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EP-4736603-A1 - DICYANOARYL COMPOUNDS FOR ORGANIC ELECTROLUMINESCENT DEVICES

EP4736603A1EP 4736603 A1EP4736603 A1EP 4736603A1EP-4736603-A1

Abstract

The present invention relates to dicyanoaryl compounds for use in electronic devices, in particular in organic electroluminescent devices, and to electronic devices, in particular organic electroluminescent devices, which contain these materials.

Inventors

  • STOESSEL, PHILIPP

Assignees

  • Merck Patent GmbH

Dates

Publication Date
20260506
Application Date
20240625

Claims (15)

  1. 1. A compound according to formula (I), where the ring Ar z represents an aromatic ring system having 6 to 60 aromatic ring atoms, which may be substituted by one or more radicals R z , where the aromatic ring system may contain Si atoms or Ge atoms which are not directly linked to one another via a bond and the aromatic ring system may comprise one or more ring elements having one or two O atoms and 6 ring atoms, where an O atom is not directly linked to an O atom, Si atom or Ge atom via a bond; the index I represents an integer in the range from 1 to 10 and Ar CN represents a group of the following formula (Ar c ) Formula (Ar c ), where X stands for CR or N, where at most 2 non-adjacent symbols X stand for N, and the dashed bond represents the attachment point of the group Ar CN to the ring Ar z ; where the following applies to the other symbols: R z is identical or different on each occurrence and represents H, D, F, CN, C(Ar') 3 , C(R 1 ) 3 , Si(Ar') 3 , Si(R 1 ) 3 , Ge(Ar') 3 , Ge(R 1 ) 3 , a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, each of which may be substituted by one or more radicals R 1 , where one or more non-adjacent CH2 groups may be replaced by -R 1 C=CR 1 -, Si(R 1 )2 and Ge(R 1 )2, and where one or more H atoms may be replaced by D, F or CN, or an aromatic ring system having 6 to 24 aromatic ring atoms, each of which may be substituted by one or more radicals R 1 . can, two substituents R z can form a ring system with each other, where, if two substituents R z form a ring system with each other, this can comprise several ring elements with 6 ring atoms which contain an O; R stands on each occurrence, identically or differently, for H, D, F, C(Ar') 3 , C(R 1 ) 3 , Si(Ar') 3 , Si(R 1 ) 3 , Ge(Ar') 3 , Ge(R 1 ) 3 , a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, each of which may be substituted by one or more radicals R 1 , where one or more non-adjacent CH2 groups may be replaced by -R 1 C=CR 1 -, Si(R 1 )2 Ge(R 1 )2 and where one or more H atoms may be replaced by D or F, or an aromatic ring system having 6 to 24 aromatic ring atoms, each of which may be substituted by one or more radicals R 1 , where two Substituents R form a ring system; Ar' is, on each occurrence, identically or differently, an aromatic ring system having 6 to 60 aromatic ring atoms which may be substituted by one or more radicals R 1 , where two radicals Ar' which are bonded to the same C atom, Si atom or Ge atom may also be bridged to one another by a single bond or a bridge selected from C(R 1 ) 2 , Si(R 1 ) 2 and Ge(R 1 ) 2 ; R 1 is, identically or differently on each occurrence, H, D, F, CN, C(Ar”) 3 , C(R 2 ) 3 , Si(Ar”) 3 , Si(R 2 ) 3 , Ge(Ar”) 3 , Ge(R 2 ) 3 , a straight-chain alkyl group having 1 to 40 C atoms or a branched or cyclic alkyl group having 3 to 40 C atoms or an alkenyl group having 2 to 40 C atoms, each of which may be substituted by one or more radicals R 2 , where one or more non-adjacent CH2 groups may be replaced by - R 2 C=CR 2 -, -C=C-, Si(R 2 )2 or Ge(R 2 )2 and where one or more H atoms may be replaced by D, F or CN, or an aromatic ring system having 6 to 60 aromatic ring atoms, each of which may be substituted by one or more radicals R 2 ; two or more radicals R 1 may form a ring system with one another; Ar" is, on each occurrence, identically or differently, an aromatic ring system having 5 to 30 aromatic ring atoms which may be substituted by one or more radicals R 2 , where two radicals Ar" which are bonded to the same C atom, Si atom or Ge atom may also be bridged to one another by a single bond or a bridge selected from C(R 2 ) 2 , Si(R 2 ) 2 , and Ge(R 2 ); R 2 is selected on each occurrence, identically or differently, from the group consisting of H, D, F, CN, an aliphatic hydrocarbon radical having 1 to 20 C atoms or an aromatic ring system having 6 to 30 aromatic ring atoms, in which one or more H atoms can be replaced by D, F or CN and which can be substituted by one or more alkyl groups each having 1 to 4 carbon atoms, where two or more R 2 substituents can form a ring system with one another; where the compound according to formula (I) does not comprise an anthracene group and a fluoranthene group.
  2. 2. A compound according to claim 1, characterized in that the group Ar z is selected from structures of the formulas (Ar z -1) to (Ar z -14) where the structures of the formulas (Ar z -1 ) to (Ar z -14) can be substituted by one or more radicals R z and the further symbols have the following meaning: n, m is each independently 0 or 1 , where 0 means that the group Y is not present; Y is C(R Z ) 2 , Si(R z ) 2 , Ge(R z ) 2 , C(R Z )=C(R Z ), an ortho-linked arylene group, a bond or 0; W is C, Si or Ge; Z is C(R Z ) 2 , Si(R z ) 2 , Ge(R z ) 2 or 0; and R z has the meaning given in claim 1.
