1395237-95-2Relevant academic research and scientific papers
Biphenyl based non-symmetrical bent-core mesogens containing a chiral moiety and an olefinic end group
Ocak, Hale,Bilgin-Eran, Belkiz
, p. 19 - 30 (2015)
New nonsymmetrical bent-core compounds consisting of a biphenyl-3,4'-diol central unit, a chiral terminal chain and an olefinic end group at the other terminus have been synthesized and characterized to study the influence of a chiral moiety, the length of terminal alkenyl chain, and the number of aromatic rings in the rod-like wings which are substituted at the 3- and 4-position of central biphenyl core on mesophase properties of bent-core mesogens. The liquid crystalline properties of the compounds were investigated by differential scanning calorimetry, optical polarizing microscopy, and electro-optic methods. Depending on the length of the olefinic chain and the number of aromatic rings in the rod-like wings, the bent-core compounds with a chiral moiety show B1 type mesophase, polar smectic C phase (SmCP) or nonmesomorphic behavior.
Effects of molecular chirality on superstructural chirality in liquid crystalline dark conglomerate phases
Ocak, Hale,Bilgin-Eran, Belkiz,Prehm, Marko,Tschierske, Carsten
, p. 7773 - 7783 (2012/09/22)
The first examples of polyphilic bent-core compounds consisting of a biphenyl central core, a chiral terminal chain and an oligo(dimethylsiloxane) end group at the other terminus have been synthesized and characterized. The mesomorphic behaviour of the compounds was investigated by differential scanning calorimetry, optical polarizing microscopy, X-ray diffraction and electro-optic methods. The olefinic precursors show monotropic or enantiotropic B1 type mesophases. The siloxane substituted analogues containing a racemic chain exhibit dark conglomerate phases (DC[*] phases) which are composed of chiral domains with opposite chirality, whereas the siloxane derivatives with a homogeneously chiral moiety show "dark enantiomer" phases (DE* phases) with uniform chirality. Under electric fields, different types of ferroelectric switching (FE) smectic and modulated smectic phases were induced. The effects of chain branching, spacer length and molecular chirality on the stability of the DCFE [*] and DEFE* phases and on the field-induced smectic and modulated smectic phases were investigated. The Royal Society of Chemistry 2012.
