act and L has one carbon atom and one nitrogen atom as coordination atoms.

[0057] Iridium and a ligand or ancillary ligand L actIt is further preferred if the metallocycle formed from and L is a five-membered ring. This is shown diagrammatically below:

[0058] [ka] where N is a coordinating nitrogen atom, C is a coordinating carbon atom, and the carbon atom shown is a ligand or an ancillary ligand L act or an atom of L.

[0059] As described above, the partial structure Ir(L) is a partial structure Ir(L) having an optically active ligand or an ancillary ligand. act ) has a higher triplet energy than Ir(L). This allows the emission from the complex to be mainly due to the substructure Ir(L). act ) to achieve the effect that results from the

[0060] In a preferred embodiment of the invention, the ligand or ancillary ligand L act and L is a structure of the following formula (L-1) or (L-2): act and L are different from each other, and the two ligands or ancillary ligands L may be the same or different, but are preferably the same.

[0061] [ka] where the dotted bond is the bond to the ancillary ligand V in formula (2) and is not present in formula (1), and other symbols used herein are as follows: CyC is the same or different in each occurrence and is a substituted or unsubstituted, aryl or heteroaryl group having 5 to 14 aromatic ring atoms and in each case coordinated to the metal via a carbon atom, which is bound to CyD via a covalent bond; CyD, which may be the same or different at each occurrence, is a substituted or unsubstituted heteroaryl group having 5 to 14 aromatic ring atoms and coordinating to the metal via a nitrogen atom or a carbene carbon atom, which is attached to CyC via a covalent bond; At the same time, two or more optional substituents may together form a ring system; the optional radicals are preferably selected from the R radicals defined below.

[0062] CyD coordinates through an uncharged nitrogen atom or through a carbene carbon atom, and CyC coordinates through an anionic carbon atom.

[0063] It is also possible for two or more substituents, especially two or more R radicals, to form a ring system, where the ring system is formed from substituents directly attached to adjacent carbon atoms. Furthermore, the substituents of CyC and CyD, or two CyD groups, may together form a ring, so that CyC and CyD together form a single fused aryl or heteroaryl group as a bidentate ligand.

[0064] Preferably, all ligands or subligands L act and L has the structure of formula (L-1), or all of the ligands or ancillary ligands L act and L has the structure of formula (L-2). act is different from L, and the two ancillary ligands L are preferably identical.

[0065] In a preferred embodiment of the invention, CyC is an aryl or heteroaryl group having 6 to 13 aromatic ring atoms, more preferably 6 to 10 aromatic ring atoms, and most preferably 6 aromatic ring atoms, which coordinates to the metal via a carbon atom, is optionally substituted by one or more R radicals, and is attached to CyD via a covalent bond.

[0066] Preferred forms of the CyC group are the structures of the following formulae (CyC-1) to (CyC-19), where in each case the CyC group is bonded to CyD at the position indicated by # and coordinates to iridium at the position indicated by *.

[0067] [ka] where the symbols used are: X is the same or different at each occurrence and is CR or N, provided that at most two symbols X per ring are N; W is the same or different at each occurrence and is NR, O, or S; R may be the same or different at each occurrence and may be H, D, F, Cl, Br, I, N(R 1 )2, OR 1 , S.R. 1 , CN, NO2, COOR 1 , C(=O)N(R 1 )2, Si(R 1 )3, B(OR 1 )2, C(=O)R 1 , P(=O)(R 1 )2, S(=O)R 1 , S(=O)2R 1 , OSO2R 1 , a linear alkyl group having 1 to 20 carbon atoms, or an alkenyl or alkynyl group having 2 to 20 carbon atoms, or a branched or cyclic alkyl group having 3 to 20 carbon atoms, wherein the alkyl, alkenyl or alkynyl group is in each case composed of one or more R 1 radicals, where one or more non-adjacent CH groups are Si(R 1 )2, C=O, NR 1 , O, S or CONR 1 or 5 to 40 aromatic ring atoms, in each case one or more non-aromatic R 1 an aromatic or heteroaromatic ring system optionally substituted by a radical; and at the same time, two R radicals may together form a ring system; R 1 are the same or different for each occurrence and are H, D, F, Cl, Br, I, N(R 2 )2, OR 2 , S.R. 2 , CN, NO2, Si(R 2 )3, B(OR 2 )2, C(=O)R 2 , P(=O)(R 2)2, S(=O)R 2 , S(=O)2R 2 , OSO2R 2 , a linear alkyl group having 1 to 20 carbon atoms, or an alkenyl or alkynyl group having 2 to 20 carbon atoms, or a branched or cyclic alkyl group having 3 to 20 carbon atoms, wherein the alkyl, alkenyl or alkynyl group is in each case composed of one or more R 2 radicals, where one or more non-adjacent CH groups are Si(R 2 )2, C=O, NR 2 , O, S or CONR 2 or 5 to 40 aromatic ring atoms, in each case one or more aromatic R 2 an aromatic or heteroaromatic ring system, optionally substituted by a radical; 1 The radicals may together form a ring system; R 2 are identical or different at each occurrence and are H, D, F, or an aliphatic organic radical, in particular a hydrocarbyl radical, having 1 to 20 carbon atoms, in which one or more hydrogen atoms may be replaced by F; However, if bridge V is attached to CyC in formula (2), one symbol X is C and bridge V is attached to a carbon atom. If a CyC group is attached to bridge V, the attachment is preferably via the position marked "o" in the above formula, and therefore in this case the symbol X marked "o" is preferably C. The above structures not containing the symbol X marked "o" are preferably not directly attached to bridge V, since attachment to such a bridge is not advantageous for steric reasons.

[0068] Two R's or R's 1When radicals together form a ring system, it can be monocyclic or polycyclic, aliphatic, heteroaliphatic, aromatic or heteroaromatic.In this case, the radicals together forming a ring system can be adjacent, which means that the radicals are bonded to the same carbon atom or carbon atoms directly adjacent to each other, and they can also be removed from each other.Preferably, this type of ring formation occurs in radicals bonded to carbon atoms directly bonded to each other.

[0069] In the sense of the present invention, the term two or more radicals may together form a ring is understood to mean, inter alia, that two radicals are linked to one another by a chemical bond with the formal deletion of two hydrogen atoms, as illustrated by the following scheme: [ka]

[0070] Furthermore, the above terms are also understood to mean that when one of the two radicals is hydrogen, the second radical is attached at the position where the hydrogen atom is attached to form a ring, as shown by the following scheme: [ka]

[0071] Furthermore, the above terms are understood to mean that when two radicals are alkenyl groups, the radicals together form a ring, forming a fused aryl group. Similarly, in the case of aryloxy substituents, the formation of fused benzofuran groups is also possible, and in the case of arylamino substituents, the formation of fused indole groups is also possible. These are illustrated by the following schemes: [ka]

[0072] A cyclic, alkyl, alkoxy or thioalkoxy group in the sense of the present invention is understood to mean a monocyclic, bicyclic or polycyclic group.

[0073] In the sense of the present invention, C1- to C 20-Alkyl groups (furthermore, each hydrogen atom or CH2 group thereof may be replaced by the groups mentioned above) include, for example, methyl, ethyl, n-propyl, i-propyl, cyclopropyl, n-butyl, i-butyl, s-butyl, t-butyl, cyclobutyl, 2-methylbutyl, n-pentyl, s-pentyl, t-pentyl, 2-pentyl, neopentyl, cyclopentyl, n-hexyl, s-hexyl, t-hexyl, 2-hexyl, 3-hexyl, neohexyl, cyclohexyl, 1-methylcyclopentyl, 2-methylpentyl, n-heptyl, 2-heptyl, 3-heptyl, 4-heptyl, cycloheptyl, 1-methylcyclohexyl, n-octyl, 2-ethylhexyl, cyclooctyl, 1-bicyclo[2.2.2]octyl, 2-bicyclo[2.2.2]octyl, 2-(2,6-dimethyl)octyl, 3-(3,7-dimethyl)octyl, adamantyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, 1,1-dimethyl-n-hexyl 1,1-dimethyl-n-hept-1-yl, 1,1-dimethyl-n-oct-1-yl, 1,1-dimethyl-n-dec-1-yl, 1,1-dimethyl-n-dodec-1-yl, 1,1-dimethyl-n-tetradec-1-yl, 1,1-dimethyl-n-hexadec-1-yl, 1,1-dimethyl-n-octadec-1-yl, 1,1-diethyl-n-hex-1-yl, 1,1-diethyl-n-hept-1-yl, 1,1-diethyl-n-oct-1-yl, 1,1-diethyl- n-Deca-1-yl, 1,1-diethyl-n-dodec-1-yl, 1,1-diethyl-n-tetradec-1-yl, 1,1-diethyl-n-hexadec-1-yl, 1,1-diethyl-n-octadec-1-yl, 1-(n-propyl)cyclohex-1-yl, 1-(n-butyl)cyclohex-1-yl, 1-(n-hexyl)cyclohex-1-yl, 1-(n-octyl)cyclohex-1-yl and 1-(n-decyl)cyclohex-1-yl radicals are understood to mean.An alkenyl group is understood to mean, for example, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl or cyclooctadienyl. An alkynyl group is understood to mean, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl or octynyl. OR. 1 The radicals are taken to mean, for example, methoxy, trifluoromethoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy or 2-methylbutoxy.

[0074] Within the meaning of the present invention, an aryl group contains 6 to 30 carbon atoms; within the meaning of the present invention, a heteroaryl group contains 2 to 30 carbon atoms and at least one heteroatom, provided that the sum of carbon atoms and heteroatoms is at least 5. The heteroatoms are preferably selected from N, O and / or S. An aryl or heteroaryl group is understood here to mean a single aromatic ring, i.e., benzene, or a single heteroaromatic ring, such as pyridine, pyrimidine, thiophene, etc., or fused aryl or heteroaryl groups, such as naphthalene, anthracene, phenanthrene, quinoline, isoquinoline, etc. Aromatic systems connected to each other by a single bond (e.g., biphenyl), in contrast, are not referred to as aryl or heteroaryl groups, but as aromatic ring systems.

[0075] In the sense of the present invention, an aromatic ring system has 6 to 40 carbon atoms, preferably 6 to 30 carbon atoms, in the ring system. In the sense of the present invention, a heteroaromatic ring system has 2 to 40 carbon atoms, preferably 2 to 30 carbon atoms, and at least one heteroatom, provided that the total number of carbon atoms and heteroatoms is at least 5. The heteroatom is preferably selected from N, O, and / or S. In the sense of the present invention, an aromatic or heteroaromatic ring system is understood to mean a system that does not necessarily contain only aryl or heteroaryl groups, but in which two or more aryl or heteroaryl groups can also be linked by non-aromatic units, such as carbon, nitrogen, or oxygen atoms. These are also understood to mean systems in which two or more aryl or heteroaryl groups are directly bonded to each other, such as biphenyl, terphenyl, bipyridine, or phenylpyridine. For example, systems such as fluorene, 9,9'-spirobifluorene, 9,9-diarylfluorene, triarylamine, diaryl ether, stilbene, etc. are also considered aromatic ring systems within the meaning of the present invention, as are systems in which two or more aryl groups are linked, for example, by short alkyl groups. Preferred aromatic or heteroaromatic ring systems are simple aryl or heteroaryl groups, groups in which two or more aryl or heteroaryl groups are directly linked to each other (e.g., biphenyl or bipyridine), and fluorene or spirobifluorene.

[0076] having 5 to 40 aromatic ring atoms, in each case as defined above in R 2The aromatic or heteroaromatic ring systems, which may be substituted by radicals or hydrocarbyl radicals and which may be linked to the aromatic or heteroaromatic ring system via any position, are in particular benzene, naphthalene, anthracene, benzanthracene, phenanthrene, pyrene, chrysene, perylene, fluoranthene, benzofluoranthene, naphthacene, pentacene, benzopyrene, biphenyl, biphenylene, terphenyl, terphenylene, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, propylene, cis- or trans-indenofluorene, cis- or trans-indenocarbazole, cis- or trans-indolocarbazole, truxene, isotruxene, spirotruxene, spiroisotruxene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6, 7-quinoline, benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthimidazole, phenanthrimidazole, pyridimidazole, pyrazinimidazole, quinoxalimidazole, oxazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, 1,2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, hexaazatriphenylene, benzopyridazine, pyrimidine, benzopyrimidine , quinoxaline, 1,5-diazaanthracene, 2,7-diazapyrene, 2,3-diazapyrene, 1,6-diazapyrene, 1,8-diazapyrene, 4,5-diazapyrene, 4,5,9,10-tetraazapyrylene, pyrazine, phenazine, phenoxazine, phenothiazine, fluorubine, naphthyridine, azacarbazole, benzocarboline, phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,It is understood to mean radicals derived from 4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, tetrazole, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine, purine, pteridine, indolizine and benzothiadiazole, or radicals derived from combinations of these systems.

[0077] Preferably, a total of no more than two of the symbols X in CyC are N, more preferably no more than one of the symbols X in CyC is N, and most preferably all of the symbols X are CR, with the proviso that when a bridge V in formula (2) is attached to CyC, one symbol X is C and the bridge V is attached to this carbon atom.

[0078] Particularly preferred CyC groups are groups of the following formulae (CyC-1a) to (CyC-20a): [ka]

[0079] [ka] wherein the symbols used have the meanings described above, and wherein if the bridge V is attached to CyC in formula (2), one R radical is absent and the bridge V is attached to the corresponding carbon atom. If a CyC group is attached to the bridge V, the attachment is preferably via the position marked "o" in the above formula, in which case the R radical at this position is preferably absent. The above structures which do not contain any carbon atoms marked "o" are preferably not directly attached to the bridge V.

