Veerabhadraswamy, B. N.; Bhat, Sachin A.; Hiremath, Uma S.; Yelamaggad, Channabasaveshwar V. published the artcile< Light-emitting chiral nematic dimers with anomalous odd-even effect>, Category: esters-buliding-blocks, the main research area is liquid crystal chiral oligomers microphase dimer Schiff base; chiral nematic phase; dimers; liquid crystals; odd-even effect; photoluminescence.
In this report, based on the results derived from the extensive study into the thermal and photophys. properties, an anomalous mesomorphic behavior of photoluminescent, chiral nematic (N*) liquid crystalline dimers, belonging to two different series has been revealed. They comprise cholesterol and fluorescent three-ring Schiff base or salicylaldimine core interlinked via an ω-oxyalkanoyloxy spacer of varying length and parity. The effect of mol. structure on the liquid crystal (LC) behavior and photophys. properties of both the series has been probed by varying the length of the terminal n-alkoxy tails for a fixed (odd or even) parity of the spacer. The detailed investigations using complementary techniques not only evidenced the existence of the N* phase in all the dimers synthesized but also the occurrence of an intriguing odd-even effect; blue phases (BPs) exist in all the dimers comprising even-membered spacer, which surprisingly remains totally absent in their odd-membered counterparts. While the results reported hitherto are exactly opposite to the aforesaid findings, this atypical behavior has been interpreted in terms of the over-all shape of the dimers rendered by the orientation of terminal tails. Photophys. studies carried out clearly revealed the intrinsic light emitting feature of the dimers not only in their dilute solutions but also in their three condensed states viz., solid, N* phase, and isotropic liquid state; the emission intensities of the N* phase varies with the change in temperature, as expected. CD spectra of the N* phase recorded as a function of temperature show bisignate CD band characteristically, signifying large chiral correlations in the mol. self-assembly, while the origin of bands from pos. to neg. region suggests a right-handed twist of the N* helix.
ChemPhysChem published new progress about Cholesteric liquid crystals. 112-63-0 belongs to class esters-buliding-blocks, and the molecular formula is C19H34O2, Category: esters-buliding-blocks.
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics