Synthese chiraler Azobenzole und Untersuchung der in nematischen Fluessigkristallen durch sie induzierten cholesterischen Phasen
The chiral cis- and trans-azo compounds 8a - d and 9a - d with para- or ortho-standing chiral side chains as well as the trans-azoxy derivatives 17a - d and 18a - d are synthesized.The influence of the molecular structure and the distance of the chiral centre from the aromatic nucleus on screw sense and pitch of induced cholesteric phases is investigated.The cis-azo compounds 9c and d show atropisomerism.