[0080] Among the (CyC-1) to (CyC-19) groups, preferred are (CyC-1), (CyC-3), (CyC-8), (CyC-10), (CyC-12), (CyC-13) and (CyC-16) groups, and particularly preferred are (CyC-1a), (CyC-3a), (CyC-8a), (CyC-10a), (CyC-12a), (CyC-13a) and (CyC-16a) groups.

[0081] In a further preferred embodiment of the invention, CyD is a heteroaryl group having 5 to 13 aromatic ring atoms, more preferably 6 to 10 aromatic ring atoms, coordinated via an uncharged nitrogen atom or via a carbene carbon atom, optionally substituted by one or more R radicals, and attached to CyC via a covalent bond.

[0082] Preferred forms of the CyD group are the structures of the following formulae (CyD-1) to (CyD-18), in which the CyD group is in each case bound to CyC at the position indicated by # and to iridium at the position indicated by *.

[0083] [ka] where X, W and R have the meanings given above, with the proviso that if bridge V is attached to CyD, one symbol X is C and bridge V is attached to this carbon atom. If a CyD group is attached to bridge V, the attachment is preferably via the position marked "o" in the above formula, so that in this case symbol X marked "o" is preferably C. The above structures not containing symbol X marked "o" are preferably not directly attached to bridge V, since attachment to such a bridge is not advantageous for steric reasons.

[0084] In this case, the (CyD-1) to (CyD-4) and (CyD-7) to (CyD-18) groups coordinate to iridium via uncharged nitrogen atoms, and the (CyD-5) and (CyD-6) groups coordinate to iridium via carbene carbon atoms.

[0085] Preferably, a total of not more than two of the symbols X in CyD are N, more preferably not more than one of the symbols X in CyD is N, and especially preferably all of the symbols X are CR, with the proviso that when a bridge V in formula (2) is attached to CyD, one symbol X is C and the bridge V is attached to this carbon atom.

[0086] Particularly preferred CyD groups are those of the following formulae (CyD-1a) to (CyD-18a): [ka] wherein the symbols used have the meanings described above, and wherein when the bridge V is attached to CyD in formula (2), one R radical is absent and the bridge V is attached to the corresponding carbon atom. When a CyD group is attached to the bridge V, the attachment is preferably via the position indicated by "o" in the above formula, in which case the R radical at this position is preferably absent. The above structures not containing the carbon atom indicated by "o" are preferably not directly attached to the bridge V.

[0087] Of the (CyD-1) to (CyD-12) groups, preferred are (CyD-1), (CyD-2), (CyD-3), (CyD-4), (CyD-5) and (CyD-6) groups, particularly (CyD-1), (CyD-2) and (CyD-3), and particularly preferred are (CyD-1a), (CyD-2a), (CyD-3a), (CyD-4a), (CyD-5a) and (CyD-6a) groups, particularly (CyD-1a), (CyD-2a) and (CyD-3a).

[0088] In a preferred embodiment of the present invention, CyC is an aryl or heteroaryl group having 6 to 13 aromatic ring atoms, and CyD is a heteroaryl group having 5 to 13 aromatic ring atoms. More preferably, CyC is an aryl or heteroaryl group having 6 to 10 aromatic ring atoms, and CyD is a heteroaryl group having 5 to 10 aromatic ring atoms. Most preferably, CyC is an aryl or heteroaryl group having 6 aromatic ring atoms, and CyD is a heteroaryl group having 6 to 10 aromatic ring atoms. At the same time, CyC and CyD may be substituted by one or more R radicals.

[0089] The preferred groups (CyC-1) to (CyC-20) and (CyD-1) to (CyD-18) described above may be optionally linked together, provided that at least one of the CyC or CyD groups has a suitable linkage site to bridge V, the suitable linkage site being marked with "o" in the formula above.

[0090] It is particularly preferred that the CyC and CyD groups identified as being particularly preferred (ie groups of formulae (CyC-1a) to (CyC-20a) and (CyD1-a) to (CyD-18a)) are linked to one another.

[0091] It is particularly preferred that one of the (CyC-1), (CyC-3), (CyC-8), (CyC-10), (CyC-12), (CyC-13) and (CyC-16) groups, in particular the (CyC-1a), (CyC-3a), (CyC-8a), (CyC-10a), (CyC-12a), (CyC-13a) and (CyC-16a) groups, is bound to one of the (CyD-1), (CyD-2) and (CyD-3) groups, in particular to one of the (CyD-1a), (CyD-2a) and (CyD-3a) groups.

[0092] Preferred ancillary ligands (L-1) are structures of formulae (L-1-1) and (L-1-2), and preferred ancillary ligands (L-2) are structures of formulae (L-2-1) to (L-2-4): [ka] wherein the symbols used have the meanings described above, and "o" in the compound of formula (2) indicates the position of attachment to the bridge V, in this case the corresponding X is C.

[0093] Particularly preferred ancillary ligands (L-1) are structures of formulae (L-1-1a) and (L-1-2b), and particularly preferred ancillary ligands (L-2) are structures of formulae (L-2-1a) to (L-2-4a). [ka] Here, the symbols used have the meanings described above, and "o" in formula (2) indicates the bonding position to the bridge V, in which case there is no corresponding R.

[0094] When two R radicals, one attached to CyC and the other to CyD, together form an aromatic ring system, this forms a bridged ligand or an ancillary ligand, L 1 or L 2 In this case, several of these bridged ancillary ligands together form one larger heteroaryl group, such as benzo[h]quinoline. The ring between the substituents on CyC and CyD is preferably formed by one of the groups of formulae (3) to (12): [ka] where R 1 has the meaning described above, and the dotted bond represents a bond to CyC or CyD. Here, each of the asymmetric groups described above may be incorporated in two possible ways. For example, in the group of formula (12), the oxygen atom may be bonded to the CyC group and the carbonyl group to the CyD group, or the oxygen atom may be bonded to the CyD group and the carbonyl group to the CyC group.

[0095] At the same time, the group of formula (9) is particularly preferred when it forms a 6-membered ring, as shown, for example, in formulae (L-21) and (L-22).

[0096] Preferred ligands, which arise through ring formation between two R radicals on different rings, are structures of formulae (L-3) to (L-30) shown below: [ka]

[0097] [ka] Here, the symbols used have the meanings described above, and "o" in formula (2) indicates the position where this ancillary ligand is bonded to the V group.

[0098] In a preferred embodiment of the ligands or ancillary ligands of formulae (L-3) to (L-30), one symbol X is N and another symbol X is CR, or all symbols X are CR.

[0099] In a further aspect of the invention, in the groups (CyC-1) to (CyC-20) or (CyD-1) to (CyD-18), or in the ligands or ancillary ligands (L-3) to (L-30), when the R group attached as a substituent adjacent to the nitrogen atom is not hydrogen or deuterium, it is preferred that one of the atoms X is N. This applies analogously to the preferred structures (CyC-1a) to (CyC-20a) or (CyD-1a) to (CyD-18a), where the substituent attached adjacent to the non-coordinating nitrogen atom is preferably an R group that is not hydrogen or deuterium.

[0100] In this case, the substituent R is preferably CF3, OCF3, an alkyl group having 1 to 10 carbon atoms, in particular a branched or cyclic alkyl group having 3 to 10 carbon atoms, OR 1 (where R 1is a group selected from an alkyl group having 1 to 10 carbon atoms, particularly a branched or cyclic alkyl group having 3 to 10 carbon atoms, a dialkylamino group having 2 to 10 carbon atoms, or an aryl or heteroaryl group having 5 to 10 aromatic ring atoms. These groups are sterically bulky groups. More preferably, this R radical may form a ring with the adjacent R radical.

[0101] Further suitable bidentate ligands or ancillary ligands are those of formula (L-31) or (L-32) below: [ka] where R has the meaning described above, * indicates the coordination position to iridium, "o" in formula (2) indicates the attachment position of the ancillary ligand to V, and other symbols used are as follows: X is the same or different at each occurrence and is CR or N, with the proviso that not more than one symbol X per ring is N.

[0102] When two R radicals attached to adjacent carbon atoms in the ligands or ancillary ligands (L-31) and (L-32) form an aromatic ring together, this ring together with the two adjacent carbon atoms preferably has the structure of formula (13): [ka] where the dotted bond indicates the attachment of this group within a ligand or subligand, Y may be the same or different at each occurrence, and CR 1 or N, and preferably at most one of the symbols Y is N.

[0103] In preferred forms of the ligand or ancillary ligand (L-31) or (L-32), not more than one such fused group is present. Thus, the ligand or ancillary ligand is preferably of the following formulae (L-33) to (L-38): [ka] wherein X is the same or different at each occurrence and is CR or N, provided that the R radicals together do not form an aromatic or heteroaromatic ring system, and the further symbols have the meanings given above.

[0104] In a preferred embodiment of the present invention, in the ligands or ancillary ligands of formulae (L-31) to (L-38), a total of 0, 1 or 2 symbols X and, if present, Y are N. More preferably, a total of 0 or 1 symbols X and, if present, Y are N.

[0105] Preferred embodiments of formulae (L-33) to (L-38) are structures of the following formulae (L-33a) to (L-38f): [ka]

[0106] [ka]

[0107] [ka] where the symbols used have the meanings given above, and "o" indicates the position of attachment to the bridge V, in which case there is no corresponding R group.

[0108] In a preferred embodiment of the invention, the X group which coordinates to the metal in the ortho position is CR, in which the R bonded to the metal for coordination in the ortho position is preferably selected from the group consisting of H, D, F and methyl.

[0109] In a further aspect of the invention, one of the atoms X is preferably N, provided that the substituent bonded adjacent to this nitrogen atom is an R group that is not hydrogen or deuterium. In this case, the substituent R is preferably CF3, OCF3, an alkyl group having 1 to 10 carbon atoms, in particular a branched or cyclic alkyl group having 3 to 10 carbon atoms, OR1 (where R 1 is a group selected from an alkyl group having 1 to 10 carbon atoms, particularly a branched or cyclic alkyl group having 3 to 10 carbon atoms, a dialkylamino group having 2 to 10 carbon atoms, or an aryl or heteroaryl group having 5 to 10 aromatic ring atoms. These groups are sterically bulky groups. More preferably, the R radical may also form a ring together with the adjacent R radical.

[0110] In a preferred embodiment of the present invention, L act is a ligand or ancillary ligand of the following formula (L-39), which coordinates to iridium via two D groups and is connected to V via a dotted line when the complex is one of formula (2), in which case the corresponding X is C: [ka] where: D is C or N, provided that one D is C and the other D is N; X is identical or different at each occurrence and is CR or N; Z is CR', CR, or N, with the proviso that exactly one Z is CR' and the other Z is CR or N; where at most one symbol X or Z per ring is N; R' is a group of formula (14) or (15): [ka] where the dotted lines indicate the attachment of radicals; R" at each occurrence may be the same or different and is H, D, F, CN, a straight-chain alkyl group having 1 to 10 carbon atoms (wherein one or more hydrogen atoms may be replaced by D or F), a branched or cyclic alkyl group having 3 to 10 carbon atoms (wherein one or more hydrogen atoms may be replaced by D or F), or an alkenyl group having 2 to 10 carbon atoms (wherein one or more hydrogen atoms may be replaced by D or F); at the same time, two adjacent R" radicals or two R" radicals on adjacent phenyl groups may together form a ring system; or two R" on adjacent phenyl groups may together form C(R 1 )2, NR 1 , O and S, wherein the two phenyl rings together with the bridging group form a carbazole, dibenzofuran or dibenzothiophene, and further R″ is as defined above; n is 0, 1, 2, 3, 4 or 5.

[0111] In the case of ring formation by two substituents R" on adjacent phenyl groups, the result may be fluorene, phenanthrene, or triphenylene. Similarly, as noted above, when two R" on adjacent phenyl groups together form NR 1 , O and S, and the two phenyl groups together with the bridging group can be carbazole, dibenzofuran or dibenzothiophene.

[0112] In a preferred embodiment of the present invention, X is the same or different at each occurrence and is CR. More preferably, one Z group is CR and the other Z group is CR'. More preferably, in the ligand or ancillary ligand of formula (L-39), X is the same or different at each occurrence and is CR, and simultaneously, one Z group is CR and the other Z is CR'. The ligand or ancillary ligand L 1preferably has a structure of one of the following formulae (L-39a) or (L-39b), where the bond to the bridge V for the multi-legged structure of formula (L-39) is via the position marked "o" and there is no R radical attached at this position. [ka] Here, the symbols used have the meanings given above.

[0113] More preferably, the ancillary ligand L of formula (L-39) has a structure of one of the following formulae (L-39a') or (L-39b'), wherein the bond to the bridge V for the multipodal structure of formula (L-39) is via the position marked "o" and there is no R radical attached at this position. [ka] Here, the symbols used have the meanings given above.

[0114] Ancillary ligands L of formula (L-39) or formulae (L-39a), (L-39b), (L-39a') and (L-39d') act The R radical in is preferably H, D, CN, OR 1 a linear alkyl group having 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms, or a branched or cyclic alkyl group having 3 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms (each of which may be one or more R 1 and one or more non-aromatic R 1 phenyl groups optionally substituted by R radicals, wherein two or more adjacent R radicals may together form a ring system.

[0115] In this case, the substituent R attached to the coordinating atom in the ortho position is preferably selected from the group consisting of H, D, F and methyl, more preferably H, D and methyl, especially H and D.

[0116] Furthermore, it is preferred that all substituents R ortho to R' are H or D.

