New series of 4-(4′-octyloxybiphenyl-4-yloxymethyl)benzoic acid derivatives with mesogenic properties
作者:Jadwiga Szydłowska、Damian Pociecha、Ewa Górecka、Dorota Kardaś、Józef Mieczkowski、Jan Przedmojski
DOI:10.1039/a805151h
日期:——
Three homologous series of (4â²-octyloxybiphenyl-4-yloxymethyl)benzoic acid derivatives were synthesised and studied. The compounds, substituted by n-alkyl esters, reveal strong discrimination of the tilted phases formation upon elongation of the alkyl group. In compounds with 2 methylalkyl chains, tilted phases were exclusively observed with both ferroelectric and antiferroelectric properties. It has been observed that for chiral derivatives an elongation of the chiral chain leads to odd-even effect on the polar properties. Also elongation of non-chiral alkoxy terminal chains affects the polar properties. For short homologues the antiferroelectric phases dominate, while for long homologues only ferroelectric behaviour is observed. The influence of strongly polar lateral groups (Cl, Br, NO
2
) attached to the biphenyl ring on LC phase properties was also determined. It was detected that mono-substituted compounds have lower mesogenic stability then their disubtituted counterparts. The effect is probably related to restricted rotation around the phenyl-O bond that leads to a more rigid core structure.
合成并研究了三个同系系列的(4-辛氧基联苯-4-基氧基甲基)苯甲酸衍生物。这些被正烷基酯取代的化合物显示出在烷基伸长时对倾斜相形成的强烈区分。在具有 2 个甲基烷基链的化合物中,仅观察到具有铁电和反铁电性质的倾斜相。据观察,对于手性衍生物,手性链的延长会导致极性性质的奇偶效应。非手性烷氧基末端链的延长也会影响极性特性。对于短同系物,反铁电相占主导地位,而对于长同系物,仅观察到铁电行为。强极性侧基(Cl、Br、NO)的影响
2
)还测定了连接到联苯环上的 LC 相性质。据检测,单取代化合物的介晶稳定性低于其二取代化合物。这种效应可能与苯基-O 键周围的旋转受限有关,从而导致核心结构更加刚性。