DE102016106103B4 - Organic molecules with two non-conjugated bridges between donor and acceptor, their use to emit light, and opto-electronic devices and their manufacture - Google Patents

Abstract

Organic molecule for emitting light, in particular for use as an emitter in an optoelectronic device, comprising or consisting of a structure according to formula XVIII with:Q1 to Q6 are independently selected from the group consisting of H, CH3, C2H5, C3H7, C4H9, C5H11, C6H13, phenyl, tolyl, xylyl, benzyl, thienyl, azolyl, diazolyl, triazolyl, tetrazolyl, oxazolyl, oxadiazolyl, furanyl and carbazolyl group; where Q1 and Q2, Q3 and Q4, and Q5 and Q6 are optionally linked to form a cycloalkyl or an aromatic spiro system;Alk1 to Alk10 are independently H or a straight or branched aliphatic group or a cycloalkyl group.

Description

The invention relates to organic molecules for optoelectronic devices and optoelectronic devices containing such organic molecules. These organic molecules have a donor and an acceptor unit, the spatial positions of which are connected to one another by two organic non-conjugated bridges. The organic molecules exhibit small triplet-singlet energy gaps for effective delayed fluorescence, making the molecules particularly suitable for application in opto-electronic devices.

background

For many optoelectronic applications, luminescent molecules (=emitter molecules) are to be used which have the shortest possible emission decay time τ and a high photoluminescence quantum yield φ _PL . In addition, for such applications with purely organic emitter molecules, ie with molecules that do not represent metal complex compounds, it is important to include the electronic occupation of the lowest excited triplet state T ₁ in the emission process. This requirement can be met by setting a sufficiently small energy difference ΔE(S ₁ -T ₁ ) between the Ti state and the overlying singlet state Si in order to achieve thermally activated delayed (delayed) fluorescence (TADF) at room temperature to allow ( 1 ). This process is known to those skilled in the art (see e.g. BCA Parker, CG Hatchard; Trans. Faraday, Royal Society of Chem. 1961, 57, 1894) and is also referred to as E-type up-conversion (since first discovered for eosin ). As a result of an effective TADF, it can be achieved that the decay time of the luminescence (=emission) τ(TADF) involving the long-lived triplet state is reduced by several orders of magnitude compared to that of the phosphorescence τ(T ₁ ). Furthermore, in many cases it can be achieved that the emission quantum yield ϕ _PL is significantly increased, because the non-radiative processes from the T ₁ state (shown wavy in 1 ) are less important because of the competing faster reset process T ₁ → k _B T → S ₁ .

It is known from the prior art that a TADF can occur in many molecules with an intramolecular charge transfer (CT) transition between a donor (D) segment and an acceptor (A) segment. However, the energy differences ΔE(S ₁ - T ₁ ) found so far are still far too large, and thus the photophysical properties desired for many applications, such as a short decay time τ(TADF), cannot be achieved.

DE 10 2015 112 501 A1 , KR 10 2011 0 110 508 A , JP 2010 - 24 149 A , as well as HOLZAPFEL, M.; LAMBERT, C.: Photoinduced Charge Separation and Recombination in Acridine-Triarylamine-Based Redox Cascades. In: J.Phys. Chem. C, Vol. 112, 2008, No. 4, pp. 1227-1243. - ISSN 1932-7447 disclose generic molecules useful in opto-electronic applications.

description

Surprisingly, it has now been possible to find a method (molecular construction principle) that allows the energy difference ΔE(S ₁ -T ₁ ) to be reduced in a targeted manner in order to provide corresponding purely organic molecules. This energy difference is approximately proportional to the quantum mechanical exchange integral according to equation (1) $$\mathrm{\Delta }\text{E}\left({\text{<figure-callout id="1" label="S" filenames="DE102016106103B4\_0049.png,DE102016106103B4\_0050.png" state="{{state}}">S</figure-callout>}}_1-{\text{T}}_1\right)\approx \text{const}.<{\mathrm{\psi }}_{\text{D}}\left({\text{right}}_1\right){\mathrm{\psi }}_{\text{A}}*\left({\text{right}}_2\right)\left|{\text{right}}_{12}{}^{-1}\right|{\mathrm{\psi }}_{\text{D}}\left({\text{right}}_2\right){\mathrm{\psi }}_{\text{A}}*\left({\text{right}}_1\right)>$$

Here r ₁ and r ₂ are the electron coordinates and r ₁₂ is the distance between electron 1 and electron 2. Ψ _D is the wave function of the HOMO (highest occupied molecular orbital), which for the type of molecule according to the invention extends mainly over the donor part D of the molecule, while Ψ _A * represents the LUMO (lowest unoccupied molecular orbital) and extends predominantly over the acceptor part A of the molecule. Equation (1) shows that ΔE(S ₁ -T ₁ ) becomes small when the product of the wave functions [Ψ _D (r ₁ )Ψ _A *(r ₂ )] becomes small. This requirement cannot be met for a large number of molecules with intra-molecular CT transitions, because spatial extensions of the wave functions Ψ _D (r ₁ ) and Ψ _A *(r ₂ ) lead to pronounced superpositions and thus to large ΔE(S ₁ - T ₁ ) values. According to the invention, molecular structures are proposed which have significantly reduced overlapping of the wave functions. This is achieved through a molecular structure in which the donor and acceptor parts of the molecule are separated from one another by non-conjugated, small chemical groups (bridges). Thereby the extent of the HOMO in the acceptor area and the LUMO in the donor area is greatly reduced.

Formula I shows the molecular structure of the organic molecules according to the invention with two organic bridges between the donor segment and the acceptor segment. By choosing these bridges appropriately, the spatial overlapping of HOMO (mainly located on the donor) and LUMO (mainly located on the acceptor) can be significantly reduced. A slight overlap of the orbitals makes sense in order not to let the transition probability between the electronic ground state So and the excited Si state become too small. In addition, the double bridging leads to a stiffening of the molecule. This achieves an increase in the emission quantum yield and a reduction in the emission half-width. The latter is in many cases to achieve a defined emission color (color purity) for light generation z. B. useful in OLEDs.

Formula I shows the molecular structure of an embodiment of the organic molecules according to the invention with two chemical bridges. These bridges significantly reduce the conjugation between D and A or the overlapping of HOMO and LUMO and stabilize the molecular structure.

Formula I shows the molecular structure of the organic molecules according to the invention consisting of an aromatic or a heteroaromatic donor segment D and an aromatic or a heteroaromatic acceptor segment A bonded via two non-conjugated bridges B1 and B2 pronounced overlap of the donor HOMO and the acceptor LUMO.

For an opto-electronic application with a requirement for a small ΔE(S ₁ -T ₁ ) value, it is also important that the segments D and A each have a sufficiently high donor or acceptor strength. (These terms are known to those skilled in the art.) Corresponding strengths can be described by the strengths of the electron-pushing (for the donor strength) or the electron-withdrawing (for the acceptor strength) effects.

