The material characteristics of liquid crystals play a crucial role in shaping the structure, order, and properties of a particular mesophase and its adjacent phases. This is vital for the development of high-performance optoelectronic devices such as liquid crystal displays, light modulators, apertures, and filters. While the elasticity and viscosity constants are seldom measured, they are essential for evaluating a material's applicability. Leveraging the ferroelectric and antiferroelectric properties of smectics enhances various parameters of information visualization devices, including grayscale, switching speed, contrast, and information content [1, 2].

The newly established method for calculating the absolute values of the coefficients related to the linear and quadratic electro-optical effects in low electric fields enables the assessment of elasticity constants (derived from the depth of light modulation) and rotational viscosity (based on frequency dependence), all while maintaining laminar flow and low strain conditions. Additionally, the type and characteristics of the phase transformations that occur in the material being examined can significantly impact both the magnitude of the determined coefficients and their dependence on temperature [3].

This study focuses on reviewing the methods employed to assess viscoelastic effects in ferroelectric and antiferroelectric chiral liquid crystals, their mixtures, composite materials, and even dielectric systems. The goal is to establish a universal method that permits the application of relatively low electric fields. For chiral liquid crystals with ferroelectric and antiferroelectric phases, as well as their subphases, the following principle holds: adherence to Hooke’s law (for elastic coefficients) and maintenance of laminar flow (for viscosity coefficients) [4].

References

[1] D. Dardas, Phase Transitions, 89 (4), 368-375 (2016)

[2] D. Dardas, Rheological Acta, 58, 193-201 (2019)

[3] D. Dardas, S. Lalik , Z. Nowacka, T. Yevchenko, M. Marzec, Crystals, 13, 164 (2023)

[4] D. Dardas, Materials, 17(16), 3993 (2024)

Acknowledgments: The work was supported by the Polish National Science Center, Project No. 2019/03/X/ST3/01516.

This work reports the design, development, and validation of an integrated system that couples electromigration-based lithium isotope separation with controlled crystallization of lithium carbonate enriched in lithium-6 (⁶Li). The research aims to provide a sustainable and scalable technological alternative for isotope enrichment processes, with direct relevance to nuclear materials and next-generation battery applications.

The experimental setup combines a dual-module electromigration cascade with a thermostated crystallization unit, interconnected through a fully automated robotic and fluidic transfer system. This configuration enables continuous operation, real-time process control, and zero-loss transfer of the Li⁶-enriched cathodic solution. Four types of ion-conducting membranes were investigated: Nafion 212, Nafion 117, Celgard 2325, and a novel PEG-crosslinked PS-9 prototype developed at ICSI ENERGY. All membranes were tested under constant potential (5 V) for 120 h, ensuring comparable electrochemical conditions.

Following separation, the Li⁶-enriched cathodic solution underwent a crystallization protocol optimized for pH (7.2–7.5), concentration, and temperature (4 °C). Ammonium carbonate ((NH₄)₂CO₃) was used as a controlled nucleating agent, promoting selective precipitation of Li₂CO₃ (⁶Li). FTIR analysis confirmed the presence of Li–O and CO₃²⁻ vibrational bands, indicating pure lithium carbonate formation. SEM characterization revealed uniform prismatic microcrystals (1–3 µm), with morphology dependent on membrane architecture, well-faceted for Nafion, compact for PS-9, and large aggregates for Celgard.

Crystallization kinetics were evaluated using the Avrami model, yielding n ≈ 2.8 and k = 0.3 h⁻ⁿ, consistent with instantaneous nucleation followed by three-dimensional diffusion-controlled growth. The entire process achieved a Li⁶ recovery of 95.7 ± 0.3% and >98% crystalline purity.

The results confirm the system’s efficiency, reproducibility, and full automation, demonstrating a novel technological pathway for lithium isotope enrichment through synchronized electromigration–crystallization coupling.

