In the present study, a series of new pyridine-embedded 1,3,4-oxadiazole derivatives (OXn series) bearing terminal long-chain alkoxy groups like decyloxy, dodecyloxy, tetra decyloxy, and hexadecyloxy groups have been systematically synthesized. Further, the presence of these long-chain alkoxy groups in the OXn series would help to improve the overall molecular lipophilicity and ability to penetrate the lipid-rich mycobacterial cell membrane. Molecular docking has been performed against the mycobacterial InhA enzyme to gain an insight into the possible interactions with the protein, which could pave the way for our endeavor to identify potent antitubercular candidates. Also, these compounds were evaluated for their in vitro antitubercular activities. Among the screened compounds of OXn series, the compound (OX-14) have exhibited potent antitubercular activity against Mycobacterium tuberculosis H37Rv strain with MIC value 32.0 μg/mL and IC50 value of 10.4 μg/mL. We believe that further optimization of this molecule may lead to potent antitubercular agents.

This work investigates the synthesis, in silico properties, photophysical characteristics, and evaluation of a new class of benzisoxazoles as potential anticancer drugs. Six benzisoxazoles were synthesized in three steps and are characterized by FTIR, 1H NMR, 13C NMR, and mass spectrometry. In silico analysis provides information about the different types of interactions of ligands with protein (PDB: 1Y6A), stability of ligand-protein interactions, and pharmacokinetic properties of ligands. All the synthesized compounds were screened for anticancer activity against MCF-7 and HepG2 cell lines. Among the tested compounds, 5c showed a significant IC50 value of 12.19 mu M against the MCF-7 cell line. The optical properties of compounds 5b and 5e are studied using UV-Visible and photoluminescence spectroscopy. The results obtained suggest that structural modifications to benzisoxazoles could lead to the development of more effective anticancer agents in the future.

This study presents the synthesis and characterization of a new donor-acceptor-acceptor-based molecule with aggregation-induced emission properties. The molecule was thoroughly characterized using ATR-IR, NMR, and Mass spectrometry. Further, its thermal stability, photophysical behavior, electrochemical properties, and aggregation-induced emission effects were systematically investigated. Solvent-dependent absorption and emission properties highlighted that the molecule is significantly responsive toward the variations of solvent polarity. The molecule demonstrated good thermal stability with an initial decomposition temperature (5

This review article reports an overview of the recent developments in the field of electron delocalization study in organic conjugated molecules by utilizing the vibration frequencies exhibited by the attached functional groups such as nitrile (-C≡N), alkyne (-C≡C-), or carbonyl (-C=O). A brief introduction to electron delocalization, methods for study, and their importance is given first, followed by the application of infrared spectroscopy in organic molecules. Details of molecules with various infrared reporter groups have been explained in respective subsections based on the functional groups. All the reported organic molecules have been structured and presented with the electron delocalization properties studied using an infrared reporter group. Finally, an outlook on this recently promising, exciting, and interesting field of probing electron delocalization using infrared reporter groups is provided.

Advanced electrode materials that combine large surface area, adjustable porosity, and redox activity are essential to meet the growing need for greener and efficient energy storage devices. Since, conventional carbon-based materials frequently don’t provide the redox activity and adaptability that are required for high performance supercapacitor, researchers started to use various materials as replacement. One of the remarkable options is the use of porous organic polymers (POPs) as the electrode materials for supercapacitors. There have been many POPs reported till now; however, the majority of reported synthesis required suitable organic solvents as a synthesis medium, which is often a time-consuming and potentially hazardous process. Thus, the solvent-free synthesis of POPs for supercapacitor application is important but still in its infancy. By considering these points, this research deals with solvent-free synthesis of triazine-based porous organic polymer (T-POP) with a good yield and lower reaction time, in contrast to typical synthetic methods that utilize harsh conditions. The resultant T-POP has a specific surface area of 33.91 m ^−2 g ^−1 , a micro-/mesoporous architecture that is hierarchical, and a large number of nitrogen functionalities that are redox active. These characteristics allow for effective charge storage by combining pseudocapacitive and electric double-layer processes. The T-POP exhibits a high specific capacitance of 3703 μF cm ^−2 at 0.01 mA cm ^−2 , when used as a supercapacitor electrode. In addition to presenting a solvent-free method for creating high-performance porous polymers, this study emphasises POPs’ promise as next-generation materials for effective and sustainable energy storage applications.