[0117] Ancillary ligand L of formula (L-39) act When the R radicals together form a ring system, it is preferably an aliphatic, heteroaliphatic or heteroaromatic ring system. act and preferably forms a phenanthridine or a phenanthridine which may further contain a nitrogen atom. When the R radicals together form a heteroaromatic ring system, this is preferably quinoline, isoquinoline, dibenzofuran, dibenzothiophene and carbazole (each of which may contain one or more R 1 The fused structures may be substituted by radicals, and form a structure selected from the group consisting of dibenzofuran, dibenzothiophene, and carbazole (wherein each carbon atom in dibenzofuran, dibenzothiophene, and carbazole may be replaced by N). Particularly preferred are quinoline, isoquinoline, dibenzofuran, and azadibenzofuran. Here, the fused structures can be bonded at any possible position. Preferred ancillary ligands L1 having fused benzo groups are structures of the following formulae (L-39c) to (L-39j), where the bond to the bridge V for the multipodal structure of formula (L-39) is via the position specified by the dotted line. [ka] wherein each ligand may be substituted with one or more further R radicals, and the fused structure may be substituted with one or more R 1 Preferably, the group is substituted by a further R or R radical. 1 There are no radicals.

[0118] Ancillary ligands L of the preferred formula (L-39) containing a fused benzofuran or azabenzofuran group actare structures of the following formulae (L-39k) to (L-39z), in which the bond to the bridge V for the multi-leg structure of formula (L-39) is via the position identified by the dotted line, and there is no R radical bonded to this position. [ka] wherein each ligand may be substituted with one or more further R radicals, and the fused structure may be substituted with one or more R 1 Preferably, the group is substituted by a further R or R radical. 1 Similarly, if O in these structures is replaced with S or NR 1 can be replaced by

[0119] As above, R' is a group of formula (14) or (15), where the two groups are simply a group of formula (14) that is a ligand or ancillary ligand L 1 The difference is that the group of formula (15) is attached at the meta position, whereas the group of formula (16) is attached at the para position.

[0120] In a preferred embodiment of the invention, n=0, 1 or 2, preferably 0 or 1, most preferably 0.

[0121] In a further preferred form of the invention, both substituents R″ attached at the ortho position to the carbon atom by which the group of formula (14) or (15) is attached to the phenylpyridine ligand are the same or different and are H or D.

[0122] Preferred forms of the structure of formula (14) are structures of formulae (14a) to (14h), and preferred forms of the structure of formula (15) are structures of formulae (15a) to (15h). [ka]

[0123] [ka] where E is the sum of C(R 1 )2, NR 1 , O or S, and further symbols used have the above meanings. 1 is E=C(R 1 )2, each occurrence is preferably an alkyl group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, which may be the same or different, and more preferably methyl. 1 If R 1 is preferably an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, preferably 6 to 24 aromatic ring atoms, more preferably 6 to 12 aromatic ring atoms, and is especially phenyl.

[0124] Preferred substituents R″ on the group or preferred forms of formula (14) or (15) are selected from the group consisting of H, D, CN and alkyl groups having 1 to 4 carbon atoms, more preferably H, D or methyl.

[0125] The complex of formula (2) is a complex having a tripodal hexadentate ligand, in which three ancillary ligands L act and L are covalently linked to each other by a bridging unit V. These are linked to the ancillary ligands L act and has a higher stability through the covalent bond of L than the complex of formula (1).

[0126] In a preferred embodiment of the invention, the bridging unit V is a group of formula (16) below, where the dotted bond is the ancillary ligand L act and the bond position of L. [ka] where: X 1 is the same or different at each occurrence and is either CR or N; X 2 is the same or different at each occurrence and is either CR or N; A is the same or different at each occurrence and is CR-CR, CR-O, CR-NR, C(=O)-O, C(=O)-NR or a group of formula (17): [ka] where in each case the dotted line indicates the bidentate ancillary ligand L act or indicates the point of attachment of L to this structure, and * indicates the point of attachment to the central trivalent aryl or heteroaryl group of the unit of formula (17).

[0127] X 2 Preferred substituents for the group of formula (17) when =CR are selected from the R substituents described above.

[0128] In a preferred embodiment of the invention, A is identical or different at each occurrence and is CR2-CR2 or a group of formula (17), preferably in the following form: - all three A groups are the same group of formula (17); - two A groups are the same group of formula (17) and the third A group is CR2-CR2; - one A group is the same group of formula (17) and the other two A groups are the same CR2-CR2 group; or - all three A groups are identical CR2-CR2 groups.

[0129] Here, "the same groups of formula (17)" means that all of these groups have the same basic skeleton and the same substituents. Furthermore, "the same CR2-CR2 groups" means that all of these groups have the same substituents.

[0130] When A is CR2-CR2, R is preferably the same or different at each occurrence and is H or D, more preferably H.

[0131] The group of formula (17) is an aromatic or heteroaromatic 6-membered ring. In a preferred embodiment of the present invention, the group of formula (17) contains one or less heteroatoms in the aryl or heteroaryl group. This does not mean that the substituents attached to this group cannot contain heteroatoms. Furthermore, this definition does not mean that ring formation by the substituents does not result in the formation of a fused aromatic or heteroaromatic structure (e.g., naphthalene, benzimidazole, etc.). The group of formula (17) is preferably selected from benzene, pyridine, pyrimidine, pyrazine, and pyridazine.

[0132] Preferred forms of the group of formula (17) are structures of the following formulae (18) to (25): [ka] Here, the symbols used have the meanings given above.

[0133] Particularly preferred are the optionally substituted 6-membered aromatic and 6-membered heteroaromatic rings of formulae (18) to (22). Highly preferred is ortho-phenylene, i.e. the group of formula (18).

[0134] At the same time, as described above for the substituents, adjacent substituents may together form a ring system, forming a fused structure containing fused aryl and heteroaryl groups (e.g., naphthalene, quinoline, benzimidazole, carbazole, dibenzofuran, or dibenzothiophene).

[0135] Preferred forms of the bridgehead V, that is, the structure of formula (16), are described below. Preferred forms of the group of formula (16) are the structures of the following formulae (26) to (29). [ka] Here, the symbols used have the meanings given above.

[0136] More preferably, all substituents R in the central ring of formulas (26) to (29) are H, and therefore the structures are preferably selected from formulas (26a) to (29a). [ka] Here, the symbols used have the meanings given above.

[0137] More preferably, the groups of formulae (26) to (29) are selected from the structures of formulae (26b) to (29b) below. [ka] wherein R is the same or different at each occurrence and is H or D, preferably H.

[0138] Further examples of suitable bridgeheads V are the structures shown below: [ka]

[0139] [ka]

[0140] The ancillary ligand L described above act and / or L, and furthermore, a description of preferred substituents that may be present in the divalent arylene or heteroarylene group of the structure of formula (16), i.e., the structure of formula (17), follows.

[0141] In a further aspect of the invention, the metal complex of the invention comprises two R substituents or two R groups attached to adjacent carbon atoms which together form an alicyclic ring according to one of the formulae shown below: 1 In this case, the two R substituents forming the alicyclic ring may be present on the bridge and / or one or more bidentate ancillary ligands of formula (16). 1The alicyclic ring formed by the substituents joining together to form a ring is preferably represented by one of the following formulae (30) to (36): [ka] where R 1 and R 2 has the meaning given above, the dotted bond indicates the connection of two carbon atoms in the ligand, and further: G has 1, 2 or 3 carbon atoms and one or more R 2 an alkylene group optionally substituted by a radical, -CR 2 =CR 2 - or 5 or 6 aromatic ring atoms and one or more R 2 an ortho-linked arylene or heteroarylene group optionally substituted by a radical; R 3 are the same or different at each occurrence and are selected from H, F, straight-chain alkyl groups having 1 to 10 carbon atoms, branched or cyclic alkyl groups having 3 to 10 carbon atoms, where an alkyl group may in each case be one or more R 2 radical, and one or more non-adjacent CH groups may be substituted by R 2 C=CR 2 , C≡C, Si(R 2 )2, C=O, NR 2 , O, S or CONR 2 or 5 or 6 aromatic ring atoms, in each case one or more R 2 an aryl or heteroaryl group optionally substituted by a radical; and at the same time, two R 3 The radicals together may form an aliphatic or aromatic ring system, forming a spiro system; furthermore, R 3 is adjacent to R or R 1 The radicals may also form an aliphatic ring system.

[0142] In the structures of formulas (30) to (36) above and in further forms of those structures identified as preferred, a double bond is formed in a formal sense between two carbon atoms. This is a simplification of the chemical structure in which the two carbon atoms are incorporated into an aromatic or heteroaromatic ring system, and the bond between these two carbon atoms is formally between the bond order of a double bond and the bond order of a single bond.

[0143] Preferred forms of the groups of formulae (30) to (36) can be found in applications WO2014 / 023377, WO2015 / 104045 and WO2015 / 117718.

[0144] The R radical is a bidentate or ancillary ligand L act or in L, or in a divalent arylene or heteroarylene group of formula (17) bound in formula (16) or in a preferred form, these R radicals are the same or different at each occurrence and are preferably H, D, F, Br, I, N(R 1 )2, CN, Si(R 1 )3, B(OR 1 )2, C(=O)R 1 , a linear alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a branched or cyclic alkyl group having 3 to 10 carbon atoms (wherein the alkyl or alkoxy group is in each case a group consisting of one or more R 1 radicals), or one or more non-aromatic R 1 a phenyl group optionally substituted by a radical, or a group having 5 or 6 aromatic ring atoms and one or more non-aromatic R 1 and at the same time, two adjacent R radicals together or R is selected from the group consisting of R, ... 1 and together may form a monocyclic or polycyclic, aliphatic or aromatic ring system. More preferably, these R radicals are the same or different at each occurrence and are selected from H, D, F, N(R 1)2, a straight-chain alkyl group having 1 to 6 carbon atoms, a branched or cyclic alkyl group having 3 to 10 carbon atoms (wherein one or more hydrogen atoms may be replaced by D or F), or one or more non-aromatic R 1 a phenyl group optionally substituted by a radical, or a group having 6 aromatic ring atoms and one or more non-aromatic R 1 and at the same time, two adjacent R radicals together or R is selected from the group consisting of R, ... 1 Together with the radicals they may form a mono- or polycyclic, aliphatic or aromatic ring system.

[0145] Preferred R bound to R 1 The radicals may be the same or different at each occurrence and may be H, D, F, N(R 2 ) 2, CN, a linear alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a branched or cyclic alkyl group having 3 to 10 carbon atoms (wherein the alkyl group is in each case one or more R 2 radicals), or one or more R 2 a phenyl group optionally substituted by a radical, or a phenyl group having 5 or 6 aromatic ring atoms and one or more R 2 a heteroaryl group optionally substituted by a radical; and at the same time, two or more adjacent R 1 The radicals together may form a monocyclic or polycyclic aliphatic ring system. Particularly preferred R 1 The radicals may be the same or different at each occurrence and may be H, F, CN, a straight chain alkyl group having 1 to 5 carbon atoms, a branched or cyclic alkyl group having 3 to 5 carbon atoms (each of which may be formed by one or more radicals R 2 or one or more R 2 a phenyl group optionally substituted by a radical, or a phenyl group having 5 or 6 aromatic ring atoms and one or more R 2 a heteroaryl group optionally substituted by a radical; and at the same time, two or more adjacent R 1The radicals may together form a monocyclic or polycyclic aliphatic ring system.

[0146] Preferred R 2 The radicals may be the same or different in each occurrence and may be H, F, or an aliphatic hydrocarbyl radical having 1 to 5 carbon atoms, or an aromatic hydrocarbyl radical having 6 to 12 carbon atoms, and at the same time, two or more R 2 The substituents together may form a monocyclic or polycyclic aliphatic ring system.

[0147] The preferred embodiments described above may be combined with one another if desired within the scope of claim 1. In a particularly preferred embodiment of the invention, the preferred embodiments described above are applied simultaneously.

[0148] The iridium complexes according to the invention have a chiral structure. Both tripodal complexes and heteroleptic complexes of the IrL2L' or IrLL'L" type with bidentate ancillary ligands have C1 symmetry. If the tripodal ligands of the complexes are additionally chiral or have three different ancillary ligands (as is also the case for heteroleptic complexes with three different ancillary ligands, i.e., IrLL'L" type), the formation of diastereomers and multiple enantiomeric combinations is possible. In such cases, the complexes of the invention comprise mixtures of different diastereomers or the corresponding racemates, as well as the respective separated diastereomers or enantiomers.

[0149] The stereochemical relationships are described hereinafter using tripodal complexes, but apply in a generally similar manner to heteroleptic complexes of the bidentate ancillary ligand IrL2L' or IrLL'L'' type. For clarity, the complexes are not those of the present invention; instead, they are described using simple polypodal complexes, but are equally applicable to the complexes of the present invention. When tripodal ligands with two identical ancillary ligands are used in ortho-metallations, what is obtained is typically a racemic mixture of C1-symmetric complexes, i.e., Δ and Λ enantiomers. These may be separated by standard methods (optical resolution by chiral material / column chromatography or crystallization).

[0150] [ka]

[0151] Optical resolution of diastereomeric salt pairs by fractional crystallization can be carried out by conventional methods. One option for this purpose is to oxidize the uncharged Ir(III) complex (e.g., with peroxide or HO, or by electrochemical means), add the enantiomerically pure monoanionic salt (chiral salt) to the resulting cationic Ir(IV), separate the resulting diastereomeric salts by fractional crystallization, and reduce them with a reducing agent (e.g., zinc, hydrazine hydrate, ascorbic acid, etc.) to produce the enantiomerically pure uncharged complex. This is shown schematically below: [ka]

[0152] Furthermore, enantiomerically pure or enantiomerically enriched synthesis is possible by complexation in chiral media (eg, R- or S-1,1-binaphthol).

[0153] When a ligand having three different ancillary ligands is used in the complex formation, what is typically obtained is a diastereomeric mixture of complexes which can be separated by standard methods (chromatography, crystallization, etc.).