Sesquiterpenes are widely regarded as key and often defining compounds within the Artemisia genus. This group of natural products is highly diverse, with more than 5,000 identified molecules to date. They have attracted significant interest due to their broad spectrum of biological activities, including antitumor, antimicrobial, anti-inflammatory, antioxidant, antidiabetic, anti-vitiligo, cytotoxic, and neuroprotective effects [1]. However, despite these beneficial properties, terpenoids may also produce adverse effects such as respiratory distress, central nervous system disturbances, nausea, and vomiting [2]. During the investigation of the chemical composition of Artemisia scotina, the compound artapshin, previously known but lacking a characterized crystal structure, was successfully isolated. Analysis of the spectral data (UV, IR, and NMR), together with comparison to the published literature and an authentic reference sample, confirmed that the isolated compound is artapshin [3]. As part of our continued work, both the isolation and crystal structure of artapshin (1) were further examined. According to the X-ray analysis results, the asymmetric unit in the crystal consists of four molecules of the compound. Compound 1 was found to crystallize in the orthorhombic system (P2₁, Z=4). In the crystal, O—H⋯O and C—H⋯O hydrogen bonds link the molecules into infinite chains with a C₁₅H₂₄O₅ chain motif along the c-axis direction. Hirshfeld surface analysis showed that the structures are dominated by H···H, H···C/C···H and H···O/O···H contacts; these interactions present in the determined molecular structure were characterized as stabilizing factors in the unit cell.

References

1. Fattahian M., et al. Phytochemistry 203: 113411.
2. Ding, L. F., et al. Phytochemistry 216: 113871.
3. Serkerov S. V. et al. Chemistry of Natural Compounds 19(5): 543-546.

1. Introduction—Schiff bases are of significant importance in pharmaceutical chemistry due to their simple synthesis, structural flexibility, and broad biological activities. Sulfanilamide‑derived Schiff bases are particularly advantageous, as they combine the bioactive sulfonamide moiety with the azomethine linkage, often resulting in enhanced antibacterial, anticancer, and enzyme‑inhibitory properties. Their ability to form strong hydrogen bonds and π–π interactions further enhances their potential as therapeutic agents. In this work, we report the microwave-assisted synthesis, FT-IR characterization, crystal structure, Hirshfeld surface analysis, and ADME prediction of a new sulfanilamide-derived Schiff base, namely (Z)-4-(((4,5-dihydroxy-6-oxocyclohexa-2,4-dien-1-ylidene)methyl)-amino)benzenesulfonamide (I).
2. Experimental Section—Compound (I) was synthesized using microwave irradiation. The FT-IR spectra were recorded on a Diamond ATR spectrometer in the 4000–400 cm⁻¹range. Single-crystal X-ray data were collected at 296,15 K on a STOE IPDSII diffractometer, using Mo-Ka radiation and processed using the programs available in Olex2 [5]. Hirshfeld surface analysis was performed using CrystalExplorer21. ADME parameters were estimated using SwissADME(https://www.swissadme.ch).
3. Results and Discussion—The FT-IR spectra indicated the keto-enamine tautomeric form, displaying characteristic bands at 2900 and at 1610 cm^-1 corresponding to enamine and ketostretching modes, respectively. Single-crystal X-ray diffraction revealed that compound (I) crystallizes in the P -1 space group as a keto-enamine tautomer, with two crystallographically independent molecules in the asymmetric unit. The crystal features N–H⋯O, O–H⋯O and C–H⋯O hydrogen bonds, and ?⋯?. Additionally, Hirshfeld surface analysis revealed that O···H/H···O (39.0%), H···H (25.3%), and C···H/H···C (17.2%) contacts dominate the crystal packing, followed by C···C (8.5%). Finally, in silico ADME analysis suggested that (I) exhibits favorable physicochemical properties and good oral absorption, highlighting its potential as a viable pharmacological scaffold.

Conclusions—A new sulfanilamide-derived Schiff base was successfully synthesized and characterized. In silico SwissADME analysis revealed favorable physicochemical properties and good oral absorption, highlighting its potential as a promising pharmacological scaffold.

High potential of cocrystals in drug delivery¹ and functional materials² draws attention to the problems of rational design of cocrystals with desired properties. These properties including stability and solubility are determined by the difference in lattice free energy of a cocrystal and its constituents . Sublimation is used as a green and effective cocrystallization method ^{3, 4}; however, the only reports of cocrystal sublimation thermodynamics consider the systems where only one component is volatile. ^{5, 6}

We introduce the term ‘congruent sublimation’ for equilibrium of the solid cocrystal with the molecular vapor of its components of the same ratio. In the transpiration experiment, the [caffeine + 3-hydroxybenzoic acid] cocrystal vapor was carried by slow stream of nitrogen through a tube furnace and condensed downstream. The sublimate was identified as pure cocrystal by DSC, PXRD and FTIR spectroscopy. Vapor pressures of both components were determined to be close to equal according to HPLC analysis. Sublimation thermodynamic functions were derived according to Clausius-Clapeyron equation and corrected to 298.15 K using experimental solid molar heat capacities and theoretical gas-phase heat capacities. From the experimental sublimation functions of the cocrystal and literature data for pure components, cocrystallization thermodynamic functions were determined. Alternatively, the cocrystallization enthalpy and Gibbs energy were derived from solubility data of the cocrystal and pure components in acetonitrile at five different temperatures between 293 and 313 K.

