The present work explores the viscoelastic properties of a homologous series of organosilicon fluids (polymethylsiloxane fluids) using the acoustic resonant method at a frequency of shear vibrations of approximately 100 kHz. The resonant method is based on investigating the influence of additional binding forces on the resonant characteristics of the oscillatory system. The fluid under study was placed between a piezoelectric quartz crystal that performs tangential oscillations and a solid cover plate. Standing shear waves were established in the fluid. The thickness of the liquid layer was much smaller than the length of the shear wavelength, and low-amplitude deformations allowed for the determination of the complex shear modulus G* in the linear region, where the shear modulus has a constant value. The studies demonstrated the presence of a viscoelastic relaxation process at the experimental frequency, which is several orders of magnitude lower than the known high-frequency relaxation in liquids. In this work, the relaxation frequency of the viscoelastic process in the studied fluids and the effective viscosity were calculated, and the lengths of the shear wave and the attenuation coefficients were determined.

To address gaps in the characterization of Roman chamomile (Anthemis nobilis L., Asteraceae)—an ethnobotanically and commercially important species—we profiled its essential oil (EO), focusing on esters that are incompletely characterized or unreported. Comprehensive GC-MS of two commercial EOs and their chromatographic fractions, combined with synthesis and co-injection of reference compounds, enabled the identification of 190 constituents. We uncovered a homologous series of angelates, tiglates, and senecioates by partial-ion-current (PIC) screening (m/z 55, 83, 100, 101), augmented by co-injection and NMR confirmation. Among these EO constituents, four esters, methallyl 3-methylbutanoate (6h), methallyl senecioate (3h), 3-methylpentyl 2-methylbutanoate (5c), and 5-methylhexyl angelate (2g) are reported here as new natural products and previously unreported compounds in the literature. Selected methacrylates and related α,β-unsaturated esters underwent model Michael additions to methanethiol (generated in situ from dimethyl disulfide and NaBH4), confirming their thiol-acceptor reactivity. In an Artemia salina assay, the EO and most esters were non-toxic; methacrylates showed only low toxicity at the highest concentrations. These results refine the chemical map of A. nobilis EO and highlight specific ester families for future mechanistic and biological evaluation.

Helicenes are chiral π-conjugated molecules whose properties strongly depend on their lengths. Systematic studies of these compounds have been limited by synthetic challenges. Here we report a concise two-step strategy (defined as the helicene-forming sequence from aminohelicene precursors) to access a homologous series of tetraaza[7]-[15]helicenes. Optical spectra converge beyond [11]H, defining a conjugation ceiling, while chiroptical responses amplify sharply, yielding |glum| up to 0.028. Fluorescence quantum yields show a nonmonotonic dependence, with [7]H and [15]H maintaining both high ΦF (0.39 and 0.36) and large |glum|, resulting in outstanding, albeit semi-quantitative, CPL performance, with figures of merit reaching 0.010 and CPL brightness values of approximately 490. TD-DFT calculations attribute this amplification to the delayed alignment of electric and magnetic transition dipoles, while 1H NMR shifts of inner protons provide an independent probe of structural reorganization within the helical cavity. Additionally, experiment and theory have consistently identified [11]H as the critical helicene length at which the framework undergoes a qualitative transition. Notably, the [15]helicene constitutes the longest helicene ever resolved into its enantiomers, underscoring the synthetic power of this modular approach. Importantly, our synthetic route is effective for constructing higher-order helicenes, offering a generalizable platform for length-controlled, heteroatom-containing helicenes. These findings establish long tetraazahelicenes as a rare platform where through-bond conjugation and through-space orbital coupling act cooperatively to govern photophysical and chiroptical properties.

Systematic evaluation of homologous series plays a pivotal role in synthetic and medicinal chemistry. Despite their structural resemblance, the preparation of homologues often requires individual synthetic planning tailored to distinct precursors and reactions. Here we introduce a strategy that integrates single-carbon insertion into established methods, specifically redirecting alkene vicinal difunctionalization towards direct routes for 1,3-difunctionalized products. This transformation is enabled by a designer methylene dication reagent, iodomethylthianthrenium salt, which facilitates the photocatalytic conversion of alkenes into linchpin 1,3-dielectrophilic intermediates, allowing seamless incorporation of nucleophiles at distal positions. Mechanistic studies suggest that the reaction proceeds via an α-thianthrenium methyl radical with unusual ambiphilic reactivity governed by multiple stereoelectronic effects. This approach shows high compatibility in pharmaceutical and late-stage settings, providing broad access to diverse 1,3-difunctionalized products, including azetidines, 1,3-diazides and 1,3-dihalides. This work establishes 'homologative alkene difunctionalization' as a powerful platform for repurposing ubiquitous alkenes as meritorious synthetic intermediates to unveil heretofore unknown 1,3-substitution patterns.

