A mixture comprising one or more compounds of formula I and one or more compounds of formula II P-Sp-(A 1 -Z 1) a -(A 2 -Z 2) b -(A 3 -Z 3) c -(A 4 -Z 4) d -R I wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings R P, P-Sp-, H, F, Cl, Br, I, -CN, -NO 2, -NCO, -NCS, -OCN, -SCN, SF 5 or straight-chain or branched alkyl having 1 to 25 C atoms, in which, in addition, one or more non-adjacent CH 2 groups may each be replaced, independently of one another, by -C(R 0)=C(R 00)-, -C≡C-, -N(R 00)-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that O and/or S atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by F, Cl, Br, I, CN, P or P-Sp-, P a polymerisable group, Sp a spacer group or a single bond, A 1 and A 3 are trans-1,4-cyclohexylene which is optionally substituted by one or more groups L or P-Sp-, A 2 and A 4 are selected from 1,4-phenylene, pyridine and thiophene, all of which are optionally substituted by one or more groups L or P-Sp-, Z 1-4 -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -OCH 2 -, -CH 2 O-, -SCH 2 -, -CH 2 S-, -CF 2 O-, -OCF 2 -, -CF 2 S-, -SCF 2 -, -(CH 2) n1 -, -CF 2 CH 2 -, -CH 2 CF 2 -, -(CF 2) n1 -, -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH-, -CH 2 -CH 2 -CO-O-, -O-CO-CH 2 -CH 2 -, -CR 0 R 00 -, or a single bond, R 0, R 00 H or alkyl having 1 to 12 C atoms, L F, Cl, -CN, P-Sp- or straight chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein one or more non-adjacent CH 2 -groups are optionally replaced by -CR 0 =CR 00 -, -C=C-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by P-Sp-, F or Cl, R 1, R 2 methyl or methoxy, R 3 OH, methyl, methoxy, phenyl that is optionally substituted by one or more groups L, R, P or P-Sp-, or morpholine-1-yl, a, b, c, d 0, 1, 2 or 3, with a+c≥1, g 1, 2, 3 or 4, n1 1, 2, 3 or 4, r 0, 1, 2, 3 or 4, p 1, 2 or 3, with p+r ≤5, and wherein in formula II in case of g≥2 the groups (P-Sp) p and - C(=O)-CR 1 R 2 R 3 are linked to different terminal benzene rings, and in case of g ≥ 3 all benzene rings are connected with each other via para-positions. R P, P-Sp-, H, F, Cl, Br, I, -CN, -NO 2, -NCO, -NCS, -OCN, -SCN, SF 5 or straight-chain or branched alkyl having 1 to 25 C atoms, in which, in addition, one or more non-adjacent CH 2 groups may each be replaced, independently of one another, by -C(R 0)=C(R 00)-, -C≡C-, -N(R 00)-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that O and/or S atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by F, Cl, Br, I, CN, P or P-Sp-, P a polymerisable group, Sp a spacer group or a single bond, A 1 and A 3 are trans-1,4-cyclohexylene which is optionally substituted by one or more groups L or P-Sp-, A 2 and A 4 are selected from 1,4-phenylene, pyridine and thiophene, all of which are optionally substituted by one or more groups L or P-Sp-, Z 1-4 -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -OCH 2 -, -CH 2 O-, -SCH 2 -, -CH 2 S-, -CF 2 O-, -OCF 2 -, -CF 2 S-, -SCF 2 -, -(CH 2) n1 -, -CF 2 CH 2 -, -CH 2 CF 2 -, -(CF 2) n1 -, -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH-, -CH 2 -CH 2 -CO-O-, -O-CO-CH 2 -CH 2 -, -CR 0 R 00 -, or a single bond, R 0, R 00 H or alkyl having 1 to 12 C atoms, L F, Cl, -CN, P-Sp- or straight chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein one or more non-adjacent CH 2 -groups are optionally replaced by -CR 0 =CR 00 -, -C=C-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by P-Sp-, F or Cl, R 1, R 2 methyl or methoxy, R 3 OH, methyl, methoxy, phenyl that is optionally substituted by one or more groups L, R, P or P-Sp-, or morpholine-1-yl, a, b, c, d 0, 1, 2 or 3, with a+c≥1, g 1, 2, 3 or 4, n1 1, 2, 3 or 4, r 0, 1, 2, 3 or 4, p 1, 2 or 3, with p+r ≤5,