• - ΔE(S₁ - T₁)-Werte resultieren aus quantenmechanischen Rechnungen, zum Beispiel unter Verwendung käuflich zu erwerbender TD-DFT-Programme (z. B. mit dem Gaussian 09-Programm) oder der frei verfügbaren NWChem Version (z. B. Version 6.1), der CC2-Methode (TURBOMOLE GmbH, Karlsruhe) oder einer CAS-Methode (Complete Active State Methode). [Siehe z. B. D. I. Lyakh, M. Musiaz, V. F. Lotrich, R. J. Bartlett, Chem. Rev. 2012, 112, 182-243 und P. G. Szalay, T. Muller, G. Gidofalvi, H. Lischka, R. Shepard, Chem. Rev. 2012, 112, 108-181] Rechenbeispiele sind zu den Beispielen angegeben.
• - Eine experimentelle Bestimmung des ΔE(S₁ - T₁)-Wertes ist ebenfalls möglich. Die erfindungsgemäßen organischen Moleküle zeigen neben der prompten (= spontanen) Fluoreszenz-Komponente (Abklingzeit einige bis einige zehn ns) eine im Abklingbereich von unter einer µs bis zu mehreren hundert µs liegende TADF-Abkling-Komponente. Die zugehörige Abklingzeit kann mit handelsüblichen Apparaturen als Funktion der Temperatur bestimmt werden. Unter Verwendung der Gleichung (2) lässt sich anhand des Temperaturverlaufs der Emissionsabklingzeit durch Fitten der experimentellen Kurve der ΔE(S₁ - T₁)-Wert bestimmen [siehe z. B. Czerwieniec R., Kowalski K., Yersin H.; Dalton Trans. 2013, 42, 9826]:

$$\mathrm{\tau }\left(\text{T}\right)=\frac{3+\text{exp}\left(-\mathrm{\Delta }\text{E}\left({\text{<figure-callout id="1" label="S" filenames="DE102016106103B4\_0049.png,DE102016106103B4\_0050.png" state="{{state}}">S</figure-callout>}}_1-{\text{T}}_1\right)/{\text{k}}_{\text{B}}\text{T}\right)}{3/\mathrm{\tau }\left({\text{T}}_1\right)+1/\mathrm{\tau }\left({\text{S}}_1\right)\text{exp}\left(-\mathrm{\Delta }\text{E}\left({\text{<figure-callout id="1" label="S" filenames="DE102016106103B4\_0049.png,DE102016106103B4\_0050.png" state="{{state}}">S</figure-callout>}}_1-{\text{T}}_1\right)/{\text{k}}_{\text{B}}\text{T}\right)}$$

A suitable choice of the molecular structure makes it possible to reduce the energy difference to ΔE(S ₁ -T ₁ ) values of less than 2000 cm _-1 , in particular less than 1500 cm _-1 or better less than 800 cm _-1 or even better less than 400 cm _-1 or especially smaller than 200 cm _-1 . The corresponding value is determined by the individual molecule. It can be determined using various methods:

• - ΔE(S ₁ - T ₁ ) values result from quantum mechanical calculations, for example using commercially available TD-DFT programs (e.g. with the Gaussian 09 program) or the freely available NWChem version (e.g . Version 6.1), the CC2 method (TURBOMOLE GmbH, Karlsruhe) or a CAS method (Complete Active State Method). [See e.g. BDI Lyakh, M. Musiaz, VF Lotrich, RJ Bartlett, Chem. Rev. 2012, 112, 182-243 and PG Szalay, T. Muller, G. Gidofalvi, H. Lischka, R. Shepard, Chem. Rev. 2012, 112, 108-181] Calculation examples are given with the examples.
• - An experimental determination of the ΔE(S ₁ - T ₁ ) value is also possible. In addition to the prompt (=spontaneous) fluorescence component (decay time of a few to a few tens of ns), the organic molecules according to the invention also exhibit a TADF decay component in the decay range from less than one μs to several hundred μs. The associated decay time can be determined using commercially available equipment as a function of the temperature. Using equation (2), the ΔE(S ₁ - T ₁ ) value can be determined from the temperature profile of the emission decay time by fitting the experimental curve [see e.g. B. Czerwieniec R., Kowalski K., Yersin H.; Dalton Trans. 2013, 42, 9826]:

$$\mathrm{\tau }\left(\text{T}\right)=\frac{3+\text{ex}\left(-\mathrm{\Delta }\text{E}\left({\text{<figure-callout id="1" label="S" filenames="DE102016106103B4\_0049.png,DE102016106103B4\_0050.png" state="{{state}}">S</figure-callout>}}_1-{\text{T}}_1\right)/{\text{k}}_{\text{B}}\text{T}\right)}{3/\mathrm{\tau }\left({\text{T}}_1\right)+1/\mathrm{\tau }\left({\text{S}}_1\right)\text{ex}\left(-\mathrm{\Delta }\text{E}\left({\text{<figure-callout id="1" label="S" filenames="DE102016106103B4\_0049.png,DE102016106103B4\_0050.png" state="{{state}}">S</figure-callout>}}_1-{\text{T}}_1\right)/{\text{k}}_{\text{B}}\text{T}\right)}$$

Here τ(T) is the experimentally determined, optionally averaged, decay time after the prompt emission has decayed and thermal equilibrium has been reached (a few 100 ns). τ(S ₁ ) is the decay time of the prompt emission of the Si state. The other sizes are already defined above.

The emission decay time τ(TADF) (= τ(300 K)) should be as short as possible for many applications (if possible less than a few 100 µs). In order to achieve this, in addition to setting a small ΔE(S ₁ - T ₁ ) value, it can also be useful to increase the effectiveness of the spin-orbit coupling (SBC) between the Ti state and higher molecular energy states, namely, to obtain a greater inter-system crossing (ISC) rate. A suitable example for this is a substitution of the donor segment D and/or the acceptor segment A with a halogen Cl, Br and/or I.

An increase in the ISC rate can also be achieved for the molecules according to the invention which have localized states lying on donor D and/or acceptor A that are energetically close to the CT states. The increase results from an increase in the SBK due to quantum mechanical mixing between these states. The target molecules are determined using known computer programs or quantum mechanical methods (e.g. Gaussian 09 or CC2 method). The energy gaps between the states mentioned above are less than 2000 cm _-1 , in particular less than 1500 cm _-1 , better less than 1000 cm _-1 , even better less than 400 cm _-1 and most preferably less than 200 cm _-1 . A mutual energetic shift can be achieved via changes in the donor and/or acceptor strengths and via changes in the electron-donating substitutions on the donor and/or via changes in the electron-withdrawing substitutions on the acceptor. An energetic shift can also be achieved by using more than one electron-donating and/or electron-withdrawing substitution. The CT states can also be shifted by changing the polarity of the environment (e.g. the polymer matrix).

The chemical bridges B1 and B2 between the segments D and A not only have the effect of stiffening the molecule, but surprisingly also lead to an increase in the emission quantum yield φ _PL .

In addition, the bridges cause a severe restriction of the free mobility of the donor molecule segment D compared to the acceptor molecule segment A. As a result, the variation of the ΔE(S ₁ -T ₁ ) value of a given emitter molecule built into a polymer matrix becomes large restricted. This means that the inhomogeneity of the ΔE(S ₁ - T ₁ ) values is significantly reduced. Furthermore, an improvement in the color purity of the emission is achieved by reducing the half-width of the emission band.

Description of acceptor A and donor D of formula I

The emitter molecules of the formula I consist of two segments covalently connected via two bridges B1, B2, namely a donor segment D and an acceptor segment A. The donor and acceptor segments consist of aromatic or heteroaromatic groups which have further substitutions can have. The bridges B1, B2 are short aliphatic or heteroaliphatic fragments that greatly reduce the conjugation (delocalization) between the aromatic segments A and D. The chemical structure of the molecule segments A and D is explained using formulas II (not according to the invention) and III (according to the invention).