[0154] Enantiomerically pure C1-symmetric complexes can also be selectively synthesized as shown in the following scheme: To this end, an enantiomerically pure C1-symmetric ligand is prepared, complexed, the resulting diastereomeric mixture is separated, and the chiral groups are separated.

[0155] [ka]

[0156] The tripod complexes according to the invention can be prepared primarily by various processes. Generally, for this purpose, an iridium salt is reacted with the corresponding free ligand.

[0157] Therefore, the present invention further provides a method for preparing the compounds according to the invention by reacting a suitable free ligand with an iridium alkoxide of formula (37), an iridium ketoketonate of formula (38), an iridium halide of formula (39), or an iridium carboxylate of formula (40).

[0158] [ka] wherein R is as defined above, Hal is F, Cl, Br or I, and the iridium reactant may be present in the form of the corresponding hydrate, and wherein R is preferably an alkyl group having 1 to 4 carbon atoms.

[0159] Similarly, iridium compounds having alkoxide and / or halide and / or hydroxy and ketoketonate radicals can be used. These compounds may be charged. Corresponding iridium compounds particularly suitable as reactants are disclosed in WO 2004 / 085449. Particularly suitable is [IrCl2(acac)2] - , such as Na[IrCl2(acac)2], those derived from metal complexes with acetylacetonate as a ligand, such as Ir(acac)3 or tris(2,2,6,6-tetramethylheptane-3,5-dionato)iridium, and IrCl3·xH2O (where x is typically a number between 2 and 4).

[0160] The synthesis of the complexes is preferably carried out as disclosed in WO 2002 / 060910 and WO 2004 / 085449. In this case, the synthesis is activated, for example, by thermal or photochemical methods and / or microwave radiation. Furthermore, the synthesis can also be carried out in an autoclave at elevated pressure and / or temperature.

[0161] The reaction can be carried out in a melt of the corresponding ortho-metallated ligand without the addition of a solvent or melting aid, or, if desired, with the addition of a solvent or melting aid. Suitable solvents are protic or aprotic solvents such as aliphatic and / or aromatic alcohols (e.g., methanol, ethanol, isopropanol, t-butanol, etc.), oligo- and polyalcohols (e.g., ethylene glycol, 1,2-propanediol, or glycerol), alcohol ethers (e.g., ethoxyethanol, diethylene glycol, triethylene glycol, polyethylene glycol, etc.), ethers (e.g., di- and triethylene glycol dimethyl ether, diphenyl ether, etc.), aromatic, heteroaromatic, and / or aliphatic hydrocarbons (e.g., toluene, xylene, mesitylene, chlorobenzene, pyridine, lutidine, quinoline, isoquinoline, tridecane, hexadecane, etc.), amides (e.g., DMF, DMAC, etc.), lactams (e.g., NMP, etc.), sulfoxides (e.g., DMSO), or sulfones (e.g., dimethyl sulfone, sulfolane, etc.). Suitable melting aids are compounds that are solid at room temperature but melt when the reaction mixture is heated to dissolve the reactants and form a homogeneous melt. Particularly suitable melting aids are biphenyl, m-terphenyl, triphenyl, R- or S-binaphthol or other racemates, 1,2-, 1,3- or 1,4-bisphenoxybenzene, triphenylphosphine oxide, 18-crown-6, phenol, 1-naphthol, hydroquinone, etc. Particular preference is given to using hydroquinone here.

[0162] Heteroleptic complexes of bidentate ligands of the IrL2L' type can be prepared according to the following scheme: [ka] The chlorodimer [LIrCl] is prepared from iridium(III) chloride hydrate by reaction with two equivalents of ligand L in a protic solvent or solvent mixture (typically 3:1 2-ethoxyethanol / water) under reflux. For further ortho-metallation, this is first converted to the methanol triflate [LIr(HOMe)]OTf by reaction with silver triflate and methanol, typically in dichloromethane / methanol, and then further reacted with ligand L' to give the product. This method, which is often used to prepare heteroleptic complexes of bidentate ligands IrL,L', is described, for example, in WO 2010 / 027583 or US 2014 / 0131676.

[0163] These steps (optionally followed by purification such as chromatography, recrystallization, thermal extraction and / or sublimation) provide compounds of the invention in high purity, preferably 99% ( 1 This allows for the production of compounds with higher purity (as determined by H NMR and / or HPLC).

[0164] The compounds of the present invention can be used as active components in electronic devices, preferably as emitters in the light-emitting layer. The present invention therefore further provides for the use of the compounds of the present invention as emitters in the light-emitting layer of electronic devices, in particular OLEDs.

[0165] The present invention further provides an electronic device comprising at least one compound according to the invention.

[0166] An electronic device is understood to mean any device comprising an anode, a cathode, and at least one layer, the layer comprising at least one organic or organometallic compound. Thus, an electronic device according to the present invention comprises an anode, a cathode, and at least one layer containing at least one iridium complex according to the present invention. Preferred electronic devices are selected from the group consisting of organic electroluminescent devices (OLEDs, PLEDs), organic integrated circuits (O-ICs), organic field-effect transistors (O-FETs), organic thin-film transistors (O-TFTs), organic light-emitting transistors (O-LETs), organic solar cells (O-SCs), the latter being understood to mean both purely organic solar cells and dye-sensitized solar cells, organic optical detectors, organic photoreceptors, organic field-quenched devices (O-FQDs), light-emitting electrochemical cells (LECs), oxygen sensors, and organic laser diodes (O-lasers), which comprise at least one compound according to the present invention in at least one layer. Infrared-emitting compounds are suitable for use in organic infrared electroluminescent devices and infrared sensors. Particularly preferred is an organic electroluminescence device. The compound of the present invention exhibits particularly good properties as a light-emitting material in an organic electroluminescence device. Therefore, a preferred embodiment of the present invention is an organic electroluminescence device.

[0167] An organic electroluminescent device comprises a cathode, an anode and at least one light-emitting layer, which may also comprise further layers, such as in each case one or more hole-injection layers, hole-transport layers, hole-blocking layers, electron-transport layers, electron-injection layers, exciton-blocking layers, electron-blocking layers, charge-generating layers and / or organic or inorganic p / n bonds. In this case, one or more hole-transporting layers can also be p-doped, for example with metal oxides such as MoO3 or WO3, or (per)fluorinated electron-deficient aromatics, or electron-deficient cyano-substituted heteroaromatics (e.g., according to JP 4747558, JP 2006-135145, US 2006 / 0289882, WO 2012 / 095143), or quinoids (e.g., according to EP 1336208), or Lewis acids, or boranes (e.g., according to US 2003 / 0006411, WO 2002 / 051850, WO 2015 / 049030), or carboxylates of elements of main group III, IV or V metals, and / or one or more electron-transporting layers can also be n-doped.

[0168] Similarly, an intermediate layer may be introduced between the two light-emitting layers, e.g., having an exciton-blocking function and / or controlling the charge balance in the electroluminescent element and / or generating charges (a charge-generating layer, e.g., in a layer system with two or more light-emitting layers, e.g., in a white-emitting OLED component). However, it should be noted that each of these layers does not necessarily have to be present.

[0169] In this case, the organic electroluminescent device may include one or more emitting layers. When multiple emitting layers are present, they preferably have multiple emission maxima across the entire 380 nm to 750 nm wavelength range, resulting in a white light emission overall. That is, various emitting compounds capable of emitting fluorescence or phosphorescence are used in the emitting layers. Particularly preferred embodiments are three-layer systems in which three layers emit blue, green, and orange or red light (see, for example, WO 2005 / 011013 for the basic structure), or systems with more than three emitting layers. This system may also be a hybrid system in which one or more layers emit fluorescence and one or more layers emit phosphorescence. A preferred embodiment is a tandem OLED. White-emitting organic electroluminescent devices may be used for lighting applications or together with color filters in full-color displays.

[0170] In a preferred embodiment of the present invention, the organic electroluminescent device comprises an iridium complex according to the present invention as light-emitting compound in one or more light-emitting layers.

[0171] When the iridium complexes according to the present invention are used as luminescent materials in the luminescent layer, they are preferably used in combination with one or more matrix materials. The mixture of the iridium complexes according to the present invention and the matrix material contains 0.1% to 99% by volume, preferably 1% to 90% by volume, more preferably 3% to 40% by volume, and in particular 5% to 15% by volume of the iridium complexes according to the present invention, based on the total mixture of the luminescent material and the matrix material. Correspondingly, the mixture contains 99.9% to 1% by volume, preferably 99% to 10% by volume, more preferably 97% to 60% by volume, and in particular 95% to 85% by volume of the matrix material, based on the total mixture of the luminescent material and the matrix material.

[0172] The matrix material used may generally be any material known for that purpose in the art. The triplet level of the matrix material is preferably higher than that of the triplet unit of the emitter. Suitable matrix materials for the compounds of the present invention include ketones, phosphine oxides, sulfoxides, and sulfones (e.g., according to WO2004 / 013080, WO2004 / 093207, WO2006 / 005627, or WO2010 / 006680), triarylamines, carbazole derivatives (e.g., CBP (N,N-biscarbazonylbiphenyl)), m-CBP, or carbazole derivatives (e.g., WO2005 / 039246, US2005 / 0069729, JP20 04 / 288381, EP1205527, WO2008 / 086851 or US2009 / 0134784), biscarbazole derivatives, indolocarbazole derivatives (for example, according to WO2007 / 063754 or WO2008 / 056746), indenocarbazole derivatives (for example, according to WO2010 / 136109 or WO2011 / 000455), azacarbazoles (for example, according to EP1617710, EP1617711, EP1731584, JP2005 / 347160), bipolar matrix materials (e.g., according to WO2007 / 137725), silanes (e.g., according to WO2005 / 111172), azaboroles or boronic acid esters (e.g., according to WO2006 / 117052), diazasilol derivatives (e.g., according to WO2010 / 054729), diazaphosphole derivatives (e.g., according to WO2010 / 054730), triazine derivatives (e.g., according to WO2010 / 015306, WO2007 / 063754, or WO2008 / 056746), zinc complexes (for example according to EP 652273 or WO2009 / 062578), dibenzofuran derivatives (for example WO2009 / 148015, WO2015 / 169412, WO2017 / 148564 or WO2017 / 148565), or bridged carbazole derivatives (for example US2009 / 0136779, WO2010 / 050778, WO2011 / 042107 or WO2011 / 088877).

[0173] It is also preferred to use a mixture of several different matrix materials, in particular at least one electron-conducting matrix material and at least one hole-conducting matrix material. A preferred combination is, for example, the use of aromatic ketones, triazine derivatives, or phosphine oxide derivatives together with triarylamine derivatives or carbazole derivatives as a mixed matrix for the metal complex according to the present invention. Similarly, it is also preferred to use a mixture of a charge-transporting matrix material and an electrically inactive matrix material (called a "wide band gap host") that does not significantly participate, if at all, in charge transport (for example, as disclosed in WO2010 / 108579 or WO2016 / 184540). Similarly, it is also preferred to use two electron-transporting matrix materials, for example, a triazine derivative and a lactam derivative (for example, as disclosed in WO2014 / 094964).

[0174] Furthermore, it is preferable to use two or more triplet emitters, particularly two or three triplet emitters, with one or more matrix materials. Here, a triplet emitter with a shorter wavelength emission spectrum serves as a co-matrix for a triplet emitter with a longer wavelength emission spectrum. Thus, for example, a metal complex of the present invention can be combined with a trimetallic complex emitting a shorter wavelength (e.g., blue, green, or yellow) as a co-matrix. For example, a metal complex of the present invention can also be used as a co-matrix with a triplet emitter emitting a longer wavelength (e.g., a red-emitting triplet emitter). Here, it is also preferable that both the metal complex emitting a shorter wavelength and the metal complex emitting a longer wavelength are compounds according to the present invention. In the case of using a mixture of three triplet emitters, a preferred embodiment is when two are used as co-hosts and one is used as an emitting material. These triplet emitters preferably have green, yellow, and red emission, or blue, green, and orange emission.

[0175] A preferred mixture in the light-emitting layer comprises an electron-transporting host material, a so-called "wide band gap" host material, which, due to its electronic properties, does not participate, or does not participate to a significant extent, in charge transport in the layer, a codopant, which is a triplet emitter emitting at a shorter wavelength than the compound according to the invention, and a compound of the invention.

[0176] A further preferred mixture in the light-emitting layer comprises an electron-transporting host material, a so-called "wide band gap" host material (which, due to its electronic properties, does not participate, or does not participate to a significant extent, in charge transport in the layer), a hole-transporting host material, a codopant (which is a triplet emitter that emits at a shorter wavelength than the compounds of the invention), and a compound of the invention.

[0177] The compounds of the present invention can be used in other functions in electronic devices, such as hole transport materials in hole injection or transport layers, charge generation materials, electron blocking materials, hole blocking materials, or electron transport materials, for example, in electron transport layers.Similarly, the compounds of the present invention can be used as matrix materials for other phosphorescent metal complexes in light-emitting layers.

[0178] The cathode preferably comprises a metal, metal alloy, or multilayer structure with a low work function, such as alkaline earth metals, alkali metals, main group metals, or lanthanides (e.g., Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.). Also suitable are alloys comprising alkali metals or alkaline earth metals and silver (e.g., alloys comprising magnesium and silver). In the case of multilayer structures, additional metals with relatively high work functions, such as Ag, may also be used in addition to the metals. In this case, metal combinations such as Mg / Ag, Ca / Ag, or Ba / Ag are commonly used. It may also be preferable to introduce a thin intermediate layer of a material with a high dielectric constant between the metal cathode and the organic semiconductor. Examples of materials that can be used for this purpose are fluorides of alkali metals or alkaline earth metals, as well as the corresponding oxides or carbonates (e.g., LiF, Li2O, BaF2, MgO, NaF, CsF, Cs2CO3, etc.). Likewise usable for this purpose are organic alkali metal complexes, such as Liq (lithium quinolinate).The layer thickness of this layer is preferably between 0.5 and 5 nm.

