Metal complexes
The invention relates to iridium complexes that are suitable for use in organic electroluminescent devices, in particular as emitters.
1 . A compound of formula (1)
where the symbols and indices used are as follows:
L 1 is a bidentate subligand which coordinates to the iridium via one carbon atom and one nitrogen atom or via two carbon atoms;
L 2 , L 3 are the same or different at each instance and are monodentate subligands selected from an aryl or heteroaryl group having 5 to 14 aromatic ring atoms or a heteroalicyclic group having 5 to 7 ring atoms, each of which coordinates to the iridium via a carbon atom or a nitrogen atom, each of which is part of the aryl or heteroaryl group or the heteroalicyclic group, and which may be substituted by one or more R radicals;
L 4 is a bidentate ligand or is the same or different at each instance and is a monodentate ligand;
a is 1 when L 4 is a bidentate ligand, and is 2 when L 4 is a monodentate ligand;
V is a group of formula (2) or (3)
where the dotted bonds each represent the position of linkage to the subligands L 1 , L 2 and L 3 , and in addition:
A is the same or different at each instance and is CR 2 —CR 2 or a group of the following formula (4):
where the dotted bond in each case represents the position of the bond of the subligands L 1 , L 2 or L 3 and * represents the position of the linkage of the unit of the formula (4) to the central trivalent aryl or heteroaryl group in formula (2) or to the central cyclohexane group in formula (3);
X 1 is the same or different at each instance and is CR or N;
X 2 is the same or different at each instance and is CR or N; or two adjacent X 2 groups together are NR, O or S, thus forming a five-membered ring, and the remaining X 2 groups are the same or different at each instance and are CR or N; or two adjacent X 2 groups together are CR or N when one of the X 3 groups in the cycle is N, thus forming a five-membered ring, and the remaining X 2 groups are the same or different at each instance and are CR or N; with the proviso that not more than two adjacent X 2 groups in each ring are N;
X 3 is C at each instance in the same cycle or one X 3 group is N and the other X 3 group in the same cycle is C; with the proviso that two adjacent X 2 groups together are CR or N when one of the X 3 groups in the cycle is N;
R is the same or different at each instance and is H, D, F, Cl, Br, I, N(R 1 ) 2 , OR 1 , SR 1 , CN, NO 2 , COOH, C(═O)N(R 1 ) 2 , Si(R 1 ) 3 , Ge(R 1 ) 3 , B(OR 1 ) 2 , C(═O)R 1 , P(═O)(R 1 ) 2 , S(═O)R 1 , S(═O) 2 R 1 , OSO 2 R 1 , a straight-chain alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group may in each case be substituted by one or more R 1 radicals and where one or more nonadjacent CH 2 groups may be replaced by Si(R 1 ) 2 , C═O, NR 1 , O, S or CONR 1 , or an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and may be substituted in each case by one or more R 1 radicals; at the same time, two R radicals together may also form a ring system;
R 1 is the same or different at each instance and is H, D, F, Cl, Br, I, N(R 2 ) 2 , OR 2 , SR 2 , CN, NO 2 , Si(R 2 ) 3 , Ge(R 2 ) 3 , B(OR 2 ) 2 , C(═O)R 2 , P(═O)(R 2 ) 2 , S(═O)R 2 , S(═O) 2 R 2 , OsO 2 R 2 , a straight-chain alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group may in each case be substituted by one or more R 2 radicals and where one or more nonadjacent CH 2 groups may be replaced by Si(R 2 ) 2 , C═O, NR 2 , O, S or CONR 2 , or an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and may be substituted in each case by one or more R 2 radicals; at the same time, two or more R 1 radicals together may form a ring system;
R 2 is the same or different at each instance and is H, D, F or an aliphatic, aromatic and/or heteroaromatic organic radical, especially a hydrocarbyl radical, having 1 to 20 carbon atoms, in which one or more hydrogen atoms may also be replaced by F.
