Acta Crystallogr B Struct Sci Cryst Eng Mater
December 2020
Structural characteristics of solid and liquid crystalline phases of 7OS5 (4-n-pentylphenyl-4'-n-heptyloxythiobenzoate), the achiral smectogenic mesogen with the shortest terminal carbon chain in the nOS5 homologous series, are studied by complementary methods. Simultaneously perfomed X-ray diffraction and differential scanning calorimetry occur to be a powerful tool to study metastable phases. The single crystal structure of a high-temperature phase, supercooled from the room temperature down to -183°C [orthorhombic crystal system; space group Pca2; a = 54.
View Article and Find Full Text PDFThe results of studies conducted by means of complementary methods, differential scanning calorimetry, transmitted light intensity measurements, polarized optical microscopy, the electro-optical method, as well as dielectric relaxation spectroscopy of two new liquid crystal mixtures are presented. The first mixture is an equimolecular binary mixture consisting of two ferroelectric chiral liquid crystals from the homologous series, abbreviated as (S)-MHOBSn. The second mixture is a multicomponent mixture and consists of four mesogens from the homologous series of nOS5 as the base of the mixture, abbreviated as 610712 and chiral MHOBS8.
View Article and Find Full Text PDFThe polymorphism of resorcinol has been complementary studied by combining Raman, time-domain terahertz, and inelastic neutron scattering spectroscopy with modern solid-state density functional theory (DFT) calculations. The spectral differences, emerging from the temperature-induced structural phase transition, have been successfully interpreted with an emphasis on the low-wavenumber range. The given interpretation is based on the plane-wave DFT computations, providing an excellent overall reproduction of both wavenumbers and intensities and revealing the source of the observed spectral differences.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
March 2013
The complementary studies of the mesomorphic properties of a novel antiferroelectric liquid crystal (AFLC) (S)-2-octile 4-S-(4'decyloxybiphenyl-4-tiocarboxy)benzoate, known under MHPSBO10 acronym have been undertaken. The polymorphism has been complementary studied in details by Differential Scanning Calorimetry (DSC), Transmitted Light Intensity (TLI) and Polarization Microscopy (POM). The switching characteristics along with multiple macroscopic parameters describing the mesomorphic properties were determined by using electro-optic measurements, both upon cooling and heating.
View Article and Find Full Text PDFThe temperature-dependent infrared spectroscopy studies of one novel antiferroelectric liquid crystal (AFLC), known under the MHPSBO10 acronym, have been undertaken. The FT-IR measurements have been performed for homeotropic and planar heterogeneous sample geometries. The main order parameters have been determined and followed with temperature.
View Article and Find Full Text PDFThe experimental and theoretical vibrational spectroscopic study of one of a novel antiferroelectric liquid crystals (AFLC), known under the MHPSBO10 acronym, have been undertaken. The interpretation of both FT-IR and FT-Raman spectra was focused mainly on the solid-state data. To analyze the experimental results along with the molecular properties, density functional theory (DFT) computations were performed using several modern theoretical approaches.
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