The study explores carbazole‐based organic molecules as transport layers in durable perovskite solar cells, focusing on their optoelectronic and charge transfer properties. Thirteen carbazole derivatives are systematically analyzed via density functional theory (DFT) calculations to understand their structure and optoelectronic characteristics. Substituents like bromo, phenyl, thiophenyl, and pyridyl at positions 3,6‐ and 2,7‐ of carbazole were studied. Phenyl and thiophenyl substitutions lowered highest occupied molecular orbital (HOMO) energy levels, while bromo and pyridyl increased them, tuning HOMO energies from −5.45 to −6.03 eV. These energies align well with perovskite materials valence bands, with absorbance primarily below 400 nm, complementing perovskite absorption. The compounds showed high light‐harvesting efficiencies (LHEs) (0.22 to 0.94) and improved radiative lifetimes. Theoretical investigations identified most compounds as effective p‐type hole‐transport materials (HTM), except 3,6‐ and 2,7‐dithiophenyl carbazoles, which exhibited n‐type behavior due to low hole reorganization energies. Overall, the study highlights computational design's role in developing carbazole derivatives as promising charge carrier precursors for perovskite solar cells.

The use of conducting polymers in devices makes them desirable due to their allowance for the fabrication of flexible, lightweight, and potentially inexpensive devices. This review explores the synthetic strategies and characterizations of 3,6-substituted carbazole-based polymers, emphasizing the influence of these modifications on their electronic structure and absorption properties. Polymers containing carbazole substituents are widely studied due to their unique optical and electronic properties, high electron-donating ability, and photoconductivity. The structural adaptability of the carbazole with the 3,6-substitution makes it as an outstanding candidate for their integration into polymers and also possesses improved stability and triplet energy. The role of intramolecular charge transfer (ICT) was highlighted by donor–acceptor architectures with tailoring energy levels to extract their advantageous physicochemical characteristics and optimized performances. Collectively, this comprehensive review delves into the burgeoning field of 3,6-substituted carbazole-based polymers and their crucial role in advancing optoelectronic applications. By amalgamating materials design, synthetic strategies, and application-driven insights, the review serves as a valuable resource for researchers to understand the structure–property relationships and foster innovative solutions for next-generation opto-electronic applications.

Materials for perovskite solar cell (PSC) are being developed as possible contenders for the upcoming photovoltaics generation. However, despite their high efficiency, perovskite materials containing lead are not suitable for commercialization due to their toxic nature. As a result, tin (Sn)-based perovskites have emerged as a promising alternative. Tin-based perovskites possess similar ionic sizes to lead and exhibit exceptional light absorption properties. Nevertheless, these materials are hindered by the oxidation from Sn2+ to Sn4+, which results in poor stability and suboptimal conversion efficiency. This review provides a comprehensive exploration of the oxidation mechanism of Sn2+ and presents an in-depth discussion of recent advancements in various strategies aimed at preventing this oxidation in FASnI3 PSCs.

Over the past few decades, conductive polymers have captured significant focus due to their distinct conducting properties and enhanced application in energy storage devices. In this regard, a novel strategy of donor-acceptor type polymer have been synthesized via the direct arylation polymerization method using palladium acetate as a catalyst. The conducting polymer (named SP) exhibited a good thermal stability of 286.5 degrees C and possessed a lower band gap of 2.3 eV which was determined from the optical and electrochemical techniques. The SP polymer exhibits a three-electrode specific capacitance of 611.2 F g-1 in 1 M KOH at a current density of 1 A g-1. Further, the synthesized polymer was applied as a positive electrode material, and activated carbon was used as a negative electrode material in the asymmetric system. At 2 A g-1 current density, the specific capacitance of the supercapacitor device was determined to be 140.13 F g-1. It was observed that an excellent energy density of 52.69 W h kg-1 at 2334 W kg-1 power density exhibited good cyclic stability up to 10,500 cycles with a retained initial capacity of 92.6%.

