Influence of molecular structure on the liquid-crystalline properties of 1,5-dihetero-spiro[5.5]undecane- and -dispiro[5.2.5.2]hexadecane derivatives

The synthesis and liquid-crystalline properties of 1,5-dioxa- and 1,5-dithiaspiro[5.5]undecane, 7,16-dioxa-dispiro[5.2.5.2]hexadecane and 1,5,10,14-tetraoxa-dispiro[5.2.5.2]hexadecane derivatives are described. The effects of terminal sub-stituents and molecular structure on the liquid-crystalline properties of these materials are discussed.