1107064-47-0Relevant articles and documents
Highly frustrated liquid crystal phases in optically active dimers: Synthesis and rich phase transitional behavior
Nayak, Rashmi Ashwathama,Bhat, Sachin A.,Shanker,Rao, D. S. Shankar,Yelamaggad
, p. 2148 - 2162 (2019)
Herein we report on the synthesis and characterization of four new series of optically active, nonsymmetric dimers in which cholesterol is covalently linked to a Schiff base core through an ω-oxyalkanoyl spacer. While the Schiff base core is substituted with n-butyloxy, n-hexyloxy, n-octyloxy, n-decyloxy and n-dodecyloxy tails, three even-parity spacers, namely, 4-oxybutanoyl, 6-oxyhexanoyl, 8-oxyoctanoyl, and an odd-parity spacer, namely, 5-oxypentanoyl, have been used to join the two cores. The experimental results show that the length and parity of the spacer and the length of the terminal tail play a vital role in deciding the phase sequences of the dimers. In general, the dimers possessing an even-parity spacer display enantiotropic LC phases such as chiral nematic (N?), twist grain boundary (TGB), smectic A (SmA), chiral smectic C (SmC?) and twist grain boundary phase with SmC? slabs (TGBC?). Some of these dimers display TGBC? over a wide temperature range. The dimers with an odd-parity (5-oxypentanoyl) spacer display, unlike their even-membered counterparts, blue phases (BPIII/II/I); besides, they stabilize N? and/or unknown smectic (SmX) phases. The circular dichroism (CD) measurements were carried out as a function of temperature on the planar texture formed by three even-membered dimers and an odd-membered dimer. The occurrence of a strong negative CD band in the N? phase of the even-membered dimers suggests a left-handed screw sense of the macroscopic helical structure, and the scenario is opposite in the case of an odd-membered dimer.
Synthesis and characterization of cholesterol-based nonsymmetric dimers terminated with ferrocenyl core
Majumdar,Chakravorty, Santanu,Pal, Nilashish,Sinha, Randhir K.
, p. 7998 - 8006 (2009)
The molecular design, synthesis, and thermal behavior of cholesterol-based nonsymmetric dimers, which can also be regarded as metallomesogens, consisting of either two- or three-ring aromatic cores terminated with ferrocenyl unit are reported. The spacer
Room temperature helical fluids in single-component systems
Shanker,Bindushree,Chaithra,Pratap,Gupta, Ravindra Kumar,Achalkumar,Yelamaggad
, p. 849 - 858 (2018/12/10)
Technologically significant chiral nematic (N*) phase is a helicoidal superstructure, that is generally formed by the spontaneous self-assembly of entire chiral mesogens (mostly calamitics) or by the LC mixtures where a chiral dopant is being added to the
Synthesis and characterization of cholesterol-based tetramers
Majumdar,Ponra,Chakravorty
, p. 113 - 119 (2011/05/12)
Novel symmetrical liquid-crystal tetramers were designed and synthesized. The length of the central spacer and the outer spacers has been varied. The molecular structures of the target compounds were confirmed by Fourier transform infrared and proton nucl
Synthesis and characterization of novel cholesterol based mesogenic compounds using 'click' chemistry
Majumdar,Mondal, Shovan,Sinha, Randhir K.
, p. 1255 - 1260 (2010/09/17)
An efficient route for the synthesis of hitherto unreported non-symmetric dimesogens consisting of a cholesteryl moiety and an aromatic mesogenic unit interconnected through a pentamethylene or decamethylene spacer by Cu(i)-catalyzed azide-alkyne cycloadd
Synthesis and thermal behavior of chiral oligomers derived from cholesterol
Majumdar,Chakravorty,Pal,Rao, Nandiraju V.S.
experimental part, p. 152 - 157 (2009/04/07)
Synthesis and thermal properties of a series of Schiff base oligomers derived from naturally occurring cholesterol are described. In particular, four of them show smectic A and/or chiral nematic phase/s or an unknown mesophase, while the other is non-meso
