To evolve liquid crystals towards efficient nano-electronics, we report oxadiazole-functionalized anthraquinones showing room-temperature columnar rectangular mesophases. Exhibiting nearly temperature-independent ambipolarity with maximum hole and electron mobilities on the order of 10-4 cm2 V-1 s-1 and 10-3 cm2 V-1 s-1, respectively, it is a pioneering study on solution-processable charge-carrier mobilities of this class of deep-green dyes.

Achieving a high degree of structural ordering in monolayers of disc-shaped molecules, typically comprising large aromatic cores and flexible alkyl chains, is exceptionally challenging yet essential for developing functional materials in organic electronics and optoelectronics. Here, we present a strategy, solely based on supramolecular nanoarchitectonics, wherein a careful molecular design combined with tailored self-assembly pathways enables precise control over molecular ordering. Using ambipolar amphiphilic heterocoronene derivatives, we demonstrate the ability to direct either face-on or edge-on alignment at interfaces. Incorporation of oxadiazole linkers between the heterocoronene core and peripheral alkyl chains yields mechanically robust, hydrophilic, and atomically smooth monolayers with face-on orientation, in sharp contrast to the hydrophobic, edge-on alignment observed for the parent heterocoronene lacking these linkers. The markedly enhanced elastic modulus and surface potential of the oxadiazole-functionalized monolayers at the air-water interface arise from in-plane dipolar reorganization driven by mesoscopic restructuring, as supported by joint analysis of surface-pressure and surface-potential isotherms and corroborated by atomic force microscopy measurements. These findings establish a molecular design principle for engineering cooperative dipolar alignment in two-dimensional organic architectures, offering guidelines for nanoarchitectonic control in monomolecular films and providing pathways toward emerging technologies including organic ferroelectrics, dipolar electronics, and quantum-responsive interfaces.

In this article, we have presented a simplified Ginzburg-Landau theory, based on a single scalar order-parameter, for the study of mixtures comprising surfactants and water systems. The local concentration of surfactants in aqueous solutions represents the scalar order parameter, and the local free energy density is formulated as a linear combination of both the second and fourth powers of the scalar order parameter. The phase diagrams are derived by optimizing the free energy functional of the various phases with respect to the variational parameters. Our analysis has revealed several ordered lyotropic phases, including the body-centered cubic () phase, present in both direct (I) and inverse (II) forms, the hexagonal () phase, also in both direct (I) and inverse (II) forms, and the lamellar phase denoted as . These phase diagrams illustrate the sequence of ordered phases: body-centered cubic () - hexagonal () - lamellar () - hexagonal () - body-centered cubic (), with an increasing concentration of surfactants, which is frequently observed in systems containing aqueous solutions of single-chain surfactants. Furthermore, a three-dimensional phase diagram has been developed, adding an additional dimension to our analysis.

Mesostructuring of Prussian blue analogues (PBAs) can impart high surface area and anisotropic magnetic behavior, making them desirable for practical applications as switches, sensors and display devices. Herein, we present the first report of alkylated {[Fe3Co3]2Co} tridecanuclear PBAs exhibiting magnetic bistability co-existing with thermochromism (green -> red) and crystal to liquid-crystal phase change. The rational design strategy led to the isolation of these tridecanuclear complexes with general formula {[FeIITp(CN)3]3[CoIII(L-Cn)2]3}2CoIIA-ysolvents (For 1-Cn; A- = 7BF4-[FeIIITp(CN)3]-, y = 64H2O and for 2-Cn; A- = 8ClO4-, y = 8H2O), where n = carbon chain length, i.e. 4, 6, 8, 10, 12, 14, 16; Tp = hydrotris(1-pyrazolyl)borate and L-Cn = N-alkylated 2,2 '-dipyridylamine with the respective carbon chain lengths. The transition and melting temperatures of the complexes are in synchronisation and decrease with increasing carbon chain length. This occurs due to higher flexibility of longer alkyl chains. The flexible chains not only induce liquid crystalline properties in the complexes, but also allow their fabrication into thin films with nearly no compromise in the magnetic bistability and thermochromic behavior. This strategy to functionalise PBAs with flexible alkyl chains provides an array of mesostructures with tunable magnetic, optical, and electronic properties.

