| abstract |
The invention relates to compounds of formula I ##STR1## wherein R 1 is C 12 -C 30 alkyl, R 2 is hydrogen or C 1 -C 30 alkyl, R 3 is C 1 -C 3 -alkyl or C 1 -C 3 alkoxy, R 4 may have one of the meanings of R 3 or is halogen, k and n are each independently of the other 0, 1 or 2, and R 5 and R 6 are each independently of the other C 1 -C 4 alkyl, any of which alkyl groups as defined herein may also be partly fluorinated or perfluorinated, with the proviso that R 1 is alkyl of not less than 18 carbon atoms if R 2 is hydrogen or alkyl of less than 12 carbon atoms. n From these compounds it is possible to prepare molecular aggregates, especially LB layer systems, which have reversible thermochromic and solvatochromic properties. The invention also relates to intermediates of formula II ##STR2## wherein R 1 , R 2 , R 3 and n are as defined above. |