SOME 3-RING ESTERS CONTAINING A PYRAZINE RING - A COMPARISON OF THEIRLIQUID-CRYSTAL PROPERTIES

Two novel series of pyrazine-containing esters, together with an analo gous phenyl system have been prepared, and their liquid crystalline ph ase behaviour compared in order to establish how the replacement of a phenyl ring by a pyrazine ring affects the liquid crystal behaviour of these esters. Both of the heterocyclic-containing ester series show s ignificant suppression of the smectic phases, and some suppression of the nematic phase, when compared with the non-heterocyclic series.