The equality of vapor pressures of caffeine and hydroxybenzoic acid confirms the congruent sublimation across the experimental temperature range. No gas-phase complexes were observed in the synchronous DSC/TG/MS experiment. The cocrystal formation process was found to be enthalpy-determined. The cocrystallization enthalpy and Gibbs energy values derived from the sublimation and solubility cycles were found to be within 2 kJ/mol, which supports the proposed sublimation mechanism.

Understanding and controlling the structure of molecular crystals is essential for advancing high-performance molecular electronics and biocompatible devices. Among organic semiconductors, rubrene, a tetraphenyl derivative of tetracene, stands out due to its exceptional charge carrier mobility in single-crystal form. In this work, we investigate the crystallographic and molecular orientation of rubrene thin films grown by hot-wall epitaxy on mica substrates using ex-situ polarized Raman spectroscopy.

Polarized Raman spectroscopy provides a powerful, non-destructive approach to probe both molecular anisotropy and chemical identity. By exploiting the symmetry properties of Raman tensors and the polarization dependence of scattered light, we determine the orientation of rubrene molecules within crystalline films. Measurements were performed using a 784 nm polarized laser in a backscattering configuration, with systematic in-plane rotation of the sample to resolve angular-dependent Raman responses.

Rubrene films exhibit a characteristic evolution from an amorphous phase to spherulitic structures and finally to a coalesced crystalline film. Across all growth stages, the Raman breathing mode at 1003 cm⁻¹ remains invariant, serving as a robust spectral fingerprint. To extract molecular orientation, additional internal vibrational modes associated with phenyl groups were analyzed under different polarization conditions. The resulting dataset enabled the construction and iterative solution of Raman tensor elements through a back-and-forth computational approach.

The analysis reveals clear anisotropic behavior and provides quantitative insight into molecular alignment and dipole–dipole interactions within the films. These results demonstrate the capability of polarized Raman spectroscopy to resolve crystallographic properties of organic molecular solids using relatively low-energy excitation, offering a versatile tool for the structural characterization of functional molecular materials.

The five-membered heterocyclic compounds with a heteroatom of the sequence N-N-N are copper(1)-catalysed azide–alkyne cycloaddition reactions. In the case of anticancer drugs, there are several specific requirements: they must be stable and non-differentiating between cancer and non-cancerous cells, have minimal toxicity and lack side effects, requiring different mechanisms for successful treatment. In recent years, 1,2,3-triazoles have become one of the most attractive research objects in heterocyclic chemistry [1]. 1H-1,2,3-Triazoles are used in pharmaceuticals as anti-inflammatory agents and as herbicides in agriculture. In addition, 1,2,3-triazoles have antimicrobial, anti-inflammatory, anti-leishmania, and antidiabetic activities [2]. In the present study, we provide a detailed structural analysis of 3-((1-(p-tolyl)-1H-1,2,3-triazol-4-yl)methyl)thieno[3,2-d]pyrimidin-4(3H)-one (1) based on experimental X-ray diffraction. We conducted a 1,3-bipolar cycloaddition reaction of synthesised propargyl ethers using para-azidobenzoic acid ethyl ether. The progress of the reaction was monitored by thin-layer chromatography. The precipitate was filtered off, dried and recrystallised through methanol; the product was obtained at an 84% yield. Compounds 1 crystallise in the orthorhombic space group Pna2₁. The asymmetric unit of a title compound consists of one molecule. Energy framework analysis is an important quantitative analysis of the interaction energies and architecture of molecules in a single crystal. It can give information on the interaction energy of new triazole organic compounds, for example, and can detect interactions such as C–H··· π, C–O··· π, C–N··· π; in addition, Hirshfeld surface analysis provides information about the interaction between close contacts of hydrogen and another molecule in the triazole compounds. In one crystal, the central 1,2,3-triazole and benzene rings are almost planar. In the crystal structure of the title compound, the molecules are linked by intermolecular C—H⋯O, C—H⋯S, and C—H⋯N hydrogen bonds. These interactions, in combination with C—H⋯Cg, contact form a three-dimensional framework.