[0179] A preferred anode is a material with a high work function. Preferably, the anode has a work function greater than 4.5 eV relative to vacuum. First, metals with high redox potentials are suitable for this purpose, such as Ag, Pt, or Au. Second, metal / metal oxide electrodes (e.g., Al / Ni / NiOx, Al / PtOx) are also preferred. In some applications, at least one electrode should be transparent or partially transparent to allow emission or light emission (OLED / PLED, O-laser) of organic materials (O-SC). Here, preferred anode materials are highly conductive mixed metal oxides. Particularly preferred are iridium tin oxide (ITO) or indium tin oxide (IZO). Furthermore, preferred are conductive doped organic materials, especially conductive doped polymers, such as PEDOT, PANI, or derivatives of these polymers. More preferably, when a p-doped hole transport material is applied to the anode as a hole injection material, suitable p-dopants are metal oxides such as MoO3 or WO3 or (per)fluorinated electron-deficient aromatic systems. Further suitable p-dopants are HAT-CN (hexacyanohexaazatriphenylene) or the compound NPD9 manufactured by Novaled. Such layers facilitate hole injection in materials with low HOMO, i.e., large HOMO values.

[0180] Any material used for a layer in the prior art can generally be used for the further layer, and a person skilled in the art will be able to combine the respective material with the material according to the invention in an electronic device without any inventive effort.

[0181] Suitable charge transport materials that can be used in the hole injection or hole transport layer, electron blocking layer, or electron transport layer of the organic electroluminescent device of the present invention are, for example, the compounds disclosed in Y. Shirota et al., Chem. Rev. 2007, 107(4), 953-1010, or other materials used in these layers in the prior art. Examples of preferred hole transport materials that can be used in the hole transport, hole injection, or electron blocking layer of the electroluminescent device of the present invention include indenofluorene amine derivatives (e.g., WO06 / 122630 or WO06 / 100896), amine derivatives disclosed in EP1661888, hexaazatriphenylene derivatives (e.g., according to WO01 / 049806), amine derivatives having a fused aromatic ring (e.g., US5,061,569), amine derivatives disclosed in WO95 / 09147, monobenzoyl indenofluoreneamines (for example according to WO08 / 006449), dibenzoindenofluoreneamines (for example according to WO07 / 140847), spirobifluoreneamines (for example according to WO2012 / 034627, WO2014 / 056565), fluoreneamines (for example according to EP2875092, EP2875699 and EP2875004), spirobibenzopyranamines (for example according to EP2780325), and dihydroacridine derivatives (for example according to WO2012 / 150001).

[0182] Since the lifetime of such elements is dramatically shortened in the presence of water and / or air, the elements are structured (depending on the application), connected and finally sealed accordingly.

[0183] More preferably, it is an organic electroluminescent device in which one or more layers are applied by sublimation. In this case, the materials are typically -5 less than mbar, preferably 10 -6 It is applied by vapor deposition in a vacuum sublimation system at an initial pressure of less than 10 mbar. The initial pressure can be lower or higher, for example, 10 -7 It may be less than mbar.

[0184] Likewise preferred are organic electroluminescent devices characterized in that one or more layers are applied by using the OVPD (organic vapor phase deposition) method or by means of carrier gas sublimation. In this case, the material is 10 -5 It is applied at pressures of mbar to 1 bar. A special method of this method is the OVJP (organic vapor jet printing) method, in which the material is applied directly through a nozzle and thus structured.

[0185] Furthermore, organic electroluminescent devices are preferred, characterized in that one or more layers are produced from solution, for example by spin coating or by any printing method, such as screen printing, flexographic printing, offset printing or nozzle printing, particularly preferably by LITI (light-induced thermal imaging, thermal transfer printing) or inkjet printing. For this purpose, soluble compounds are required, which can be obtained, for example, by suitable substitution.

[0186] Organic electroluminescent devices can also be fabricated as hybrid systems by applying one or more layers from solution and one or more other layers by vapor deposition, for example, an emissive layer comprising a metal complex of the present invention and a matrix material can be applied from solution, and a hole-blocking layer and / or an electron-transporting layer can be applied by vapor deposition under reduced pressure.

[0187] These methods are generally known to those skilled in the art and can be applied to organic electroluminescent devices comprising the compounds of the present invention without any problems by those skilled in the art. In a preferred embodiment of the present invention, the light-emitting layer is applied by sublimation.

[0188] The electronic devices, particularly organic electroluminescent devices, of the present invention are distinguished over the prior art by one or more of the following advantages: 1. The iridium complexes of the present invention are highly efficient when used as emitters in OLEDs. More specifically, the external quantum efficiency (EQE) is much better than that of complexes with an optical anisotropy θ>0.24°. 2. The iridium complexes of the present invention exhibit only a very small, if any, voltage shift when used as emitters in OLEDs, where the voltage shift relates to a shift to a higher operating voltage when the emitter concentration in the emissive layer increases. This results in a lower operating voltage compared to materials that have a voltage shift. More specifically, the voltage shift is optically directed but not due to the transition dipole moment μ act and the electron dipole moment d are >40°. Apart from the operating voltage, the reduction in the voltage shift also leads to an improvement in lifetime. 3. The iridium complexes of the present invention exhibit very good lifetimes when used as emitters in OLEDs. More specifically, the lifetimes exhibit good directionality, but the transition dipole moment μ act This is an improvement over the case of iridium complexes where the angle α between the electron dipole moment d and the electron dipole moment d is >40°.

[0189] The present invention will now be illustrated in more detail by examples, without any limitation being intended thereby: using the details described, those skilled in the art will be able, without any inventive effort, to manufacture further electronic elements according to the invention and thereby implement the invention throughout the scope of the claims. [Brief explanation of the drawings]

[0190] [Figure 1] Figure 1: Flowchart for the discovery of suitable complexes with optical orientation anisotropy θ ≦ 0.24 and angle α(μact,d) ≦ 40° between the transition dipole moment μact of the active ligand and the electronic dipole moment d of the complex by the extension of one ligand and the modification of two other ligands (QC = quantum chemical calculation). [Figure 2]Figure 2: One of the three ppy ligand transition dipole moments μL, and the electronic dipole moment d of the singlet ground state of Ir(ppy). [Figure 3a] Figure 3a: Selection of expansion units based on the ratio between the square roots of the eigenvalues ​​λz ≥ λy ≥ λx of the gyration tensor. [Figure 3b] Figure 3b: Effect of the extension unit R on the optical alignment anisotropy θ using the example Ir(ppy-CN)2(ppy-R). [Figure 4] Figure 4: a) Definition of the long axis pz and the attachment position of the extension unit. b) Diagram for finding the attachment position to the ligand via the angle βcn between the transition dipole moment μL of the ligand and pz. [Figure 5] Figure 5: Transition dipole moment of the active ligand in the heteroleptic complex Ir(ppy)2 (ppy-C3-biphenyl). The active ligand μact; it resides closer to the extended axis pz than predicted from the homoleptic complex Ir(ppy)3 (μL of the homoleptic complex, dotted line). [Figure 6] Figure 6a: Electronic dipole moment of C3 axial symmetry in the homoleptic complex Ir(ppy)3 (α(μact,d) = 80°). Figure 6b: Loss of symmetry due to the extension of the active ligand. d is positioned somewhat more towards the active ligand, and at the same time, there is a change in the direction of μact compared to Ir(ppy)3 (α(μact,d) = 55°). Figures 6c and d: Further distancing of d from the C3 axial symmetry due to the electronically active cyano groups at C8 or C7 of the two co-ligands (α(μact,d) = 25° in the case of Ir(ppy-C7-CN)2 (ppy-C3-biphenyl)). [Figure 7a] Figure 7a: Complex Ir(L)2 with the active ppy-C3-terphenyl ligand. The electron-modified ppy co-ligand L results in a small angle between the transition dipole moment μact and the electronic dipole moment d of the overall complex Ir(L). The length of the arrow corresponds to the magnitude of the electronic dipole moment of the ligand. [Figure 7b-1] The angle between the transition dipole moment and the electron dipole moment (α(μact,d) [°] [Figure 7b-2]b) Optical orientation anisotropy θ and angle α (μact,d) of the co-ligand from the combination with a) active (ppy-C3-terphenyl), without and with multipodal bridges (multipodal bridges are identified in the nomenclature by the addition "poly"), as shown on the right side of the structure. [Figure 8] Figure 8: Simulation box of 263 matrix molecules of the depicted structure showing an isotropic substrate for the deposition process of a light emitter (e.g., Ir(ppy)3 (described in part 2 of the Examples)). [Figure 9] Figure 9: Voltage shift with change in phosphor concentration from 5% to 15% of the amount of reference phosphor with angle α(μact,d) of 40°. [Example]

[0191] Working Example: Part 1: active ligand μ act The angle α(μ) between the transition dipole moment of and the electronic dipole moment d of the entire complex act , d) by quantum chemical calculation 1.1 Emitter triplet energy E of the co-ligand Ir(L) T1,L and E T1,act Quantum chemical calculation of and the electronic dipole moment d of the whole complex To determine the energies of the three lowest triplet states of the emitter, each centered on one of the ligands (relativistic effects not being considered), the geometries are optimized in the UB3LYP / LANL2DZ+6-31G(d) level, using 6-31G(d) as the basis for all nonmetallic atoms, with LanL2DZ used for the iridium atom. The resulting three triplet energies are

number

number

number

number

[0192] The electronic dipole moment d of the overall complex is determined from this singlet ground state calculation, and the structure is used in the force field for the molecular dynamics simulations in Part 2.

[0193] The triplet energies of each ligand i=1, 2, 3 are:

number

[0194] The ligand with the lowest triplet energy is hereafter referred to as the active ligand, and its triplet energy is E T1,act the other two are called co-ligands, and their triplet energy is E T1,L (Note: the triplet energies of the two co-ligands are not strictly degenerate, but are simply approximately the same).

[0195] The triplet state of the organic extension unit is determined by similar calculations. For this purpose, the neutral ground state of the extension unit is optimized with B3LYP / 6-31G(d), and the vibrational frequencies for the determination of the zero-point energy are calculated. Similarly, the triplet state is optimized with UB3LYP / 6-31G(d), and its zero-point energy is calculated. Similar to the triplet energy of the ligands of the metal complex, the zero-point energy-corrected adiabatic transition is calculated for the triplet energy of the aromatic extension unit.

[0196] 1.2 Quantum chemical calculation of the electronic dipole moment of each ligand The electronic dipole moment of each ligand (with Ir replaced by H) was calculated using B3LYP / 6-31G(d) based on the B3LYP / 6-31G(d)-optimized ground state structure, and the electronic dipole moment of the entire complex was predicted by vector addition in the octahedral bonding state.

[0197] All quantum chemical calculations use the Gaussian 09 software package with standard convergence settings.

[0198] 1.3 Transition dipole moments μ of co-ligands and activating ligands L and μ act Quantum chemical calculations of Luminous body μ iThe transition dipole moments of the three ligands (i = 1, 2, 3) are calculated with TD-B3LYP and the relativistic ZORA Hamiltonian (zeroth-order normal approximation). This is done using the triplet energies of the three ligands optimized in the UB3LYP / LANL2DZ+6-31G(d) level (see 1.1 above), with 6-31G(d) as the basis for all nonmetallic atoms and LanL2DZ for the iridium atom. Assuming that the population of excited triplet states approximates a Boltzmann distribution, only the geometry of the lowest-energy triplet state, i.e., the state expected to emit, is used (see 2.2). In TD-DFT calculations with B3LYP, which explicitly considers spin-orbit coupling with the relativistic ZORA Hamiltonian, the all-electron DZP basis set of the ADF is used for all nonmetallic atoms, while the all-electron TZP basis set is used for iridium. Transition dipole moments are obtained from all spin sub-states. The actual transition dipole moment used for a ligand is the vector of the brightest spin sub-state of the ligand. This usually corresponds to the third lowest state of the ligand. The brightest state is the one with the largest transition dipole moment or highest oscillator strength, and therefore the highest radiative rate R i The transition dipole moment of ligand i is projected onto the real axis in the complex plane, μ i The ligand with the lowest triplet energy is also called the active ligand (see 1.1), and its transition dipole moment is μ act and the two other ligands have transition dipole moments μ L For this calculation, the ADF program is used (considering standard convergence criteria and the complete kernel function).

[0199] 1.4 Transition dipole moment μ of the active ligand act and the angle α(μ act ,d) Calculation The electronic dipole moment d of the complex and the transition dipole moment μ of the active ligand act angle (μ act,d) is calculated by using the arccosine of the scalar product (*) of two vectors and their magnitude (||) to find α(μ act ,d)=acos[μ act *d / (|μ act ||d|)]x180° / π, which is initially calculated as α(μ act ,d) = 0°~+180°, μ act describes a dipole that oscillates back and forth (i.e., μ act Ha-μ act (which describes exactly the same physical property as α), values ​​α > 90° require the use of α' = 180° - α instead, e.g., instead of α = 120°, α' = 180° - 20° = 60° is used. Thus, α(μ act , d) are limited to values ​​between 0° and 90°, preferably smaller angles.