Formulas II and III: structure of the D and A molecule segments. The donor and acceptor segments consist of different aromatic/heteroaromatic fragments which, independently of one another, can be a five- or six-membered ring system and have substitutions or extensions (also with fused ring systems). Depending on the individual structure, there is a donor or an acceptor segment.

# marks the points at which the donor part D and the acceptor part A are connected to the bridges B1 and B2. The meaning of the groups X1 to X7 and Y1 to Y4 is chosen such that the definitions of the patent claims are fulfilled.

The embodiments of the molecules according to the invention have two ring systems of the formula III. The ring systems show a different substitution pattern.

The aromatic or heteroaromatic rings connected by two bridges B1, B2 belonging to the donor or acceptor fragments are not fused to other aromatic or heteroaromatic rings; the donor segment D and the acceptor segment A thus each have only one aromatic or heteroaromatic ring.

In one embodiment of the invention, the aromatic and/or heteroaromatic ring systems or the bridges of the organic molecules can also be substituted with a halogen (Cl, Br or I) to increase the spin-orbit coupling.

The molecular systems of the formula II (five ring system) and of the formula III (six ring system) can act as donors or acceptors. In order to achieve a specific donor effect, the HOMO must represent an electron-rich region and be largely localized on the donor part. In order to achieve a specific acceptor effect, the LUMO must represent an electron-deficient region and be largely localized on the acceptor part. This in 2 The orbital scheme shown is intended to illustrate the energetic requirements for the realization of a molecule according to the invention (DA emitter molecule).

The HOMO and LUMO energies of the separate donor and acceptor segments can usually be determined electrochemically. To get a substance with the in 2 To realize the orbital properties shown, the following must be true: (1) The oxidation potential of the donor segment is smaller than that of the acceptor segment: E _OX (D) < E _OX (A) (E _OX = oxidation potential), (2) The Reduction potential of the acceptor segment is greater than that of the donor segment: E _RED (D) < E _RED (A) (E _RED = reduction potential). Redox properties of many conventional aromatic compounds can e.g. B. be taken from the following reference [M. Montalti, A. Credi, L. Prodi, MT Gandolfi, Handbook of Photochemistry, 3rd ed., CRC Tayler & Francis, Boca Raton, 2006]. Accordingly, electronically excited states can occur in a donor-acceptor molecule, which are characterized by a significant shift in electron density from the donor to the acceptor compared to the molecule in the electronic ground state (So). Such states are referred to as charge transfer (CT) states. As is known to those skilled in the art, this results in singlet excited states CT (corresponding to the Si states defined above) and triplet excited states ₃ CT (corresponding to the Ti states defined above).

Electron-rich donor or electron-poor acceptor segments can be realized by introducing certain heteroatoms into the fused ring system and/or by certain substitutions with electron-donating or electron-withdrawing functional groups. So causes z. B. an introduction of a heteroatom, typically nitrogen (there are aza-aromatics), in the aromatic six-membered ring system - due to the mesomeric effect known to the person skilled in the art - a stabilization of the π and π* orbitals. As a result, the one-electron reduction and oxidation potentials of the aza-aromatics are higher than the redox potentials of the corresponding purely aromatic (non-heteroatomic) hydrocarbons. In contrast, in aromatic five-membered rings, the introduction of a heteroatom, typically nitrogen, leads to a destabilization of the π and π* orbitals via the mesomeric effect, leading to lower oxidation and reduction potentials. Further adaptations of the orbital energies are made by substitutions with electron-withdrawing (EWG = electron withdrawing group) or -pushing (EDG = electron donating group) functional groups. Substitutions with EWGs typically result in lower HOMO and LUMO energies, while substitutions with EDGs typically result in higher HOMO and LUMO locations. The following EWGs or EDGs are typically used: [M. Smith, J. March; March's Advanced Organic Chemistry, Reaction, Mechanism and Structure, 6th ed. John Wiley & Sons, Inc., Hoboken, New Jersey, 2007].

In one embodiment, the organic molecule according to the invention has a structure according to formula XVIII or XIX.

In the donor area, the emitter molecule has an aromatic amino group. The acceptor moiety is a dicyanobenzene group, where the two CN substituents may be in an ortho, meta, or para position to each other and to the bridging aliphatic groups.

Q1 through Q6 are independently selected from the group consisting of H, CH ₃ , C ₂ H ₅ , C ₃ H ₇ , C ₄ H ₉ , C ₅ H ₁₁ , C ₆ H ₁₃ , phenyl, tolyl, xylyl , benzyl, thienyl, azolyl, diazolyl, triazolyl, tetrazolyl, oxazolyl, oxadiazolyl, furanyl and carbazolyl group.

Q1 and Q2, Q3 and Q4, and Q5 and Q6 can be linked to one another, resulting in a cycloalkyl or an aromatic spiro system (e.g. to stabilize the molecular structure).

Alk1 through Alk10 are independently H or aliphatic, normal or branched, (C _n H _2n+1 ; n = 1, 2, 3, 4, 5, or 6) or cycloalkyl (C _n H _2n+1 ; n = 5 or 6) group.

Alternatively, the organic molecule according to the invention has a structure according to one of the following formulas 1-7, 9, 12-28, 30-33 or 36-38:

examples

The molecules according to the invention and comparison molecules given below by way of example can also have at least one Cl, Br and/or I substitution in order to increase the spin-orbit coupling (SBC). The suitable position for such a substitution can be determined by means of quantum mechanical calculations by using computer programs that also record the SBK (e.g. ADF, ORCA program). DFT or CC2 calculations can also be carried out to record the trend. The position of the halogen substitution is then determined by the fact that halogen atomic orbitals with a significant proportion z. B. in HOMO, HOMO-1, HOMO-2 and / or z. B. contained in LUMO, LUMO+1, LUMO+2. The substitution pattern determined in this way must also be taken into account, namely e.g. For example, using TDDFT or CC2 calculations, the energy difference ΔE(S ₁ - T ₁ ) between the lowest excited singlet (S ₁ ) and underlying triplet (T ₁ ) states of the organic molecule is less than 2,000 cm _-1 , in particular less than 1500 cm _-1 , preferably less than 800 cm _-1 , particularly preferably less than 400 cm _-1 and most preferably less than 200 cm _-1 .

The materials can be synthesized using catalytic coupling reactions known to those skilled in the art (e.g. Suzuki coupling reaction, Buchwald-Hartwig cross-coupling reaction) or by various condensation reactions.

example 1

Im Folgenden wird das unter Beispiel 1 gezeigte Molekül detaillierter diskutiert. Die in 3 gezeigten Grenzorbitale lassen erkennen, dass HOMO und LUMO in deutlich verschiedenen Raumbereichen des Moleküls lokalisiert sind. Das lässt bereits erwarten, dass die Aufspaltung zwischen dem untersten Triplett- und dem darüber liegenden Singulett-Zustand klein genug ist, damit das Molekül einen ausgeprägten TADF-Effekt zeigt. Eine Rechnung für das Beispielmolekül 1 im Rahmen einer TD-DFT-Rechnung (Funktional B3LYP; Basissatz 6-31G(d,p)) zeigt, dass diese Energiedifferenz für die optimierte Triplett-Geometrie mit ΔE (S₁ - T₁) = 75 cm_-1 beträgt. Somit repräsentiert Beispielmolekül 1 einen guten TADF-Emitter.

