DE102017008794A1 - Materials for use in electronic devices - Google Patents

Abstract

The present application relates to a compound of the formula (I), a process for the preparation of the compound and its use in electronic devices, in particular as a hole transport, hole injection or matrix material in an organic light emitting device (OLED) or an organic photovoltaic device (OPV) , The present application further relates to organic electronic devices comprising such compounds in at least one layer.

Description

The present application relates to a compound of the formula (I), which is defined hereinafter, a process for the preparation of the compound and its use in electronic devices, in particular as a hole transport material, a hole injection material or a matrix material in an organic light emitting device (OLED) or an organic photovoltaic device (OPV).

In the context of this application, electronic devices are to be understood as so-called organic electronic devices which contain organic semiconductor materials as functional materials. In particular, these include OLEDs and / or OPVs.

The general structure and mode of operation of OLEDs and OPVs are known to those skilled in the art. In general, the term OLED is understood to mean electronic devices which comprise one or more layers which comprise organic compounds and emit light when electrical voltage is applied. The term OPV is generally understood to mean electronic devices comprising one or more layers comprising organic compounds that absorb light to generate electricity.

There is a great interest in improving the performance data, in particular the service life, efficiency and operating voltage, in electronic devices, in particular OLEDs and OPVs. In these aspects, it has not yet been possible to find a completely satisfactory solution.

Large impact on the performance of electronic devices has holes with hole transport function, for example hole injection layers, hole transport layers, electron barrier layers and emission layers. There is a constant search for new materials with hole transport and hole injection properties for use in these layers.

Typically, in these layers, organic materials of the amorphous type are used as materials having the hole-transporting or hole-injecting properties, for example, monotriarylamines, such as, for example JP 1995/053955 . WO 2006/123667 and JP 2010/222268 described, or bis- or other oligoamines, such as in US 7504163 or US 2005/0184657 described.

In the literature ( J. Hanna, Opt-Electron. Rev., 13, 295 (2005 ); H. lino, T. Usui, J. Hanna, Nat. Commun., 6, 6828 (2015 )), it is known that smectic liquid crystal (LC) materials have larger carrier mobilities (approximately in the range of 10 ^-3 cm ² / Vs - 10 cm ² / Vs) than the commonly used amorphous type organic materials (approximately ≤ 10 ^-3 cm ² / Vs). Nevertheless, smectic LC materials have not heretofore been used on a commercial basis for electronic devices such as OLEDs and OPVs. One of the main reasons for this is that such high carrier mobilities can not be achieved unless the LC molecules in the devices are properly aligned. However, there are not yet fully developed alignment techniques for practical use with respect to these devices.

In the case of smectic LC materials, higher carrier mobility develops in the direction perpendicular to the molecular axis. It is known that smectic LC molecules align themselves uniformly perpendicular to the surface of a substrate if they are applied to a substrate by spin-coating or thermal evaporation in vacuo ( H. lino, J. Hanna, Mol. Crys. Liq. Crys., 510, 259 (2009 ); H. lino, J. Hanna, J. Appl. Phys., 109, 074505 (2011 )). However, the perpendicular orientation is not an advantageous circumstance for OLEDs and OPVs because the electron current in the LC layer flows in the direction perpendicular to the layer surface. In this case, the LC molecules must be aligned parallel to the layer surface in order to obtain a high current.

To achieve parallel alignment of smectic LC materials JP 4857519 the use of a polyimide layer. However, insertion of an insulating layer such as polyimide is not acceptable for electronic devices such as OLEDs or OPVs.

Another technique for achieving parallel orientation is to thermally treat the LC material that has already been applied to the substrate, such as in FIG JP 2005-251414 explained. Accordingly, a layer applied to a substrate is heated once to its isotropic phase and then cooled to its smectic phase. After holding the smectic temperature for some time, the substrate is rapidly cooled to room temperature. However, there is no further description of the Conditions of thermal treatment before, and no further experimental examples are given. Thus, the effect of thermal treatment on vehicle mobility is not clear.

A similar thermal treatment is described by Haramoto et al. using a styryl type LC compound (Haramoto et al., Liquid Crystals, 32, 909 (2005 ); Haramoto et al., Liquid Crystals, 35, 675 (2008 )). Parallel orientation of the LC molecules is achieved by heating a LC layer applied to a substrate by thermal evaporation in vacuo for 10 minutes up to 200 ° C under a nitrogen atmosphere. According to Haramoto et al. For example, the density of current flowing in the LC layer of the Styryl-type LC compound after the thermal treatment has a value 10 ⁷ times higher than that without the thermal treatment.

As already mentioned, however, there is great interest in further improving the performance data, in particular the service life, efficiency and operating voltage, of electronic devices, in particular OLEDs and OPVs.

Accordingly, there is still a need for new smectic LC materials that have improved hole transport properties, such as hole mobility and hole conductivity, and that can be easily processed, i. h., which have a low smectic temperature, so that parallel alignment of the molecules with respect to the layer surface can be easily achieved, thereby enabling their practical use in electronic devices.

It is therefore an object of the present invention to provide a smectic LC material which is suitable for use in electronic devices, in particular as hole transport, hole injection or matrix material in OLEDs and OVPs, and which has increased hole mobility and hole conductivity.

The present inventors have surprisingly found that the aforementioned objects can be achieved by the compound of formula (I).

wobei:

• X für F, CF₃ oder CN steht und Y für H steht, oder X und Y miteinander verbunden sind, um einen anellierten Ring zu bilden, wobei die resultierende kondensierte polycyclische Gruppe aromatisch oder teilweise nicht aromatisch ist und 9 bis 14 Ringatome umfasst, wobei eines oder mehrere der Ringatome von einem anderen Element als Kohlenstoff sein können, und wobei ein oder mehrere Wasserstoffe, die in einer Position benachbart zu F an den anellierten Ring gebunden sind, durch eine Substitutionsgruppe substituiert sind, die aus F, CF₃ und CN ausgewählt ist, um eine lateral substituierte polycyclische Gruppe zu bilden;
• A für eine Oligothiophenstruktur der folgenden Formel (II) steht:
  
  wobei:
• n = 0 bis 4;
• R₁ ausgewählt ist aus der Gruppe bestehend aus linearem oder verzweigtem C4-C20-Alkyl, cyclischem C6-C10-Alkyl, C4-C20-Alkenyl, cyclischem C6-C8-Alkenyl, C4-C20-Alkinyl, C4-C20-Alkoxyl, C4-C20-Thioalkyl, cyclischem C4-C10-Alkoxyl, C4-C20-Alkenyloxy;
• R₂, R₂', R₃, R₃', R₄ und R₄' unabhängig ausgewählt sind aus der Gruppe bestehend aus H, linearem oder verzweigtem C1-C20-Alkyl, cyclischem C6-C20-Alkyl, C3-C20-Alkenyl, cyclischem C6-C20-Alkenyl, C3-C20-Alkinyl, C1-C20-Alkoxyl, C4-C20-Thioalkyl, C4-C20-Alkenyloxy; oder
• ein Paar von Gruppen R₂ und R₂', ein Paar von Gruppen R₃ und R₃' und/oder ein Paar von Gruppen R₄ und R₄' verbunden ist, um einen Alkyl-, Alkenyl-, Alkoxyl-, Thioalkyl- oder Oxothioalkylring zu bilden, der mit dem Thiophenring, an welchen das jeweilige Paar von Gruppen R₂ und R₂', R₃ und R₃' und/oder R₄ und R₄' gebunden ist, anelliert ist.

The present invention therefore provides a compound of the following formula (I):

in which:

• X is F, CF ₃ or CN and Y is H, or X and Y are joined together to form a fused ring, wherein the resulting fused polycyclic group is aromatic or partially nonaromatic and comprises 9 to 14 ring atoms, wherein may be one or more of the ring atoms of an element other than carbon, and wherein one or more hydrogens bonded to the fused ring in a position adjacent to F are substituted by a substitution group selected from F, CF ₃ and CN is to form a laterally substituted polycyclic group;
• A represents an oligothiophene structure represented by the following formula (II):
  
  in which:
• n = 0 to 4;
• R _{1 is} selected from the group consisting of linear or branched C 4 -C 20 -alkyl, cyclic C 6 -C 10 -alkyl, C 4 -C 20 -alkenyl, cyclic C 6 -C 8 -alkenyl, C 4 -C 20 -alkynyl, C 4 -C 20 -alkoxyl, C4-C20 thioalkyl, C4-C10 cyclic alkoxyl, C4-C20 alkenyloxy;
• R ₂ , R ₂ ', R ₃ , R ₃ ', R ₄ and R ₄ 'are independently selected from the group consisting of H, linear or branched C 1 -C 20 -alkyl, cyclic C 6 -C 20 -alkyl, C 3 -C 20- Alkenyl, cyclic C6-C20 alkenyl, C3-C20 alkynyl, C1-C20 alkoxyl, C4-C20 thioalkyl, C4-C20 alkenyloxy; or
• a pair of R ₂ and R ₂ 'groups, a pair of R ₃ and R ₃ ' groups and / or a pair of R ₄ and R ₄ 'groups to form an alkyl, alkenyl, alkoxyl, thioalkyl or oxo-thioalkyl ring fused to the thiophene ring to which the respective pair of groups R ₂ and R ₂ ', R ₃ and R ₃ ' and / or R ₄ and R ₄ 'is bonded.

The dashed line in formula (II) indicates the attachment of the oligothiophene structure to the phenyl ring of formula (I).

As used herein, the term "liquid crystal (LC)" refers to a material having liquid crystal mesophases in some temperature ranges (thermotropic LCs). The mesophases may be characterized by the order type of LC molecules (eg, smectic phase, nematic phase). By the term "liquid crystal (LC) compound" is meant a compound capable of inducing liquid crystal phase (or mesophase) behavior. Accordingly, the term "smectic liquid crystal (LC) compound" as used herein refers to a compound capable of inducing smectic phase behavior.

In the context of this application, a smectic LC material is to be understood as an LC material which has various smectic phases in a specific temperature range (smectic subphases). In general, smectic phases are defined by the molecules (the "smectic liquid crystals") being positionally ordered along one direction to thereby form well-defined layers. There are many different smectic subphases, all characterized by different location and orientation order types and degrees, and well known in the art. For example, the molecules in the smectic A phase (SmA) are oriented along the surface normal, while in the smectic C phase (SmC) they are tilted away.

In the context of the present application, a fused ring consists of two or three simple cycles which are fused together to result in a fused polycyclic group. Annulation between cycles is to be understood herein to mean that the cycles share at least one edge. Preferably, the simple cycles according to the present invention are five- or six-membered cycles, so that the resulting condensed polycyclic group consists entirely of fused five- or six-membered cycles or mixtures thereof.

