Organic electroluminescent device

An atropisomer mixture capable of forming diastereomers and having the formula (1)

• wherein
• A is on each occurrence, identically or differently, a condensed aryl or heteroaryl group having 9 to 40 aromatic ring atoms, optionally substituted by R, with the proviso that A is substituted by R in all positions ortho to the bond to B, C, D, E, G, or J, or A if m>1, wherein R is optionally also bonded to B, C, D, E, G, or J, or, if A is a condensed aromatic ring system, that said positions ortho to the bond to B, C, D, E, G, or J, or A if m>1 is blocked by a part of said condensed aromatic ring system;
• and with the further proviso that a single bond about which free rotation is possible is not present in the aromatic or heteroaromatic ring system;
• B, C, D, E, G, and J are on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, optionally substituted by R, with the proviso that B, C, D, E, G, and J are substituted with at least one aromatic radical R in the position ortho to the bond to A, wherein said at least one aromatic radical R is optionally also condensed onto B, C, D, E, G, and J;
• R is on each occurrence, identically or differently, F, Cl, Br, I, a straight-chain alkyl or alkoxy group having up to 40 C atoms, optionally substituted by R1, or a branched or cyclic alkyl or alkoxy group having 3 to 40 C atoms, optionally substituted by R1;
• wherein one or more non-adjacent C atoms are optionally replaced by N—R1, O, S, C═O, O—CO—O, CO—O, SO, SO2, P(═O)R1, Si(R1)2, —CR1═CR1— or —C≡C—, wherein one or more H atoms are optionally replaced by F, Cl, Br, I or CN, or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, optionally substituted by one or more radicals R1, or a combination of two, three, four or five of these systems;
• and wherein two or more radicals R optionally define a mono- or polycyclic, aliphatic or aromatic ring system;
• R1 is on each occurrence, identically or differently, H or an aliphatic or aromatic hydrocarbon radical having up to 20 C atoms;
• n is on each occurrence, identically or differently, 0 or 1;
• m is on each occurrence, identically or differently, 1, 2, 3, 4 or 5;
• and
• wherein said atropisomer mixture has an atropisomeric excess of at least 70%, and
• wherein said at least one atropisomeric organic compound comprises one or more single bonds having an activation energy for rotation about said one or more single bonds of at least 140 kJ/mol.