In the following, the molecule shown under Example 1 is discussed in more detail. In the 3 Frontier orbitals shown indicate that HOMO and LUMO are located in distinctly different spatial regions of the molecule. This already suggests that the splitting between the lowest triplet and the singlet above it is small enough for the molecule to show a pronounced TADF effect. A calculation for example molecule 1 as part of a TD-DFT calculation (functional B3LYP; basis set 6-31G(d,p)) shows that this energy difference for the optimized triplet geometry with ΔE (S ₁ - T ₁ ) = 75 cm _-1 . Thus example molecule 1 represents a good TADF emitter.

The chemical synthesis of example molecule 1 is illustrated in the following reaction scheme:

Reactants and reaction conditions:

• (1) (tC ₄ H ₉ - C ₆ H ₅ ) ₂ NH, Pd(CH ₃ COO) ₂ , P[(C(CH ₃ ) ₃ ] ₃ , (CH ₃ ) ₃ CONa, 90 °C, 19 h .
• (2) K ₄ [Fe(CN) ₆ ], Pd(CH ₃ COO) ₂ , P[(C(CH ₃ ) ₃ ] ₃ , Na ₂ CO ₃ , (CH ₃ ) ₂ NCHO, 140 °C, 12 H.

The synthesis can also be carried out according to the following more detailed reaction scheme:

• (1) CH₃CO₂Na, 230°C, 3 h.
• (2) HPO₂, I₂, roter P, CH₃COOH, 80 °C, 24 h.
• (3) (H₃PO₄)_n, 175 °C, 5 h.
• (4) Al[OCH(CH₃)₂]₃, 275 °C, 3 h.
• (5) (t-C₄H₉- C₆H₅)₂NH, Pd(CH₃COO)₂, P[(C(CH₃)₃]₃, (CH₃)₃CONa, 90 °C, 19 h.
• (6) K₄[Fe(CN)₆], Pd(CH₃COO)₂, P[(C(CH₃)₃]₃, Na₂CO₃, (CH₃)₂NCHO, 140 °C, 12 h.

Reactants and reaction conditions:

• (1) CH3 _CO2 Na, 230°C, ₃ h.
• (2) HPO ₂ , I ₂ , red P, CH ₃ COOH, 80 °C, 24 h.
• (3) (H ₃ PO ₄ ) _n , 175 °C, 5 h.
• (4) Al[OCH(CH ₃ ) ₂ ] ₃ , 275 °C, 3 h.
• (5) (tC ₄ H ₉ - C ₆ H ₅ ) ₂ NH, Pd(CH ₃ COO) ₂ , P[(C(CH ₃ ) ₃ ] ₃ , (CH ₃ ) ₃ CONa, 90 °C, 19 h .
• (6) K ₄ [Fe(CN) ₆ ], Pd(CH ₃ COO) ₂ , P[(C(CH ₃ ) ₃ ] ₃ , Na ₂ CO ₃ , (CH ₃ ) ₂ NCHO, 140 °C, 12 H.

Chemical analyzes:

R _f (hexane/ethyl acetate 10:1): 0.52. ₁ H NMR (CDCl ₃ , 300 MHz, δ ppm): 1.31 (s, 18 H), 3.13 (m, 4H), 4.05 (s, 2H), 6.84 (dd, J=3.6 Hz, J=12.0 Hz, 1H), 6.90 (s, 1H), 6.95 (s, 1H), 6.95 (d, J=9Hz, 5H), 7.22 (d, J=9Hz, 4H), 7.55 (s, 2H). ₁₃ C-NMR (300MHz _CDCl3 , δppm): 30.72 (CH2), 31.46 (CH3), 32.80 (CH2), 34.31 (CH2), 40.56 (Cquat), 113.16 (Cquat), 113.73 (Cquat), 115.59 (Cquat), 122.35 (Cquat), 123.48 (CH), 123.78 (Cquat), 126.03 (CH), 130.57 (Cquat), 130.94 (CH), 133.86 (CH), 134.48 (CH), 136.63 (Cquat), 144.91 (Cquat), 145.40 (Cquat), 145.69 (Cquat), 146.31 (Cquat).

MS (ES - MS = Electrospray Mass Spectrometry) m/z: 523 (M ₊ ). MS (HR - ES - MS = high resolution electrospray mass spectrometry) m/z: C37 _H37 N3 yields: _523.2979 , found: _523.2980 (M ₊ ). C ₃₇ H ₃₇ N ₃ yields: C 84.86, H 7.12, N 8.02%, found: C 84.54, H 7.36, N 7.90%.

Example molecule 1 can be dissolved in many organic solvents, e.g. B. in dichloromethane (CH ₂ Cl ₂ ), toluene, n-hexane, n-octane, tetrahydrofuran (THF), acetone, dimethylformamide (DMF), acetonitrile, ethanol, methanol, xylene or benzene. The good solubility in dichloromethane also enables it to be doped into polymethyl methacrylate (PMMA) or polystyrene (PS).

The emitter material according to example 1 can be sublimated (temperature 170 °C; pressure 10 _-3 mbar.)

Photophysical measurements of example molecule 1 in PMMA or PS (with a doping concentration of c≈1% by weight) demonstrate the occurrence of a TADF and favorable emission properties. At very low temperatures, e.g. B. at T = 2 K, a thermal activation is not possible. The emission shows two very different decay times, namely a very short component, which corresponds to the S ₁ → S ₀ - fluorescence transition with about 4 ns in PMMA and 25 ns in PS and a very long component, which corresponds to the phosphorescence according to the T ₁ → S ₀ transition is associated with τ(phos) ≈ 550 ms in PMMA and τ(phos) ≈ 450 ms in PS. (Note: The sample was purged with nitrogen.).

In 4 the corresponding time-resolved emission spectra are shown in PS, ie the short-term spectrum without time delay (t = 0 ns) with a detection time window of Δt = 100 ns, which is the corresponds to fluorescence, and the long-term spectrum (t = 500 µs and Δt = 900 ms) corresponding to phosphorescence. Using these spectra, the energy difference ΔE(S ₁ - T ₁ ) can be roughly estimated if it is assumed that the corresponding 0-0 transitions are reflected in the intersections of the high-energy (extrapolated) flanks of the emission curves with the abscissa. This results in a ΔE(S ₁ - T ₁ ) value of about 100 cm _-1 . This also shows that example molecule 1 represents a TADF substance.

An increase in temperature to T = 300 K leads to a drastic change in the spectra and the decay behavior, which already supports the occurrence of a TADF. 5 shows time-resolved emission spectra of example molecule 1 dissolved in PS for the short-lived region (spontaneous fluorescence) and the long-lived region. Since both spectra have largely the same peak positions, the long-lived component can also be interpreted as fluorescence - in this case as TADF emission. The fluorescence decay time remains around 4 ns in PMMA and 25 ns in PS, but the long component is greatly reduced, to ≈ 10 µs in PMMA and also ≈ 10 µs in PS.

A comparison of the emission quantum yields at T = 300 K under nitrogen flushing (of the sample doped in PMMA) with the value found under ambient air is meaningful. The values are Φ _PL (nitrogen) = 40% and Φ _PL (air) = 25%. This decrease shows that the triplet state is involved in the emission process because atmospheric oxygen usually only causes the quenching of a long-lived triplet state (see AM Prokhorov et al., J. Am. Chem. Soc. 2014, 136, 9637 ). Since triplet occupancy is a prerequisite for the occurrence of a TADF, this behavior again suggests that example molecule 1 has the desired TADF property. Note: The emission maximum in PMMA is at T = 300 K in the blue-white region at A(max) = 475 nm (CIE x: 0.198; y: 0.287) and in PS at T = 300 K in the blue region at A( max) = 450 nm (CIE x: 0.174; y: 0.154).