Stability issues in organic-inorganic perovskite solar cells (PSCs) hinder their commercial use primarily due to defects in the perovskite layer. Addressing these defects, the introduction of passivating agents as additives has significantly advanced the PSC technology. In this work, we synthesized and characterized a donor-acceptor-donor molecule, 4,6-bis(9-ethyl-9H-carbazol-3-yl)-2-oxo-1,2-dihydropyridine-3-carbonitrile (CzCy), designed to address surface defects in perovskite films through passivating Lewis groups. CzCy's strong polarity ensures effective solvation in dimethyl sulfoxide (DMSO) but limited solubility in chlorobenzene (CB). We applied CzCy both as a passivation layer and to dope it into the perovskite to assess its impact on optical and electronic properties and device performance. The Lewis groups in CzCy effectively passivate positive charge defects by coordinating with uncoordinated lead (Pb2+), demonstrating its efficiency in mitigating charged defects within the perovskite layer. When used as a surface passivator in planar devices, CzCy increased the power conversion efficiency (PCE) to 20.51 from 19.48% in devices without it. This improvement is due to the enhanced nonbonding interaction between CzCy and the perovskite surface, boosting photovoltaic performance and extending material lifespan.

A new 6′-oxo-1′,6′-dihydro-[4,2′:4′,4′'-terpyridine]-5′-carbonitrile (Terpyridine analogue) has been designed and synthesized via one-pot synthesis. Thermal studies showed that the compound is stable up to 346.42 ℃ and the degradation starts to occur above this temperature. The compound displayed the behaviour of a bluish-green emitter in its solution state with a relative quantum yield of 20.45 %. Also, the compound exhibited aggregation induced emission properties in DMSO/water mixtures. Further, its variable temperature dependence photoluminescence study in DMSO solvent showed that its emission intensity decreases while heating and the emission intensity increases while cooling the solution. The compound showed the p-type behaviour and utilized as an electrode which exhibited the maximum specific capacitance of 39.2 F g−1 at a current density of 1 A g−1 through galvanostatic charge–discharge analysis. Finally, its experimental results were correlated to the theoretical results.

Most of the polymeric materials are generally made up of hydrocarbon chains, which are liable to burn when subjected to flame with liberating enormous amount of heat and smoke. In recent decades, the polymeric materials were broadly used in diverse fields such as building, transportation, and electric devices because of their better performance and cost efficient. In fact, the majority of the polymeric materials are basically combustible material and lead to the fire risk. In this context, a lot of research has focused on improvement of the flame retardancy of the polymeric materials by integrating certain flame retardants into the polymer matrix to produce high-quality flame-retardant polymer composites. Further, these flame retardants are macro- or nanoparticles and help to control the combustion process at the decomposition stage and ignition phase, thus in turn reducing the oxygen concentration in flame zone and heat production. The main mechanism of flame retardants includes the buildup of protective layers that reduces the concentration of oxygen in flame zone; flame retardants do not allow temperature of the material to reach the pyrolytic temperature. Over the past decades, flame-retardant polymeric nanocomposite got noticed due to their excellent flame retardancy and powered performance. When nanomaterials are combined through chemical or physical methods, they shows great optimizable flame retardancy and mechanical performance in the resulting polymeric nanocomposites. Hence, this chapter deals with flame retardants, interaction of polymer and nanocomposites, types of polymer nanocomposites, physical properties, and different techniques for thin films and coatings of nanocomposites and application.

The present study focused on the development and characterization of four new low-cost hole-transporting materials (HTMs), ZZ01, DJ01, PR01, and PM01, designed based on the concepts of donor-acceptor-donor (D-A-D) or acceptor-acceptor-donor (A-A-D) for application in perovskite solar cells (PSCs). These molecules were systematically synthesized and extensively analyzed for their structural, photophysical, electrochemical, thermal, density functional theory (DFT), and charge transport properties. The absorption and emission spectra of the synthesized molecules exhibited bands in the ranges of 380-393 and 457-495 nm, respectively, and demonstrated appropriate energy levels, with a band gap ranging from 2.78 to 2.91 eV, which matches well with the requirements for PSCs. The thermogravimetric analysis confirmed their thermal stability up to 230-418 degrees C, which is crucial for device durability. Theoretical calculations via DFT and TD-DFT corroborated the experimental findings, validating that the HOMO-LUMO energy levels and reorganization energies were conducive to effective hole transport. Xerographic time-of-flight measurements indicated superior hole mobility of 2 x 10-5 cm2/Vs for ZZ01, highlighting its potential as an efficient HTM. Overall, this research underscores the promising candidacy of synthesized pi-conjugated molecules as HTMs in PSCs, offering a pathway toward enhancing device performance and commercial viability in the field of renewable energy.

