The dielectric properties of synclinic (ferroelectric SmC*) and anticlinic (antiferroelectric SmC*) smectic liquid crystals composed of molecules of one chiral version (S) are presented and compared with properties of racemic mixture (R, S), showing SmC and SmC phases. The racemic mixture completely loses its ferroelectric and antiferroelectric properties. Surprisingly, only one dielectric mode observed in the antiferroelectric SmC* phase disappeared in the dielectric response of the racemic SmC phase. Additionally, we observed that in the SmC phase, seen in the racemic mixture, the weak dielectric mode (named the X mode) is detected, which seems to be the continuation of the P mode existing in the racemic SmC. Moreover, this mode in the racemic SmC has nothing to do with the Goldstone mode, typical for the SmC* phase. This paper describes in detail the real and imaginary parts of dielectric permittivity in smectic phases for the enantiomer and racemate with and without a DC field, compares the properties of the X and P modes, and discusses the full scheme of dielectric modes in enantiomer and racemate.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC11243658 | PMC |
| http://dx.doi.org/10.3390/ma17133335 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The continuing significance of chiral agrochemicals.
Pest Manag Sci
January 2025
Heinrich-Heine-University Düsseldorf, Institute of Organic Chemistry and Macromolecular Chemistry, Duesseldorf, Germany.
Chemical crop protection is one of the most cost-effective methods for agriculture, as crop failures can be prevented, and sustainable growth can be enabled regardless of the seasons. Agricultural production must be significantly increased in the future to meet the food needs of a growing world population. However, the continued loss of established active ingredients due to consumer perceptions, changing needs of farmers and ever-changing regulatory requirements is higher than annually new active ingredients introduced to the market.
View Article and Find Full Text PDFLC-MS/MS Analyzing Praziquantel and 4-Hydroxypraziquantel Enantiomers in Black Goat Plasma and Mechanism of Stereoselective Pharmacokinetics.
Biomed Chromatogr
February 2025
Guangdong Provincial key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China.
Praziquantel (PZQ) is the most effective treatment for schistosomiasis, commonly administered as a racemic mixture of the two enantiomers. Despite many reports on the pharmacokinetics of PZQ, the stereoselective pharmacokinetics of PZQ and its major metabolite 4-hydroxypraziquantel (4-OH-PZQ) remain poorly understood in goats. In this study, the chiral LC-MS/MS method was further optimized for separating and quantifying PZQ, trans-4-OH-PZQ, and cis-4-OH-PZQ and their enantiomers and then applied for the molecular pharmacokinetics of three analytes in black goat plasma.
View Article and Find Full Text PDFAmino-Acid-Induced Circularly Polarized Luminescence of Octahedral Lanthanide Cage.
Angew Chem Int Ed Engl
January 2025
Henan Key Laboratory of Crystalline Molecular Functional Materials, College of Chemistry, Zhengzhou University, Zhengzhou, 450001, China.
Chiral metal organic cage compounds with excellent circularly polarized luminescent performance have broad application prospects in many fields. Herein, two lanthanide complexes with luminescent properties in the form of racemic hexagonal octahedral cages were synthesized using a tri (β-diketone) ligand. Eu(CHFO)(HO) exhibited red light emission with high quantum yields of 61 %.
View Article and Find Full Text PDFCuatrec. and (Kunth) Cass.: Chemical and Enantioselective Analyses of Two Unprecedented Essential Oils from Ecuador.
Plants (Basel)
December 2024
Departamento de Química, Universidad Técnica Particular de Loja (UTPL), Calle Paris s/n y Praga, Loja 110107, Ecuador.
This study presents the first chemical and enantioselective analyses of essential oils (EOs) derived from the leaves of two endemic species, Cuatrec. and (Kunth) Cass., from Loja, Ecuador.
View Article and Find Full Text PDFKetamine Reduces Avoidance Responses During Re-Exposition to Aversive Stimulus: Comparison Between ()-Isomer and Racemic Mixture.
Brain Sci
December 2024
Department of Biophysics and Pharmacology, Federal University of Rio Grande do Norte, Natal 59078-900, Brazil.
Background/objectives: Recent studies have investigated the effects of ketamine on fear memory in animals. However, it is unclear if ketamine might affect avoidance memory and emotional behaviors concomitantly. In this study, we compared the effects of (,)- and ()-ketamine in modulating avoidance responses, depression- and anxiety-related behaviors in stressed mice.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!