The thermal activation energy ΔE(S ₁ - T ₁ ) can also be determined well if the emission in the liquid phase is analyzed photophysically. Therefore, investigations were carried out on the example molecule 1, dissolved in toluene (with a concentration of c ≈ 10 _-5 mol/l). It should be pointed out here that the simple measurements of the emission quantum yields again—as explained above—can also be expected to occur for the molecule dissolved in toluene, because the emission quantum yields are significantly reduced in air. The corresponding measured values are Φ _PL (nitrogen) = 30% and Φ _PL (air) = 5%.

The investigations were carried out in a temperature range in which no phase change occurs for toluene and the sample remains liquid. The temperature range of about 200 K to 300 K is well suited.

6 shows time-resolved emission spectra of example molecule 1 dissolved in toluene for the short-lived region (spontaneous fluorescence) and the long-lived region. Since both spectra have largely the same peak positions, the long-lived component can also be interpreted as fluorescence - in this case as TADF emission.

The decay behavior of the long-lived component of the emission of example molecule 1 dissolved in toluene can be measured well for various temperatures. A largely monoexponential decay is observed. The corresponding measured values are in 7 shown as an Arrhenius plot (Boltzmann plot). Equation 3 can be approximately expressed for the experimentally determined emission decay time τ _exp using Equation 2. This results in (see also C. Baleizao, MN Berberan-Santos, J. Chem. Phys., 2007, 126, 204510): $$\text{ln}\left(\frac{1}{{\mathrm{\tau }}_{\text{ex}}}\right)=\text{A}-\frac{\mathrm{\Delta }E\left({\text{<figure-callout id="1" label="S" filenames="DE102016106103B4\_0049.png,DE102016106103B4\_0050.png" state="{{state}}">S</figure-callout>}}_1-{\text{T}}_1\right)}{{\text{k}}_{\text{B}}T}$$

Here A is a constant.

Using Equation 3, the measurement points can be fitted by a straight line. The slope of the straight line gives an activation energy of ΔE(S ₁ - T ₁ ) = 85 cm _-1 . Thus, the occurrence of a TADF for example molecule 1 is experimentally proven. Corresponding results are also obtained for the TADF behavior of example molecule 1 dissolved in PMMA.

It should be emphasized that this also shows that the calculated energy difference with ΔE(S ₁ -T ₁ ) = 75 cm _-1 (see caption to 4 ) is in good agreement with the experimentally determined activation energy.

example 2

In the following example molecule 2 is discussed in more detail. In the 8th Frontier orbitals shown indicate that HOMO and LUMO are located in distinctly different spatial regions of the molecule. This already suggests that the splitting between the lowest triplet and the singlet above it is small enough for the molecule to show a pronounced TADF effect. A calculation for example molecule 2 as part of a TD-DFT calculation (functional B3LYP; basis set 6-31G(d,p)) shows that this energy difference for the optimized triplet geometry ΔE(S ₁ - T ₁ ) = 85 cm is _-1 . Thus example molecule 2 represents a good TADF emitter.

The chemical synthesis of example molecule 2 is illustrated in the following reaction scheme.

• (1) CH₃CO₂Na, 230 °C, 3 h.
• (2) HPO₂, I₂, roter P, CH₃COOH, 80 °C, 24 h.
• (3) (H₃PO₄)_n, 175 °C, 5 h.
• (4) Al[OCH(CH₃)₂]₃, 275 °C, 3 h.
• (5) (t-C₄H₉- C₆H₅)₂NH, Pd(CH₃COO)₂, P[(C(CH₃)₃]₃, (CH₃)₃CONa, 90 °C, 19 h.
• (6) K₄[Fe(CN)₆], Pd(CH₃COO)₂, P[(C(CH₃)₃]₃, Na₂CO₃, (CH₃)₂NCHO, 140 °C, 12 h.

Reactants and reaction conditions:

• (1) CH ₃ CO ₂ Na, 230 °C, 3 h.
• (2) HPO ₂ , I ₂ , red P, CH ₃ COOH, 80 °C, 24 h.
• (3) (H ₃ PO ₄ ) _n , 175 °C, 5 h.
• (4) Al[OCH(CH ₃ ) ₂ ] ₃ , 275 °C, 3 h.
• (5) (tC ₄ H ₉ - C ₆ H ₅ ) ₂ NH, Pd(CH ₃ COO) ₂ , P[(C(CH ₃ ) ₃ ] ₃ , (CH ₃ ) ₃ CONa, 90 °C, 19 h .
• (6) K ₄ [Fe(CN) ₆ ], Pd(CH ₃ COO) ₂ , P[(C(CH ₃ ) ₃ ] ₃ , Na ₂ CO ₃ , (CH ₃ ) ₂ NCHO, 140 °C, 12 H.

Example 3

In the following, the molecule shown under Example 3 is discussed in more detail. In the 9 Frontier orbitals shown indicate that HOMO and LUMO are located in distinctly different spatial regions of the molecule. This already suggests that the splitting between the lowest triplet and the singlet above it is small enough for the molecule to show a pronounced TADF effect. A calculation for example molecule 3 as part of a TD-DFT calculation (functional B3LYP; basis set 6-31G(d,p)) shows that this energy difference for the optimized triplet geometry with ΔE (S ₁ - T ₁ ) = 55 cm _-1 . Thus example molecule 3 represents a good TADF emitter.

The chemical synthesis of example molecule 3 is illustrated in the following reaction scheme.

• (1) CH₃CO₂Na, 230 °C, 3 h.
• (2) HPO₂, I₂, roter P, CH₃COOH, 80 °C, 24 h.
• (3) (H₃PO₄)_n, 175 C, 5 h.
• (4) (C₂H₅)₂O, 30 °C, 24 h. NH₄Cl, H₂O.; F₃CCO₂H, 3 h, 50 °C.
• (5) Carbazol, Pd(CH₃COO)₂, P[(C(CH₃)₃]₃, (CH₃)₃CONa, 90 °C, 19 h.
• (6) K₄[Fe(CN)₆], Pd(CH₃COO)₂, P[(C(CH₃)₃]₃, Na₂CO₃, (CH₃)₂NCHO, 140 °C, 12 h.

Reactants and reaction conditions:

• (1) CH ₃ CO ₂ Na, 230 °C, 3 h.
• (2) HPO ₂ , I ₂ , red P, CH ₃ COOH, 80 °C, 24 h.
• (3) (H ₃ PO ₄ ) _n , 175 C, 5 h.
• (4) (C2 _{H5 )2 O} , 30°C, 24 h. NH ₄ Cl, H ₂ O.; _F3CCO2H , ₃ h, 50°C.
• (5) Carbazole, Pd(CH ₃ COO) ₂ , P[(C(CH ₃ ) ₃ ] ₃ , (CH ₃ ) ₃ CONa, 90 °C, 19 h.
• (6) K ₄ [Fe(CN) ₆ ], Pd(CH ₃ COO) ₂ , P[(C(CH ₃ ) ₃ ] ₃ , Na ₂ CO ₃ , (CH ₃ ) ₂ NCHO, 140 °C, 12 H.

example 4

In the following, the example molecule 4 shown is discussed in more detail. In the 10 shown frontier orbitals show that HOMO and LUMO in clearly different spatial regions of the Mole are localized. This already suggests that the splitting between the lowest triplet and the singlet above it is small enough for the molecule to show a pronounced TADF effect. A calculation for example molecule 4 as part of a TD-DFT calculation (functional B3LYP; basis set 6-31G(d,p)) shows that this energy difference for the optimized triplet geometry ΔE(S ₁ - T ₁ ) = 88 cm is _-1 . Thus example molecule 4 represents a good TADF emitter.