Stimuli-responsive materials based on pi-conjugated donor-acceptor systems have great potential for sensing applications in solution and solid state. The photophysical properties of an oligo(p-phenylenevinylene) series consisting of five push-pull type molecules were systematically investigated to switch their absorption and emission properties by using trifluoroacetic acid as a specific external analyte. During the trifluoracetic acid sensing, the terminal pyridine units of the molecules undergo the protonation and lead to the broader absorption band at a longer wavelength region owing to the pi-pi* characteristics of molecules. Upon exposing solid samples to the trifluoracetic acid vapors, the initial color of solid samples changed from yellow to orange for three-ring system-based molecules and brick red to wine red color for five-ring system-based molecules with the shifting of emission band to the longer wavelength region. Furthermore, exposing the trifluoracetic acid-fumed solid samples to triethylamine vapors, the color of the solid samples reverted to their original colors and emission properties. The DFT analysis indicated a decreased energy band gap for the protonated molecules compared to the neutral molecules, suggesting a redshift in both the absorption and emission spectra of the protonated molecules. Thus, all the molecules of an Oligo(p-phenylenevinylene) series can be utilized effectively for volatile acid detection. The oligo(p-phenylenevinylene) series displays notable solvatochromism, acidochromism, and reversible color alterations under trifluoroacetic acid and triethylamine vapors. With robust thermal stability and protonation-triggered charge transfer, these molecules are ideal for volatile acid detection, data security, and recording technologies. Their visible color shifts and excellent reversibility underscore their promising utility across diverse applications. image

Perovskite solar cells have drawn global attention due to their low cost and comparable efficiency to that of conventional silicon-based solar cells. Moreover, the perovskite solar cells exhibit high efficiencies when spiro-OMeTAD has been used as the hole transport material (HTM). To attain higher PSC efficiency, spiro-OMeTAD must be in its pure form. However, the multistep synthetic protocols and purification methods required to produce high-purity spiro-OMeTAD render it economically unfeasible. Thus, there is a need to develop low-cost new organic HTMs through easy synthetic and purification methods having good solubility, good hole mobility, and thermal stability. Therefore, certain carbazole-based derivatives bearing 4,4′-dimethoxydiphenylamines (DMPA) have been investigated previously as the affordable organic HTMs alternative to the widely used spiro-OMeTAD. Thus, our current review systematically examines the most recent molecular design strategies, hole-transporting properties, power conversion efficiency, and thermal stability of organic HTMs that have been made of various carbazole derivatives bearing two, three, four, six, and eight DMPA units, as reported in the past five years.

Hydrogen bonds are the best non-covalent interactions for building supramolecular structures. Nowadays, hydrogen bonded supramolecular liquid crystals are quickly evolving into a versatile, simple, and affordable method for new smart materials. Therefore, through intermolecular hydrogen bond interactions, a homologous series of supramolecular mesogenic systems are prepared in the present study. The non-mesogenic hydrogen bond acceptors i.e. 2-(4-alkoxyphenyl)-5-(pyridin-4-yl)-1,3,4-oxadiazoles (OXn) are synthesized, the structures are confirmed using various techniques (1H NMR, 13C NMR, ESI-MS, and elemental analysis) and their photophysical properties are studied in the solid state as well as in solution state. Moreover, the DFT study indicated the planar structure with greater intramolecular charge transfer between donors and acceptors. In addition, these molecules (OXn) are made to form a hydrogen bond with the non-mesogenic fatty acid i.e. Lauric acid (LA). The formation of the hydrogen bonds in the prepared supramolecular complex (OXn/LA) is confirmed by using the ATR-IR analysis. Further, red shifted solid state emission spectra are noted for the complexes (OXn/LA) compared to the parent molecules (OXn). The mesogenic properties of the prepared OXn/LA complexes are studied via differential scanning calorimetry, polarized optical microscopy, and X-ray diffractometry. It was found that the complexes OX-8/LA and OX-10/LA exhibit monotropic SmA mesophase, however, the remaining complexes are non-mesogenic in nature.

