X-ray Photgraphic Studies of Liquid Crystals: IV. The Isotropic, Nematic, and Smectic A Phases of Some 4-Alkoxybenzal-4′-Ethylanilines
X-ray Photgraphic Studies of Liquid Crystals: IV. The Isotropic, Nematic, and Smectic A Phases of Some 4-Alkoxybenzal-4′-Ethylanilines
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液晶的 X 射线摄影研究：IV. 一些 4-烷氧基苯甲醛-4-乙基苯胺的各向同性、向列相和近晶 A 相
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发表时间：
1973
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影响因子：
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通讯作者：
A. D. Vries
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作者：
A. D. Vries
摘要 根据一些 4-烷氧基苯甲醛-4′-乙基苯胺 (CnH2n+1O—C6H4—CH=N—C6H4—C2H5; n = 5, 6, 7) 的 X 射线照片，我们计算了各向同性、向列型和近晶 A 相中相邻平行分子之间的平均分子间距离 (D)、各向同性相分子的表观长度 (l) 和厚度(d) 近晶层。近晶相和向列相的所有 D 值均在 4.94 和 5.03 A 之间。在各向同性相中，C6 和 C7 的 D 与 t 图的斜率（分别为 0.0024 和 0.0028 A/°C）大约等于之前报道的值，但对于 C5，斜率稍大一些（0.0038）。向列相的 D 与 t 图的斜率约为 0.01 A/°C，而对于 C7 的近晶相，斜率约为该斜率的一半；对于向列相，斜率似乎随着稳定范围长度的减小而增加。所有 l 与 t 图都绝对是凹的。将曲线外推到 N-I 点得出 l 值...
Abstract From X-ray photographs of some 4-alkoxybenzal-4′-ethylanilines (CnH2n+1O—C6H4—CH=N—C6H4—C2H5; n = 5, 6, 7) we have calculated the average intermolecular distance (D) between neighboring parallel molecules in the isotropic, nematic and smectic A phases, the apparent length (l) of the molecules in the isotropic phase, and the thickness (d) of the smectic layers. All D values for the smectic and nematic phases are between 4.94 and 5.03 A. In the isotropic phase, the slopes of the D versus t plots for C6 and C7 (0.0024 and 0.0028 A/°C, respectively) are approximately equal to those reported earlier, but for C5 the slope is somewhat larger (0.0038). The slopes of the D versus t plots for the nematic phase are of the order of 0.01 A/°C, and for the smectic phase of C7 the slope is about half of this; for the nematic phases the slope appears to increase with decreasing length of the stability range. All l versus t plots were definitely concave. Extrapolation of the curves to the N-I point yielded l valu...