In the context of the present application, a fused aromatic polycycle consists of two or three simple aromatic rings fused together. In the context of this invention, an aromatic cycle is understood to mean either an aromatic cycle comprising only carbon ring atoms, for example naphthyl or anthracenyl, or an aromatic cycle, where one or more of the ring atoms, preferably one or two, especially one of the ring atoms Ring atoms to an element other than carbon, d. H. a heteroatom, to thereby form a so-called heteroaromatic cycle. Preferably, the heteroatom of the heteroaromatic cycle is selected from N, Si, O and S, in particular N, O and S. In other words, a condensed aromatic polycycle in the context of this invention may also be a fused heteroaromatic polycycle consisting of two or three simple aromatic rings fused together, wherein at least one of the aromatic rings is a heteroaromatic cycle, for example, quinolinyl. Preferably, only one of the aromatic cycles is a heteroaromatic cycle. In particular, the one heteroaromatic cycle comprises exactly one heteroatom. Notably, the condensed aromatic polycycle according to the present invention comprises only carbon ring atoms, so that it is an aromatic hydrocarbyl group.

In the context of this invention, a condensed partially non-aromatic polycycle consists of two or three simple cycles fused together, wherein at least one of the simple cycles is a non-aromatic cycle and at least one is an aromatic cycle. For example, a simple aromatic cycle and a simple non-aromatic cycle are fused together, such as 1, 2,3,4-tetrahydronaphthalenyl, or two simple aromatic cycles and a simple non-aromatic cycle are fused together, such as 9,10-dihydrophenanthrenyl. By a non-aromatic cycle in the context of this invention is meant either a non-aromatic cycle comprising only carbon ring atoms or a non-aromatic cycle, where one or more of the ring atoms, preferably one or two, especially one of the ring atoms, is is a heteroatom. Preferably, the heteroatom is selected from N, O, Si and S, in particular N, O and S. Accordingly, in the context of this invention, a fused partially non-aromatic polycycle may also consist of two or three simple cycles fused together as defined above, wherein at least one of the simple cycles contains a heteroatom, such as 3,4-dihydro-2H- -1-benzopyranyl. Preferably, only one of the simple cycles contains one or more heteroatoms. In particular, the one heteroatom-containing simple cycle comprises exactly one heteroatom. Notably, the condensed partially non-aromatic polycycle of the present invention comprises only carbon ring atoms, so that it is a non-aromatic hydrocarbyl group.

When X and Y are joined together to form a fused ring, in accordance with the present invention, the resulting fused aromatic or partially non-aromatic polycyclic group comprises 9 to 14 ring atoms wherein one or more of the ring atoms is other than carbon, i. H. a heteroatom, can be. In a preferred embodiment of the present invention, one or two of the ring atoms may contain an element other than carbon, i. H. a heteroatom. In a particularly preferred embodiment of the present invention, exactly one of the ring atoms may contain an element other than carbon, i. H. a heteroatom. In other words, within the compound of formula (I), either each of the ring atoms of the fused polycyclic group is a carbon atom, or each of the ring atoms of the fused polycyclic group is a carbon atom, with one or more carbon atoms, preferably one or two carbon atoms, especially one Carbon atom, are replaced by a heteroatom or is.

In another preferred embodiment of the present invention, the resulting fused aromatic or partially non-aromatic polycyclic group comprises 9 or 10 ring atoms, preferably 10 ring atoms.

In a particularly preferred embodiment of the present invention, the resulting fused aromatic or partially non-aromatic polycyclic group comprises 9 or 10 carbon ring atoms, especially 10 carbon ring atoms.

If X and Y are joined together to form a fused ring, according to the present invention, one or more hydrogens bonded to the fused ring in a position adjacent to F are substituted by a substitution group selected from F, CF ₃ and CN is selected to form a laterally substituted polycyclic group. In a preferred embodiment of the present invention, the substitution group is F.

In the present application, the terms "substituent" and "substitution group" are used interchangeably.

In the context of the present application, the term "laterally substituted" is to be understood to mean that all substituents, ie substitution groups F, CF ₃ or CN, are located on the same side of the molecular structure with respect to the group F. With regard to the compounds of the formula (I), this means that when hydrogen is substituted in a position adjacent to the group F to the fused ring, the substituent groups F, CF ₃ and / or CN are used to unilaterally substitute the resulting condensed polycyclic group becomes. In other words, all substituents on the polycyclic group are on the same side with respect to a plane which i) is perpendicular to the plane created by the planar phenyl group of formula (I), and ii) which comprises the bonds of A to the phenyl group and of Y to the phenyl group of formula (I) (as shown in Scheme 1 below), provided that the substituents in a position adjacent to the group F are attached to the fused ring.

The term "adjacent" in the context of the present invention encompasses any position on the polycyclic group which is separated from the group F by 3 to 6 chemical bonds and consists of a secondary or tertiary carbon ring atom. Accordingly, the term "one or more hydrogens attached to the fused ring at a position adjacent to F" as used herein includes any hydrogen bonded to a carbon ring atom that is substituted by 3 to 6 chemical bonds is separated from the group F, provided that the carbon atom (s) are located on the same side of the molecular structure with respect to the group F as defined above. Scheme 1 shows the number of chemical bonds, the term "adjacent" being defined using an exemplary polycyclic group according to the invention. In this example, hydrogen atoms attached to the annulated ring in positions (ie, carbon atoms) separated from the initial group F by 3, 5, and 6 chemical bonds were substituted by F. The dashed line indicates the direction of the plane perpendicular to the plane created by the planar phenyl group of formula (I) (previously defined).

According to the present invention, the number of lateral substitution groups depending on the cycle (s) and the number of simple cycles fused together is preferably in the range of 2 to 6. Accordingly, in the context of the present invention, if only one six-membered cycle (ie, X and Y are not joined together to form a fused ring), a lateral substitution can be obtained, for example, when the number of lateral substitution groups is 2. For example, if a six- and a five-membered cycle are fused together, lateral substitution can be obtained in the context of the present invention if the number of lateral substitution groups is 2 or 3. For example, if two six-membered rings are fused together, lateral substitution can be obtained in the context of the present invention if the number of lateral substitution groups is in the range of 2 to 5. For example, if three six-membered rings are fused together, lateral substitution can be obtained in the context of the present invention if the number of lateral substitution groups is in the range of 3 to 6.

In the context of the present application, a "linear or branched C4-C20 alkyl" refers to a "linear or branched alkyl group of 4 to 20 carbon atoms". The same applies to the other groups denoted by R ₁ , R ₂ , R ₂ ', R ₃ , R ₃ ', R ₄ and R ₄ ', for example "cyclic C ₆ -C 10 -alkyl", among which a cyclic alkyl group with 6 to 10 carbon atoms, and so on. Professionals are familiar with this notation.

In the context of the present application, among a linear or branched C 1 -C 20 -alkyl, cyclic C 6 -C 20 -alkyl, C 3 -C 20 -alkenyl, cyclic C 6 -C 20 -alkenyl or C 3 -C 20 -alkynyl, preferably the methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl, cyclopentyl, neopentyl , n-hexyl, cyclohexyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, propenyl Butenyl, pentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, propynyl, butynyl, pentynyl, hexynyl or octynyl radicals.

Among a linear or branched C1-C20-alkoxyl, C4-C20-thioalkyl, cyclic C4-C10-alkoxyl or C4-C20-alkenyloxy is preferably methoxy, trifluoromethoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i Butoxy, s-butoxy, t-butoxy, n-pentoxy, s -pentoxy, 2-methylbutoxy, n-hexoxy, cyclohexyloxy, n-heptoxy, cycloheptyloxy, n-octyloxy, cyclooctyloxy, 2-ethylhexyloxy, pentafluoroethoxy, 2,2 , 2-trifluoroethoxy, butenyloxy, pentenyloxy, hexenyloxy, heptenyloxy, octenyloxy, n-butylthio, i-butylthio, s-butylthio, t-butylthio, n-pentylthio, s-pentylthio, n-hexylthio, cyclohexylthio, n-heptylthio, cycloheptylthio , n-octylthio, cyclooctylthio, 2-ethylhexylthio, trifluoromethylthio, pentafluoroethylthio, 2,2,2-trifluoroethylthio, ethenylthio, propenylthio, butenylthio, pentenylthio, cyclopentenylthio, hexenylthio, cyclohexenylthio, heptenylthio, cycloheptenylthio, octenylthio, cyclooctenylthio, ethynylthio, propynylthio, butynylthio , Pentynylthio, hexynylthio, heptynylthio or octynylthio.

In a preferred embodiment of the present invention, the fused polycyclic group is selected from naphthyl, anthracenyl, indenyl, dihydroindenyl, tetrahydronaphthalenyl, dihydronaphthalenyl, fluorenyl, dihydrophenanthrenyl, dihydrobenzopyranyl, dihydrobenzothiopyranyl, dibenzopyranyl, dibenzothiopyranyl, quinolinyl, isoquinolinyl.

(1) (2) (3)

(4) (5) (6)

(7) (8) (9)

(10) (11) (12)

(13) (14) (15)

(16) (17) (18)

(19) (20) (21) In a still more preferred embodiment of the present invention, the condensed laterally substituted polycyclic group is selected from the group consisting of formulas (1) to (21), wherein "(F)" means that either F or H in this position is the respective one Formula can be present:

(1) (2) (3)

(4) (5) (6)

(7) (8th) (9)

(10) (11) (12)

(13) (14) (15)

(16) (17) (18)

(19) (20) (21)

In a further preferred embodiment of the present invention in the compound of formula (I) X is F and Y is H or X and Y are joined together to form a fused aromatic ring, the resulting fused, laterally substituted polycyclic Group following is:

In another preferred embodiment of the present invention, n in the structure of formula (II) is 1 or 2. It is especially preferred that n = 1.

In a further preferred embodiment of the present invention, R ₁ in the structure of the formula (II) is a linear C 4 -C 20 -alkyl. In particular, R _{1 is} selected from n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl and n-dodecyl, and most preferably R _{1 is} n-octyl.

In yet another preferred embodiment of the present invention, R ₂ , R ₂ ', R ₃ , R ₃ ', R ₄ and R ₄ 'in the structure of formula (II) are H.

In an alternative embodiment of the present invention it is preferred that the alkyl, alkenyl, alkoxyl, thioalkyl or oxothioalkyl ring in the structure of formula (II) resulting from the annulation by any pair of R ₂ and R _{2 groups} ', R ₃ and R ₃ ' and / or R ₄ and R ₄ 'with the thiophene ring of the formula (II) results, to which the respective pair of groups R ₂ and R ₂ ', R ₃ and R ₃ 'and / or R ₄ and R ₄ 'is bonded, is selected from:

5-n-Octyl-5"-[7-(1,2,8-trifluornaphthyl)]-2,2':5',2"-terthiophen; oder

5-n-Octyl-5"-[6-(1,2-difluorphenyl)]-2,2':5',2"-terthiophen; oder

5-n-Octyl-5"'-[6-(1,2 -difluorphenyl)]-2,2':5',2":5",2'''-quarterthiophen; oder

5-n-Octyl-5'''-[7-(1,2,8-trifluornaphthyl)]-2,2':5',2":5",2'''-quarterthiophen.Preferably, the compound is according to the present invention

-terthiophene: "2 2.2 - - [7- (1,2,8-trifluornaphthyl)] '5''; 5-n-octyl-5 or

-terthiophene: "2 2.2 - - [6- (1,2-difluorophenyl)] '5''; 5-n-octyl-5 or

5-n-octyl-5 "'- [6- (1,2-difluorophenyl)] - 2,2': 5 ', 2": 5 ", 2''' - quaterthiophene;

5-n-octyl-5 '''- [7- (1,2,8-trifluornaphthyl)] - 2,2': 5 ', 2 ": 5", 2''' - quarterthiophen.