Azochromophore-bound hyperbranched polymers have substantial scientific interest in modern technological and sensing applications. Our study explores the self-assembly and photoresponsive behavior of two compositionally similar polymeric amphiphiles (HBP-Azo-TDP and HBP-OEG-Azo) in aqueous solution and at liquid-crystal (LC)-aqueous interfaces. These two amphiphiles consisted of a common hyperbranched core with hydrophobic and hydrophilic segments randomly grafted from it. We installed photoresponsive azobenzene units either in hydrophobic or in hydrophilic segments, so that their location could differ substantially within the self-assembled structure. The amphiphiles self-assemble into spherical micellar aggregates in an aqueous medium and tune the anchoring transition of LC molecules at the LC-aqueous interfaces. However, the optimum doping concentration required to attain homeotropic alignment of LC at the LC-aqueous interfaces was lower for the HBP-Azo-TDP amphiphiles (≥0.3 wt.%) than in HBP-OEG-Azo amphiphiles (≥1 wt.%). Also, despite similar compositions, HBP-OEG-Azo exhibits a faster optical response upon photoillumination, which can be attributed to its location at the periphery of the nanoaggregates and to the intrinsic topology of the polymeric amphiphiles. In contrast, the photoresponsive behavior of the HBP-Azo-TDP amphiphile at the LC-aqueous interface was hindered by the azobenzene's location within the micellar nanoaggregates core. Therefore, the location of photoresponsive units plays a vital role in the design of a new class of LC-aqueous interfaces for the reversible photoisomerization of azo-bound polymeric amphiphiles in a label-free manner.

Polydiacetylenes (PDAs) play a pivotal role in sensing and recognition owing to their stimuli‐responsive optoelectronic properties. Inducing chirality in polydiacetylenes provides an additional handle for generating tunable chiroptical behavior in materials toward chiral optoelectronics and photonics. A photopolymerizable diacetylene (DA) tethered with chiral ( R / S ) phenylalanine and an azobenzene photoswitch ( 1 R/S ‐DA ) is designed, with a suitable control molecule 2 DA devoid of the chiral motif. The designed molecules self‐assemble in aqueous and organic solvent systems. The chiral PDAs show better packing efficiency in monolayers and record higher photoisomerization percentages as compared to the achiral analog. Further, higher photoisomerization percentages are observed in the organic solvent system. In both chiral ( 1 S‐ PDA ) and achiral ( 2 PDA ) polymers, E ‐Z photoisomerization leads to the weakening of the self‐assembly. Microscopic and X‐ray scattering investigation suggest excellent birefringence in E‐ 1° S‐ PDA owing to better molecular ordering in comparison to Z‐ 1° S‐ PDA and E‐ 1 a S‐ PDA . Better molecular ordering of the conjugated polymer in organic solvent ( E ‐1° S‐ PDA ) renders a higher charge storage propensity as compared to the aqueous solvent. Finally, photo‐controlled E‐Z isomerization in the azobenzene motifs embedded within polymer domains exhibits modulation in conductivity with E ‐1° S‐ PDA having ≈3‐fold superior conductivity than Z ‐1° S‐ PDA in solution‐processed thin films.

The future of next-generation electronics relies on low-cost organic semiconductors that are tailored to simultaneously provide all requisite optoelectronic properties, focusing greatly on ambipolar charge-transport and solution processability. In this regard, room-temperature discotic liquid crystals (DLCs) are potential candidates, where quasi-1D self-assembly affords a charge-transport channel along their columnar axis. This work shows a molecular design strategy by utilizing anthraquinone as the primary motif, surrounded by ester functionalized tri-alkoxy phenyl units to develop room-temperature DLCs (1.1-1.3). Here, the polar ester functionality stabilizes the columnar mesophase over a wide range through the involvement of dipole-dipole interaction along with the pi-pi stacking. Throughout the entire mesophase transition, reported compounds 1.1-1.3 exhibit a highly ordered 2D columnar oblique (Colob) self-assembly. Space charge limited current (SCLC) experiments reveal balanced ambipolar charge transport, with the maximum hole and electron mobilities of 5.04 and 4.93 cm2 V-1 s-1, respectively. From the conoscopic results, their propensity to align in a highly homeotropic fashion is demonstrated. It is further justified by the azimuthal plot corresponding to the (11) peak of grazing incidence small angle X-ray scattering (GISAXS), denoting the crucial role of the design and alignment for efficient movement of charge carriers in the material.