The chemical synthesis of example molecule 4 is illustrated in the following reaction scheme.

• (1) CH₃CO₂Na, 230 °C, 3 h.
• (2) HPO₂, I₂, roter P, CH₃COOH, 80 °C, 24 h.
• (3) (H₃PO₄)_n, 175 °C, 5 h.
• (4) Al[OCH(CH₃)₂]₃, 275 °C, 3 h.
• (5) (t-C4H₉- C₆H₅)₂NH, Pd(CH₃COO)₂, P[(C(CH₃)₃]₃, (CH₃)₃CONa, 90 °C, 19 h.
• (6) K₄[Fe(CN)₆], Pd(CH₃COO)₂, P[(C(CH₃)₃]₃, Na₂CO₃, (CH₃)₂NCHO, 140 °C, 12 h.

Reactants and reaction conditions:

• (1) CH ₃ CO ₂ Na, 230 °C, 3 h.
• (2) HPO ₂ , I ₂ , red P, CH ₃ COOH, 80 °C, 24 h.
• (3) (H ₃ PO ₄ ) _n , 175 °C, 5 h.
• (4) Al[OCH(CH ₃ ) ₂ ] ₃ , 275 °C, 3 h.
• (5) (t-C4H ₉ - C ₆ H ₅ ) ₂ NH, Pd(CH ₃ COO) ₂ , P[(C(CH ₃ ) ₃ ] ₃ , (CH ₃ ) ₃ CONa, 90 °C, 19 h .
• (6) K ₄ [Fe(CN) ₆ ], Pd(CH ₃ COO) ₂ , P[(C(CH ₃ ) ₃ ] ₃ , Na ₂ CO ₃ , (CH ₃ ) ₂ NCHO, 140 °C, 12 H.

Example 5

In the following, the example molecule 5 shown is discussed in more detail. In the 11 Frontier orbitals shown indicate that HOMO and LUMO are located in distinctly different spatial regions of the molecule. This already suggests that the splitting between the lowest triplet and the singlet above it is small enough for the molecule to show a pronounced TADF effect. A calculation for example molecule 5 as part of a TD-DFT calculation (functional B3LYP; basis set 6-31G(d,p)) shows that this energy difference for the optimized triplet geometry with ΔE (S ₁ - T ₁ ) = 150 cm _-1 . Thus example molecule 5 represents a good TADF emitter.

The chemical synthesis of example molecule 5 is illustrated in the following reaction scheme.

• (1) CH₃CO₂Na, 230 °C, 3 h.
• (2) HPO₂, I₂, roter P, CH₃COOH, 80 °C, 24 h.
• (3) (H₃PO₄)_n, 175 °C, 5 h.
• (4) Al[OCH(CH₃)₂]₃, 275 °C, 3 h.
• (5) (t-C₄H₉- C₆H₅)₂NH, Pd(CH₃COO)₂, P[(C(CH₃)₃]₃, (CH₃)₃CONa, 90 °C, 19 h.
• (6) K₄[Fe(CN)₆], Pd(CH₃COO)₂, P[(C(CH₃)₃]₃, Na₂CO₃, (CH₃)₂NCHO, 140 °C, 12 h.

Reactants and reaction conditions:

• (1) CH ₃ CO ₂ Na, 230 °C, 3 h.
• (2) HPO ₂ , I ₂ , red P, CH ₃ COOH, 80 °C, 24 h.
• (3) (H ₃ PO ₄ ) _n , 175 °C, 5 h.
• (4) Al[OCH(CH ₃ ) ₂ ] ₃ , 275 °C, 3 h.
• (5) (tC ₄ H ₉ - C ₆ H ₅ ) ₂ NH, Pd(CH ₃ COO) ₂ , P[(C(CH ₃ ) ₃ ] ₃ , (CH ₃ ) ₃ CONa, 90 °C, 19 h .
• (6) K ₄ [Fe(CN) ₆ ], Pd(CH ₃ COO) ₂ , P[(C(CH ₃ ) ₃ ] ₃ , Na ₂ CO ₃ , (CH ₃ ) ₂ NCHO, 140 °C, 12 H.

Example 6

In the following, the example molecule 6 shown is discussed in more detail. In the 12 Frontier orbitals shown indicate that HOMO and LUMO are located in distinctly different spatial regions of the molecule. This already suggests that the splitting between the lowest triplet and the singlet above it is small enough for the molecule to show a pronounced TADF effect. A calculation for example molecule 6 as part of a TD-DFT calculation (functional B3LYP; basis set 6-31G(d,p)) shows that this energy difference for the optimized triplet geometry with ΔE (S ₁ - T ₁ ) = 30 cm _-1 . Thus example molecule 6 represents a good TADF emitter.

Example 7

In 13 the frontier orbitals HOMO and LUMO are shown for example molecule 7. Since they are localized in distinctly different spatial regions of the molecule, it can be expected that the splitting between the lowest triplet and the singlet above it is small enough for the molecule to show a pronounced TADF effect. A calculation for example molecule 5 in the context of a TD-DFT calculation (functional B3LYP; basis set 6-31G(d,p)) indeed shows that this energy difference for the optimized triplet geometry ΔE(S ₁ - T ₁ ) = 550 cm _-1 . Thus example molecule 7 represents a good TADF emitter.

The chemical synthesis of example molecule 7 is illustrated in the following reaction scheme:

• (1) CH₃CO₂Na, 230 °C, 3 h.
• (2) HI (57 prozentige Wasserlösung), roter P, 80 °C, 24 h.
• (3) (H₃PO₄)_n, 175 °C, 5 h.
• (4) Al[OCH(CH₃)₂]₃, 275 °C, 3 h.
• (5) (CH₃)₂NH, Pd(CH₃COO)₂, P[(C(CH₃)₃]₃, (CH₃)₃CONa, 90 °C, 19 h.

Beispiel 8 (Vergleichsbeispiel)

Reactants and reaction conditions:

• (1) CH ₃ CO ₂ Na, 230 °C, 3 h.
• (2) HI (57% water solution), red P, 80 °C, 24 h.
• (3) (H ₃ PO ₄ ) _n , 175 °C, 5 h.
• (4) Al[OCH(CH ₃ ) ₂ ] ₃ , 275 °C, 3 h.
• (5) (CH ₃ ) ₂ NH, Pd(CH ₃ COO) ₂ , P[(C(CH ₃ ) ₃ ] ₃ , (CH ₃ ) ₃ CONa, 90 °C, 19 h.

Example 8 (comparative example)

In the 14 Frontier orbitals shown indicate that HOMO and LUMO are located in distinctly different spatial regions of the molecule. This already suggests that the split between between the lowest triplet and the singlet above it is small enough for the molecule to show a pronounced TADF effect. A calculation for example molecule 8 as part of a TD-DFT calculation (functional B3LYP; basis set 6-31G(d,p)) shows that this energy difference for the optimized triplet geometry with ΔE(S ₁ - T ₁ ) = 540 cm _-1 . Thus example molecule 8 represents a good TADF emitter.