Notably, the compound according to the present invention is 5-n-octyl-5 "- [7- (1,2,8-trifluoronaphthyl)] - 2,2 ': 5', 2" -terthiophene.

The compound of formula (I) is preferably a liquid crystalline (LC) compound, especially a smectic liquid crystalline (LC) compound.

It has been found that a laterally substituted compound of formula (I), as defined herein, when heated to temperatures that are relatively low, may have various smectic phases. In addition, it has been found that a smectic LC compound of the formula (I) can have a smectic E phase which is stable at room temperature. In general, higher order smectic phases, such as the smectic E phase, are preferable because they tend to have larger carrier mobilities.

The synthesis of the compounds of the formula (I) can be carried out, for example, by using an organometallic coupling reaction; Suzuki clutch, Negishi clutch, Silent clutch, Kumada clutch and Hiyama clutch. Preferably, the organometallic coupling reaction is a Suzuki coupling. The processes and reaction conditions for this type of coupling reaction are known in the art.

Scheme 2 illustrates the synthetic route for the preparation of the compound of formula (I). It serves to illustrate the invention to those skilled in the art and should not be construed in a limiting sense. Those skilled in the art will be able to modify the illustrated synthetic route within the scope of their general skill or other ways, if deemed more advantageous.

In the following synthesis scheme, the compounds are shown in unsubstituted form. This does not exclude the presence of desired substituents in the processes.

The present application therefore also provides a process for the preparation of compounds of formula (I) which comprises reacting an oligothiophene derivative of formula (II) containing a boron-organic group with a group of formula (I) which has a leaving group in the Contains position of group A, encompassed by Suzuki coupling.

Suitable leaving groups (LG) are known in the art and may be, for example, bromine, iodine, chlorine and triflate. Suitable organoboron reactive groups are also known in the art and may be, for example, boronic or borinic acid derivatives, such as boronic esters or trifluoroborate.

Preferred catalysts, in particular for Suzuki coupling, are selected from Pd (0) complexes or Pd (II) salts. Preferred Pd (0) complexes are those having at least one phosphine ligand, for example Pd (Ph ₃ P) ₄ . Suzuki polymerization is carried out in the presence of a base, for example, sodium carbonate, potassium carbonate, lithium hydroxide, potassium phosphate, or an organic base such as tetraethylammonium carbonate or tetraethylammonium hydroxide.

It has been found that smectic LC compounds according to the present invention are suitable for use in electronic devices, especially in organic light emitting devices (OLEDs) and organic photovoltaic devices (OPVs), as hole transport, hole injection or matrix material.

The invention therefore provides the use of the compound of formula (I) in electronic devices. These electronic devices include without limitation organic field effect transistors (OFET), organic thin film transistors (OTFT), organic integrated circuits (OIC), logic circuits, capacitors, preferably semiconductor capacitors, in particular semiconductor capacitors in which the compound acts as a dielectric, radio frequency identification (RFID) Labels, devices or components, organic light emitting devices (OLED), organic light emitting transistors (OLET), organic light emitting electrochemical transistors, organic light emitting electrochemical cells (OLEC), organic field quench devices (OFQD), "organic plasmon emitting devices" ( Koller et al., Nature Photonics 2008, 1-4 ), electroluminescent displays, organic photovoltaic devices (OPV), organic solar cells (OSC), flexible OPVs and OSCs, dye-sensitized organic solar cells (ODSSC), photodiodes, organic laser diodes, photoconductors, organic photodetectors (OPD), organic photoreceptors, electrophotographic devices, electrophotographic Recording devices, organic storage devices, sensor devices, light emitting polymer diodes (PLED), Schottky diodes, planarizing layers, antistatic films, polymer electrolyte membranes (PEM), conductive substrates, conductive patterns, electrode materials in batteries, biosensors, biochips, safety markers and safety devices, and components or devices for detection and distinguishing DNA sequences, preferably organic light emitting diodes (OLEDs) and organic photovoltaic devices (OPVs).

The invention further provides the use of the compound of formula (I) as a hole transport material, hole injection material or matrix material, preferably in an organic light emitting diode or an organic photovoltaic device.

The invention further provides an electronic device comprising at least one layer containing the compound of formula (I). This electronic device is preferably selected from the aforementioned electronic devices well known to those skilled in the art. In particular, the electronic device is an organic light emitting device (OLED) or an organic photovoltaic device (OPV).

The term "layer" as used herein includes rigid or flexible coatings or layers on a carrier substrate or between two substrates.

According to the invention, an organic light-emitting device (OLED) preferably comprises an anode, a cathode and at least one emission layer, characterized in that at least one layer, which may be an emission layer, a hole transport layer or another layer, comprises the compound of the formula (I) contains.

Besides the cathode, the anode and the emission layer, the organic light-emitting device may further comprise further layers. These are, for example, each of one or more hole injection layers, hole transport layers, hole barrier layers, electron transport layers, electron injection layers, exciton barrier layers, interlayers, charge generation layers (IDMC 2003, Taiwan, Session 21 OLED (5), T. Matsumoto, T. Nakada, J. Endo, K Mori, N. Kawamura, A. Yokoi, J. Kido, Multiphoton Organic EL Device Having Charge Generation Layer) and / or organic or inorganic p / n junctions.

The order of the layers of the organic light-emitting device comprising the compound of formula (I) in at least one layer is preferably as follows:

Anode - hole injection layer - hole transport layer - optionally a further hole transport layer - optionally an electron barrier layer - emission layer - optionally a hole barrier layer - electron transport layer - electron injection layer - cathode. It is also possible that additional layers are present in the OLED.

The organic light-emitting device according to the invention may contain two or more emission layers. In this case, these emission layers preferably have a plurality of emission maxima between 380 nm and 750 nm in total, such that the overall result is white emission; in other words, various emission compounds that can fluoresce or phosphoresce and that emit blue, green, yellow, orange, or red light are used in the emission layers. In particular, three-layer systems, ie systems with three emission layers, are preferred, the three layers representing blue, green and orange or red emission (with regard to the basic structure see WO 2005/011013 ). Suitable phosphorescent and fluorescent emission compounds that can be used in organic light-emitting devices of the invention are listed below.

In a preferred embodiment of the present invention, the at least one layer containing the compound of formula (I) is selected from a hole transport layer and an emission layer.

A hole transport layer according to the present invention is a layer having a hole transport function between the anode and the emission layer.

In the context of the present application, hole injection layers and electron barrier layers are to be understood as specific embodiments of hole transport layers. A hole injection layer in the case of a plurality of hole transport layers between the anode and the emission layer is a hole transport layer directly adjacent to the anode and separated therefrom by only a single coating of the anode. An electron barrier layer in the case of a plurality of hole transport layers between the anode and the emission layer is the hole transport layer directly adjacent to the emission layer on the anode side. Therefore, according to the present invention, the compound of the formula (I) may also be present in the hole-injection layer or the electron-blocking layer or in both of them.

When the compound of the formula (I) is used as a hole transport material in a hole transport layer, a hole injection layer or an electron barrier layer, the compound may be used as a pure material, ie, in a proportion of 100% in the hole transport layer, or may be used in combination with a hole transport layer or several other compounds. In a preferred embodiment, the organic layer containing the compound of formula (I) then additionally contains one or more p-dopants. p-dopants used in accordance with the present invention are preferably those organic electron acceptor compounds capable of oxidizing one or more of the other compounds in admixture.

Particularly preferred embodiments of p-dopants are the compounds described in US Pat WO 2011/073149 . EP 1968131 . EP 2276085 . EP 2213662 . EP 1722602 . EP 2045848 . DE 102007031220 . US 8044390 . US 8057712 . WO 2009/003455 . WO 2010/094378 . WO 2011/120709 . US 2010/0096600 . WO 2012/095143 and DE 102012209523 be revealed.

Particularly preferred p-dopants are quinodimethane compounds, azaindenofluorenediones, azaphenalens, azatriphenylenes, I ₂ , metal halides, preferably transition metal halides, metal oxides, preferably metal oxides with at least one transition metal or main group 3 metal, and transition metal complexes, preferably complexes of Cu, Co, Ni, Pd and Pt with ligands containing at least one oxygen atom as a binding site. Furthermore, transition metal oxides, preferably oxides of rhenium, molybdenum and tungsten, and in particular Re ₂ O ₇ , MoO ₃ , WO ₃ and ReO ₃ , are given preference as dopants.

The p-dopants are preferably in a substantially homogeneous distribution in the p-doped layers. This can be achieved, for example, by co-evaporation of the p-dopant and the hole transport material matrix.

Preferably, the inventive OLED comprises two or more different hole transport layers. The compound of formula (I) may then be used in one or more or all of the hole transport layers. In one embodiment, the compound of formula (I) is used in exactly one hole transport layer, and other compounds, preferably aromatic amine compounds, are used in the other hole transport layers that are present.

In a further embodiment of the present invention, the compound of formula (I) is used in an emission layer as matrix material in combination with one or more emission compounds, that is, one or more phosphorescent emission compounds, and / or one or more fluorescent emission compounds.

The term "phosphorescent emission compounds" typically includes compounds in which the emission of light by a spin-prohibiting transition, for example, a transition from an excited triplet state or a state with a higher spin quantum number, for example, a quintet state causes becomes.

Suitable preferred phosphorescent emission compounds (= triplet emitters) are, in particular, compounds which emit light preferably in the visible range upon suitable excitation and also contain at least one atom of an atomic number of more than 20, preferably more than 38 and less than 84, in particular more than 56 and less than 80. Compounds containing copper, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, iridium, palladium, platinum, silver, gold or europium, and especially compounds containing iridium, platinum or copper, are preferred for use as phosphorescent emission compounds. In the context of the present invention, all luminescent iridium, platinum or copper complexes are considered to be phosphorescent emission compounds.

Examples of phosphorescent emission compounds are in the applications WO 00/70655 . WO 01/41512 . WO 02/02714 . WO 02/15645 . EP 1191613 . EP 1191612 . EP 1191614 . WO 05/033244 . WO 05/019373 and US 2005/0258742 to find. In general, all the phosphorescent complexes used for phosphorescent OLEDs according to the prior art and known to those skilled in the art of organic electroluminescent devices are suitable. It is also possible for those skilled in the art, without resorting to inventive skills, to use further phosphorescent complexes in combination with the compounds of formula (I) in organic electroluminescent devices.

