Liquid-Crystalline Properties of Alkyl 4-[2-(Perfluorooctyl)ethoxy]benzoates

Abstract

This paper describes the liquid-crystalline properties of alkyl 4-[2-(perfluorooctyl)ethoxy]benzoates (1) and bromo (2) and nitro (3) substituted compounds. For 1, the lower members show a smectic A phase; also the smectic A-isotropic transition temperatures and the latent heats decrease with increasing the carbon number of the hydrocarbon chain. An X-ray examination indicated that the smectic A phase has an interdigited arrangement of molecules. The results are discussed in terms of inter- and intra-layer fluorophilic interactions around the perfluorooctyl groups.

Mesomorphic phase transition behavior of novel triphenylene compounds possessing fluoroalkylated side chains

“…As for the identification of compounds, 1 H NMR (500.0 MHz) and 19 F NMR (376.1 MHz) spectra were obtained on JEOL ALPHA-500 and JEOL JNM-AL400 FT-NMR spectrometers, respectively. MALDI-TOF mass spectra were also measured on a Applied Biosystems/Voyager TM DE STR-D1 spectrometer.…”

“…In general, terminal fluoro-, trifluoromethyl-, and trifluoromethoxy-substituted mesogenic molecules have been shown to be useful by themselves, or as additives for formulated practical mixtures with other more conventional cyano-terminated mesogens, because they are chemically stable and possess moderate positive dielectric anisotropy with lower viscosity [1]. It was reported that the fluorophilic and fluorophobic interactions around fluoroalkyl chains enhance the mesophase thermal stability and facilitates the formations of the smectic phase [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Furthermore, it was reported that the combination of the suitable length of aliphatic chain and the ratio of the perfluorinated alkane segment to the perhydrogenated one in the chain relates to the microsegregation at the molecular level [21][22][23][24][25][26][27][28].…”

Effect of the semi‐fluorinated chiral alkane on the formation of the antiferroelectric phase

“…For example, several studies by different groups show that fluorination of the hydrocarbon chain strongly favours the formation of the smectic phase [1][2][3][4][5][6][7]. In addition to its effect on mesophase formation, fluorination has other benefits for liquid crystal materials such as low viscosity, lower birefringence and enhanced chemical stability [8][9][10][11][12][13][14][15][16].…”

Ferroelectric liquid crystals derived from (S)‐2‐(6‐methoxy‐2‐naphthyl)propionic acid with non‐fluorinated or semi‐fluorinated alkanes at a chiral terminal chain

“…Recently, many studies have focused on the modification of achiral chains by the introduction of a semi-fluorinated alkyl chain, the results indicating that the smectic phase is strongly promoted thereby [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. These, include examples of single-benzene-ring compounds with a semi-fluorinated chain unexpectedly exhibiting stable smectic phase [8][9][10][11][12][13][14]. It may be possible to use one-or two-benzene-ring rigid cores with a semi-fluorinated alkyl chain as a means for molecular design that will introduce a ferroelectric SmC* phase.…”