The recently discovered heliconical ferroelectric nematic (NTBF) phase is a unique example of spontaneous chiral symmetry breaking in a proper ferroelectric fluid. In this study, we investigate four homologous series of mesogenic compounds, differing in the degree of fluorination of the mesogenic core and bearing lateral alkoxy substituents of varying lengths, to understand how molecular architecture influences the formation and stability of the NTBF phase. Increasing the length of the lateral chain lowers the phase transition temperatures and suppresses smectic layer formation, enabling the emergence of the NTBF phase which replaces the orthogonal ferroelectric smectic A (SmAF) phase. This indicates a competition between lamellar and heliconical polar ordering, driven by the interplay of strong molecular dipoles and the self-segregation of chemically incompatible molecular segments that typically favour layered structures. Notably, the NTBF phase in these compounds exhibits exceptionally short helical pitch lengths, on the order of a few hundred nanometers, as revealed by selective light reflection and atomic force microscopy (AFM). Furthermore, for one of the studied compounds AFM imaging revealed a regular array of screw dislocations within the NTBF phase, suggesting a possible link to more complex modulated or twist-grain-boundary-like structures.

A homologous series of (E)-4-[(4-decyloxyphenyl)diazenyl]phenyl alkanoates (10OABOOCm, m = 1-19) was synthesized and investigated for thermal, structural, and photoresponsive properties. Phase behavior was studied by polarized optical microscopy, differential scanning calorimetry, and thermo-optical analysis. All derivatives exhibited liquid crystalline properties: nematic phase for short chains (m = 1-11), smectic A for two derivatives (m = 1 and 2), smectic C for most compounds (m = 2-19), additional hexatic smectic phases in narrower ranges (SmF: m = 6-13; SmI: m = 9-19), and crystal-like G phase (m = 2-9). X-ray diffraction and Fourier transform infrared spectroscopy confirmed layered packing and characteristic intermolecular interactions, while dielectric spectroscopy revealed relaxation processes in the crystalline phases. UV-vis absorption demonstrated efficient E-Z photoisomerization in solution, with a photostationary state reached within ∼100 s and a rate constant k = 2.81 × 10-2 s-1. These findings show that the terminal chain length influences mesophase formation, molecular organization, and photoresponsivity in this family of azobenzene-based liquid crystals.

Moving beyond the engineering of known materials and elemental substitution within common structure types is critical for designing unique properties. Here, we present a new homologous series, ACu2Q2(MQ2)n (A = Sr, Ba, 2Na; MQ2 = ZrS2, HfSe2), establishing 11 new members. In β-BaCu2Q2 and Na2Cu2Se2 (n = 0), the [Cu2Q2]2- motifs extend in two dimensions, whereas those in α-BaCu2Q2 extend in three dimensions. Hence, there are two structural evolutions within the ACu2Q2(MQ2)n family driven by the polymorphism of the host structures. MQ2 (n → ∞) displays 2D layers of edge-sharing [MQ6]8- octahedra that are 1-octahedron-thick and connected via van der Waals bonding. Each insertion of MQ2 into ACu2Q2 incorporates [MQ6]8- octahedra extending infinitely in one direction, confined to being 1-octahedron-thick in the second direction, with n controlling the number of [MQ6]8- octahedra in the third direction. Therefore, increasing n predictively expands the [Cu2MnQ2n+2]2- network in the direction controlled by n and relative to the A+/A2+ ions. We demonstrate that for a given set of elements, one can enforce a "Host(Insertion)n" formula to systematically evolve both crystal and electronic structures from the host (n = 0) to the insertion (n → ∞) materials through intermediate values of n. Specifically, the energetic misalignment of the electronic band extrema of the parents predictively determines the band extrema and the resulting band gaps of all intermediate n members.

It is known that medicinal thermal and mineral waters have a beneficial effect on the human body due to the high content of minerals. As a rule, the therapeutic effect of thermal mineral waters on human health is associated with the inorganic dissolved fraction. For example, various silicon compounds, such as silicic acid, in combination with water temperature, prove useful when using thermal waters in various resorts and balneological clinics. However, these waters, along with inorganic components, contain a variety of dissolved organic substances, which are also likely to have medical significance. On the one hand, they may have a beneficial effect on the human body; on the other hand, cause harm due to the presence of toxic compounds. Various issues of the balneological influence of organic components in the Altai Territory hot springs, as well as their probable negative impact, are considered in this manuscript. Using the method of capillary gas chromatography-mass spectrometry and solid-phase extraction of the Belokurikha deposit thermal waters in the Altai Territory, it has been identified various hydrocarbons and their derivatives, constituting 16 homologous series, and revealed the prevalence of aliphatic (mainly normal and iso-alkanes) and aromatic hydrocarbons (arenes and heteroaromatic compounds). Besides, in thermal waters it has been found carboxylic acids and their esters. Their origin in the studied Belokurikha hot springs is associated with biogenic processes, including bacterial activity. A number of identified components may indicate minor man-made pollution. According to the results of the study, the presence of such components as carboxylic acids, esters, aldehydes, ketones, alcohols, and molecular sulfur in the medicinal waters has a positive effect on the population health in the Belokurikha resort. Although toxic compounds of benzene and its derivatives are present in the Belokurikha waters, their concentrations are not high and do not pose a danger to human health.