[0200] Calculation of the eigenvalues ​​of the rotation tensor of the 1.5 aromatic extension unit As an extension unit, the rotation tensor S mn is the position

number

number

[0201] The three eigenvectors of the rotation tensor (extension p z (for the definition of the axes) and the eigenvalue λ for determining the "flatness" of the extended unit x,y,z For the calculation of the root, the atomic coordinate r (i)can also be transferred to, for example, the polystat module of the free software package GROMACS (J. Chem. Theory Comput. 4(3):435-447, 2008), which gives the eigenvalues ​​and roots of the eigenvectors, where p z is the largest eigenvalue λ z are the eigenvectors of

[0202] Part 2: Calculation of optical orientation anisotropy θ by molecular dynamics simulation of deposition process 2.1 Simulation of complex orientation To calculate the optical orientation anisotropy θ, the deposition process of the phosphor was simulated using molecular dynamics. For this purpose, 576 independent substrates (on which the phosphor will subsequently be deposited) were first simulated, each consisting of an isotropic film of the matrix material TMM shown below, for appropriate statistics. For each substrate, 263 randomly oriented matrix molecules were placed in a cubic simulation box with an edge length L = 9 nm. The molecules were then equilibrated in x, y, and z by molecular dynamics with an NPT ensemble (constant particle number N, constant pressure P = 1 bar, and constant temperature = 700 K) and periodic boundary conditions, and cooled at a cooling rate of 10 K / ns, resulting in a cubic box with an edge length of 6 nm. All molecular dynamics conditions were performed using the free software GROMACS (J. Chem. Theory Comput. 4(3):435-447, 2008) with a time increment of 0.002 ps and a frozen bond length. The pressure was kept constant by a Berendsen thermostat (J. Chem. Phys., 81(8):3684, 1984), and the compressibility was 4.5x10 -5 bar; temperature is addressed by velocity scaling (J. Chem. Phys., 126(1):014101, 2007) using a time constant of 2 ps and electrostatic interactions by the particle-mesh-Ewald method (J. Chem. Phys., 103:8577-8592, 1995).

[0203] For the force fields of the matrix and emitter molecules, the basis used is the OPLSaa ("Optimized for Liquid Simulations all atoms") force field (J. Am. Chem. Soc., 110(6):1657-1666, 1988) with geometric averaging of Lennard-Jones parameters. However, the geometries used in the force fields are quantum chemistry-optimized singlet ground state geometries (described in Part 1.1) at the B3LYP / 6-31G(d) level for TMM and B3LYP / LANL2DZ+6-31G(d) for the Ir complexes. Bond lengths, angles, and equilibrium positions of torsional potentials are also used from this singlet ground state geometry, and atomic charges are generated using the Merz-Kolmann method by fitting the electrostatic potential (ESP) to the electron density from these quantum chemistry calculations. Bond lengths are frozen during molecular dynamics simulations, and the unknown force constants of the angular and torsional potentials are calculated by quantum chemical energy scans (Ruhle et al., J. Chem. Theory Comput., 2011, 7(10), pp3335-3345).

[0204] According to the present invention, the following materials are used as TMMs: [ka]

[0205] For all substrates, the z direction is defined as the surface normal, and the simulation box is extended 12 nm along z while maintaining periodic boundary conditions in x and y. A randomly oriented phosphor with a center of mass is then placed on the matrix film at random x and y coordinates and z = 3 nm (defined as the highest z coordinate of all matrix atoms; see Figure 8), and starts at a velocity of 0.1 nm / ps toward the substrate. The deposition process of this phosphor on the substrate is then simulated in the NVT (constant particle number N, constant volume, and constant temperature = 300 K) ensemble for 6 ns, with the phosphor's coordinates read every 20 ps. A simulation box with 263 depicted structures of matrix molecules representing an isotropic substrate for the deposition process of a phosphor (e.g., Ir(ppy)3) is shown in Figure 8.

[0206] 2.2. Calculation of optical orientation anisotropy θ To calculate the optical orientation anisotropy θ, an average is calculated over all substrates and illuminants read, giving a total of N=576*6000ps / 20ps=172800 possible position determinations.

[0207] For this purpose, the three transition dipole moments μ of the three ligands are determined from quantum chemical calculations (see part 1.3 of the Examples). i (i=1, 2, 3) are rotated around each emitter read from the molecular dynamics, and appropriate rotations and translations of atomic coordinates are selected from the singlet ground state calculations (see part 1.1 of the Examples) so that the iridium atom and the six atoms bonded to it from the quantum chemical calculations differ spatially minimally from those from the molecular dynamics.

[0208] Average optical orientation anisotropy θ for transition dipole moments i=1, 2, 3 i In the simulation box, the transition dipole moment for n=1...N is rotated.

number

number

[0209] The three average optical orientation anisotropies of the three transition dipole moments of the three ligands are used to make a final average of the entire complex by the Boltzmann mass and the quantitative mass, finally

number

number

number

[0210] The optical orientation anisotropy θ thus determined is in good agreement with the angle-dependent photoluminescence measurements of 10% emitters in the triplet matrix material TMM described above (correlation coefficient R 2 =0.70, 30 luminescent analysis).

[0211] Part 3: Measurement of phosphor orientation in evaporated films To experimentally confirm the orientation of the complex in the light-emitting layer, a layer of each complex in a host material (matrix material) is deposited on a quartz glass substrate using a Sunic Clustertool. In the layer, there is 10% by volume of complex and 90% of matrix. The sample is sealed. The optical properties of the pure matrix material, measured using the physical laws of optics, can be used to calculate the potential consequences of 100% horizontal and vertical molecular alignment. According to the present invention, the TMM used is the material described in Part 2 of the Examples.

[0212] In the measurement setup, a vapor-deposited sample containing the complex is irradiated with a laser, the molecules are excited, and the emitted photoluminescence spectrum is measured in an angle-dependent manner. The measurements are then fitted to the calculated extreme orientations (see paragraph above), and the orientation factor (optical orientation anisotropy) is determined. A perfectly horizontal orientation of the molecules is expressed as θ = 0, while an isotropic case is θ = 0.33, and a perfectly vertically aligned case is θ = 1. This value reflects the average orientation across all molecules in the layer excited by the photoluminescence process, meaning that all complex molecules are located within the measurement spot illuminated by the laser. However, it is not possible to determine the orientation of a single molecule using this method.

[0213] Part 4: Photoluminescence quantum efficiency (PLQE) measurements In a glovebox, under a protective gas atmosphere containing a maximum of 5 ppm oxygen, 1 mg of the complex is weighed out and dissolved in toluene seccosolv at a concentration of 1 mg / 100 ml. The dissolved complex is introduced into an analytical cuvette. Absorption and photoluminescence spectra are measured using a Perkin-Elmer Lambda 9 spectrometer and a Hitachi F4500. The absorption band edge is identified. The PLQE is then measured using a commercial setup from Hamamatsu (C9920-01, -02). First, the sample is placed in an integrating sphere. Measurements begin approximately 10 nm below the absorption edge of the identified complex, and measurements are continued with a step width of 10 nm. Measurements are always alternated between the reference and sample before a new excitation wavelength is set and the next measurement begins. The wavelength is then increased and measurements are taken until there is a clear increase in quantum efficiency. Measurement averaging is then performed to quantify the PLQE value of the analyzed material.

[0214] Part 5: Synthesis of the complex The following syntheses are carried out in dry solvents under a protective gas atmosphere unless otherwise stated. Metal complexes are further handled in the absence of light or under yellow light. Solvents and reagents can be purchased, for example, from Sigma-Aldrich or ABCR. The numbers in brackets or indicated for individual compounds refer to the CAS numbers of compounds known from the literature. In the case of compounds that may have multiple isomeric, tautomeric, diastereomeric or enantiomeric forms, they are indicated in a representative manner.

[0215] A: Synthesis of synthon S and bidentate ligand L Example S1: [ka]

[0216] A mixture of 20.6 g (100 mmol) of methyl 2,5-dichloropyridine-3-carboxylate [67754-03-4], 15.5 g (110 mmol) of (2-fluoropyridin-3-yl)boronic acid [174669-73-9], 41.4 g (300 mmol) of potassium carbonate, 702 mg (1 mmol) of bis(triphenylphosphine)palladium(II) chloride [13965-03-2], 300 ml of methanol and 300 ml of acetonitrile is heated under reflux for 16 hours. After cooling, the reaction mixture is stirred with 3 L of water and stirred for another 30 minutes, and the precipitated product is suction filtered, washed three times with 50 ml of methanol each, dried under reduced pressure, taken up in 500 ml of DCM, and filtered through a silica gel bed in the form of a DCM slurry, the silica gel bed is washed with 500 ml of DCM, the DCM is mostly removed under reduced pressure, and the residue is recrystallized from acetonitrile. Yield: 20.9 g (78 mmol), 78%; purity: about 95% 1 By H NMR.

[0217] [ka] A mixture of 26.7 g (100 mmol) of A), 16.8 g (300 mmol) of potassium hydroxide, 250 ml of ethanol, and 75 ml of water is stirred at 70°C for 16 hours. After cooling, the mixture is acidified to pH 5 by adding 1N hydrochloric acid and stirred for another hour. The precipitated product is suction filtered, washed once with 50 ml of water and once with 50 ml of methanol, and dried under reduced pressure. Yield: 23.8 g (95 mmol), 95%; purity: about 97%. 1 By H NMR.

[0218] C) S1 A mixture of 25.1 g (100 mmol) B) and 951 mg (5 mmol) of p-toluenesulfonic acid monohydrate in 500 ml of toluene is heated under reflux on a water separator for 16 hours. After cooling, the reaction mixture is stirred in an ice / water bath for another hour. The solid is suction filtered, washed with 50 ml of toluene, and dried under reduced pressure. The solid is then extracted by stirring with 300 ml of water, suction filtered, and washed with 100 ml of water to remove p-toluenesulfonic acid. After suction filtration and drying under reduced pressure, final drying is carried out by azeotropic drying twice with toluene. Yield: 20.5 g (88 mmol), 88%; purity: approx. 97% 1 By H NMR.

[0219] In a similar manner, the following compounds can be prepared: [Table 1]

[0220] Example S10: [ka] [ka] A mixture of 27.4 g (100 mmol) of 2,5-dichloro-4-iodopyridine [796851-03-1], 19.8 g (100 mmol) of 4-biphenylboronic acid [5122-94-1], 41.4 g (300 mmol) of potassium carbonate, 702 mg (1 mmol) of bis(triphenylphosphine)palladium(II) chloride [13965-03-2], 300 ml of methanol, and 300 ml of acetonitrile was heated under reflux for 16 hours. After cooling, the reaction mixture was stirred with 3 L of warm water and stirred for another 30 minutes. The precipitated product was suction filtered, washed three times with 50 ml of methanol each, dried under reduced pressure, taken up in 500 ml of DCM, filtered through a silica gel bed in the form of a DCM slurry, and recrystallized from acetonitrile. Yield: 28.5 g (95 mmol), 95%; Purity: approx. 97% 1 By H NMR.

[0221] [ka] Variant 1: The procedure described in A) was repeated except that 12.2 g (100 mmol) of phenylboronic acid [98-80-6] was used instead of 4-biphenylboronic acid. Reaction time: 24-30 h. Yield: 26.0 g (76 mmol), 76%; Purity: approx. 97%. 1 By H NMR.

[0222] Variant 2: Alternatively, the Suzuki coupling can be carried out in a biphasic toluene / dioxane / water system (2:1:2 vv) using 3 equivalents of tripotassium phosphate and 1 mol % of bis(triphenylphosphine)palladium(II) chloride.

[0223] C) S10 A mixture of 34.2 g (100 mmol) of S10 (Stage B), 17.2 g (110 mmol) of 2-chlorophenylboronic acid [3900-89-8], 63.7 g (300 mmol) of potassium phosphate tribasic, 1.64 g (4 mmol) of SPhos, 449 mg (2 mmol) of palladium(II) acetate, 600 mL of THF, and 200 mL of water was heated under reflux for 24 h. After cooling, the aqueous phase was removed, the organic layer was concentrated to dryness, and the glassy residue was taken up in 200 mL of ethyl acetate / DCM (4:1 v / v). The core fraction was then filtered through a silica gel bed (approximately 500 g of silica gel) in the form of a 4:1 v / v slurry to isolate the core fraction. The core fraction was concentrated to approximately 100 mL, and the crystallized product was suction filtered, washed twice with 50 mL of methanol, and dried under reduced pressure. Further purification was carried out under reduced pressure (~10 -3 -10 -4 This was performed by fractional Kugelrohr distillation at 1000 psi (2000 psi) and 1000 psi (2000 psi) at 1000 psi (2000 psi) to remove traces of S10 stage B) in the first fraction, leaving longer oligomers. Yield: 29.7 g (71 mmol), 71%; Purity: ca. 95% 1 By H NMR.

[0224] Similarly, by using the corresponding boronic acids / esters in A), B) and C), the following compounds can be prepared:

[0225] [Table 2]

[0226] [Table 3]

[0227] Example S50: [ka] To a mixture of 41.8 g (100 mmol) of S10, 20.0 g (110 mmol) of (3,5-dimethoxyphenyl)boronic acid [192182-54-0], 63.7 g (300 mmol) of potassium phosphate tribasic, 300 mL of toluene, 150 mL of dioxane, and 300 mL of water, 1.64 g (4 mmol) of SPhos, and 449 mg (2 mmol) of palladium(II) acetate were added with vigorous stirring, and the mixture was heated under reflux for 24 h. After cooling, the organic phase was removed and washed twice with 300 mL of water and once with 300 mL of saturated sodium chloride solution, then dried over magnesium sulfate. The drying agent was filtered, the filtrate was concentrated to dryness under reduced pressure, and the crude glassy product was recrystallized by boiling from acetonitrile. Yield: 40.0 g (77 mmol), 77%; Purity: approx. 95% 1 By H NMR.

