Bireactive calamitic liquid crystals derived from fluorene ester linkage

Synthesis and properties of new liquid crystals derivatives of 2,7-diethynyl-9,9-dihexylfluorene

“…We used a fixed chain length of six carbon atoms because previous studies have determined that a linear increase in the number of carbon atoms in these chains leads to a minimum of influence in the transition temperatures [14]. Compound 1 was synthesised in two steps starting from fluorene, as reported by Lee et al [16]; after column purification the obtained 2,7-diiodo-9,9-dihexylfluorene was recrystallised from 1-propanol which yields yellow clear crystals.…”

“…A series of synthetic methods have been reported in order to extend the conjugation and to retain the geometric anisotropy in the molecules. Phenylene, biphenylene and thiophene have been coupled by means of the Suzuki reaction to give rise to a great spectrum of molecules with liquid crystalline properties [13,14]. On the other hand, *Corresponding author.…”

“…Ethynyl [17] and fluorene [3,[12][13][14] have contributed separately to the synthesis of luminescent liquid crystals. Here we present the incorporation of both groups in one molecule and we carry out structural variations (Scheme 1) to improve the liquid crystalline properties of the 2,7-diethynyl-9,9-dihexylfluorene core.…”

Crystal structure and mesogenic behaviour of a new fluorene derivative: 9,9-dimethyl-2,7-bis(4-pentylphenyl)-9H-fluorene

“…A remarkable example of a fully hydrocarbon bent mesogenic core is provided by 2,7-diyl-9,9-dialkyl-9H-fluorene. Fluorene-containing materials are mainly investigated as electroluminescent materials for a new generation of flatpanel displays (Redecker et al, 1999;Aldred et al, 2004), while liquid crystalline compounds based on fluorene mesogenic cores are relatively few (Davison et al, 1985;Boardman et al, 2002;Aguilera et al, 2007;Morel et al, 2012). One point that is worthy of being addressed in calamitic liquid crystals containing the fluorene mesogenic core is the effect of the two alkyl tails in position 9 on the mesogenic behaviour.…”

Fluorocarbon and Hydrocarbon Benzodioxocycloalkane (C8–C10) End Groups: Effects on Mesomorphism

“…The interest in the development of new liquid crystal materials continues at a very high level, [1][2][3][4][5][6][7][8] particularly for stable mesophases with broad mesomorphic ranges [9,10] and low viscosities. [11][12][13][14] One of the special interest is liquid crystal compound having alkyl or fluorine-substituted benzodioxane ring, because it offers significant advantages over currently used liquid crystal materials.…”