Preferred fluorescent emission compounds are selected from the class of arylamines. In the context of this invention, an arylamine or an aromatic amine is to be understood as meaning a compound which contains three substituted or unsubstituted aromatic or heteroaromatic ring systems which are bonded directly to the nitrogen. Preferably, at least one of these aromatic or heteroaromatic ring systems is a fused ring system which has in particular at least 14 aromatic ring atoms. Preferred examples thereof are aromatic anthracene amines, aromatic anthracenediamines, aromatic pyrenamines, aromatic pyrenediamines, aromatic chrysenamines or aromatic ones Chrysenediamines. By an aromatic anthracene amine is meant a compound in which a diarylamino group is preferably attached in position 9 directly to an anthracene group. An aromatic anthracenediamine is understood to mean a compound in which two diarylamino groups, preferably in position 9, 10, are bonded directly to an anthracene group. Aromatic pyrenamines, pyrendiamines, chrysenamines and chrysenediamines are defined analogously, the diarylamino groups in the pyrene preferably being bonded in position 1 or positions 1, 6. Further preferred emission compounds are indenofluoreneamines or diamines, for example according to WO 2006/108497 or WO 2006/122630 Benzoindenofluoreneamines or diamines, for example according to WO 2008/006449 , and dibenzoindenofluoreneamines or diamines, for example according to WO 2007/140847 , and the indenofluorene derivatives with fused aryl groups, which in WO 2010/012328 be revealed. Likewise, the pyrenarylamines which are preferred in WO 2012/048780 and in WO 2013/185871 be revealed. Likewise, the in WO 2014/037077 Benzoindenofluoreneamines disclosed in U.S. Pat WO 2014/106522 disclosed benzofluorenamines and those in WO 2014/111269 disclosed extended benzoindenofluorenes.

The proportion of the matrix material in the emission layer in this case is between 50.0% by volume and 99.9% by volume, preferably between 80.0% by volume and 99.5% by volume and in particular between 92.0% by volume and 99.5% by volume % for fluorescent emission layers and between 85.0% and 97.0% by volume for phosphorescent emission layers.

Accordingly, the proportion of the emission compound is between 0.1% by volume and 50.0% by volume, preferably between 0.5% by volume and 20.0% by volume and in particular between 0.5% by volume and 8.0% by volume for fluorescent emission layers and between 3.0% by volume and 15.0% by volume for phosphorescent emission layers.

If the organic light-emitting device according to the invention contains two or more emission layers which may be different from each other, as already mentioned, then the compound of formula (I) may be used in one or more or all of the light-emitting layers.

An emission layer of an organic light emitting device may also include systems comprising a plurality of matrix materials (mixed matrix systems).

In an alternative embodiment of the present invention, the compounds of formula (I) are used as a component of mixed matrix systems. The mixed matrix systems preferably comprise two or three different matrix materials, in particular two different matrix materials. In this case, preferably, one of the two materials is a material having hole transporting properties, and the other material is a material having electron transporting properties. The compound of the formula (I) is preferably the matrix material having hole transport properties. However, the desired electron transport and hole transport properties of the mixed matrix components may also be principally or completely united in a single mixed matrix component, in which case the further mixed matrix component (s) perform other functions. The two different matrix materials may be present in a ratio of 1:50 to 1: 1, preferably 1:20 to 1: 1, more preferably 1:10 to 1: 1, and most preferably 1: 4 to 1: 1. One source with more detailed information about mixed matrix systems is logging in WO 2010/108579 ,

The mixed matrix systems may comprise one or more emission compounds, preferably one or more phosphorescent emission compounds. In general, mixed matrix systems are preferably used in phosphorescent organic electroluminescent devices.

Particularly suitable matrix materials for phosphorescent emission compounds that can be used in combination with the inventive compounds of the formula (I) as matrix components of a mixed matrix system are aromatic ketones, aromatic phosphine oxides or aromatic sulfoxides or sulfones, for example according to WO 2004/013080 . WO 2004/093207 . WO 2006/005627 or WO 2010/006680 , Triarylamines, carbazole derivatives, e.g. CBP (N, N-biscarbazolylbiphenyl), or the carbazole derivatives described in U.S. Pat WO 2005/039246 . US 2005/0069729 . JP 2004/288381 . EP 1205527 or WO 2008/086851 Indolocarbazole derivatives, for example according to WO 2007/063754 or WO 2008/056746 Indenocarbazole derivatives, for example according to WO 2010/136109 . WO 2011/000455 or WO 2013/041176 , Azacarbazolderivate, for example according to EP 1617710 . EP 1617711 . EP 1731584 . JP 2005/347160 , bipolar matrix materials, for example according to WO 2007/137725 , Silane, for example, according to WO 2005/111172 , Azaborole or Boronester, for example according to WO 2006/117052 , Triazine derivatives, for example according to WO 2010/015306 . WO 2007/063754 or WO 2008/056746 , Zinc complexes, for example according to EP 652273 or WO 2009/062578 , Diazasilol or tetraazasilol derivatives, for example according to WO 2010/054729 . Diazaphospholderivate, for example according to WO 2010/054730 , bridged carbazole derivatives, for example according to US 2009/0136779 . WO 2010/050778 . WO 2011/042107 . WO 2011/088877 or WO 2012/143080 , Triphenylene derivatives, for example according to WO 2012/048781 , or lactams, for example, according to WO 2011/116865 or WO 2011/137951 ,

Particularly suitable matrix materials for fluorescent emission compounds that can be used in combination with the inventive compounds of the formula (I) as matrix components of a mixed matrix system include materials of various classes of substances. Preferred matrix materials are selected from the classes of oligoarylenes (for example 2,2 ', 7,7'-tetraphenylspirobifluorene according to US Pat EP 676461 or dinaphthylanthracene), in particular the oligoarylenes with fused aromatic groups, the oligoarylenevinylenes (eg DPVBi or spiro-DPVBi according to US Pat EP 676461 ), the polypodal metal complexes (for example according to WO 2004/081017 ), the hole-conducting connections (for example according to WO 2004/058911 ), the electron-conducting compounds, in particular ketones, phosphine oxides, sulfoxides, etc. (for example according to WO 2005/084081 and WO 2005/084082 ), the atropisomers (for example according to WO 2006/048268 ), the boronic acid derivatives (for example according to WO 2006/117052 ) or the benzanthracenes (for example according to WO 2008/145239 ). Particularly preferred matrix materials are selected from the classes of the oligoarylenes, the naphthalene, anthracene, benzanthracene and / or pyrene or atropisomers of these compounds, the oligoarylenevinylenes, the ketones, the phosphine oxides and the sulfoxides. Very particularly preferred matrix materials are selected from the classes of oligoarylenes, which include anthracene, benzanthracene, benzophenanthrene and / or pyrene or atropisomers of these compounds. In the context of this invention, an oligoarylene is to be understood as meaning a compound in which at least three aryl or arylene groups are bonded to one another. The anthracene derivatives found in WO 2006/097208 . WO 2006/131192 . WO 2007/065550 . WO 2007/110129 . WO 2007/065678 . WO 2008/145239 . WO 2009/100925 . WO 2011/054442 and EP 1553154 be disclosed, and the pyrene compounds, which are in EP 1749809 . EP 1905754 and US 2012/0187826 are given preference is given.

Preferred embodiments of the various functional materials in the electronic device are listed below:

Suitable charge transport materials that can be used in the hole injection or hole transport layer or electron barrier layer or in the electron transport layer of the electronic device of the invention are, like the compounds of formula (I), for example, the compounds described in U.S. Pat Y. Shirota et al., Chem. Rev. 2007, 107 (4), 953-1010 , or other materials used in these layers according to the prior art.

Materials used for the electron transport layer may be any materials used in the prior art as electron transport materials in the electron transport layer. Particularly suitable are aluminum complexes, for example Alq ₃ , zirconium complexes, for example Zrq ₄ , lithium complexes, for example Liq, benzimidazole derivatives, triazine derivatives, pyrimidine derivatives, pyridine derivatives, pyrazine derivatives, quinoxaline derivatives, quinoline derivatives, oxadiazole derivatives, aromatic ketones, lactams, boranes, diazaphosphole derivatives and phosphine oxide derivatives. Other suitable materials are derivatives of the aforementioned compounds, as in JP 2000/053957 . WO 2003/060956 . WO 2004/028217 . WO 2004/080975 and WO 2010/072300 disclosed.

Preferred cathodes of the electronic device are low work function metals, metal alloys or multilayer structures composed of various metals, for example alkaline earth metals, alkali metals, main group metals or lanthanides (eg Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.). In addition, alloys composed of an alkali metal or alkaline earth metal and silver, for example, an alloy consisting of magnesium and silver are suitable. In the case of multilayer structures, in addition to the metals mentioned, other metals with a relatively high work function may also be used, for example Ag or Al, in which case generally combinations of the metals, such as Ca / Ag, Mg / Ag or Ba / Ag, be used. It may also be preferable to insert a thin intermediate layer of a high dielectric constant material between a metallic cathode and the organic semiconductor. Examples of materials which can be used for this purpose are alkali metal or alkaline earth metal fluorides, but also the corresponding oxides or carbonates (eg LiF, Li ₂ O, BaF ₂ , MgO, NaF, CsF, Cs ₂ CO ₃ , etc.). It is also possible to use lithium quinolinate (LiQ) for this purpose. The layer thickness of this layer is preferably 0.5 to 5 nm.

Preferred anodes are high workfunction materials. The anode preferably has a work function of over 4.5 eV against vacuum. First, metals with a high redox potential, for example Ag, Pt or Au, suitable for this purpose. Secondly, metal / metal oxide electrodes may be preferred (eg. As Al / Ni / NiO _x, Al / PtO _x). For some applications, at least one of the electrodes must be permeable or partially transmissive to allow for radiation of the organic material (organic solar cell) or emission of light (OLED, O-LASER). Preferred anode materials are conductive mixed metal oxides. In particular, indium tin oxide (ITO) or indium zinc oxide (IZO) is preferred. Furthermore, preference is given to conductive doped organic materials, in particular conductive doped polymers. In addition, the anode may also consist of two or more layers, for example an inner layer of ITO and an outer layer of metal oxide, preferably tungsten oxide, molybdenum oxide or vanadium oxide.

An OPV device according to the present invention may be of any type known in the literature (see, for example, Waldauf et al., Appl. Phys. Lett. (2006), 89, 233517).