Defect concentrations in crystalline matter can be tuned by growth and postsynthesis processing conditions. Point defects may condense into extended defects, and their ordering into periodic arrays creates novel materials. We show that Mo-rich mirror-twin grain boundary (MTB) loops in MoTe2 arrange into periodic phases under conditions that balance Te-chemical potential and thermal activation. These MTB phases give rise to a homologous series with various stoichiometries. While there are many possible arrangements of MTBs, our ab initio calculations show that the observed phases all lie on or very close to the convex hull. These thermodynamic equilibrium considerations provide a unified theory for the stability of the five MTB phases reported here. Density functional theory simulations indicate that these MTB phases exhibit Kagome-like flat bands with potential for exhibiting many-body phenomena and thus suggesting an approach for defect-engineering quantum properties in systems with reduced dimensionality.

Abstract The alternating organic–inorganic layers of 2D perovskites induce quantum and dielectric confinement effects that strongly influence their electronic structure. To decouple the effects of screening environment from structural distortion, it systematically modifies the screening environment of 2D perovskites using a homologous series of organic spacers. This approach preserves the structure of the inorganic framework, enabling a clear investigation of the effect of the screening environment. The direct measurements reveal a notable divergence: while the exciton energy remains constant, the quasiparticle bandgap ( E g , qp ) observed via photoelectron and inverse‐photoelectron spectroscopies progressively increases with increasing spacer length. This trend leads to a significant increase in exciton binding energy ( E b ), consistent with reports on layered perovskite systems. The structurally well‐controlled approach experimentally validates that such variations originate from changes in the screening environment. To rationalize these observations, the Keldysh model is applied by introducing a phenomenological dielectric constant (ɛ ph ), defined as a spatially averaged value. The results show that E b exhibits a clear dependence on 1/ɛ ph , with fitted exponents closely compatible with the trend anticipated from the Keldysh model. Overall, this study provides an experimentally validated basis for predicting excitonic properties and engineering‐oriented insights relevant to design in quasi‐2D semiconductors.

In the present content, we have developed a homologous series of 4-(((4-bromo-2-methylphenyl)imino)methyl)phenyl n-alkoxy-methoxybenzoate derivatives, aimed at systematically investigating the influence of molecular structure on mesomorphic behavior. The synthesized compounds were characterized for the structural elucidation, microscopic textural appearance and mesophase behavior. As a result, each sample exhibited liquid crystalline behavior characteristic of the nematic phase. Theoretical calculations were applied to discuss energy and relevant parameters like polarizability, dipole moment, aspect ratio etc. for the present series. Furthermore, the results of antimicrobial studies indicate potential biological activity, suggesting further applications in the biomedical fields.

We describe a compositionally guided structural evolution within a stoichiometrically conserved framework, BaSbQ3 (Q = Te1-xSx), where each value of x gives rise to a distinct phase. The fundamental building blocks, A1 (BaSbSTe2) and Bn (BanSbnSn-1Te2n+1), were composed of modular double rocksalt slabs stacked with functional polytelluride zigzag chains, with each phase differing only in the size and assembly of these blocks. Ten compounds were synthesized that maintained a coherent chemical identity that arose from this isovalent, isoelectronic substitution of Te and S. We envision that the phase formation at a molecular level unfolds in stages of extension, termination, and assembly and propose a design concept of "anionic disparity," where phase homologies and polytelluride hierarchical networks can be controlled by leveraging differences in anion electron affinity and sizes.

Relationship between Lattice Parameters and Cation Radius in the Homologous Series of Rare-Earth Oxofluorides with the fluorite structure

Homologous Series of 15 RF3 (ZR = 57La–71Lu) in the Categorical Crystallochemical Tetrahedron: “Polymorphism–Isomorphism–True Morphotropy–Structural Homology”

Probing the interfacial structure and ion mobility in structurally-related ionic liquids via dynamic wetting measurements.

