Patent ID: 6217792
Filing Date: 2001-04-17
Classification: C07D,C09K

Abstract:
A chiral dopant of formula I:R.sup.1 --X.sup.1 --MG.sup.1 --G--MG.sup.2 --X.sup.2 --R.sup.2whereinR.sup.1 and R.sup.2 are each independently a straight-chain or branched alkyl radical with up to 25 C atoms which may be unsubstituted, mono- or polysubstituted by halogen or CN, it being also possible for one or more non-adjacent CH.sub.2 groups to be replaced, in each case independently from one another, by --O--, --S--, --NH--, --N(CH.sub.3)--, --CO--, --COO--, --OCO--, --OCO--O--, --S--CO--, --C)--S-- or --C.tbd.C-- in such a manner that oxygen atoms are not linked directly to one another,X.sup.1 and X.sup.2 are independently of each other --O--, --S--, --CO--, --COO--, --OCO--, --OCO--O--, --S-- CO--, --CO--S-- or a single bond,G is the following structure element ##STR23##MG.sup.1 and MG.sup.2 are each independently a mesogenic or mesogenity supporting group of the formula:--(A.sup.1 --Z).sub.m --A.sup.2 --withZ denoting --COO--, --OCO--, --CH.sub.2 CH.sub.2 --, --OCH.sub.2 --, --CH.sub.2 O--, --CH.dbd.CH--, --CH.dbd.CH--COO--, --OCO--CH.dbd.CH--, --C.tbd.C-- or a single bond,A.sup.1 and A.sup.2 being each independently 1,4-phenylene in which, in addition, one or more CH groups may be replaced by N, 1,4-cyclohexylene in which, in addition, one or two non-adjacent CH.sub.2 groups may be replaced by O and/or S, 1,4-cyclohexenylene, 1,4-bicyclo(2,2,2)octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl, or 1,2,3,4-tetrahydronaphthalene-2,6-diyl, it being possible for all these groups to be unsubstituted, mono- or polysubstituted with halogen, cyano or nitro groups or alkyl, alkoxy or alkanoyl groups having 1 to 7 C atoms wherein one or more H atoms may be substituted by F or l, andm being 0, 1, 2 or 3with the proviso that both MG.sup.1 and MG.sup.2 are not simultaneously 1,4-phenylene.