Physico-Chemical Properties of New Liquid Crystals Incorporating a Benzofuran-2-one Skeleton
作者:Yuki Morita、Fusheng Zhang、Takeyasu Tasaka、Remuto Yamaguchi、Hiroaki Okamoto、Shunsuke Takenaka
DOI:10.1246/bcsj.79.163
日期:2006.1
The liquid crystal properties of 3H-2-oxobenzofuran-6-yl 4-(n-CnH2n+1O)benzoates (1-n, n = 5–12), 4′-(n-CnH2n+1O)biphenyl-4-carboxylates (2-n, n = 6–10), and 4-(n-CnH2n+1)benzoates (3-n, n = 4–6) are described. The n = 5–8 homologues of 1-n exhibit a nematic (N) phase, and the n = 8–12 homologues exhibit a smectic A (SmA) phase, where the layer spacing is ca. 1.3 times of the calculated molecular length. The homologues of 2-n show a complex phase-transition behavior involving a smectic C (SmC), two kinds of SmA, reentrant nematic, and N phases, where the SmC phase is exhibited by the n = 6–8 homologues. The layer spacings of SmA phases formed at high and low temperature regions correspond to 1.3 and 1.0 times of the molecular lengths, respectively. The polar interactions around the terminal lactone moiety are assumed to play important roles for the complex polymesomorphism and diversity of the smectic layer structure.
3H-2-氧代苯并呋喃-6-基4-(n-CnH2n+1O)苯甲酸酯(1-n,n = 5–12)、4′-(n-CnH2n+1O)联苯-4-羧酸盐(2-n,n = 6–10)和4-(n-CnH2n+1)苯甲酸酯(3-n,n = 4–6)的液晶性质被描述。1-n 的 n = 5–8 homologues 展现出向列相(N),而 n = 8–12 的 homologues 则表现出 smectic A(SmA)相,其层间距约为计算分子长度的 1.3 倍。2-n 的 homologues 显示出复杂的相变行为,涉及 smectic C(SmC)、两种 SmA、回温向列相和 N 相,其中 n = 6–8 的 homologues 显示出 SmC 相。在高温和低温区域形成的 SmA 相的层间距分别对应于分子长度的 1.3 倍和 1.0 倍。假设端基内酯官能团周围的极性相互作用在复杂的多晶相变和层结构多样性中起着重要作用。