• - gegebenenfalls ein Substrat;
• - eine Elektrode mit einer höheren Austrittsarbeit, die vorzugsweise ein Metalloxid wie beispielsweise Indiumzinnoxid („ITO“) umfasst und als Anode dient, und eine Elektrode mit einer niedrigeren Austrittsarbeit, die vorzugsweise ein Metall wie beispielsweise Aluminium umfasst und als Kathode dient;
• - eine optionale leitende Schicht oder Löchertransportschicht, die vorzugsweise ein organisches Polymer oder eine organische Polymermischung, zum Beispiel PEDOT:PSS (Poly(3,4-ethylendioxythiophen):Poly(styrolsulfonat), oder eine organische Verbindung, wie beispielsweise TBD (N,N'-Diphenyl-N-N'-bis(3-methylphenyl)-1,1'biphenyl-4,4'-diamin) oder NBD (N,N'-Diphenyl-N-N'-bis(1-napthylphenyl)-1,1'biphenyl-4,4'-diamin), umfasst;
• - eine Schicht, die auch als „aktive Schicht“ bezeichnet wird und einen organischen p-Typ- und einen organischen n-Typ-Halbleiter umfasst, und die zum Beispiel als eine p-Typ-/n-Typ-Doppelschicht oder als individuelle p-Typ- und n-Typ-Schichten oder als eine Mischung oder ein Gemisch von p-Typ- und n-Typ-Halbleiter vorliegen, die/das einen Volumen-Heteroübergang bildet (BHJ);
• - gegebenenfalls eine Schicht mit Elektronentransporteigenschaften, die zum Beispiel LiF umfasst, auf der Seite der Elektrode mit niedriger Austrittsarbeit gegenüber der aktiven Schicht, und/oder eine Schicht mit Löchersperreigenschaften, die vorzugsweise ein Metalloxid wie TiOx oder Zn_x umfasst, auf der Seite der Elektrode mit hoher Austrittsarbeit gegenüber der aktiven Schicht,

wobei mindestens eine der Elektroden, vorzugsweise die Anode, für sichtbares Licht durchlässig ist, und
wobei der p-Typ-Halbleiter ein smektisches LC-Material gemäß der vorliegenden Erfindung ist.An OPV device according to the invention comprises the following layers:

• optionally a substrate;
• a higher work function electrode, preferably comprising a metal oxide such as indium tin oxide ("ITO"), serving as an anode and a lower work function electrode, preferably comprising a metal such as aluminum and serving as a cathode;
• an optional conductive layer or hole transport layer, preferably an organic polymer or an organic polymer mixture, for example PEDOT: PSS (poly (3,4-ethylenedioxythiophene): poly (styrenesulfonate), or an organic compound, such as TBD (N, N '-Diphenyl-N-N'-bis (3-methylphenyl) -1,1'biphenyl-4,4'-diamine) or NBD (N, N'-diphenyl-N-N'-bis (1-naphthylphenyl) -1,1'biphenyl-4,4'-diamine);
• a layer, also referred to as an "active layer" comprising an organic p-type and an organic n-type semiconductor, and which may be used, for example, as a p-type / n-type double layer or as an individual p And a mixture or mixture of p-type and n-type semiconductors forming a volume heterojunction (BHJ);
• optionally, a layer having electron transport properties comprising, for example, LiF on the side of the low work function electrode to the active layer, and / or a layer having hole blocking properties, preferably comprising a metal oxide such as TiOx or Zn _x , on the side of the electrode high work function over the active layer,

wherein at least one of the electrodes, preferably the anode, is transparent to visible light, and
wherein the p-type semiconductor is a smectic LC material according to the present invention.

The substrate used for the present electronic device may be any suitable material. Examples of such materials are silicon wafers, glass and polymer materials. Preferred polymeric materials include, but are not limited to, alkyd resins, allyl esters, benzocyclobutenes, butadiene styrene, cellulose, cellulose acetate, epoxies, epoxy polymers, ethylene-chlorotrifluoroethylene copolymers, ethylene-tetrafluoroethylene copolymers, glass fiber reinforced polymers, fluorohydrocarbon polymers, hexafluoropropylene vinylidene fluoride copolymer, polyethylene high density, parylene, polyamide, polyimide, polyaramid, polydimethylsiloxane, polyethersulfone, polyethylene, polyethylene naphthalate, polyethylene terephthalate, polyketone, polymethyl methacrylate, polypropylene, polystyrene, polysulfone, polytetrafluoroethylene, polyurethanes, polyvinyl chloride, polycycloolefin, silicone gums and silicones. Of these, polyethylene terephthalate, polyimide, polycycloolefin and polyethylene naphthalate materials are more preferred. Alternatively, the substrate may be a polymer material, metal or glass coated with one or more of the aforementioned polymer materials.

In a preferred embodiment, the electronic device according to the present invention is characterized in that one or more layers are applied by a sublimation process. In this case, the materials are deposited by vapor deposition in vacuum sublimation systems at an initial pressure of less than 10 ^-5 mbar, preferably less than 10 ^-6 mbar. However, in this case it is also possible for the initial pressure to be even lower, for example below 10 ^-7 mbar.

Also, preference is given to an electronic device characterized in that one or more layers are deposited by the process of organic vapor deposition (OVDP) or by carrier-gas sublimation. In this case, the materials are applied at a pressure of 10 ^-5 mbar to 1 bar. A special case of this process is the process of organic Steam jet printing (OVJP), wherein the materials are directly applied through a nozzle and patterned in this way (for example, MS Arnold et al., Appl. Phys. Lett., 2008, 92, 053301).

In addition, preference is given to an electronic device which is characterized in that one or more layers of solution, for example by spin coating or by any printing process, for example screen printing, flexographic printing, jet printing or offset printing, but preferably LITI (light-induced thermography, heat transfer printing) or ink jet printing are applied.

It is further preferable that an electronic device of the invention is made by applying one or more layers of solution and one or more layers by a sublimation process.

For the processing of the inventive compound of formula (I) from the liquid phase, for example by spin coating or by printing processes, formulations of the inventive compounds of formula (I) are required. These formulations may be, for example, solutions, dispersions or emulsions. For this purpose, it may be preferable to use mixtures of two or more solvents. Suitable and preferred solvents are, for example, toluene, anisole, o-, m- or p-xylene, methyl benzoate, mesitylene, tetralin, veratrole, THF, methyl THF, THP, chlorobenzene, chloroform, dichlorobenzene, dichloromethane, dioxane, phenoxytoluene, in particular 3-phenoxytoluene, (-) - fenchone, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, 1-methylnaphthalene, 2-methylbenzothiazole, 2-phenoxyethanol, 2-pyrrolidinone, 3-methylanisole, 4-methylanisole, 3,4-dimethylanisole, 3,5-dimethylanisole, acetophenone, α-terpineol, benzothiazole, butylbenzoate, cumene, cyclohexanol, cyclohexanone, cyclohexylbenzene, decalin, dodecylbenzene, ethylbenzoate, indane, methylbenzoate, NMP, p-cymene, Phenol, 1,4-diisopropylbenzene, dibenzyl ether, diethylene glycol butyl methyl ether, triethylene glycol butyl methyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, tripropylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 2-isopropylnaphthalene, pentylbenzene, hexylbenzene, heptylbenzene n, octylbenzene, 1,1-bis (3,4-dimethylphenyl) ethane or mixtures of these solvents.

The invention therefore further provides a formulation, in particular a solution, dispersion or emulsion, which comprises at least one compound of the formula (I) and at least one solvent, preferably an organic solvent. The manner in which such solutions can be made is well known to those skilled in the art and is described, for example, in US Pat WO 2002/072714 . WO 2003/019694 and the technical literature cited therein.

As already mentioned, the molecules of the compounds according to the present invention uniformly align themselves perpendicular to the surface of the substrate when applied by spin-coating or thermal evaporation in vacuo to thereby form a smectic LC phase. The vertical orientation, however, is not an advantageous circumstance, in particular for OLEDs and OPVs.

The present inventors have found that the actual performance of organic electronic devices, particularly OLEDs and OPVs, can be improved by subjecting the compound of formula (I) to thermal treatment after being applied to a substrate, thereby obtaining a smectic LC phase with the axis of the molecules forming the smectic phase aligned parallel to the layer surface to which they are applied.

Therefore, the present invention also relates to an electronic device, in particular an organic light-emitting device or organic photovoltaic device, wherein the compound according to the present invention forms a smectic phase, wherein the axis of the molecules is aligned parallel to a substrate surface.

The present invention further provides a process for manufacturing the electronic devices according to the present invention, in particular for the manufacture of OLEDs and OPVs.

1. a) Aufdampfen oder Auftragen der Verbindung der Formel (I) aus Lösung auf ein Substrat, um eine Schicht zu bilden;
2. b) Erhitzen der Schicht von Schritt (a) auf eine Temperatur, bei der eine smektische Phase gebildet wird;
3. c) anschließendes Tempern der in Schritt (b) gebildeten smektischen Phase; und
4. d) Abkühlen auf Raumtemperatur.

In a general aspect, the process according to the invention comprises the following steps:

1. a) evaporating or applying the compound of formula (I) from solution to a substrate to form a layer;
2. b) heating the layer of step (a) to a temperature at which a smectic phase is formed;
3. c) subsequent annealing of the smectic phase formed in step (b); and
4. d) Cool to room temperature.

• I-a) Bereitstellen eines Substrats;
• I-b) Bilden einer Elektrode auf dem Substrat;
• I-c) Auftragen eines leitenden Materials auf die Elektrode, um eine leitende Schicht zu bilden;
• I-d) Aufdampfen oder Auftragen der Verbindung nach einem oder mehreren der Ansprüche 1 bis 10 aus Lösung auf die leitende Schicht, um eine Löchertransportschicht oder eine Emissionsschicht zu bilden;
• I-e) Erhitzen der Löchertransportschicht oder Emissionsschicht auf eine Temperatur, bei der eine smektische Phase gebildet wird, anschließendes Tempern der smektischen Phase und danach Abkühlen auf Raumtemperatur.

In a more specific aspect, the present invention provides a process comprising the following steps:

• Ia) providing a substrate;
• Ib) forming an electrode on the substrate;
• Ic) applying a conductive material to the electrode to form a conductive layer;
• Id) evaporating or applying the compound according to one or more of claims 1 to 10 from solution to the conductive layer to form a hole transport layer or an emission layer;
• Ie) heating the hole transport layer or emission layer to a temperature at which a smectic phase is formed, then annealing the smectic phase and then cooling to room temperature.

The electrode may be applied to the substrate by any of the methods previously described. The same applies to the application of the conductive material to the electrode.

The process conditions for forming the layer of the compound of formula (I) by thermal evaporation or solution coating are the same as previously mentioned. The layer thus formed may be any layer which may contain the inventive compound, preferably a hole transport layer, a hole injection layer, an electron barrier layer and / or an emission layer, all as defined hereinbefore in this application.

According to the present invention, it is preferable that the layer of the compound of the formula (I) has a thickness of 350 nm. However, the layer thickness can be selected according to the relevant requirements.