The unique combination of fluidity like liquids and directional organization like solids in liquid crystals (LCs) gives rise to their special properties. This article presents a theoretical study on Schiff's base thermotropic LC, tetraphthalylidene-bis-p-n-alkylaniline (TBnA) homologous series (n = 4-8). The aim is to understand the relationship between the molecular design and physical properties with varying alkyl chain length. Optimized molecular geometries, electronic, thermodynamic, and nonlinear optical (NLO) parameters are calculated theoretically. The polarizability of the LCs is high, and the first-order hyperpolarizability is not zero, which makes them a good candidate for NLO applications. A consistent 3.55eV energy gap across a series indicates a uniform electronic structure, positioning them as promising candidates for optoelectronics applications, and chemically stable and tunable wide band gap requiring fields. UV-Vis absorption spectra calculated using TD-DFT explored oscillator strength and involved electronic transitions. Raman and IR modes aid in characterizing functional groups and phase transition markers. The results reveal valuable insights into the electronic distribution, stability, and excitation of TBnA, providing a theoretical foundation for the design and optimization of LCs for advanced optoelectronic applications. The widely accepted DFT with B3LYP functional is used for the simulation along with 6-311G(d,p) basis set in Gaussian 09 software. All the frontier orbitals, thermodynamic, NLO, and spectroscopic studies are performed at the same computational level. Time-dependent DFT (TDDFT) and the multiwfn software are used for the UV-Vis spectra. Vibrational spectroscopy assignment analyses are done using VEDA software and GaussView animation.

Perfluorocarbons (PFCs) as well as related gases such as sulfur hexafluoride (SF6) or nitrogen trifluoride (NF3) are examples of F-gases, a subclass of per- and polyfluoroalkyl substances (PFAS). F-gases are anthropogenic greenhouse gases with the highest global warming potentials known and thus contribute significantly to global warming. To reduce their amount in the atmosphere, selectively adsorbing materials would be beneficial, but such materials are rare. A homologous series of porous organic cages with fluorinated side-chains is synthesized and depending on the targeted gas as well as operating temperature, different cages have high selectivities for certain F-gases against N2, CO2, and O2. Within this series, new benchmark selectivities against, e.g., perfluoro propane (PFC-218) and perfluoro cyclobutane (PFC-318) have been achieved based on attractive fluorine-fluorine interactions. Furthermore, these interactions are exploited for the first time in the adsorption of sulfur hexafluoride and nitrogen trifluoride.

Imidazolium-based ionic liquids bearing a homologous series of oxychlorine anions-1-butyl-3-methylimidazolium chlorite, chlorate, and perchlorate-were synthesized and characterized to relate anion oxygenation to density, thermal expansivity, viscosity, electrical and molar conductivity, ionicity, and antimicrobial performance. Temperature-dependent measurements were carried out from 293.15 to 323.15 K: density and viscosity were recorded and modeled to obtain thermal expansion coefficients; electrical and molar conductivities were measured under identical conditions; and activation parameters were extracted by Arrhenius analysis for viscous flow and for conductivity. Ionicity was assessed from Walden plots and quantified by vertical deviation from the potassium-chloride reference (Angell approach). Complementary DFT calculations provided optimized ion-pair geometries, noncovalent contact patterns, molecular electrostatic potential maps, and frontier-orbital descriptors. In silico ADMET properties were computed to contextualize pharmacokinetic and safety flags. Antimicrobial activity was evaluated by broth microdilution against Escherichia coli, Staphylococcus aureus, Bacillus cereus, and Candida quilliermondii; [Bmim]Cl was included as a comparator to isolate the effect of anion oxygenation. The combined experimental-computational workflow delineates how chlorite, chlorate, and perchlorate shape physicochemical behavior, ionicity, and bioactivity in [Bmim] ionic liquids, providing design guidance for future applications.

Enhanced Pickering interfacial biocatalysis in phosphatidylserine synthesis via phospholipase D immobilization with optimized bifunctional strategy.

Oral cancer (OC) is an aggressive malignancy with poor prognosis due to late-stage diagnosis and limited early detection tools. Volatile organic compounds (VOCs) have emerged as potential biomarkers for early OC detection, offering a non-invasive approach. However, the optimal sample collection and analytical workflow remains unclear. This study compares the diagnostic potential and clinical feasibility of exhaled breath, lesional air, and lesional brushings using thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) and gas chromatography-ion mobility spectrometry (GC-IMS). Twenty-six participants (13 OC or high-grade lesion patients, 13 controls) were recruited. Multivariate analysis assessed group separation and identified key discriminatory features. TD-GC-MS detected more VOCs and demonstrated stronger separation between OC and controls across all sample types compared to GC-IMS. Lesional brushings provided the best separation between groups, followed by lesional air and exhaled breath. Key discriminatory compounds included various alkanes, alkenes, aromatic hydrocarbons, phenylmethanol, and a homologous series of saturated ketones, many of which have been reported as OC biomarkers. Lesional brushings and lesional air analyzed by TD-GC-MS emerged as the most promising approaches for OC detection. GC-IMS, despite limitations, holds potential as a valuable point-of-care OC screening tool. VOC-based diagnostics offer a promising non-invasive approach for early OC detection.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-15510-x.