Three novel tetra substituted p‑tert-butylthiacalix[4]arene derivatives (3, 4, and 5) with five coordinating carbonyl groups at the lower rims were synthesized. Accordingly, diethyl tetra-t‑butyl‑trihydroxy-tetrathia-tetrabenzenacyclooctaphanyl)oxy)malonate react with ethyl bromoacetate, phenacyl bromide and 2‑chloro-N-(p-tolyl)acetamide, to produce new p‑tert-butylthiacalix[4]arenes in of 60, 90, and 80% yields, respectively. The molecular structures of the products were verified using FT-IR, ¹H NMR, and ¹³C NMR spectroscopy. Metal ions such as Na⁺, K⁺, Cs⁺, Hg²⁺, Cd²⁺, Pb²⁺, Ni²⁺, Co²⁺, Cu²⁺, and Ag⁺ are easily chelated by the new thiacalixarene derivatives using liquid-liquid extraction technique. These compounds surprisingly show high efficiency in liquid-liquid extraction of alkali, heavy, and transition metal ions. Uptake efficiencies of 71.00% (for Co(II)), 46.00% (for Cu(II), and 15.00% (for Hg(II)) were attained by thiacalixarene 3, 4, and 5. These derivatives were subjected to DFT-based computational analysis with the aim of increasing the efficiency with which thiacalixarene (as a nucleophilic) interacts with the metal ion (3, 4, and 5 in the role of electrophile).

This paper reports on a study of the photophysical properties, density functional theory (DFT) calculations, infrared (IR), ultraviolet (UV) and nuclear magnetic resonance (NMR) spectroscopic techniques of a series of aurone compounds. The photophysical properties were investigated using UV absorption and fluorescence spectroscopy in a dimethyl sulfoxide (DMSO) solution. Furthermore, the fluorescence quantum yields of the target compounds (1–24) were also investigated. Remarkably, these compounds revealed high quantum yields (Φ = 0.001–0.729) as compared to the already existing aurones in literature. The DFT calculations were performed to elucidate the electronic structure, energy levels and draw a comparison between experimental and theoretical findings. The simulated properties such as molecular frontier orbitals, the density of states, reactivity descriptors (GCRD), electrostatic potential distribution, transition density matrix, electron localization function (ELF) and localized orbital locator (LOL) have been calculated using DFT. The DFT calculations provided insight into the electronic structure and energy levels of the aurone compounds, while the IR and UV spectroscopy results shed light on their functional groups and electronic transitions, respectively. The results of this study contribute to a better understanding of the photophysical properties of aurone compounds and suggest their potential use in technological applications.

Imidazopyridazines are fused heterocycles, like purines, with a pyridazine ring replacing the pyrimidine ring in purines. Imidazopyridazines have been primarily studied for their kinase inhibition activity in the development of new anticancer and antimalarial agents. In addition to this, they have also been investigated for their anticonvulsant, antiallergic, antihistamine, antiviral, and antitubercular properties. Herein, we review the background and development of different imidazopyridazines as potential pharmacological agents. Moreover, the scope of this relatively less charted heterocyclic scaffold is also highlighted.

An unprecedented and efficient three-component 1,3-dipolar cycloaddition reaction using (E)-2-(benzo[d]thiazol-2-yl)-3-(aryl)acrylonitriles 4a–g and an in situ generated azomethine ylide 3 from isatin and N-methylglycine is described. The reaction exhibits exclusive regioselectivity, resulting in the formation of 3′-(benzo[d]thiazol-2-yl)-1′-methyl-2-oxo-4′-(aryl)spiro[indoline-3,2′-pyrrolidine]-3′-carbonitriles regioisomers through exo/endo approaches. The diastereoselectivity of the reaction is highly dependent on the substitution pattern of the phenyl ring in dipolarophiles 4a–g, leading to the formation of exo-/endo-cycloadducts in varying ratios. To understand the stereoselectivity, the transition state structures were optimized using the TS guess geometry with the QST3-based method. The reaction mechanism and regioselectivity were elucidated by evaluating global and local electrophilicity and nucleophilicity descriptors at the B3LYP/cc-pVTZ level of theory, along with considerations based on the HSAB principle. The analysis of global electron density transfer (GEDT) showed that the reactions are polar and electron density fluxes from azomethine ylide 3 toward dipolarophile 4a–g. It was found from the molecular electrostatic potential map (MESP) that at the more favorable transition state, approach of reactants locates the oppositely charged regions over each other resulting in attractive forces between the two fragments. The computational results are consistent with the experimental observations, confirming that the reactions proceed through an asynchronous one-step mechanism.

Isatin derivatives were condensedby refluxing ethanol with thiazolobenzimidazole, yielding four linked 2-oxoindolin-3-ylidene)benzo [4,5]imidazo-[2,1-b]thiazol-3(2H)-ones. Thermal evaporation was used to deposit thin films of the produced 2-oxoindolin-3-ylidene)benzo [4,5]imidazo-[2,1-b]thiazol-3(2H)-one derivatives, which underwent thorough analysis employing UV–Vis and NIR spectroscopy. The spectral profiles of these materials were scrutinized with respect to their absorption, dielectricconstants, and dispersion propertiesand compared to previously published data. The current samples were suitable for application in optoelectronic devices, particularly as solar-absorbent materials, due to their high absorption coefficient (α > 10⁵cm⁻¹) at a solar maximum wavelength (λ = 500 nm). Additionally, their band and optical gap energies have been determined as 3.60, 3.56, 2.53, and 3.24 eV. The conclusions drawn from geometry optimization and nonlinear optical (NLO) calculations, performed using density functional theory (DFT) with the Becke, 3-parameter, Lee–Yang–Parr (B3LYP) approach at the 6–311G (d,p) level, further support these findings.