[0228] In a similar manner, the following compounds can be prepared: [Table 4]

[0229] [Table 5]

[0230] Example S100: [ka] A mixture of 52.0 g (100 mmol) of S50 and 231.2 g (2 mol) of pyridinium hydrochloride is heated to 220 °C on a water separator (heating mantle), occasionally discarding the distillate. The reaction mixture is cooled, and 1000 ml of water is added dropwise, starting at a temperature of ∼150 °C (Caution: delayed boiling). The mixture is stirred for 2 hours, and then neutralized by adding 10% ammonia while stirring. The mixture is stirred for another 5 hours, and 10% ammonia is added again as needed until the reaction is neutral. The solid is filtered off with suction, washed three times with 70 ml of MeOH each time, and dried under reduced pressure. Residual water still present is removed by azeotropic drying with ethanol. Yield: 42.3 g (86 mmol), 86%; purity: approx. 95%. 1 By H NMR.

[0231] In a similar manner, the following compounds can be prepared:

[0232] [Table 6]

[0233] [Table 7]

[0234] Example S150: [ka] A suspension of 49.2 g (100 mmol) of S100 in 500 ml of DCM was cooled to 0°C with ice and, with vigorous stirring, 31.6 ml (400 mmol) of pyridine was added, followed by dropwise addition of 50.4 ml (300 mmol) of trifluoromethanesulfonic anhydride. The mixture was stirred at 0°C for 1 hour and then at room temperature for 4 hours. The reaction solution was poured onto 3 L of ice water and stirred for another 15 minutes. The organic phase was removed and washed once with 300 ml of ice water, once with 300 ml of saturated sodium bicarbonate, and once with 300 ml of saturated sodium chloride solution, dried over magnesium sulfate, the desiccant was filtered off, the filtrate was concentrated to dryness, and the foam was recrystallized by boiling from ethyl acetate. Yield: 49.1 g (65 mmol), 65%; purity: approximately 95%. 1 By H NMR.

[0235] In a similar manner, the following compounds can be prepared:

[0236] [Table 8]

[0237] [Table 9]

[0238] Example S200: [ka] To a mixture of 23.9 g (100 mmol) of 6-bromo-2,3-dihydro-2,2-dimethyl-1H-inden-1-one [165730-10-9], 26.7 g (105 mmol) of bis(pinacolato)diborane, 29.4 g (300 mmol) of anhydrous potassium acetate, 50 g of glass beads (3 mm diameter), and 300 ml of THF, 821 mg (2 mmol) of SPhos and 225 mg (1 mmol) of palladium(II) acetate were added with vigorous stirring, and the mixture was heated under reflux for 8 hours. After cooling, the salts and glass beads were removed by suction filtration through a Celite bed in the form of a THF slurry, which was washed with a little THF, and the filtrate was concentrated to dryness. The residue is taken up in 300 ml of ethyl acetate, washed twice with 200 ml of water each and once with 200 ml of saturated sodium chloride solution, and dried over magnesium sulfate. The drying agent is filtered through a silica gel bed in the form of an ethyl acetate slurry, the filtrate is concentrated to dryness, the residue is taken up in 100 ml of DCM and 100 ml of n-heptane, and the DCM is gradually removed under reduced pressure to recrystallize the product. The crystallized product is suction filtered, washed twice with 30 ml of n-heptane each, and dried under reduced pressure. Yield: 23.8 g (83 mmol), 83%; purity: approximately 95%. 1 By H NMR.

[0239] In a similar manner, the following compounds can be prepared: [Table 10]

[0240] Example S250: [ka] A mixture of 23.7 g (100 mmol) of 2,5-dibromopyridine [624-28-2], 28.6 g (100 mmol) of S200, 27.6 g (200 mmol) of potassium carbonate, 50 g of glass beads (3 mm diameter), 702 mg (1 mmol) of bis(triphenylphosphine)palladium(II) chloride [13965-03-2], 200 ml of acetonitrile, and 200 ml of methanol was heated under reflux for 16 hours. After cooling, the solvent was mostly removed under reduced pressure, and the residue was taken up in 500 ml of ethyl acetate, washed three times with 200 ml of water and once with 300 ml of saturated sodium chloride solution, and dried over magnesium sulfate. The drying agent was filtered, the filtrate was concentrated to dryness, and the solid was recrystallized from acetonitrile. Yield: 22.1 g (70 mmol), 70%; Purity: approx. 95% 1 By H NMR.

[0241] In a similar manner, the following compounds can be prepared: [Table 11]

[0242] B: Synthesis of tripodal ligands Ligand L1: [ka] Prepared by GAMolander et al., Organic Letters (2009), 11(11), 2369-2372. To a well-stirred suspension of 13.4 g (100 mmol) of potassium vinyltrifluoroborate [13682-77-4] in 500 ml of THF cooled to 0 °C, 200 ml (100 mmol) of 9-BBN solution (0.5 M in THF) was added dropwise, and the mixture was stirred at room temperature for 2 hours. To this solution, 27.5 g (50 mmol) of S154, 17.4 g (300 mmol) of anhydrous KF, 1.18 g (3 mmol) of DavePhos, and 449 mg (2 mmol) of palladium(II) acetate were added, and the reaction mixture was stirred at 50 °C for 60 hours. The THF is then removed under reduced pressure, the residue is taken up in 500 ml of toluene, 100 ml of water, 23.2 g (1 mmol) of S4, 41.5 g (300 mmol) of potassium carbonate, and 1.87 g (3 mmol) of RuPhos are added, and the mixture is heated under gentle reflux for 30 hours. After cooling, the aqueous phase is removed, and the toluene phase is washed once with 200 ml of water and once with 200 ml of saturated sodium chloride solution, and then dried over magnesium sulfate. The desiccant is filtered, the toluene is removed under reduced pressure, and the residue is chromatographed on silica gel using n-heptane / ethyl acetate 3:1 > 1:1 (vv). Yield: 16.3 g (18 mmol), 36%; purity: ca. 97%. 1 By H NMR.

[0243] In a similar manner, the following compounds can be prepared:

[0244] [Table 12]

[0245] [Table 13]

[0246] [Table 14]

[0247] [Table 15]

[0248] C: 1) Synthesis of tripodal metal ligands Example Ir(L1): [ka] A mixture of 9.06 g (10 mmol) of ligand L1, 4.90 g (10 mmol) of trisacetylacetonatoiridium(III) [15635-87-7], and 120 g of hydroquinone [123-31-9] was initially introduced into a 1000 ml two-neck round-bottom flask equipped with a glass-coated magnetic bar. The flask was equipped with a water separator (for media less dense than water) and an argon-blanketed air condenser. The flask was placed on a metal heating bath. The apparatus was purged with argon from the top of the argon-blanket system for 15 minutes, with argon flowing through the side of the two-neck flask. A glass-coated Pt-100 thermocouple was introduced into the flask through the side of the two-neck flask, with its end positioned just above the magnetic stirrer core. The apparatus was insulated with several loose wraps of household aluminum foil, with the insulation reaching the center of the water separator's riser tube. The apparatus is then rapidly heated to 250-255°C (measured by a Pt-100 temperature sensor attached to the molten stirred reaction mixture) using the laboratory's stirring and heating system. The reaction mixture is maintained at 250-255°C for an additional 2 hours, during which time a small amount of condensate is distilled off and collected in a water separator. After 2 hours, the mixture is cooled to 190°C, the heating mantle is removed, and 100 ml of ethylene glycol is added dropwise. After cooling to 100°C, 400 ml of methanol is added slowly dropwise. The resulting yellow suspension is filtered through a double-ended frit, and the yellow solid is washed three times with 50 ml of methanol and dried under reduced pressure. The crude yield is quantitative. The resulting solid is dissolved in 1500 ml of dichloromethane and, in the dark, with the exclusion of air, filtered through a silica gel (column diameter approximately 18 cm) in a dichloromethane slurry, leaving the original dark component. The core fraction is removed and concentrated on a rotary evaporator with the simultaneous continuous dropwise addition of MeOH until crystallization.After suction filtration, washing with a small amount of MeOH, and drying under reduced pressure, the orange product is further purified by successive hot extractions, with careful exclusion of air and light, three times with dichloromethane / isopropanol 1:1 (v / v) and three times with dichloromethane / acetonitrile 1:1 (v / v) (initial volume approximately 200 ml in each case, extraction thimble: Whatman cellulose standard Soxhlet thimble). Losses in the mother liquor can be adjusted by adjusting the ratio of dichloromethane (low boiling point and good solubility) to isopropanol or acetonitrile (high boiling point and low solubility). Typically, the loss should be 3-6% by weight. Hot extraction can also be performed with other solvents, such as toluene, xylene, ethyl acetate, or butyl acetate. Finally, the product is extracted under high vacuum at approximately 100°C. -6 Fractional sublimation at mbar and T about 400-430° C. Yield: 6.46 g (5.8 mmol), 58%; purity: >99.8% by HPLC.

[0249] Metal complexes are typically obtained as a 1:1 mixture of Λ and Δ isomers / enantiomers. Henceforth, the images of the complexes shown will show only one isomer. When a ligand with three different ancillary ligands is used, or when a chiral ligand is used as a racemate, the resulting metal complex is obtained as a diastereomeric mixture. These can be separated by fractional crystallization or chromatography (e.g., an automated column system (Combiflash, according to A. Semrau)). When a chiral ligand is used in enantiomerically pure form, the resulting metal complex is obtained as a diastereomeric mixture, which can be separated into pure enantiomers by fractional crystallization or chromatographic separation. The separated diastereomers or enantiomers can be further purified as described above, for example, by thermal extraction.

[0250] In a similar manner, the following compounds can be prepared:

[0251] [Table 16]

[0252] [Table 17]

[0253] [Table 18]

[0254] [Table 19]

[0255] 2) Bromination of metal complexes To a solution or suspension of 10 mmol of iridium complexes bearing an AxC-H group (A = 1, 2, or 3) at the para-position in 500 mL to 2000 mL of dichloromethane (depending on the solubility of the metal complex), 10.5 mmol of Ax N-halosuccinimide (halogen: Cl, Br, I) is added at -30 to +30°C in the dark and with the exclusion of air. The mixture is stirred for 20 hours. Complexes that are poorly soluble in DCM may be converted to other solvents (TCE, THF, DMF, chlorobenzene, etc.) at elevated temperatures. The solvent is then substantially removed under reduced pressure. The residue is extracted with 100 mL of methanol by boiling, and the solid is suction filtered, washed three times with 30 mL of methanol, and dried under reduced pressure. This produces an iridium complex brominated at the para-position to iridium. Complexes with HOMO(CV)s of approximately -5.1 to -5.0 eV and lower magnitudes are prone to oxidation (Ir(III) → Ir(IV)), with the oxidant being bromine released from NBS. This oxidation reaction is evident by a distinct green, otherwise luminescent, yellow-to-red solution or suspension. In such cases, an additional equivalent of NBS is added. In summary, 300 to 500 ml of methanol and 2 ml of hydrazine hydrate are added as reducing agents, causing the green solution or suspension to turn yellow (reduction of Ir(IV) → Ir(III)). The solvent is then substantially removed under reduced pressure, 300 ml of methanol is added, and the solid is suction filtered, washed three times with 100 ml of methanol each, and dried under reduced pressure.

[0256] Substoichiometric brominations (e.g., mono- or dibromination of iridium complexes bearing a 3C-H group in the para position) are generally less selective than equivalent brominations. These crude brominated products can be separated chromatographically (CombiFlash Torrent by A. Semrau).

[0257] Synthesis of Ir(L11-2Br): [ka] To a stirred suspension of 10.7 g (10 mmol) of Ir(L11) in 500 mL of DCM at 0°C, 3.7 g (21.0 mmol) of N-bromosuccinimide was added in one portion, and the mixture was stirred for an additional 20 h. After approximately 450 mL of DCM was removed under reduced pressure, 100 mL of methanol was added to the yellow suspension, and the solid was suction filtered, washed three times with approximately 50 mL of methanol, and dried under reduced pressure. Yield: 11.7 g (9.5 mmol), 95%; Purity: >99.5% by NMR.

[0258] In a similar manner, the following compounds can be prepared: [Table 20]

[0259] 3) Cyanation of metal complexes A mixture of 10 mmol of the brominated complex, 20 mmol of copper(I) cyanide per bromine function, and 300 ml of NMP is stirred at 180°C for 40 hours. After cooling, the solvent is removed under reduced pressure. The residue is taken up in 500 ml of dichloromethane, the copper salts are filtered using Celite, the dichloromethane is concentrated to near dryness under reduced pressure, 100 ml of ethanol is added, the precipitated solid is suction filtered, washed twice with 50 ml of ethanol each time, and dried under reduced pressure. The crude product is purified by chromatography and / or thermal extraction. The thermal treatment is carried out under high vacuum (approximately 10 -6 The sublimation is carried out in a temperature range of about 200-300°C at a pressure of about 100 mbar. -6 The sublimation is carried out in the temperature range of about 350-450° C. at 1000 K (mbar) and preferably in the form of fractional sublimation.

[0260] Synthesis of Ir(L11-2CN): [ka] Using 12.3 g (10 mmol) of Ir(L11-2Br) and 3.6 g (40 mmol) of copper(I) cyanide. Chromatography on silica gel with dichloromethane, hot extraction six times with dichloromethane / acetonitrile (2:1 v / v), sublimation. Yield: 6.1 g (5.5 mmol), 55%; purity: approximately 99.9% by HPLC.

