Compounds of the formula, where the symbols and indices used have the following meaning: R 1, R 3 are on each occurrence, identically or differently, H, F, a straight-chain alkyl or alkoxy chain having 1 to 40 C atoms or a branched or cyclic alkyl or alkoxy chain having 3 to 40 C atoms, which may in each case be substituted by R 11, in which, in addition, one or more non-adjacent C atoms may be replaced by N-R 11, O, S, CO, O-CO-O, CO-O, Si(R 11) 2, SO, SO 2, PO(R 11), -CR 11 =CR 11 - or -C≡C- and in which, in addition, one or more H atoms may be replaced by F, Cl, Br, I or CN, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may also be substituted by one or more radicals R 11; with the proviso that at least one of the two radicals R 1 and R 3 is not equal to H; R 2, do not stand for substituents, but instead form a bond to one another, giving a phenanthrene system instead of the dihydrophenanthrene system; R 5, R 6, R 7, R 8, R 9, R 10 are on each occurrence, identically or differently, H, F, Cl, Br, I, CN, NO 2, B(OR 11) 2, a straight-chain alkyl or alkoxy chain having 1 to 40 C atoms or a branched or cyclic alkyl or alkoxy chain having 3 to 40 C atoms, which may in each case be substituted by R 11, in which, in addition, one or more non-adjacent C atoms may be replaced by N-R 11, O, S, CO, O-CO-O, CO-O, SO, SO 2, POR 11, -CR 11 =CR 11 - or -C≡C- and in which, in addition, one or more H atoms may be replaced by F, Cl, Br, I or CN, or an aromatic or hetero-aromatic ring system having 5 to 60 aromatic ring atoms, which may also be substituted by one or more radicals R 11; two or more radicals R 5 to R 10 may also form a further mono- or polycyclic ring system with one another; X is - -; Y is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R 11 or may be unsubstituted; two groups Y may form a ring system with one another; R 11 is on each occurrence, identically or differently, H, a straight-chain alkyl or alkoxy chain having 1 to 22 C atoms or a branched or cyclic alkyl or alkoxy chain having 3 to 22 C atoms, in which, in addition, in each case one or more non-adjacent C atoms may be replaced by O, S, SO, SO 2, CO, O-CO-O, CO-O, -CH=CH-, -C≡C- and in which, in addition, one or more H atoms may be replaced by F, Cl, Br, I or CN, or an aryl, heteroaryl, aryloxy or heteroaryloxy group having 5 to 40 C atoms, which may also be substituted by one or more non-aromatic radicals R 11; n is on each occurrence, identically or differently, 0 or 1, where at least one n is equal to 1; m is on each occurrence, identically or differently, 0 or 1, with the proviso that at least one index m is not equal to 0. R 1, R 3 are on each occurrence, identically or differently, H, F, a straight-chain alkyl or alkoxy chain having 1 to 40 C atoms or a branched or cyclic alkyl or alkoxy chain having 3 to 40 C atoms, which may in each case be substituted by R 11, in which, in addition, one or more non-adjacent C atoms may be replaced by N-R 11, O, S, CO, O-CO-O, CO-O, Si(R 11) 2, SO, SO 2, PO(R 11), -CR 11 =CR 11 - or -C≡C- and in which, in addition, one or more H atoms may be replaced by F, Cl, Br, I or CN, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may also be substituted by one or more radicals R 11; with the proviso that at least one of the two radicals R 1 and R 3 is not equal to H; R 2, do not stand for substituents, but instead form a bond to one another, giving a phenanthrene system instead of the dihydrophenanthrene system; R 5, R 6, R 7, R 8, R 9, R 10 are on each occurrence, identically or differently, H, F, Cl, Br, I, CN, NO 2, B(OR 11) 2, a straight-chain alkyl or alkoxy chain having 1 to 40 C atoms or a branched or cyclic alkyl or alkoxy chain having 3 to 40 C atoms, which may in each case be substituted by R 11, in which, in addition, one or more non-adjacent C atoms may be replaced by N-R 11, O, S, CO, O-CO-O, CO-O, SO, SO 2, POR 11, -CR 11 =CR 11 - or -C≡C- and in which, in addition, one or more H atoms may be replaced by F, Cl, Br, I or CN, or an aromatic or hetero-aromatic ring system having 5 to 60 aromatic ring atoms, which may also be substituted by one or more radicals R 11; two or more radicals R 5 to R 10 may also form a further mono- or polycyclic ring system with one another; X is - -; Y is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R 11 or may be unsubstituted; two groups Y may form a ring system with one another; R 11 is on each occurrence, identically or differently, H, a straight-chain alkyl or alkoxy chain having 1 to 22 C atoms or a branched or cyclic alkyl or alkoxy chain having 3 to 22 C atoms, in which, in addition, in each case one or more non-adjacent C atoms may be replaced by O, S, SO, SO 2, CO, O-CO-O, CO-O, -CH=CH-, -C≡C- and in which, in addition, one or more H atoms may be replaced by F, Cl, Br, I or CN, or an aryl, heteroaryl, aryloxy or heteroaryloxy group having 5 to 40 C atoms, which may also be substituted by one or more non-aromatic radicals R 11; n is on each occurrence, identically or differently, 0 or 1, where at least one n is equal to 1; m is on each occurrence, identically or differently, 0 or 1, with the proviso that at least one index m is not equal to 0.