  3. 3. A compound according to claim 1 or 2, characterized in that the group Ar z is selected from structures of the formulas (Ar z -1 a) to Formula (Ar z -12e) Formula (Ar z -13a) Formula (Ar z -14b) where the dashed bond or bonds represent the attachment point(s) of the ring Ar z to the Group/groups Ar CN are marked/marked and the other symbols have the following meaning: n, m is each independently 0 or 1, where 0 means that the group Y is not present and radicals R z are bonded to the corresponding carbon atoms instead; Y is C(R Z ) 2 , Si(R z ) 2 , Ge(R z ) 2 , C(R Z )=C(R Z ), an ortho-linked arylene group, a bond or 0; W is C, Si or Ge; Z is C(R Z ) 2 , Si(R z ) 2 , Ge(R z ) 2 or 0; k is 0 or 1 ; i is 0, 1 or 2; j is 0, 1 , 2 or 3; h is 0, 1 , 2, 3 or 4; g is 0, 1 , 2, 3, 4 or 5; and R z has the meaning given in claim 1.
  4. 4. A compound according to one or more of claims 1 to 3, characterized in that the compound according to formula (I) has at least one fluorene group or one spiro group.
  5. 5. A compound according to one or more of claims 1 to 4, characterized in that the index I in formula (I) is an integer in the range from 2 to 6.
  6. 6. A compound according to one or more of claims 1 to 5, characterized in that the compound corresponds to one of the following formulas (II-1) to (II-34): Formula (11-1 ) Formula (II-2) where the symbols R and R z have the meaning given in claim 1, the indices and symbols n, m, Y, W and Z have the meanings given in claim 2, and furthermore: k is 0 or 1; i is 0, 1 or 2; j is 0, 1, 2 or 3; h is 0, 1, 2, 3 or 4; and g is 0, 1, 2, 3, 4 or 5.
  7. 7. Compound according to one or more of claims 1 to 6, characterized in that the group Ar CN is selected from structures of the formulas (Ar c -1 ) to (Ar c -3) and/or the group in formulas (11-1 ) to (II-34) is selected from structures of the formulas (Ar c -1 ) to (Ar c -3) where the dashed bond or bonds mark the attachment point of the group Ar CN to the ring Ar z and the other symbols have the following meaning: R a is F, H or D; R b is an aromatic ring system having 6 to 24 aromatic ring atoms, each of which may be substituted by one or more radicals R 1 , where R 1 has the meaning given in claim 1.
  8. 8. A compound according to claim 7, characterized in that the compound according to formula (I) comprises at least one group Ar CN according to formula (Ar c -3).
  9. 9. A compound according to one or more of claims 1 to 8, characterized in that the compound corresponds to one of the following formulas (III-1) to (III-64): Formula (III-3) Formula (III-4) Formula (III-63) Formula (III-64) wherein the symbol R z has the meaning given in claim 1, the symbols and indices n, m, Y, W and Z have the meanings given in claim 2, the symbols R a and R b have the meanings given in claim 9 and furthermore: k is 0 or 1; i is 0, 1 or 2; j is 0, 1, 2 or 3; h is 0, 1, 2, 3 or 4; and g is 0, 1, 2, 3, 4 or 5.
  10. 10. A compound according to one or more of claims 1 to 9, characterized in that at least one radical R, R z is selected identically or differently on each occurrence from the group consisting of an aromatic ring system selected from the Groups of the following formulas Ar-1 to Ar-40 and/or the group Ar' is selected identically or differently on each occurrence from the groups of the following formulas Ar-1 to Ar-40 where R 1 has the meanings given above, the dashed bond represents the bond to the corresponding group and furthermore: Ar 1 is, identically or differently at each occurrence, a divalent aromatic ring system having 6 to 18 aromatic ring atoms, which may each be substituted by one or more radicals R 1 ; A is the same or different on each occurrence and is C(R 1 ) 2; p is 0 or 1, where p = 0 means that the group Ar 1 is not present and that the corresponding aromatic group is directly bonded to the corresponding radical; q is 0 or 1, where q = 0 means that no group A is bonded at this position and radicals R 1 are bonded to the corresponding carbon atoms instead.
  11. 11. A compound according to at least one of the preceding claims, characterized in that the compound comprises at least 4 aryl radicals.
  12. 12. Formulation containing at least one compound according to one or more of claims 1 to 11 and at least one further Compound, wherein the further compound is preferably selected from one or more solvents.
  13. 13. Composition comprising at least one compound according to one or more of claims 1 to 11 and at least one further compound selected from the group consisting of fluorescent emitters, phosphorescent emitters, emitters exhibiting TADF, host materials, electron transport materials, electron injection materials, hole conductor materials, hole injection materials, electron blocking materials and hole blocking materials, preferably host materials.
  14. 14. Use of a compound according to one or more of claims 1 to 11 in an electronic device, preferably as host material, electron injection material, electron transport material or hole blocking material, particularly preferably as electron injection material, electron transport material or hole blocking material.
  15. 15. Electronic device containing at least one compound according to one or more of claims 1 to 11.