The conductive material forming the conductive layer may be any organic polymer or organic polymer mixture or charge transport material as defined above that can be used in a hole injection layer, hole transport layer, electron barrier layer, or emission layer of the electronic device of the invention.

In order to obtain the smectic phase with the axis of the LC molecules aligned parallel to the layer surface of the electronic device, the LC layer is subjected to a thermal treatment which comprises heating the layer to a temperature at which the smectic phase is formed ( the so-called "smectic region"), followed by annealing the smectic phase and then rapidly cooling to room temperature. The cooling rate is preferably over 100 ° C / min.

The smectic region is unique for each LC compound, but those skilled in the art know the methods for determining the smectic region. Preferably, the heating and annealing of the smectic phase comprises thermally treating the smectic phase at temperatures of 80 ° C to 250 ° C, and more preferably at temperatures of 120 ° C to 200 ° C. Any suitable heater known to those skilled in the art may be selected, but a hot plate is preferably used.

According to a further preferred embodiment of the present invention, the duration of the tempering is in the range of 5 minutes to 1 hour, preferably in the range of 5 minutes to 30 minutes and is in particular 10 minutes. In addition, the annealing is preferably carried out in air, but other tempering atmospheres, for example, a nitrogen atmosphere, may be selected.

It has been found that the compound of the formula (I) after a thermal treatment under conditions which allow practical use in electronic devices, particularly in OLEDs and OVPs and allow easy processing, shows a large increase in hole conductivity and hole mobility.

The invention will be illustrated in more detail by the following examples, which are not to be construed as limiting in any respect.

list of figures

• 1 illustrates polarized optical micrographs of a compound according to the present invention showing optical textures of its phases: (a) nematic (202 ° C), (b) SmA (192 ° C), (c) SmC (180 ° C), and ( d) SmE (124 ° C).
• 2 FIG. 10 illustrates an exemplary test cell for measuring hole conductivity and hole mobility. FIG.
• 3 FIG. 10 illustrates an example process for manufacturing a test cell. FIG.
• 4 and 5 illustrate the hole conductivity and hole mobility of a compound according to the present invention with and without smectic phase annealing.
• 6 Fig. 12 illustrates the observation of molecular orientation under polarized light for a compound according to the present invention.
• 7 compares the hole conductivity of a compound according to the present invention with compounds of the prior art.
• 8th FIG. 12 illustrates polarized light cell observation for a compound of the present invention as compared to prior art compounds. FIG.

working examples

Four new smectic LC compounds, the naphthyl-type compounds 8-TTTfNaph and 8-TTTTfNaph, and the phenyl-type compounds 8-TTTY and 8-TTTTY, are synthesized. The hole conductivity performance of 8-TTTfNaph is compared with that of three existing smectic compounds, namely 8-QTP-8, Haramoto-C10 and Haramoto-C12. 8-QTP-8 is a typical hole-conducting smectic LC and is said to have a hole mobility of 6.15 x 10 ^-2 cm ² / Vs (K. Nakano, H. lino, T. Usui, and J. Hanna, Appl. Lett. 2011 ), 98, 103302). Haramoto-C10 and Haramoto-C12 are styryl-type smectic LC compounds developed by Prof. Haramoto (Y. Haramoto, Y. Kawada, A. Mochizuki, M. Nanasawa, S. Ujiie, M. Funahashi, K Hiroshima, and T. Kato, Liquid Crystals ( 2005 ) 32. 909). C10 and C12 represent the number of carbon atoms in an alkyl group.

Synthesis of smectic LC compounds

Unless otherwise stated, all reactions are carried out under nitrogen using Schlenk techniques. Tetrahydrofuran and diethyl ether are bought and used pre-dried. The catalysts Ni (dppp) Cl ₂ (dppp = Ph ₂ P (CH ₂ ) ₃ PPh ₂ ) and Pd (PPh ₃ ) ₄ are purchased and used without further purification. Sublimation is carried out by a combination with a sublimation unit of a Buchi glass tube furnace and a Pfeiffer turbomolecular vacuum pumping system. ¹ H NMR spectra are obtained on a JEOL JNM ECX-400P spectrometer and related to a signal from TMS (tetramethylsilane) or solvent residue. Melting points are measured by Mettler-Toledo FP81HT MBC Cell and FP90 Central Processor.

Example 1 - Synthesis of 5-n-octyl-5 "- [7- (1,2,8-trifluoronaphthyl)] - 2,2 ': 5', 2" -terthiophene (8-TTTfNaph)

4,4,5,5-tetramethyl-2- [5 "-n-octyl- (2,2 ': 5', 2" -terthiophene) -5-yl] -1,3,2-dioxaborolane (2, 27 g, 4.665 mmol), 1,7,8-trifluoronaphthalene-2-yl trifluoromethanesulfonate (1.69 g, 5.122 mmol), Pd (PPh ₃ ) ₄ (270 mg, 0.233 mmol) and K ₂ CO ₃ (2.58 g, 18.66 mmol) in 23 ml of a solvent system of 5: 5: 2 toluene / THF / H ₂ O are heated at reflux and stirred for 18 h. After cooling the reaction mixture to room temperature, 20 ml of water are added to the reaction mixture. A dark yellow precipitate appears, which is collected and washed with water and MeOH. The solid is dissolved in hot THF, and the Solution is suspended with Al ₂ O ₃ (25 g, neutral type). Then the Al ₂ O _{3 is} filtered off and the organic filtrate is evaporated. Recrystallization from THF / 2-PrOH gives a tan solid. This roughly purified solid is further purified by sublimation (2.4 × 10 ^-6 mbar, 250 ° C., 46 h). Yield: 1.24 g (yellow-green solid, 50%). ¹ H NMR (400 MHz, THF-d ₈ ) δ (ppm) 0.89 (t, J = 6.8 Hz, 3H), 1.25-1.40 (m, 10H), 1.66-1 , 72 (m, 2H), 2.81 (t, J = 7.5 Hz, 2H), 6.72 (dd, J = 0.9, 3.7 Hz, 1H), 7.05 (dd, J = 1.4, 3.7 Hz, 1H), 7.08 (dd, J = 0.9, 3.7 Hz, 1H), 7.29 (d, J = 3.7 Hz, 1H), 7.48 (dd, J = 9.1, 16.5 Hz, 1H), 7.66 (dd, J = 0.9, 4.1 Hz, 1H), 7.69-7.74 (m, 2H), 7.86 (t, J = 8.2 Hz, 1H); Melting point: 203.5 ° C.

Example 2 - Synthesis of 5-n-octyl-5 "- [6- (1,2-difluorophenyl)] - 2,2 ': 5', 2" -terthiophene (8-TTTY)

5-Bromo-5 "-n-octyl-2,2 ': 5', 2" -terthiophene (1.99 g, 4.528 mmol), 2,3-difluorophenylboronic acid (1.07 g, 6.792 mmol), Pd ( PPh ₃ ) ₄ (262 mg, 0.226 mmol) and Na ₂ CO ₃ (1.44 g, 13.58 mmol) in 24 mL of a 12: 1 DME / H ₂ O solvent system are heated at 85 ° C and 18 h stirred for a long time. After cooling the reaction mixture to room temperature, 40 ml of water are added to the reaction mixture. A dark yellow precipitate appears, which is collected and washed with water and MeOH. The solid is dissolved in hot THF and the THF solution is suspended with Al ₂ O ₃ (20 g, neutral type). Then the Al ₂ O _{3 is} filtered off and the organic filtrate is evaporated. Solid residue is dissolved in hot THF, whereupon a yellow-boron solid is obtained by recrystallization from THF / 2-PrOH. This roughly purified solid is further purified by sublimation (1.9 × 10 ^-5 mbar, 200 ° C., 19.5 h). Yield: 1.51 g (yellow solid, 73%). ¹ H NMR (400 MHz, THF-d ₈ ) δ (ppm) 0.89 (t, J = 6.8 Hz, 3H), 1.32-1.41 (m, 10H), 1.66-1 , 73 (m, 2H), 2.81 (t, J = 7.8 Hz, 2H), 6.71 (dd, J = 0.9, 3.2 Hz, 1H), 7.04 (d, J = 3.2 Hz, 1H), 7.07 (d, J = 3.2 Hz, 1H), 7.15-7.20 (m, 3H), 7.25 (dd, J = 0.9 , 3.2Hz, 1H), 7.47-7.52 (m, 2H); ¹³ C NMR (100 MHz, THF-d ₈ ) δ (ppm) 14.1, 23.5, 30.0, 30.2, 30.3, 30.8, 32.6, 32.8, 116, 4, 116.5, 123.8, 124.4, 124.5, 124.8, 124.9, 125.5, 125.6, 125.9, 128.8, 128.9, 135.1, 135.5, 138.3, 139.1, 139.2, 146.4; Melting point: 152.6 ° C.

Example 3 - Synthesis of 5-n-octyl-5 '' '- [6- (1,2-difluorophenyl)] - 2,2': 5 ', 2 ": 5", 2' '' - quaterthiophene (8 -TTTTY)

5-Bromo-5 "-n-octyl-2,2 ': 5', 2" -quarterthiophene (1.0g, 1.917mmol), 2,3-difluorophenyl boronic acid (454mg, 2.686mmol), Pd (PPh ₃ ) ₄ (61 mg, 0.053 mmol) and Na ₂ CO ₃ (610 mg, 5.751 mmol) in 13 mL of a 12: 1 DME / H ₂ O solvent system are heated at 85 ° C and stirred for 18 h. After cooling the reaction mixture to room temperature, 20 ml of water are added to the reaction mixture. A dark brown precipitate appears, which is collected and washed with water and MeOH. The solid is dissolved in hot THF and the THF solution is suspended with Al ₂ O ₃ (10 g, neutral type). Then, the Al ₂ O _{3 is} filtered off, and the organic filtrate is concentrated, and recrystallized from THF / 2-PrOH to give a yellow-boron solid. The solid is further purified by sublimation (4.0 x 10 ^-7 mbar, 240 ° C, 18 h). Yield: 862.4 mg (yellow solid, 81%). ¹ H NMR (400 MHz, THF-d ₈ ) δ (ppm) 0.89 (t, J = 6.8 Hz, 3H), 1.30-1.41 (m, 10H), 1.66-1 , 73 (m, 2H), 2.81 (t, J = 7.8 Hz, 2H), 6.73 (d, J = 3.7 Hz, 1H), 7.04 (d, J = 3, 7Hz, 1H), 7.07 (d, J = 3.7Hz, 1H), 7.16-7.19 (m, 4H), 7.25 (d, J = 3.7Hz, 1H) , 7.29 (dd, J = 0.9, 4.1 Hz, 1H), 7.50-7.51 (m, 2H); ¹³ C NMR (100 MHz, THF-d ₈ ) δ (ppm) 14.4, 23.5, 30.0, 30.2, 30.3, 30.8, 32.6, 32.8, 116, 5, 116.6, 123.9, 124.4, 124.5, 125.2, 125.2, 125.4, 125.4, 125.8, 125.8, 125.9, 125.9, 128.8, 128.9, 135.2, 135.7, 136.2, 137.4, 138.0, 1 146.4; Melting point: 202.4 ° C.