The chemical synthesis of example molecule 8 is illustrated in the following reaction scheme.

• (1) CH₃CO₂Na, 230 °C, 3 h.
• (2) HI (57 prozentige Wasserlösung), roter P, 80 °C, 24 h.
• (3) CH₂N₂, SO₂Cl₂, 80 °C, 2 h; (CH₃)₃COH, C₆H₅COOAg, Et₃N, 90 °C, 2 h.
• (4) (H₃PO₄)_n, 175 °C, 5 h.
• (5) Al[OCH(CH₃)₂]₃, 275 °C, 3 h.
• (6) (CH₃)₂NH, Pd(CH₃COO)₂, P[(C(CH₃)₃]₃, (CH₃)₃CONa, 90 °C, 19 h.
• (7) K₄[Fe(CN)₆], Pd(CH₃COO)₂, P[(C(CH₃)₃]₃, Na₂CO₃, (CH₃)₂NCHO, 140 °C, 12 h.

Reactants and reaction conditions:

• (1) CH ₃ CO ₂ Na, 230 °C, 3 h.
• (2) HI (57% water solution), red P, 80 °C, 24 h.
• (3) CH ₂ N ₂ , SO ₂ Cl ₂ , 80 °C, 2 h; (CH ₃ ) ₃ COH, C ₆ H ₅ COOAg, Et ₃ N, 90 °C, 2 h.
• (4) (H ₃ PO ₄ ) _n , 175 °C, 5 h.
• (5) Al[OCH(CH ₃ ) ₂ ] ₃ , 275 °C, 3 h.
• (6) (CH ₃ ) ₂ NH, Pd(CH ₃ COO) ₂ , P[(C(CH ₃ ) ₃ ] ₃ , (CH ₃ ) ₃ CONa, 90 °C, 19 h.
• (7) K ₄ [Fe(CN) ₆ ], Pd(CH ₃ COO) ₂ , P[(C(CH ₃ ) ₃ ] ₃ , Na ₂ CO ₃ , (CH ₃ ) ₂ NCHO, 140 °C, 12 H.

example 9

In 15 the frontier orbitals HOMO and LUMO are shown for example molecule 9. Since they are localized in distinctly different spatial regions of the molecule, it can be expected that the splitting between the lowest triplet and the singlet above it is small enough for the molecule to show a pronounced TADF effect. A calculation for example molecule 9 in the context of a TD-DFT calculation (functional B3LYP; basis set 6-31G(d,p)) indeed shows that this energy difference for the optimized triplet geometry ΔE(S ₁ - T ₁ ) = 550 cm _-1 . Thus example molecule 9 represents a good TADF emitter.
Example 10 (comparative example)

In 16 the frontier orbitals HOMO and LUMO are shown for example molecule 10. Since they are localized in distinctly different spatial regions of the molecule, one can already expect that the splitting between the lowest triplet and the singlet above it is small enough for the molecule to show a pronounced TADF effect. A calculation for example molecule 10 as part of a TD-DFT calculation (functional B3LYP; basis set 6-31G(d,p)) shows that this energy difference for the optimized ground state geometry ΔE(S ₁ - T ₁ ) = 140 cm _-1 amounts to. Thus example molecule 10 represents a good TADF emitter.

Example 11 (comparative example)

In 17 the frontier orbitals HOMO and LUMO are shown for example molecule 11. Since they are localized in distinctly different spatial regions of the molecule, it can be expected that the splitting between the lowest triplet and the singlet above it is small enough for the molecule to show a pronounced TADF effect. A calculation for example molecule 11 in the context of a TD-DFT calculation (functional B3LYP; basis set 6-31 G(d,p)) indeed shows that this energy difference for the optimized triplet geometry ΔE(S ₁ -T ₁ ) = 420 cm _-1 . Thus example molecule 11 represents a good TADF emitter.

Example 12

In 18 the frontier orbitals HOMO and LUMO are shown for example molecule 12. Since they are localized in distinctly different spatial regions of the molecule, the splitting between the lowest triplet and the singlet above it can be expected to be small enough for the molecule shows a pronounced TADF effect. A calculation for example molecule 12 as part of a TDDFT calculation (functional B3LYP; basis set 6-31G(d,p)) shows that this energy difference for the optimized triplet geometry ΔE(S ₁ - T ₁ ) = 1250 cm _-1 amounts to. Thus example molecule 12 represents a good TADF emitter.

In 19 further example molecules according to the invention and not according to the invention are shown.