The formation of fluid inclusions is often an anathema for many applications of crystallized phases. For instance: Active Pharmaceutical Ingredients (solvent content above ICH guidelines), second harmonic generation (yield in the intensity of the secondary beam and chemical degradation of the SHG material), energetic material (shock sensitivity), solid oxidizers (loss of the rocket booster power) [1-2], etc…

This study focuses on two organic compounds: dicumyl peroxide [3-4] and benzoyl peroxide. Besides the obvious similarity in their formulas and the propensity of dissolved CO₂ to induce the formation of fluid Inclusions [5], these fluid inclusions present different: thermal behaviors, shapes and frequencies which will be detailed. They reveal different formation and relaxation mechanisms. Further extension of these findings to other peroxides are currently under investigations.

1-Evidence of Two Types of Fluid Inclusions in Single Crystals; E. Bobo, B. Lefez, M-C. Caumon, S. Petit, and G. Coquerel; CrystEngComm. 2016, 18, 5287–5295

2- Growth rate dispersion at single crystal level E. Bobo, S. Petit, G. Coquerel; Chemical Engineering & Technology, 2015, 38, (6), 1011-1016

3- Formation mechanism of liquid inclusions in dicumyl peroxide crystals; Zhou, J.; Hao, L.; Hao, H.; Ji, X.; Li, J.; Zhou, L. CrystEngComm, 2021, 23, 4214–4228.

4- Behaviors of Gas-Rich Crystalline Fluid Inclusions. L. Salgado-Paredes, F. Faure, G. Coquerel, Crystals, 2025, 15, 740. https://doi.org/10.3390/cryst15080740

Cross-linked enzyme crystals (CLECs) are highly purified and stabilized biocatalysts produced through enzyme crystallization followed by chemical cross-linking, which locks the enzymes into an insoluble crystalline matrix. This self-immobilization approach exhibits high stability, controllable size, and easy reuse, turning them into particularly attractive and efficient biocatalysts for a variety of applications. Furthermore, CLECs have been explored as microporous platforms for the controlled and sustained release of protein and peptide therapeutics, as integral components of CLECs-based biosensors, and for several promising medical and biotechnological applications [2, 3]. However, their principal limitation is the strict requirement for enzyme crystallization, an expensive, time-consuming, and labor-intensive process that necessitates highly purified enzymes and carefully optimized crystallization conditions [1].

By optimizing crystal morphology and crystallization conditions, CLECs can preserve catalytic activity and selectivity similar to those of soluble enzymes in aqueous media, while also maintaining functional behavior comparable to crude enzymes in organic solvents [3]. In this work, we have purified, crystallized, and produced CLECs of a new penicillin-binding protein showing D-amidase activity from Rhizobium species (RhiDamid). After enzyme characterization in solution, its crystallization conditions were systematically optimized in order to obtain well-formed and stable crystals suitable for further processing. The resulting crystals were then successfully cross-linked with glutaraldehyde to obtain Cross-Linked Amidase Crystals (CLACs), retaining D-amidase catalytic activity after the cross-linking step. Preliminary data regarding the physicochemical and catalytic characterization of these CLACs is presented, highlighting their potential stability and applicability as reusable biocatalysts in future biotechnological developments.

In the history of protein crystallization, one of the earliest purposes of crystallization was separation and purification of proteins from mixtures. Nowadays, the rising demand for pure proteins in biomedicine, biochemical research, and the food industry highlights the need for cost-effective purification methods. Although chromatography dominates large-scale processes, crystallization offers a low-cost alternative for obtaining highly purified products, though its industrial implementation remains challenging.^[1] In this context, crystallization is re-emerging as a promising strategy due to its inherent selectivity and potential for cost-effective scalability.

Phycobiliproteins (PBPs) are water-soluble light-harvesting pigment-proteins from cyanobacteria and red algae.^[2] In addition to their role in photosynthetic energy capture, they exhibit diverse biological activities, including antioxidant, antibacterial, and anticancer effects, which make them promising candidates for biotechnological applications in fields such as biomedicine, bioenergy, and scientific research.^[3] Among PBPs, C-phycocyanin (C-PC) is a high-value pigment widely used in health, food, and analytical applications. Current downstream processes, however, rely mostly on multistep chromatographic workflows that increase production costs and complexity.^[4]

Through this work, we are exploring protein crystallization as an alternative route for C-PC purification from raw materials, aiming to establish its feasibility as a scalable method that integrates high product quality with improved process sustainability. Preliminary results support the potential of crystallization to enhance recovery of C-PC, thereby contributing to more efficient bioprocessing.