The growing demand for advanced photonic and electro-optical devices necessitates the rational design of novel functional materials. Liquid crystals (LCs) are particularly promising due to their highly tunable electro-optical properties. Building on this potential, we synthesized a series of polar bent-core LCs, F4-na (dipole moment ∼9.4 D), featuring a tetrafluorinated terminal motif and varying terminal chains. Distinct structure-property relationships are observed in this series of compounds, with the shorter chain homologues forming polar cybotactic clusters (Ncyb phase) alongside nematic and tilted smectic phases. Dielectric spectroscopy reveals non-trivial dipolar ordering, attributed to short-range polar order within cybotactic clusters, notably present without net macroscopic polarization. Under an AC field, the materials form electroconvection patterns, suggesting potential for optical modulation devices. Furthermore, the F4-na materials, particularly the lower homologues showing cybotactic clusters, stabilize the otherwise unstable blue phase (BP) at room temperature when doped with a chiral additive, achieving a maximum BP range of 22.9 °C. This overcomes the challenges in achieving room-temperature BP with our easily synthesizable materials, holding strong potential for 3D photonic applications. Overall, our findings offer promising opportunities for advancing room-temperature photonic and electro-optical devices while enhancing the understanding of self-assembly in soft functional materials.

Listeriolysin O (LLO) is a crucial cholesterol-dependent cytolysin (CDC) secreted by Listeria monocytogenes. LLO lyses the phagosomal membrane via pore-formation, resulting in pathogenesis. CDCs' ability to recognize and bind to membrane cholesterol is a hallmark in the pathogenesis of these pore-forming toxins, distinguishing them from other toxins. Conservation of the cholesterol-recognition motif (CRM) has been discovered to be one of the prerequisites for the membrane binding of some CDCs, but the role of the CRM for LLO binding and pore-formation is still unclear. Therefore, we investigated LLO-mediated lipid remodelling at a nanomolar concentration using the interfacial properties of a biomimetic liquid crystal (LC)-aqueous interface. The examination addresses the significance of the CRM in protein structure and membrane reorganizations for the cholesterol-mediated binding of LLO. We report that the CRM assists in the binding of LLO in a unique amphipathic environment, especially at low cholesterol levels. However, eliminating or substituting the CRM from LLO significantly alters the threshold cholesterol level required for its activity. This study also reveals the effect of cholesterol-dependent membrane dynamics in the association and activity of LLO. Our findings suggest a novel paradigm that opens up an array of possibilities for discovering sequential mutations and delineating the molecular mechanisms of CDCs in nanomolar concentration regimes.

Antibiotic-resistant latent tuberculosis mandates sensitive, label-free screening platforms that permit the detection of changes in bacterial membranes as a potential therapeutic target. Growth stage-induced alterations in the mycobacterial lipidome, which underlie drug tolerance, further intensify this goal. In this work, liquid crystal (LC)-based detection captured the selective, spatiotemporal modulation of lipid membranes induced by bacterial dormancy. The LC-aqueous interface effectively differentiated responses across the bacterial cell envelope layers. Next, subtle changes in mycobacterial membranes were detected upon interaction with specific antimicrobial peptides (AMPs) at various growth stages. This showcased the potential of the LC-aqueous interface as a label-free membrane screening diagnostic tool. Collectively, the LC-aqueous interface detected membrane order across envelope layers, dormancy-induced lipidome changes, and mycobacterial membrane disruption by AMPs. The distinct behaviour of the LC-aqueous interface in detecting alterations in lipid membranes during different infection stages could be developed in the future to diagnose latent/active pathogens in tuberculosis or other infectious diseases.