Example 4 - Synthesis of 5-n-octyl-5 '''- [7- (1,2,8-trifluoronaphthyl)] - 2,2': 5 ', 2 ": 5", 2''' - quaterthiophene (8-TTTTfNaph)

4,4,5,5-tetramethyl-2- [5 '''- n-octyl (2,2': 5 ', 2 ": 5", 2''' - quarterthiophen) -5-yl] - 1,3,2-dioxaborolane (442.8 mg, 0.799 mmol), 1,7,8-trifluoronaphthalene-2-yl trifluoromethanesulfonate (282.8 mg, 0.856 mmol), Pd (PPh ₃ ) ₄ (45.0 mg, 0.039 mmol) and K ₂ CO ₃ (430.7 mg, 3.116 mmol) in 7.2 mL of a 5: 5: 2 toluene / THF / H ₂ O solvent system are heated to reflux and stirred for 18 h. After cooling the reaction mixture to room temperature, 10 ml of water are added to the reaction mixture. A dark brown precipitate appears, which is collected and washed with water and MeOH. The solid is dissolved in hot THF and the solution is suspended with Al ₂ O ₃ (5 g, neutral type). Then the Al ₂ O _{3 is} filtered off and the organic filtrate is evaporated. Recrystallization from THF / 2-PrOH gives an orange solid. This roughly purified solid is further purified by sublimation (3.0 x 10 ^-7 mbar, 270 ° C, 20 h). Yield: 300.3 mg (orange solid, 68%). ¹ H NMR (400 MHz, THF-d ₈ ) δ (ppm) 0.89 (t, J = 6.8 Hz, 3H), 1.30-1.41 (m, 10H), 1.66-1 , 73 (m, 2H), 2.81 (t, J = 7.3 Hz, 2H), 6.73 (d, J = 3.2 Hz, 1H), 7.04 (d, J = 3, 2 Hz, 1H), 7.07 (d, J = 3.2 Hz, 1H), 7.17 (d, J = 3.2 Hz, 1H), 7.20 (d, J = 3.2 Hz , 1H), 7.28 (d, J = 3.2 Hz, 1H), 7.34 (dd, J = 1.8, 3.2 Hz, 1H), 7.47-7.52 (m, 1H), 7.69 (d, J = 4.1 Hz, 1H), 7.72-7.76 (m, 2H), 7.88 (dd, J = 6.8, 9.1 Hz, 1H ); Melting point: 209.8 ° C.

Comparative Example 1 - Synthesis of 5,5 "'- di-n-octyl-2,2': 5 ', 2": 5 ", 2' '' - quaterthiophene (8-QTP-8, CAS # 882659- 01-0).

The synthesis is carried out according to previously published reports ( lino, H. & Hanna, J., Adv. Mater. (2011), 23, 1748-1751 ). 8-QTP-8 is isolated by recrystallization from hot THF / ethyl acetate ( 2 : 1, 5 times). Then, the crystals are purified by sublimation (275 ° C, 1.9 × 10 ^-6 mbar, 46 h). Yield: 1.31 g (orange solid, 81%).

Comparative Example 2 Synthesis of 1,4-bis [(1E) -2- [4- (decyloxy) phenyl] ethenyl] benzene ("Haramoto-C10", CAS No. 131692-25-6)

Synthesis will be performed according to previously published reports ( Haramoto, et. al, Liquid Crystals (2005), 32 (7), 909-912 ; Hudson et. al, J. Mater. Chem. (1995), 5 (II), 1867-1870). "Haramoto-C10" is purified by sublimation (277 ° C, 2.2 x 10 ^-6 mbar, 46 h, pale yellow-green crystal).

Comparative Example 3 Synthesis of 1,4-bis [(1E) -2- [4- (dodecyloxy) phenyl] ethenyl] benzene ("Haramoto-C12", CAS No. 148172-18-3)

Synthesis will be performed according to previously published reports ( Haramoto, et. al, Liquid Crystals (2005), 32 (7), 909-912 ; Hudson et. al, J. Mater. Chem. (1995), 5 (II), 1867-1870). "Haramoto-C12" is purified by sublimation (285 ° C, 1.6 x 10 ^-6 mbar, 62 h, pale yellow-green crystal).

Example 5 - Determination of Smectic Phases of LC Compounds 8th -TTTfNaph, 8-TTTY, 8-TTTTY and 8-TTTTfNaph

The phase transition temperatures of 8-TTTfNaph, 8-TTTY, 8-TTTTY and 8-TTTTfNaph as synthesized in Examples 1 to 4 are examined by using a microscope equipped with a temperature controller. For 8-TTTY and 8-TTTTY, their highly ordered smectic sub-phases could not be determined due to their undefinable textures observed under a microscope. In the following, "SmA" (or "SmC", etc.) denotes the respective smectic subphase, while "SmX" denotes a smectic subphase, which can not be defined. "N" is the lowest nematic phase. "Cr" means solid crystalline state. The specific temperatures are as follows: 8-TTTfNaph: SmE 132.5 ° C; SmC 188.8 ° C; SmA 198.9 ° C; N 208.7 ° C iso 8-TTTY: Cr 12 ° C; SmX 117 ° C; SmA 149 ° C iso 8-TTTTY: SmX 196 ° C; SmA 236 ° C iso 8-TTTTfNaph: Cr 210.3 ° C; SmC 263.9 ° C; SmA 284.7 ° C; N 297.1 ° C iso

The optical images of the textures of 8-TTTfNaph are in 1 shown. The phase transition temperatures of LC compounds 8-QTP-8 (S, Sergeyev and Y. Geerts, Chem. Lett. 2006 ) 35, 166), Haramoto-C10 and Haramoto-C12 (Y. Haramoto, Y. Kawada, A. Mochizuki, M. Nanasawa, S. Ujiie, M. Funahashi, K. Hiroshima, and T. Kato, Liquid Crystal (U.S. 2005 ), 32, 909) have been set out in the literature as follows: 8-QTP-8: Cr 82 ° C; SmX 158 ° C iso Haramoto-C10: Cr 98 ° C; SmG 187 ° C; SmF 250 ° C; SmC 255 ° C; N 270 ° C iso Haramoto-C12: Cr 137 ° C; SmG 179 ° C; SmF 242 ° C; SmC 300 ° C; N 313 ° C Iso

Example 6 - Measurement of hole mobility and hole conductivity

The hole conductivity performance of the smectic LC compound 8-TTTfNaph as synthesized in Example 1 is compared with that of the three existing smectic compounds 8-QTP-8, Haramoto-C10 and Haramoto-C12 as synthesized in Comparative Examples 1 to 3.

HOMO / LUMO MEASUREMENT

The work function and the HOMO of the materials used are measured on a photoelectron yield spectrometer (AC-2, Riken Keiki). Absorption spectra as well as emission and excitation spectra are recorded on spectrophotometers (UV-2550, Shimazu, or FP-6500, Jasco). The optical bandgap is calculated from the position of the intersection between the normalized emission and solid-film excitation spectra on a quartz plate.

Test cell manufacturing

The hole conductivities are for the synthesized smectic LCs 8th -TTTfNaph, 8-TTTY, 8-TTTTY, 8-TTTTfNaph, 8-QTP-8, Haramoto-C10 and Haramoto-C12 were measured by using test cells prepared in 2 are shown. In addition, the hole mobility for 8-TTTfNaph becomes by using the test cell with the process 1 in 3 measured. The workfunction values for ITO and Ag are 4.7 eV and 4.8 eV, respectively, while the HOMO and LUMO values of the LC materials are below -5.0 eV and above -3.0 eV, respectively. Accordingly, the current conduction in the present cells is induced only by holes. PEDOT-PSS plays a role as a hole injection layer. The active area in the cell for measurement was 6 mm ² .

The cell manufacturing process is in 3 given. Each step is carried out in a clean room. Accordingly, a glass substrate with ITO deposited thereon is first washed in an ultrasonic bath and then treated with UV / O ₃ . A layer of poly (3,4-ethylenedioxythiophene) polystyrenesulfonate (PEDOT-PSS) is spin-coated onto the glass substrate (with ITO) (layer thickness: 40 nm), which is then heated at 140 ° C for 5 minutes in air using a hot plate tempered and then naturally cooled to room temperature. Next, a layer of the LC compound is vacuum deposited by thermal evaporation (layer thickness: 350 nm), followed by either direct application of Ag by thermal evaporation in vacuo to form a 35 nm thick Ag layer (Process 1 ) or initial annealing of the LC layer on a hot plate at 150 ° C for 10 min in air followed by rapid cooling to room temperature before application of the Ag layer as described previously (Process 2 ).

According to the above-described test cell manufacturing process, two types of test cells are prepared for each measured LC compound: one is without the anneal treatment after the LC deposition, shown as a process 1 , and the other is with the annealing treatment, presented as a process 2 , The annealing temperature for 8-TTTfNaph, 8-QTP-8, Haramoto-C10 and Haramoto-C12 was 150 ° C.

Method of measuring hole mobility and hole conductivity

The hole conductivity of compound 8-TTTfNaph, as synthesized in Example 1, is at 25 ° C by one with a dielectric interface 1296 equipped Solartron impedance analyzer 1260 measured. The applied AC voltage is 50 mV (rms). The same apparatus is also used to measure hole mobility. The hole mobility is measured by measuring the space charge limited current when applying a DC bias of 4 V according to Okachi et al. determined (T. Okachi, T. Nagase, T. Kobayashi, and H. Naito, Int. Display Workshop, 2007, p 1129). The hole mobility may be for the according to the process 1 cell determined, but not for the according to the process 2 manufactured cell, since the apparatus overrides in excess of current flow in the measuring circuit. The hole conductivity σ _h is defined by the equation σ _h = en _h μ _h (e: elementary charge, n _h : hole density, μ _h : hole mobility). n _h is calculated by using the values of σ _h and μ _h , which for the cell with process 1 were measured. Then the value of μ _h for the cell with process 2 using the value of n _h and the value of σ _h calculated for process 2 were measured.

Example 7 - Observation of Molecular Orientation under Polarized Light The LC molecular orientation for the cells under polarized light at room temperature is evaluated and the correlation with the results of the conductivity measurements is discussed.

Results and discussion

Lachenleitfähiqkeit and hole mobility of 8-TTTfNaph

The for process 1 and 2 hole conductivities measured using three cells are in 4 shown. The values for process 1 are on the order of 10 ^-9 S / cm, while those for process 2 are on the order of 10 ^-5 S / cm. It can be observed that the hole conductivity of 8-TTTfNaph increases by more than three orders of magnitude compared with that without treatment by the thermal treatment as described (150 ° C, 10 min, in air). This large increase in conductivity simultaneously leads to a large increase in hole mobility, as in 5 shown. The average hole mobility calculated for the three cells is 6.6 × 10 ^-2 cm ² / Vs. In addition, it is confirmed that the effect of the thermal treatment is not obtained when the treatment is carried out after the application of the counter electrode (Ag).