[0261] In a similar manner, the following compounds can be prepared: [Table 21]

[0262] D: Heteroleptic complexes of bidentate ligands 1) Iridium complexes of the [Ir(L)2Cl]2 type Variant A: A mixture of 22 mmol of the ligand, 10 mmol of iridium(III) chloride hydrate, 75 ml of 2-ethoxyethanol, and 25 ml of water is heated under reflux with good stirring for 16-24 hours. If the ligand does not completely dissolve in the solvent mixture under reflux, 1,4-dioxane is added until a solution is formed. After cooling, the precipitated solid is filtered off with suction, washed twice with ethanol / water (1:1, vv), and dried under reduced pressure. The chlorodimer of formula [Ir(L)Cl] thus obtained is further converted without purification. [Table 22]

[0263] 2) Iridium complexes of the [Ir(L)2(HOMe)2]OTf type. To a suspension of 5 mmol of the chlorodimer [Ir(L)2Cl]2 in 150 ml of dichloromethane, 5 ml of methanol and 10 mmol of silver(I) trifluoromethanesulfonate [2923-28-6] are added, and the mixture is stirred at room temperature for 18 hours. The precipitated silver(I) chloride is filtered off with suction through a Celite bed, the filtrate is concentrated to dryness, and the yellow residue is taken up in 30 ml of toluene or cyclohexane. The solid is filtered, washed with n-heptane, and dried under reduced pressure. The product of formula [Ir(L)2(HOMe)2]OTf thus obtained is converted further without further purification. [Table 23]

[0264] 3) Phenylpyridine-type heteroleptic iridium complexes: 10 mmol of ligand L act A mixture of 10 mmol of an iridium complex of the [Ir(L)2(HOMe)2]OTf type, 11 mmol of 2,6-dimethylpyridine, and 150 ml of ethanol is heated under reflux for 40 hours. After cooling, the precipitated solid is filtered off with suction, washed three times with 30 ml of ethanol each, and dried under reduced pressure. The crude product thus obtained is chromatographed on silica gel (solvents or mixtures thereof, such as DCM, THF, toluene, n-heptane, cyclohexane) and fractionally sublimed as described in C:1) Tripodal Metal Complexes. [Table 24]

[0265] Optical orientation anisotropy θ and angle α(μ act ,d) The optical orientation anisotropy θ and angle α(μ) of the complexes whose synthesis is described above act , d) are listed in Table 1. These parameters were calculated by the methods described in Parts 1 and 2 of the Examples. [Table 25]

[0266] Example: OLED manufacturing 1) Vacuum processed elements: OLEDs according to the present invention and prior art OLEDs were produced according to the general method described in WO 2004 / 058911, adapted to the conditions described herein (layer thickness range, materials used). The following examples show the results for various OLEDs. Cleaned coated glass plates were used (cleaned in a Miele laboratory glass washer, with Merck Extrane detergent) and coated with a 50 nm thick structured ITO (indium tin oxide) and pretreated with UV ozone for 25 minutes (UVP PR-100 UV ozone generator). Subsequently, within 30 minutes, they were coated with 20 nm of PEDOT:PSS (poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate), purchased under the trade name CLEVIOS® P VP AI 4083 from Heraeus Precious Metals GmbH (Germany), spin-coated from an aqueous solution) for process improvement, and baked at 180°C for 10 minutes. These coated glass plates formed the substrates on which the OLEDs were applied.

[0267] The OLED basically has the following layer structure: substrate / Hole Injection Layer 1 (HIL1) consisting of HTM1 doped with 5% NDP-9 (available from Novaled), 20 nm / HTM1 hole transport layer 1 (HTL1), 220 nm / HTM2 hole transport layer 2, 10 nm / Emission Layer (EML) (see Table 2) / HBL1 hole blocking layer, 10 nm / ETM1:ETM2 (50%:50%) electron transport layer, 30 nm / Aluminum cathode, 100 nm. For this purpose, all materials are applied by thermal evaporation in a vacuum chamber. Here, the emission layer always consists of at least one matrix material (host material) and a light-emitting dopant (emitter), which are mixed into the matrix material in a specific volume ratio by co-evaporation. Here, a specification such as M1:M2:Ir(L1) (55%:35%:10%) means that the material M1 is present in the layer at a volumetric ratio of 55%, M2 at a volumetric ratio of 35%, and Ir(L1) at a volumetric ratio of 10%. Similarly, the electron transport layer may also consist of a mixture of two materials. The exact structure of the OLED's light-emitting layer can be seen in Table 1. The materials used in the manufacture of the OLED are listed in Table 4.

[0268] OLEDs are characterized by standard methods. For this purpose, the electroluminescence spectrum, the current efficiency (measured in cd / A), the power efficiency (measured in lm / W), and the external quantum efficiency (EQE, measured in percent) as a function of luminous density, calculated from the current / voltage / luminous flux density characteristic line (IUL characteristic line) assuming Lambertian emission characteristics, as well as the lifetime, are measured. The electroluminescence spectrum is measured at a luminous flux density of 1000 cd / m 2 The CIE1931 x and y color coordinates are calculated from this. The lifetime LT90 is the time when the luminance during operation is 10,000 cd / m 2 is defined as the time it takes for the brightness to drop to 90% of its initial brightness.

[0269] The OLED may be initially operated at different brightnesses, and the lifetime values ​​may be converted to other initial brightness values ​​using conversion formulas known to those skilled in the art.

[0270] Use of the compounds of the present invention as emitters in phosphorescent OLEDs One use of the compounds of the present invention is as a phosphorescent material in the emissive layer of an OLED. The OLED results are summarized in Table 3, where Examples Ref.-D2A and Ref.-D2B show the results of the angle α (μ act , d) 51° shows a voltage shift as the amount of phosphor changes from 5% to 15%, which is also shown in graph form in FIG.

[0271] [Table 26]

[0272] [Table 27]

[0273] [Table 28]

[0274] [Table 29]

Claims

1. A mononuclear iridium complex comprising three ortho-metallated bidentate ligands or three ortho-metallated bidentate subligands, exhibiting directional emission with optical orientation anisotropy θ ≤ 0.24, wherein the transition dipole moment μ ａｃｔ The angle α (μ) between the electron dipole moment d and the electron dipole moment d ａｃｔ A material for an organic electroluminescent element comprising a mononuclear iridium complex characterized in that d) is ≤40°, The mononuclear iridium complex is represented by the following formulas (1) and (2): 【Chemistry 1】 (Here, L act is a luminescent ortho-metallated bidentate ligand in formula (1) and a luminescent ortho-metallated secondary ligand in formula (2); unlike L act, L is either the same or different each time it appears, being an ortho-metallated bidentate ligand in formula (1) and an ortho-metallated bidentate secondary ligand in formula (2); and V in formula (2) is a bridging unit that covalently bonds the secondary ligand L act and L, forming a tripod-type hexadent ligand.) A material selected from mononuclear iridium complexes. (However, the following compounds: 【Chemistry 2-1】 【Chemistry 2-2】 Materials for organic electroluminescent elements comprising the above are excluded from the present invention.

2. The mononuclear iridium complex is in the following state with triplet energy: Ir(L ａｃｔ The material according to claim 1, characterized in that it has exactly one luminescent ligand or sub-ligand, characterized in that ) < Ir(L) (where L is an optically inactive ligand).

3. The triplet energy of ligand Ir(L) is ａｃｔ The material according to claim 2, characterized in that its triplet energy is at least 0.05 eV greater than that of ).

4. The material according to any one of claims 1 to 3, characterized in that the luminescent ligand or sub-ligand is an aromatic or heteroaromatic ring system and extends in the direction of the transition dipole moment.

5. The material according to any one of claims 1 to 4, characterized in that the optical orientation anisotropy θ is ≤ 0.

22.

6. Transition dipole moment μ ａｃｔ The angle α (μ) between the electron dipole moment d and the electron dipole moment d ａｃｔ The material according to any one of claims 1 to 5, characterized in that d) is ≤ 35°.

7. The material according to any one of claims 1 to 6, characterized in that the complex has a photoluminescence quantum efficiency greater than 0.

85.

8. L ａｃｔ The material according to any one of claims 1 to 7, characterized in that L and L coordinate to iridium via one carbon atom and one nitrogen atom, or via two carbon atoms, respectively.

9. L ａｃｔ The material according to any one of claims 1 to 8, characterized in that L and L have the structure of formula (L-1) or (L-2), respectively (where the two ligands or subligands L may be the same or different). 【Transformation 3】 (Here, the dotted line connection is the connection of the secondary ligand V in equation (2), which does not exist in equation (1), and the other symbols used here are as follows: CyC is a substituted or unsubstituted aryl or heteroaryl group, which is identical or different each time it appears, has 5 to 14 aromatic ring atoms, and in each case coordinates to the metal via carbon atoms, and is bonded to CyD via covalent bonds; CyD is a substituted or unsubstituted heteroaryl group, which is identical or different each time it appears, has 5 to 14 aromatic ring atoms, and coordinates to the metal via a nitrogen atom or carbene carbon atom, and is bonded to CyC via a covalent bond; At the same time, two or more arbitrary substituents may together form a ring system.

10. L ａｃｔ and L is each one of the structures of formula (L-1-1), (L-1-2), (L-2-1), (L-2-2), (L-2-3) or (L-2-4), the material according to any one of claims 1 to 9. 【Chemistry 4】 (Here, in the compound of formula (2), "o" indicates the bond position to V, and in this case the corresponding X is C, and here, in the compound of formula (1), "o" is undefined, and further: X is either identical or different in each occurrence, and is either CR or N, where at most two symbols X are N per ring; R is either the same or different each time it appears, and H, D, F, Cl, Br, I, N(R １ ) ２ , OR １ , SR １ , CN, NO ２ COOR １ , C(=O)N(R １ ) ２ , Si(R １ ) ３ , B (OR １ ) ２ , C(=O)R １ , P(=O)(R １ ) ２ , S(=O)R １ , S (=O) ２ R １ OSO ２ R １ , a linear alkyl group having 1 to 20 carbon atoms, or an alkenyl or alkynyl group having 2 to 20 carbon atoms, or a branched or cyclic alkyl group having 3 to 20 carbon atoms (wherein the alkyl, alkenyl or alkynyl group, in each case, one or more R １ It may be substituted with radicals, and here, one or more non-adjacent CH ２ The base is Si(R １ ) ２ , C=O, NR １ , O, S or CONR １ (may be replaced by), or having 5 to 40 aromatic ring atoms, with one or more non-aromatic R in each case. １ An aromatic or heteroaromatic ring system which may be substituted by radicals; at the same time, two R radicals may both form a ring system; R １ These are either the same or different each time they appear, H, D, F, Cl, Br, I, N(R ２ ) ２ , OR ２ , SR ２ , CN, NO ２ , Si(R ２ ) ３ , B (OR ２ ) ２ , C(=O)R ２ , P(=O)(R ２ ) ２ , S(=O)R ２ , S (=O) ２ R ２ OSO ２ R ２ , a linear alkyl group having 1 to 20 carbon atoms, or an alkenyl or alkynyl group having 2 to 20 carbon atoms, or a branched or cyclic alkyl group having 3 to 20 carbon atoms (wherein the alkyl, alkenyl or alkynyl group, in each case, one or more R ２ It may be substituted with radicals, and here, one or more non-adjacent CH ２ The base is Si(R ２ ) ２ , C=O, NR ２ , O, S or CONR ２ (may be replaced by), or having 5 to 40 aromatic ring atoms, with one or more non-aromatic R in each case. ２ A system of aromatic or heteroaromatic rings which may be substituted by radicals; and simultaneously, two or more R １ The radicals may also form a ring system together; R ２ (These are aliphatic organic radicals, particularly hydrocarbyl radicals, which are identical or different each time they appear and have H, D, F, or 1 to 20 carbon atoms (where one or more hydrogen atoms may be replaced by F)).

11. L ａｃｔ The material according to any one of claims 1 to 10, characterized in that is a ligand or sub-ligand of formula (L-39) that coordinates to iridium via two D groups, and is bonded to V via a dotted line when the complex is one of formula (2), in which case X is C. 【Transformation 5】 (Here, X, R and R １ is the definition described in claim 10, further: D is C or N, where one D is C and the other D is N; Z is CR', CR, or N, where exactly one Z is CR' and the other Zs are CR or N; Here, N is at most one symbol X or Z per ring; R' is the basis of the following equation (14) or (15): 【Transformation 6】 Here, the dotted line indicates the connection of the base; R'' may be the same or different each time it appears, and may be a linear alkyl group having 1 to 10 carbon atoms (where one or more hydrogen atoms may be replaced by D or F), or a branched or cyclic alkyl group having 3 to 10 carbon atoms (where one or more hydrogen atoms may be replaced by D or F), or an alkenyl group having 2 to 10 carbon atoms (where one or more hydrogen atoms may be replaced by D or F); at the same time, two adjacent R'' radicals or two R'' radicals on an adjacent phenyl group may together form a ring system; or two R'' on an adjacent phenyl group may both be C(R １ ) ２ , NR １ The group is selected from O and S, and the two phenyl groups together with the crosslinking group form carbazole, dibenzofuran, or dibenzothiophene, and the further group R'' is as defined above; n is 0, 1, 2, 3, 4, or 5.

12. V is the base of equation (16) (where the dotted line represents the secondary ligand L). ａｃｔ The material according to any one of claims 1 to 11, characterized in that it is the connection position of L. 【Transformation 7】 (Here, R is the definition described in claim 10, and further: X １ Each occurrence may be identical or different, and is either CR or N; A is either the same or different each time it appears, CR ２ -CR ２ CR ２ -O, CR ２ -NR, C(=O)-O, C(=O)-NR, or the basis of formula (17): 【Transformation 8】 (Here, the dotted line represents the bidentate secondary ligand L) ａｃｔ and indicate the position of the L bond in this structure, * indicates the linkage position of the unit of formula 17 to the central trivalent aryl or heteroaryl group, and X ２ (It is either the same or different each time it appears, and is either CR or N.)

13. The material according to any one of claims 1 to 12, characterized in that it is incorporated into the light-emitting layer of an organic electroluminescent element.

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