Kristallin‐flüssige trans‐4‐n‐Alkylcyclohexan‐carbonsäurephenylester

Abstract

Liquid Crystalline Phenyl‐trans‐4‐n‐alkylcyclohexanecarboxylates The syntheses of p‐substituted phenyl‐trans‐4‐n‐alkylcyclohexanecarboxylates 1–12 and cyclohexyl‐p‐n‐alkylbenzoates 15–17 and their mesomorphic properties are described. p‐n‐Alkoxyphenyl‐trans‐4‐n‐alkylcyclohexanecarboxylates 1–8 exhibit larger thermal stability of mesophases than analogous phenylbenzoates 13. Trans‐4‐subst. cyclohexyl‐p‐n‐alkylbenzoates 15–17 and S‐phenyl‐thiocylohexanecarboxylates 19 on the other side are less stable.

Chiral Dopants Derived from Ephedrine/Pseudoephedrine: Structure and Medium Effects on the Helical Twisting Power

“…For comparison, the commonly used chiral dopant CB15 ((S)-4-cyano-4 -(2-methylbutyl)biphenyl, Merck KGaA) has been involved in our measurements. As host systems, two differing nematic matrices have been selected: The multi-component mixture MLC-6650 (Merck KGaA) and the single component trans-4-n-butylcyclohexancarboxylic acid 4 -n-hexyloxyphenylester (BCHOP) [15]. As it is apparent from Table 2, both systems differ significantly with respect to their thermal, optical and dielectric behavior.…”

Ketonization in Calamitic Liquid Crystals

“…These results can be explained in terms of a reduction in the effective conjugation of the p-electron system, resulting in a shorter resonance wavelength of the UV absorption spectrum for the corresponding liquid crystals without the terminally introduced keto groups than for ketones [18], and the alkoxy derivatives show similar behavior (compounds 3-1 and 3-2, approximately). 38 V. F. Petrov…”

4′-Alkylseleno-4-cyanobiphenyls, nSeCB: synthesis and substituent effects on the phase-transition and liquid crystalline behaviors

“…51 However, their alkoxy-based homologs exhibit the odd-even oscillation at phase-transition temperatures, particularly at T NI or T IN . 52 The phase-transition temperatures of the alkoxymethylene-based homologs are considerably lower than those of their alkoxy counterparts. These trends were ascribed to the high flexibility of the alkoxymethylene group due to the lower internal rotational barrier of the C(sp 3 )-O bond and Ph-CH 2 -R moiety than those of the C(sp 3 )-CH 2 bond 53 and Ph-O-R moiety, [44][45][46] respectively [Fig.…”