The synthesis and mesomorphic properties of liquid crystals with bulky terminal groups designed for bookshelf geometry ferroelectric mixtures

Shape segregation in molecular organisation: a combined X-ray scattering and molecular dynamics study of smectic liquid crystals

“…20 In some cases, bulky non-polar end-groups have been proposed to preclude liquid-crystalline phases 16 and weaken interlayer interactions 21 due to their volume, but other studies have suggested that such groups may increase the temperature range over which the SmA phase is stable, 18 or enhance the stability of the SmC phase over the SmA phase. 22 It has also been reported that SmC stabilisation by bulky non-polar groups may only occur if the bulky group is not too large. 23 This range of effects arising from altering the steric and electrostatic properties of the end-groups illustrates the complexity in terms of phase structure and behaviour arising from relatively subtle changes in molecular structure, and demonstrates a need for improved understanding of structureproperty relationships in this field.…”

Alignment and electro-optical properties of SmC* with direct transition to N* phases

“…Trifluoroterphenyls are a good example of materials that exhibit wide SmC temperature ranges, direct N to SmC phase transitions and high birefingences (typically Δn ≥ 0.2). [7] In an attempt to increase the cone angle of a chosen trifluoroterphenyl, a silane terminated difluoroterphenyl compound [8] was added at various concentrations, each with 0.5 wt. % of BE80F2N chiral dopant.…”

Synthesis of Some Novel Aromatic Alkynyl Silanes: Mesomorphic Characterization of Ethynyl-Substituted Rod-Shaped Molecules

“…Yield = 1.26 g (73%). (6) [12]. To the 1-(4 -n-pentyloxyphenyl)-2-trimethylsilylacetylene (1 g, 0.38 mmol) was added potassium carbonate (1.0 g, 0.76 mmol) in cold methanol at ambient temperature.…”

“…All benzoic acid derivatives were prepared according to the reported literature procedures [6,29,30]. 1-(4 ;-Hydroxyphenyl)-2-trimethylsilylacetylene (2) [20] was used to prepare the compounds 3a-j.…”

“…Metallomesogens of platinum metal-carbon sigma bond having di(arylethynyl)bis(trimethylphosphine)platinum(II) complex [4] and β-Dgalactopyranoside end-groups containing chiral amphiphilic mesogenic materials with selfassembled nanostructures compounds have been reported [5]. Liquid crystals consisting of a rigid and linear molecular framework with extended π -conjugated electronic structure of difluoroterphenyl core with short and bulky trimethylsilyl terminal groups provide stability to the mesophase [6]. The pyrimidinylphenyldiacetylenes [7], azotolanes [8,9], 1,4-bis(phenylethynyl)benzene [10], 1,4-bis(2-naphthyl)-1,3-butadiynes [11], and high birefringence property having diphenyl-diacetylene-based nematogens [12] are also reported.…”