Cell observation under polarized light for 8-TTTfNaph

Photographs of cells taken under polarized light are in 6 shown. The cells were inserted between two polarizing plates and placed on a fluorescent light box. For the parallel set of two polarizing plates there is no difference of cell images between process 1 and process 2 , For the transverse set is no light transmission through the cell by process 1 to watch while for process 2 a strong translucency is observed. The light transmittance levels for the two cells do not change when the cells are rotated 45 ° from their initial states.

These optical observations indicate that the LC molecules are for process 1 Align perpendicular to the substrate surface, and that they are for process 2 at a slightly inclined angle (presumably about 90 °) from the normal to the substrate surface, but at random azimuth angles.

Hole conductivities obtained for 8-QTP-8, Haramoto-C10 and Haramoto-C12 and comparison with 8-TTTfNaph

The hole conductivities for process 2 that were measured for 8-QTP-8, Haramoto-C10 and Haramoto-C12 are in 7 and Table I in comparison with the results for 8-TTTfNaph. Each conductivity value is determined as an average for four cells. The hole conductivity of 8-QTP-8 is more than two orders of magnitude lower than that of 8-TTTfNaph. The hole conductivities of Haramoto-C10 and -C12 are higher than those of 8-QTP-8, but significantly lower than those of 8-TTTfNaph. Similar results in terms of hole conductivities are obtained for 8-TTTY, 8-TTTTY and 8-TTTTfNaph. Table I: Cellular observation under polarized light for 8-QTP-8, Haramoto-C10 and Haramoto-C12 and comparison with 8-TTTfNaph Table I. Hole conductivities of LC samples. LC-sample Conductivity (S / cm) 8-QTP-8 3.9E-07 Haramoto-C10 7,8E-06 Haramoto-C12 1.8E-06 8-TTTfNaph 4,9E-05

Photos of the cells under the transverse set of two polarizing plates for four LC compounds are in 8th given. The upper cells are according to the process 2 The lower cells are made according to the process 1 produced. For 8-QTP-8 and Haramoto-C12, there is no significant difference in transmitted light intensity between processes 1 and process 2 to observe. This result indicates that the effect of the thermal treatment on the change in LC molecule orientation is not so great for the two components. This result also shows that the LC molecules for the two components align at slightly inclined angles even without the thermal treatment. When compared between Haramoto-C10 and 8-TTTfNaph, the transmitted light intensity for 8-TTTfNaph is at process 2 much larger than the Haramoto C10. The optical phase difference Δ in the LC layer is defined as Δ = 2 πd (n _e -n _o ) / λ (d: thickness of the LC layer, ne: refractive index for extraordinary light, n _o : refractive index for ordinary light, λ: wavelength of light). Since the values of n _e -n _o for LC compounds are usually below 0.5, it is assumed that the value of Δ is smaller than π. In this state, the transmitted light intensity increases with increasing inclination angle.

As a result, the result points in 8th due to the thermal treatment, 8-TTTfNaph aligns at a greater tilt angle than the other LC compounds and induces a higher hole conductivity.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

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Claims (20)

Compound of the formula (I):

wherein: X is F, CF ₃ or CN and Y is H, or X and Y are joined together to form a fused ring, wherein the resulting fused polycyclic group is aromatic or partially non-aromatic and comprises 9 to 14 ring atoms wherein one or more of the ring atoms of an element other than carbon may be, and wherein one or more hydrogens bonded to the fused ring in a position adjacent to F are substituted by a substitution group selected from F, CF ₃ and CN is selected to form a laterally substituted polycyclic group; A represents an oligothiophene structure represented by the following formula (II):

where: n = 0 to 4; R _{1 is} selected from the group consisting of linear or branched C 4 -C 20 -alkyl, cyclic C 6 -C 10 -alkyl, C 4 -C 20 -alkenyl, cyclic C 6 -C 8 -alkenyl, C 4 -C 20 -alkynyl, C 4 -C 20 -alkoxyl, C4-C20 thioalkyl, C4-C10 cyclic alkoxyl, C4-C20 alkenyloxy; R ₂ , R ₂ ', R ₃ , R ₃ ', R ₄ and R ₄ 'are independently selected from the group consisting of H, linear or branched C 1 -C 20 -alkyl, cyclic C 6 -C 20 -alkyl, C 3 -C 20- Alkenyl, cyclic C6-C20 alkenyl, C3-C20 alkynyl, C1-C20 alkoxyl, C4-C20 thioalkyl, C4-C20 alkenyloxy; or a pair of R ₂ and R ₂ 'groups, a pair of R ₃ and R ₃ ' groups, and / or a pair of R ₄ and R ₄ 'groups to form an alkyl, alkenyl, alkoxyl, thioalkyl or oxo-thioalkyl ring which is fused with the thiophene ring to which the respective pair of groups R ₂ and R ₂ ', R ₃ and R ₃ ' and / or R ₄ and R ₄ 'is bonded. Connection to Claim 1 where the substitution group is F. Connection to Claim 1 or 2 wherein the condensed polycyclic group is selected from naphthyl, anthracenyl, indenyl, dihydroindenyl, tetrahydronaphthalenyl, dihydronaphthalenyl, fluorenyl, dihydrophenanthrenyl, dihydrobenzopyranyl, dihydrobenzothiopyranyl, dibenzopyranyl, dibenzothiopyranyl, quinolinyl, isoquinolinyl. Connection to one or more of Claims 1 to 3 in which the fused, laterally substituted polycyclic group is selected from the group consisting of the formulas (1) to (21), where (F) means that either F or H can be present in this position of the respective formula:

(1) (2) (3)

(4) (5) (6)

(7) (8th) (9)

(10) (11) (12)

(13) (14) (15)

(16) (17) (18)

(19) (20) (21) Connection to Claim 1 wherein in the compound of formula (I) X is F and Y is H or X and Y are joined together to form a fused aromatic ring, the resulting fused, laterally substituted polycyclic group being

Connection to one or more of Claims 1 to 5 where n in the structure of formula (II) is 1 or 2. Connection to one or more of Claims 1 to 6 where R ₁ in the structure of formula (II) is a linear C 4 -C 20 alkyl. Connection to one or more of Claims 1 to 7 where R ₂ , R ₂ ', R ₃ , R ₃ ', R ₄ and R ₄ 'in the structure of formula (II) are H. Connection to one or more of Claims 1 to 7 wherein the alkyl, alkenyl, alkoxyl, thioalkyl or oxothioalkyl ring resulting from the annulation by any pair of R ₂ and R ₂ ', R ₃ and R ₃ ' and / or R ₄ and R ₄ 'groups the thiophene ring of the formula (II) to which the respective pair of groups R ₂ and R ₂ ', R ₃ and R ₃ ' and / or R ₄ and R ₄ 'is bonded, is selected from:

Connection to Claim 1 which is: 5-n-octyl-5 "- [7- (1,2,8-trifluoronaphthyl)] - 2,2 ': 5', 2"-terthiophene; or 5-n-octyl-5 "- [6- (1,2-difluorophenyl)] - 2,2 ': 5', 2"-terthiophene; or 5-n-octyl-5 '''- [6- (1,2-difluorophenyl)] - 2,2': 5 ', 2 ": 5", 2''' - quaterthiophene; or 5-n-octyl-5 '''- [7- (1,2,8-trifluornaphthyl)] - 2,2': 5 ', 2 ": 5", 2''' - quarterthiophen. Process for making the connection according to one or more of Claims 1 to 10 composition comprising a Suzuki coupling reaction of an oligothiophene derivative of the formula (II) containing a boron-organic group with a group of the formula (I) containing a leaving group in the group A position. A formulation comprising at least one compound according to one or more of Claims 1 to 10 and at least one solvent. Use of a compound according to one or more of Claims 1 to 10 in an electronic device selected from the group consisting of organic field effect transistors (OFET), organic thin film transistors (OTFT), organic integrated circuits (OIC), logic circuits, capacitors, preferably semiconductor capacitors, in particular semiconductor capacitors in which the compound is a dielectric radio frequency identification (RFID) tags, devices or components, organic light emitting devices (OLED), organic light emitting transistors (OLET), organic light emitting electrochemical transistors, organic light emitting electrochemical cells (OLEC), organic field quench devices (OFQD ), "Organic plasmon-emitting devices" (DM Koller et al., Nature Photonics 2008, 1-4), electroluminescent displays, organic photovoltaic devices (OPV), organic solar cells (OSC), flexible OPVs, and OSCs, dye-sensing ized organic solar cells (ODSSC), photodiodes, organic laser diodes, photoconductors, organic photodetectors (OPD), organic photoreceptors, electrophotographic devices, electrophotographic recording devices, organic storage devices, sensor devices, light emitting polymer diodes (PLED), Schottky diodes, planarization layers, antistatic films, polymer electrolyte membranes (PEM), conductive substrates, conductive patterns, electrode materials in batteries, biosensors, biochips, security markers and security devices, as well as components or devices for detecting and distinguishing DNA sequences. Use after Claim 13 as a hole transport material, hole injection material or matrix material, preferably in an organic light emitting diode or an organic photovoltaic device. An electronic device, in particular an organic light-emitting device or an organic photovoltaic device, comprising at least one layer comprising the compound according to one or more of Claims 1 to 10 contains. Electronic device after Claim 15 wherein the at least one layer is selected from a hole transport layer and an emission layer. Electronic device after Claim 15 or 16 , wherein the compound according to one or more of Claims 1 to 10 forms a smectic phase in which the axis of the molecules is aligned parallel to a substrate surface. Process for manufacturing the electronic device according to one or more of Claims 15 to 17 wherein the process comprises the steps of: a) evaporating or applying the compound according to one or more of Claims 1 to 10 from solution to a substrate to form a layer; b) heating the layer of step (a) to a temperature at which a smectic phase is formed; c) subsequent annealing of the smectic phase formed in step (b); and d) cooling to room temperature. Process after Claim 18 the process comprising the steps of: ia) providing a substrate; Ib) forming an electrode on the substrate; Ic) applying a conductive material to the electrode to form a conductive layer; Id) evaporating or applying the compound according to one or more of Claims 1 to 10 solution on the conductive layer to form a hole transport layer or an emission layer; Ie) heating the hole transport layer or emission layer to a temperature at which a smectic phase is formed, then annealing the smectic phase and then cooling to room temperature. Process after Claim 18 or 19 wherein the heating and annealing comprises thermally treating the smectic phase at a temperature of from 80 ° C to 250 ° C, preferably from 120 ° C to 200 ° C.

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