Liquid crystalline 1,1Ј : 4Ј,1Љ-terphenyls with three and four lateral fluoro substituents and alkyl or alkoxy substituents in the 4-and 4Ј-positions have been synthesised. Synthetic strategies employed were convergent and involved the use of arylboronic acids and aryl halides in palladium-catalysed cross-coupling reactions. These syntheses are of particular interest because issues of selective metallation (at positions ortho to a fluoro substituent) and selective coupling reactions (bromo versus iodo sites) are involved, not all of which proceed as expected. All the trifluoroterphenyls and most of the tetrafluoroterphenyls generate the smectic C phase, the phase stability and temperature range of which were found to be highly dependent upon the relative lengths of the two terminal chains. The 2,2Ј,3and 2,2Ј,3,3Ј-patterns of lateral fluoro substitution in 1,1Ј : 4Ј,1Љ-terphenyls generate materials of high lateral dipole and enable the formulation of ferroelectric mixtures with a high dielectric biaxiality which is very important in τV minimum driving schemes.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

No abstract

No abstract

No abstract