The first example of luminescent, room temperature liquid crystalline molecules with methylenebis(oxy)-based linker, namely, 2,2'-(methylenebis(oxy))bis(4,6-bis(4-(alkyloxy)phenyl)nicotinonitrile) has been reported in the present work. The designed molecules have been synthesized using dichloromethane (DCM) as the reagent to obtain the methylenebis(oxy)-based linkers. The structural characterizations of the synthesized molecules were carried out by using ATR-IR, 1H NMR, 13C NMR, MALDI-TOF, and elemental analysis. Photophysical property examination of the molecules in the solution state indicated the deep blue emissive nature of the molecules with a relative quantum yield of about 27–32%. Further, electrochemical studies were performed on the molecules by using cyclic voltammetry and determined their underlying HOMO and LUMO energy levels as well as the associated band gaps. In contrast, DFT analysis was performed on the representative compound bearing methoxy groups in place of flexible alkoxy chains to obtain optimized geometry and further studied the distribution of electron density in its HOMO and LUMO energy levels. Furthermore, the liquid crystalline property examination revealed that all the molecules exhibited a smectic C phase upon cooling from isotropic temperature. Finally, the present study paves the way for the synthesis of dendrimer-type liquid crystals with methylenebis(oxy)-based linkers.

The development of perovskite solar cells (PSCs) has gained attention with the ever increasing demand for energy conversion systems across the globe. In this context, utilization of certain liquid crystals (LCs) has been found to play a crucial role in enhancing the stability and efficiency of the PSC in the last 5 years. At this point, it is a high time to cover the recent achievements of LC molecules in the fabrication of PSC devices. Thus, the present review encompasses the introduction to LC and PSC, the effect of LC-based additives to perovskite precursors, the role of LC molecules in stabilizing and enhancing the efficiency of the PSCs, and the use of LC molecules as hole-transporting materials (HTMs) or as an additive to the HTMs. Further, all of these studies revealed that the functional group and conjugation present in the LC molecules as well as their phase transition behavior play a vital role in stabilizing and enhancing the efficiency of the PSCs. The addition of LCs in PSCs is one of among various emerging strategies that started recently, and we expect that this review can guide the researchers in selecting LC molecules for PSC applications to improve the stability and power conversion efficiency (PCE) of the device in the near future.

In the present work, four new cyanopyridone derivatives bearing terminal long chain alkyloxy substituents were designed and synthesized. All the synthesized target compounds were characterized by IR, NMR and Mass spectrometry. Further, their optical properties were examined in their solution state. The optical study showed that all the compounds can exhibit blue emissive behavior in their solution state and yellow fluorescence in the solid state. Furthermore, the long-tailed target compound showed intriguing fluorescence properties under the applied mechanochromic stimuli. Finally, a simple method of grinding-fuming process confirmed the morphological changes occurring in the studied compound which further resulted in the enhancement of its emission property.

Oxadiazole-indole hybrids are interesting molecules and show excellent photophysical properties emitting light in the visible region. In the present study, the photophysical property of a series of indole-oxadiazole hydrazides 8a-f and their sugar-hydrazones 9a-f were investigated. All studied molecules were characterized using ATR-IR, 1H NMR, 13C NMR, and mass spectrometry. The optical properties of compounds were studied using UV-visible and photoluminescence spectroscopy. Density functional theory (DFT) calculations were done to study the structural properties of hydrazides and their sugar hydrazones. Emission spectra of all compounds showed bands around 385-437 nm with quantum yields ranging from 10.89 to 18.65%. Overall, the obtained results indicate that these compounds could be used as optoelectronic materials in the future.