character list

• 1 . Energy level scheme illustrating the thermally activated delayed fluorescence (TADF) process. k _B T represents the thermal energy with k _B the Boltzmann constant and T the absolute temperature. The diagram shows the radiative TADF process and the radiative and non-radiative (corrugated) deactivation processes from the T ₁ state observable at low temperature. The process of spontaneous S ₁ → S ₀ fluorescence is not shown in the diagram.
• 2 . Schematic representation of the orbital energies of a molecule having a donor and an acceptor segment (DA molecule). Because of the non-conjugated bridges, the interactions between the donor and acceptor orbitals are small. Therefore, the electronic properties of the D and A segments can be approximately considered separately, that is, the D orbital energies are approximately equal to those of the corresponding free (unconnected) donor molecules and the A orbital energies are approximately equal to those of the corresponding free (unlinked) acceptor molecules. The HOMO energy of the isolated donor (electron rich) is much higher in energy than the HOMO energy of the isolated acceptor (electron poor). The LUMO of the isolated donor is much higher in energy than the LUMO of the acceptor. Accordingly, the HOMO of the DA molecule is predominantly located on the D segment and the LUMO of the DA molecule is predominantly located on the A segment.
• 3 : Isosurfaces of the frontier orbitals for example molecule 1 (see Example 1), HOMO: left, LUMO: right Geometry optimizations for the electronic ground state were carried out. Calculation methods: DFT and TD-DFT, functional: B3LYP, basis set: 6-31G (d,p), calculation software: Gaussian09. The calculations result in ΔE(S ₁ - T ₁ ) = 75 cm _-1 (So geometry). This value shows that example 1 represents a good TADFE emitter.
• 4 : Time-resolved emission spectra of example molecule 1 doped with about 1 wt% in PS at T = 2 K. The short-term spectrum is without time delay (t = 0 ns) with a detection time window of Δt = 100 ns and the long-term spectrum with a time delay of t = 500 µs (time window Δt = 900 ms). Excitation: short-term spectrum: 375 nm, pulse width 70 ps; Long-term spectrum, excitation: 365 nm, pulse width: 10 ns.
• 5 : Time-resolved emission spectra and decay times τ of example molecule 1 doped with about 1 wt t = 1 µs (time window Δt = 100 µs). Excitation: short-term spectrum: 375 nm, pulse width 70 ps; Long-term spectrum, excitation: 355 nm, pulse width: 2.9 ns.
• 6 : Time-resolved, normalized emission spectra of example substance 1 dissolved in toluene for the short-lived range (spontaneous fluorescence) and the long-lived range. Since both spectra have largely the same peak positions, the long-lived component can be interpreted as a TADF emission. The solution was degassed by introducing nitrogen over 120 minutes. Excitation 355 nm with a pulse duration of 2.9 ns.
• 7 : Boltzmann plot according to Equation 3 for the long-lived components of the corresponding decay times of the emission of example molecule 1 dissolved in toluene. The fit leads to an activation energy ΔE(S ₁ - T ₁ ) = (85 ± 5) cm _-1 .
• 8th : Isosurfaces of the frontier orbitals for example molecule 2 (see example 2), HOMO: left, LUMO: right Geometry optimizations were carried out for the lowest triplet state T ₁ . Calculation methods: DFT and TD-DFT, functional: B3LYP, basis set: 6-31G(d,p), calculation software: Gaussian09. The calculations result in ΔE(S ₁ - T ₁ ) = 85 cm _-1 . Both values show that example 2 represents a good TADF emitter.
• 9 : Isosurfaces of the frontier orbitals for the example molecule 3 (see Example 3), HOMO: left, LUMO: right Geometry optimizations were carried out for the lowest triplet state T ₁ . Calculation methods: DFT and TD-DFT, functional: B3LYP, basis set: 6-31G(d,p), calculation software: Gaussian09. The calculations result in ΔE(S ₁ - T ₁ ) = 55 cm _-1 . This value shows that Example 3 represents a good TADF emitter.
• 10 : Isosurfaces of the frontier orbitals for the example molecule 4 (see example 4), HOMO: left, LUMO: right Geometry optimizations were carried out for the lowest triplet state T ₁ . Calculation methods: DFT and TD-DFT, functional: B3LYP, basis set: 6-31G(d,p), calculation software: Gaussian09. The calculations result in ΔE(S ₁ - T ₁ ) = 88 cm _-1 . This value shows that Example 4 represents a good TADF emitter.
• 11 : Isosurfaces of the frontier orbitals for the example molecule 5 (see Example 5), HOMO: left, LUMO: right. Geometry optimizations were made for the lowest triplet state T ₁ . Calculation methods: DFT and TD-DFT, functional: B3LYP, basis set: 6-31G(d,p), calculation software: Gaussian09. The calculations result in ΔE(S ₁ - T ₁ ) = 150 cm _-1 . This value shows that Example 5 represents a good TADF emitter.
• 12 : Isosurfaces of the frontier orbitals for the example molecule 6 (see example 6), HOMO: left, LUMO: right Geometry optimizations were carried out for the electronic ground state So and for the lowest triplet state T ₁ . Calculation methods: DFT and TD-DFT, functional: B3LYP, basis set: 6-31G(d,p), calculation software: Gaussian09. The calculations result in ΔE(S ₁ - T ₁ ) = 35 cm _-1 (So geometry) and 30 cm _-1 (T ₁ geometry). Both values show that Example 6 represents a good TADF emitter.
• 13 : Isosurfaces of the frontier orbitals for the example molecule 7 (see example 7), HOMO: left, LUMO: right A geometry optimization for the electronic Ti state was carried out. Calculation methods: DFT and TD-DFT, functional: B3LYP, basis set: 6-31G(d,p), calculation software: Gaussian09. The calculation gives ΔE(S ₁ - T ₁ ) = 550 cm _-1 , ie the example molecule 7 represents a good TADF emitter.
• 14 : Isosurfaces of the frontier orbitals for the example molecule 8 (see example 8), HOMO: left, LUMO: right Geometry optimizations were carried out for the lowest triplet state T ₁ . Calculation methods: DFT and TD-DFT, functional: B3LYP, basis set: 6-31G(d,p), calculation software: Gaussian09. The calculations result in ΔE(S ₁ - T ₁ ) = 540 cm _-1 (T ₁ geometry). This value shows that example 8 represents a good TADFE emitter.
• 15 : Isosurfaces of the frontier orbitals for the example molecule 9 (see example 9), HOMO: left, LUMO: right The geometry was optimized for the lowest triplet state T ₁ . Calculation methods: DFT and TD-DFT, functional: B3LYP, basis set: 6-31G(d,p), calculation software: Gaussian09. The calculation gives ΔE(S ₁ -T ₁ ) = 550 cm _-1 (T ₁ geometry). This value shows that Example 9 represents a good TADF emitter.
• 16 : Isosurfaces of the frontier orbitals for the example molecule 10 (see Example 10), HOMO: left, LUMO: right A geometry optimization for the electronic ground state was carried out. Calculation methods: DFT and TD-DFT, functional: B3LYP, basis set: 6- 31G(d,p), calculation software: Gaussian09. The calculation gives ΔE(S ₁ -T ₁ )=140 cm _-1 , ie the example molecule 10 represents a good TADF emitter.
• 17 : Isosurfaces of the frontier orbitals for the example molecule 11 (see Example 11), HOMO: left, LUMO: right A geometry optimization for the electronic Ti state was carried out. Calculation methods: DFT and TD-DFT, functional: B3LYP, basis set: 6-31G(d,p), calculation software: Gaussian09. The calculation gives ΔE(S ₁ - T ₁ ) = 420 cm _-1 , which means that example molecule 11 is a good TADF emitter.
• 18 : Isosurfaces of the frontier orbitals for the example molecule 12 (see Example 12), HOMO: left, LUMO: right The geometry was optimized for the lowest triplet state T ₁ . Calculation methods: DFT and TD-DFT, functional: B3LYP, basis set: 6-31G(d,p), calculation software: Gaussian09. The calculation gives ΔE(S ₁ - T ₁ ) = 1250 cm _-1 (T ₁ geometry). This value shows that Example 12 represents a good TADF emitter.
• 19 : Representation of structures of further molecules according to the invention and comparison molecules, where formulas 13-28, 30-33 and 36-38 are according to the invention, and where formulas 29, 34-35 and 39-64 are comparison molecules.

Claims (7)

Organic molecule for emitting light, in particular for use as an emitter in an optoelectronic device, comprising or consisting of a structure according to formula XVIII

with: Q1 to Q6 are independently selected from the group consisting of H, CH ₃ , C ₂ H ₅ , C ₃ H ₇ , C ₄ H ₉ , C ₅ H ₁₁ , C ₆ H ₁₃ , phenyl, tolyl, xylyl, benzyl, thienyl, azolyl, diazolyl, triazolyl, tetrazolyl, oxazolyl, oxadiazolyl, furanyl and carbazolyl group; where Q1 and Q2, Q3 and Q4, and Q5 and Q6 are optionally linked to one another, thereby forming a cycloalkyl or an aromatic spiro system; Alk1 to Alk10 are independently H or a straight or branched aliphatic group or a cycloalkyl group. Organic molecule for emitting light, in particular for use as an emitter in an optoelectronic device, comprising or consisting of a structure according to formula XIX

where the substituents are in claim 1 have the definitions mentioned. Organic molecule for emitting light, in particular for use as an emitter in an optoelectronic device, comprising or consisting of a structure according to one of the following formulas 1-7, 9, 12-28, 30-33 or 36-38

use of a molecule claim 1 until 3 for emitting light, in particular in an emitter layer in an opto-electronic device, in particular in an organic light-emitting diode (OLED). Method for producing an opto-electronic device, wherein a molecule according to claim 1 until 3 is used. Opto-electronic device comprising a molecule according to claim 1 until 3 . Opto-electronic device claim 6 , wherein the opto-electronic device is selected from the group consisting of organic light-emitting diodes (OLEDs), light-emitting electrochemical cells (LEECs or LECs), OLED sensors, in particular gas and vapor sensors that are not hermetically shielded from the outside, optical temperature sensors, organic solar cells (OSCs), organic field effect transistors, organic lasers, organic diodes, organic photodiodes and down conversion systems.

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