Design of stimuli-responsive chiral polydiacetylenes (PDAs) with an innate photoswitch offers exciting opportunities toward tunable chromogenesis and chiroptical behavior as a result of E-Z photoisomerization. We designed a series of asymmetric photopolymerizable diacetylene bisamides bearing variable alkyl chains, DAn (n = 2, 5, 10), to connect the DA with a chiral azobenzene motif. Topochemical polymerization in thin films of DA forms orange colored PDAs to furnish long-ranged fibrillar nanostructures with increasing alkyl chain lengths. The polymer nanostructures exhibit axial or lateral growth after thermal annealing due to improved ordering in the polymeric domains. The PDA self-assembly exhibits crystalline or soft-crystalline packing based on alkyl chain stacking, aromatic interactions, and hydrogen bonding. Differential molecular packing in the PDAs dictates the E to Z photoisomerization percentages, eventually resulting in diminishing chiroptical signatures and anisotropic textures. Photoisomerization-mediated dynamic disassembly in 1D nanofibers are observed in the PDAs bearing decyl chain spacers, which show prominent room temperature soft-crystalline switching behavior. Reverse photoisomerization of Z to E mediated structural reordering result recovery of the chiral packing, morphology, and birefringent patterns. Such tunable soft-crystalline PDAs provide a convenient access to soft adaptable chiroptical materials toward solid-state actuation applications.

Liquid crystals (LCs) have transformed the world of optoelectronic displays and are now recognized as useful soft materials for a broad range of biomedical applications. Combination of smart sensors with label-free imaging offers intriguing prospects for point-of-care diagnostics. Here, we outline a sophisticated collage of the most important discoveries that show how LC biosensors can be used to monitor different enzymatic activities for the diagnosis of specific disease biomarkers or infections in body fluids, cellular milieu, and clinical samples. In living organisms, enzymes have a primary regulatory role in both accelerating and controlling metabolic reactions. We mention the ubiquitous techniques that are used to fabricate LC-based enzyme biosensors in attaining specific strategies along with greater sensitivity for the detection of clinically important biomolecules.

1,2,4-Oxadiazoles are well recognized for their exceptional physical, chemical, and pharmacokinetic properties, making them promising candidates for various therapeutic applications. These include treatments for cystic fibrosis, Duchenne muscular dystrophy, Alzheimer's disease, and a broad spectrum of other therapeutic interventions such as antituberculosis, anticancer, antibiotic, anti-inflammatory, and anticonvulsant activities. In this study, single crystals of a novel 1,2,4-oxadiazole derivative, methyl-4-(5-(4-(octyloxy)phenyl)-1,2,4-oxadiazol-3-yl)benzoate, were grown by a slow evaporation technique. The structural elucidation was performed using X-ray diffraction analysis, confirming the compound's crystalline structure in the triclinic system. The analysis revealed a linear conformation with bond lengths closely aligned with Cambridge Structural Database (CSD) averages, signifying high precision in the molecular structure. A detailed CSD study identified nine principal configurations of the phenyl octyloxy moiety, underscoring the structural diversity of the compound. Hirshfeld surface analysis highlighted the predominance of C-HO and C-Hpi interactions, with dispersion energy playing a critical role in stabilizing the crystal lattice. Docking studies against key microbial targets, particularly E. coli FabH, demonstrated superior binding energies, suggesting significant antimicrobial potential. The comprehensive suite of structural and computational analyses underscores the potential of the synthesized 1,2,4-oxadiazole derivative, which may be one of the promising candidates for antimicrobial drug development. Future in vitro, in vivo studies will be supportive in optimizing the derivative for enhanced efficacy and further elucidating its pharmacological mechanisms, paving the way for potential clinical applications. This study not only provides insights into the structural and functional properties of a novel 1,2,4-oxadiazole derivative but also highlights its promising role in antimicrobial drug discovery.

With the rising demand for large-area solution-processable organic semiconductors, the high structural order of any charge-transport system needs to be supplemented with simultaneous flexibility to form uniform films in devices, especially to effectuate charge carrier extraction at its electrode interfaces. Hence, approaching nematic mesophases to induce fluidic properties in an organic charge-transport layer, without hindering its electrical conduction properties, assumes the utmost importance. In this context, we design a luminescent discotic liquid crystal (DLC) dyad molecularly engineered to tune its self-assembly to facilitate a columnar nematic (NCol) phase at room temperature, balancing the dichotomy of ordered columnar superstructures with the dynamicity of a nematic phase. Rationally collated photophysical, theoretical, and electrochemical studies demonstrate that the constituent donor and acceptor units govern electronic interactions and energy transfer in the excited state, predominantly influenced by low reorganization energies. With this uniquely ordered nematic phase rendering defect-free solution-processable nanofilms, the DLC was suited to fabrication of highly stable nanoscale devices under ambient conditions. Exhibiting a remarkable charge-extraction property in its undoped native state with an electrical conductivity of 10-4 S m-1, this report of a NCol DLC nanofilm in solution-processable vertical-transport devices is a pioneering contribution to the knowledge of self-assembly and charge conduction of ordered nematic phases in DLCs.