2 . The compound as claimed in claim 1 , wherein the group of the formula (2) is represented by formula (2a) and in that the group of the formula (3) is represented by formula (3a):
where the symbols have the definitions given in claim 1 .
3 . The compound as claimed in claim 1 , wherein the group of the formula (4) is represented by formula (4′):
where the symbols have the definitions detailed in claim 1 and X 2 is the same or different at each instance and is CR.
4 . The compound as claimed in claim 3 , wherein all three A groups are the same group of the formula (4′) with X 2 =CR, or in that two A groups are the same group of the formula (4′) with X 2 =CR and the third A group is CR 2 —CR 2 , or in that one A group is a group of the formula (4′) with X 2 =CR and the two other A groups are the same CR 2 —CR 2 group, or in that all three A groups are the same CR 2 —CR 2 group.
5 . The compound as claimed in claim 1 , wherein the group of the formula (2) is selected from the groups of the formulae (2a-1) to (2d-1) and in that the group of the formula (3) is selected from the groups of the formulae (3a-1) to (3d-1):
where the symbols have the definitions given in claim 1 .
6 . The compound as claimed in claim 1 , wherein the subligand L 1 has a structure of one of the following formulae (L 1 -1) and (L 1 -2):
where the dotted bond represents the bond of the subligand L 1 to V and the other symbols are as follows:
CyC is the same or different at each instance and is a substituted or unsubstituted aryl or heteroaryl group which has 5 to 14 aromatic ring atoms and coordinates in each case to the iridium via a carbon atom and which is bonded to CyD via a covalent bond;
CyD is the same or different at each instance and is a substituted or unsubstituted heteroaryl group which has 5 to 14 aromatic ring atoms or a substituted or unsubstituted heteroalicyclic group having 5 to 7 ring atoms, each of which coordinates to the iridium via a nitrogen atom or via a carbene carbon atom and which is bonded to CyC via a covalent bond;
at the same time, two or more of the optional substituents together may form a ring system.
7 . The compound as claimed in claim 6 , wherein CyC is selected from the structures of the formulae (CyC-1) to (CyC-20), where the CyC group binds in each case at the position identified by # to CyD and at the position identified by * to the iridium:
and in that CyD is selected from the structures of the formulae (CyD-1) to (CyD-23), where the CyD group binds in each case at the position identified by # to CyC and coordinates at the position identified by * to the iridium,
wherein
X is the same or different at each instance and is CR or N, with the proviso that at most two symbols X per ring are N;
W is the same or different at each instance and is NR, O or S, and in CyD may additionally also be CR 2 ;
with the proviso that the symbol X bonded to the bridge Vis C, where the bond to the bridge V is preferably via the position marked “o”.
8 . The compound as claimed in claim 1 , wherein L 1 is selected from the structures of the formulae (L 1 -1-1) to (L 1 -1-3) and (L 1 -2-1) to (L 1 -2-5) that coordinate to the iridium via the two positions identified by *:
where the symbols have the definitions given in claim 1 and “o” represents the position of the bond to the bridge V,
or in that L 1 is selected from the structures of the formula (L 1 -39) or (L 1 -40) that coordinate to the iridium by the two positions identified by *:
where “o” denotes the position of linkage to the bridge V, and in addition:
X is the same or different at each instance and is CR or N;
Z is CR′, CR or N, with the proviso that exactly one Z is CR′ and the other Z is CR or N;
where a maximum of one symbol X or Z in total per cycle is N;
R′ is a group of the following formula (16) or (17):
where the dotted bond indicates the linkage of the group to the subligands of the formula (L 1 -39) or (L 1 -40);
R″ is the same or different at each instance and is H, D, F, CN, a straight-chain alkyl group having 1 to 10 carbon atoms in which one or more hydrogen atoms may also be replaced by D or F, or a branched or cyclic alkyl group having 3 to 10 carbon atoms in which one or more hydrogen atoms may also be replaced by D or F, or an alkenyl group having 2 to 10 carbon atoms in which one or more hydrogen atoms may also be replaced by D or F; at the same time, two adjacent R″ radicals or two R″ radicals on adjacent phenyl groups together may also form a ring system; or two R″ on adjacent phenyl groups together are a group selected from C(R 1 ) 2 , NR 1 , O or S, such that the two phenyl rings together with the bridging group are a carbazole, fluorene, dibenzofuran or dibenzothiophene, and the further R″ are as defined above;
n is 0, 1, 2, 3, 4 or 5.
