The Synthesis of Fluorine Containing Phenyl Benzoates and Their Properties as Liquid Crystals

The effect of fluorinated terminal chains on the mesomorphic properties of 4,4′‐disubstituted phenyl benzoates

“…Synthesis of the acid 5 and its properties were reported earlier. Our melting temperature (189-192uC) was higher than that reported by [12] but agreed with the values reported by others [13][14][15]. Additionally, their 1 H NMR chemical shifts (d, PPM) of 7.31 and 7.47 do not agree with either our data or other reported data (7.87 and 8.30) [15].…”

“…Perfluorinated alkyl chains attached directly to the benzene ring either on the phenolic side (4) or the acid side (7) were prepared by copper catalysed coupling [8] of the perfluorinated iodide with either 4-iodophenol or 4-iodobenzoic acid to give the phenol 3 and the acid 5, respectively, which were esterified to the esters (scheme 1). Some of these types of intermediates and esters were prepared earlier by others [9][10][11][12][13], usually by the same methods. Our workup procedures varied from these and usually different chain lengths were prepared.…”

“…This acid was prepared by treating 4-iodobenzoic acid with tridecafluorohexyl iodide in the same manner as for the phenol 3 [10,13]. The crude product was recrystallized from abs EtOH to give the acid 5 as a colourless solid: m.p.…”

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

“…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].…”

Mesomorphic properties of symmetrical and asymmetrical triphenylene homologues possessing fluoroalkylated side chains

“…As for rod-like liquid crystals, a large number of liquid-crystalline materials incorporating fluoroalkyl chains have been synthesized. It has been reported that 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 has been reported that the combination of a 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].…”