We have investigated the effects of an organic salt, namely p-toluidine hydrochloride (PTHC), on the phase behavior of aqueous solutions of an anionic surfactant, sodium dodecyl sulfate (SDS). Specially, the behavior of SDS-PTHC-water system at 40∘C has been been studied using small angle X-ray scattering (SAXS) and polarizing optical microscopy (POM) techniques. As the concentration of PTHC increases, the system exhibits three phases, namely: hexagonal (H), a lamellar (Lα) phase with excessive water, denoted by (I+Lα), and an isotropic phase of bilayer (Lx) with excess water, symbolized by (I+Lx). Electron density maps has been reconstructed for the H and Lα phases. The Lα phase and the Lx phase are both found to be satisfactorily represented by the model of the Lα phase. It is apparent from the findings that a substantial quantity of organic salts can be utilized to screen out the ionic charges of the surfactant and stabilize the Lx phase.

Chiral bent-core molecules exhibit spontaneous symmetry breaking, forming opposing chirality domains. Molecular chirality influences supramolecular domain preferences, offering potential for chiral templating applications.

Non-symmetrical cholesterol-based dimers have emerged as crucial materials in the field of liquid crystal research, owing to their remarkable ability to stabilize various exotic mesophases, including the blue phases (BPIII, BPII, BPI), cholesteric nematic (N*) phase, smectic blue phase (SmBP), twist grain boundary (TGB) phase, smectic A/smectic A* (SmA/SmA*) phase, and smectic C/smectic C* (SmC/SmC*) phase. These mesophases have garnered considerable attention due to their diverse applications in spatial light modulation, chiro-optical devices, optical switching, thermochromic materials, and more. In this study, we present the synthesis and comprehensive characterization of a series of non-symmetrical cholesterol-based bent-shaped dimers (1/12, 1/14, 1/16) in which the cholesterol unit is intricately linked to an aromatic mesogenic core through a flexible spacer. These novel materials exhibit the intriguing ability to stabilize a variety of mesophases, including the N*, TGBA, SmA, and SmC* phases. The chiro-optical properties of the helical SmC* phase have been meticulously investigated through temperature-dependent chiro-optical measurements, shedding light on their potential for advanced optoelectronic applications. Additionally, we have conducted a thorough examination of the physical characteristics of these cholesterol-based dimers, including static permittivity measurements, dielectric spectroscopy, and electro-optical performance analysis. Remarkably, two homologues (1/14, 1/16) exhibit negative dielectric anisotropy, a crucial parameter for liquid crystal devices. Furthermore, our investigation reveals that these materials exhibit ferroelectric behaviour in the SmC* phase, with compounds 1/14 and 1/16 demonstrating substantial spontaneous polarization (PS) values of approximately 132 nC cm-2 and 149 nC cm-2, respectively. These findings underscore the potential of non-symmetrical cholesterol-based dimers as versatile components for the development of innovative electro-optical devices.

Materials that combine spin‐crossover (SCO) and liquid crystal (LC) behavior have gained significant attention due to their potential applications in technological devices, attributed to their easy processability. Herein, we report three neutral heteroleptic Fe(II) complexes: [Fe(dpa‐C4)2(NCS)2] (1), [Fe(dpa‐C6)2(NCS)2] (2), and [Fe(dpa‐C16)2(NCS)2] (3) (dpa‐Cn = N‐alkyl‐N‐(pyridin‐2‐yl)pyridin‐2‐amine; n = 4, 6 and 16), which exhibit thermal‐induced spin transition behavior. The transition profiles and temperatures are effectively modulated by the length of the alkyl chains. Longer alkyl chains result in gradual and higher T1/2 values, while the shorter chain lead to abrupt SCO with a lower T1/2 (i.e. T1/2 = 259 K (3) > 237 K (2) > 211 K (1)). Crystallographic studies reveal the impact of hydrophobic and hydrophilic packing in the crystal lattice, contributing to cooperativity and thereby affecting the SCO behavior. Complex 3 with long alkyl chain substitution, displayed non‐synchronized SCO‐LC behavior due to the thermal motion of the alkyl chains.