Description

Dicyanoaryl compounds for organic electroluminescent devices The present invention relates to dicyanoaryl compounds for use in electronic devices, in particular in organic electroluminescent devices, and to electronic devices, in particular organic electroluminescent devices, containing these materials. In organic electroluminescent devices, phosphorescent organometallic complexes are often used as emitting materials. For quantum mechanical reasons, using organometallic compounds as phosphorescence emitters can result in up to four times the energy and power efficiency. In general, there is still room for improvement in electroluminescent devices, particularly in electroluminescent devices that exhibit triplet emission (phosphorescence). The properties of phosphorescent electroluminescent devices are not only determined by the triplet emitters used. The other materials used, such as matrix materials, are also of particular importance here. Improvements to these materials can therefore also lead to significant improvements in the properties of the electroluminescent devices. In addition, many electroluminescent devices comprise additional layers in addition to an emission layer, such as one or more hole injection layers, hole transport layers, hole blocking layers, electron transport layers, electron injection layers, exciton blocking layers, electron blocking layers and/or charge generation layers. These layers have a significant influence on the performance of electroluminescent devices. In addition, electroluminescent devices that use fluorescent emitters or emitters that exhibit TADF are also known. These electroluminescent devices face corresponding challenges. Among other things, the electroluminescent devices set out above are described in document DE 10 2020 123014 A1. However, the compounds set out in DE 10 2020 123014 A1 relate in particular to materials that exhibit emission. In general, there is still room for improvement in these materials, for example for use as matrix materials, particularly in terms of lifetime, but also in terms of efficiency and operating voltage of the device. The object of the present invention is therefore to provide compounds which are suitable for use in an organic electronic device, in particular in an organic electroluminescent device, and which lead to good device properties when used in this device, as well as to provide the corresponding electronic device. In particular, the object of the present invention is to provide compounds that lead to a long service life, good efficiency and low operating voltage. Electron injection materials, electron transport materials and hole blocking materials in particular contribute to these properties. Furthermore, the properties of the matrix materials, also referred to herein as host materials, also have a significant influence on the service life and efficiency of the organic electroluminescent device. Furthermore, it is the object of the present invention to provide compounds which are characterized by a low refractive index (RI). A further object of the present invention can be seen in providing compounds which are suitable for use in a phosphorescent or fluorescent electroluminescent Devices, in particular as matrix material. In particular, it is an object of the present invention to provide matrix materials which are suitable for green or blue phosphorescent electroluminescent devices and optionally also for red or yellow phosphorescent electroluminescent devices. Furthermore, the compounds, especially when used as host material, electron injection material, electron transport material or hole blocking material in organic electroluminescent devices, should lead to devices that exhibit excellent color purity. Another task can be seen in providing electronic devices with excellent performance as cost-effectively as possible and in consistent quality Furthermore, the electronic devices should be able to be used or adapted for many purposes. In particular, the performance of the electronic devices should be maintained over a wide temperature range. Surprisingly, it has been found that certain compounds described in more detail below solve this problem, are well suited for use in electroluminescent devices and lead to organic electroluminescent devices which have very good properties, in particular with regard to lifetime, color purity, efficiency, operating voltage and refractive index. These compounds and electronic devices, in particular organic electroluminescent devices, which contain such compounds are therefore the subject of the present invention. The present invention relates to a compound according to formula (I), where the ring Ar z represents an aromatic ring system having 6 to 60 aromatic ring atoms, preferably 6 to 30 and particularly preferably 6 to 24 ring atoms, which may be substituted by one or more radicals R z , where the aromatic ring system may contain Si atoms or Ge atoms which are not directly linked t