9 . The compound as claimed in claim 1 , wherein L 2 and L 3 are the same or different at each instance and are selected from the structures of the formulae (L 2 -1)/(L 3 -1) to (L 2 -55)/(L 3 -55), where the groups each coordinate to the iridium at the position identified by * and to the bridgehead V at the position identified by “o”:
where R has the definitions given in claim 1 and the other symbols are as follows:
X is the same or different at each instance and is CR or N, with the proviso that at most two symbols X per ring are N;
W is the same or different at each instance and is NR, O or S.
10 . The compound as claimed in claim 1 , wherein the monodentate ligands L 4 are the same or different at each instance and are selected from the group consisting of carbon monoxide, nitrogen monoxide, alkyl cyanides, aryl cyanides, alkyl isocyanides, aryl isocyanides, amines, phosphines, phosphites, arsines, stibines, nitrogen heterocycles, carbenes, hydride, deuteride, fluoride, chloride, bromide, iodide, alkylacetylidene, arylacetylidene, cyanide, cyanate, isocyanate, thiocyanate, isothiocyanate, aliphatic or aromatic alkoxides, aliphatic or aromatic thioalkoxides, amides, carboxylates or aryl groups, and in that the bidentate ligands L 4 are selected from the group consisting of diamines, imines, diimines, heterocycles containing two nitrogen atoms, diphosphines, 1,3-diketonates derived from 1,3-diketones, 3-ketonates derived from 3-keto esters, carboxylates derived from aminocarboxylic acids, salicyliminates derived from salicylimines, dialkoxides derived from dialcohols, dithiolates derived from dithiols, bis(pyrazolylborates), bis(imidazolyl)borates, 3-(2-pyridyl)diazoles, or 3-(2-pyridyl)triazoles;
or L 4 is a ligand of one of the formulae (L 4 -1), (L 4 -2) and (L 4 -3):
where the symbols used are as follows:
CyC is the same or different at each instance and is a substituted or unsubstituted aryl or heteroaryl group which has 5 to 14 aromatic ring atoms and coordinates in each case to the metal via a carbon atom and which is bonded to CyD via a covalent bond;
CyD is the same or different at each instance and is a substituted or unsubstituted heteroaryl group which has 5 to 14 aromatic ring atoms and coordinates to the metal via a nitrogen atom or via a carbene carbon atom and which is bonded to CyC via a covalent bond;
at the same time, two or more of the optional substituents together may form a ring system;
or L 4 is a ligand of one of the formulae (L 4 -19) to (L 4 -24), where these ligands each coordinate to the iridium via the two atoms identified by *:
where R has the definitions given in claim 1 and X is the same or different at each instance and is CR or N, with the proviso that not more than two X are N.
11 . A formulation comprising at least one compound as claimed in claim 1 and at least one further compound and/or a solvent.
12 . An electronic device comprising at least one compound as claimed in claim 1 .
13 . The electronic device as claimed in claim 12 , which is an organic electroluminescent device, wherein the compound is used as emitter in an emitting layer in combination with one or more matrix materials selected from the group consisting of ketones, phosphine oxides, sulfur oxides, sulfones, triarylamines, carbazole derivatives, biscarbazoles, bridged carbazole derivatives, indolocarbazole derivatives, indenocarbazole derivatives, azacarbazoles, bipolar matrix materials, azaboroles, boronic esters, diazasilole derivatives, diazaphosphole derivatives, triazine derivatives, zinc complexes, dibenzofuran derivatives, dibenzothiophene derivatives or triphenylene derivatives.