Terpyridine-based metal complexes have emerged as versatile and indispensable building blocks in the realm of modern chemistry, offering a plethora of applications spanning from materials science to catalysis and beyond. This comprehensive review article delves into the multifaceted world of terpyridine complexes, presenting an overview of their synthesis, structural diversity, and coordination chemistry principles. Focusing on their diverse functionalities, we explore their pivotal roles in catalysis, supramolecular chemistry, luminescent materials, and nanoscience. Furthermore, we highlight the burgeoning applications of terpyridine complexes in sustainable energy technologies, biomimetic systems, and medicinal chemistry, underscoring their remarkable adaptability to address pressing challenges in these fields. By elucidating the pivotal role of terpyridine complexes as versatile building blocks, this review provides valuable insights into their current state-of-the-art applications and future potential, thus inspiring continued innovation and exploration in this exciting area of research.

The escalating incidence of bacterial resistance to commonly prescribed antibiotics underscores the urgent need for the rapid development of innovative antibacterial medications. Heterocyclic compounds, particularly nitrogen-containing heterocycles like pyrazoles and thiazoles, have garnered attention for their diverse biological activities, including antimicrobial properties. Here, we present a green and efficient multicomponent synthesis method for fourteen novel benzothiazole-tethered pyrazole derivatives. Utilizing the deep eutectic solvent glycerol/K₂CO₃ as a base-catalytic reaction medium at 70 °C, this synthesis approach yielded promising compounds exhibiting substantial antimicrobial activity against various pathogenic microorganisms such as Staphylococcus aureus, Bacillus cereus, and Candida albicans. Among these, 4-(benzo[d]thiazol-2-yl)-3-(4-nitrophenyl)-1-phenyl-1H-pyrazol-5-amine emerged as the most promising candidate, showcasing significant inhibitory potentials with CZD values of 24 mm, 21 mm, and 26 mm for S. aureus, B. cereus, and C. albicans, respectively. Molecular docking studies further supported the experimental observations, revealing the high binding affinity of the compound to the nitroreductase enzyme with a binding score of −8.5 kcal/mol. These findings underscore the potential of these synthesized compounds as antimicrobial agents and suggest avenues for future research in exploring their structure-activity relationships and therapeutic applications in combating bacterial infections.

Three p-tert-butylthia calix[4]arene derivatives containing p-toluenesulfonyl groups at the lower rim and characterized by their high electron density and aromatic content were synthesized. These were analyzed using FT-IR, NMR, elemental analysis, and optical absorption spectra. Thin films of the compounds were created via thermal evaporation and assessed through UV–Visible spectroscopy, with dielectric and dispersion properties compared to existing literature. The results reveal that the band energy gaps for compounds 2–4 are 3.70, 3.23, and 2.90 eV, respectively. The increased conjugation and high absorption coefficients observed make these materials promising for optoelectronic applications. The films exhibited extraordinarily high nonlinear optical properties, with refractive index and third-order nonlinear susceptibility approximately 400 times greater than those of chalcogenide and oxide materials, highlighting their suitability for nonlinear optical systems. Furthermore, our findings are consistent with density functional theory (DFT) calculations using the Becke, 3-parameter, Lee-Yang-Parr (B3LYP) approach at the 6-311G(d,p) level, validating the theoretical predictions with experimental data.

Thermally Activated Delayed Fluorescence (TADF) materials have emerged as a revolutionary class of functional compounds, driven by their unique ability to utilize excitons from both singlet and triplet states for efficient fluorescence emission. This manuscript provides an overview of recent innovations in TADF material design, focusing on molecular strategies to achieve optimal TADF properties, including small singlet–triplet energy gaps (ΔE_ST) and high photoluminescence quantum yields. We explore the diverse applications of TADF materials, spanning OLEDs, biomedical imaging, photosensitizers, photocatalysis, UV photodetectors (UVOPDs), electrogenerated chemiluminescence, triplet–triplet annihilation (TTA) sensitizers, organic hybrid microwire radial heterojunctions, multicolor luminescent micelles, mechano-luminescence (ML), light-emitting electrochemical cells (LEECs), and fluorescent probes. The integration of TADF materials in these technologies highlights their potential to enhance performance and efficiency. Through this review, we aim to elucidate the fundamental principles governing TADF behavior and present a forward-looking perspective on the synthetic methodologies and new, versatile applications of materials.

A new series of N'-[2-(1,3-benzothiazol-2-ylthio)acetoxy]aryl-2-carboximidamides (5a-5i) and 2-([(3-aryl-1,2,4-oxadiazol-5-yl)methyl]thio)-1,3-benzothiazoles (6a-6i) were successfully synthesized in good to excellent yields by reacting (1,3-benzothiazol-2-ylthio)acetic acid (2) with the respective arylamidoximes (4a-4i). The reactions were carried out in dry polar aprotic solvents, with acetonitrile used for the synthesis of 5a-5i and dimethylformamide for 6a-6i, in the presence of N,N'-carbonyldiimidazole as a coupling reagent. The structures of the target synthesized were clearly confirmed through IR, NMR, elemental analysis, and mass spectrometry data. The electronic properties and optimized geometries of compounds 5a–6i, analyzed through DFT (Density Functional Theory), provided valuable insights into their reactivity and interaction potential with biological targets. Analysis of the HOMO and LUMO highlighted regions of nucleophilic and electrophilic interactions, which are influenced by the presence of electron-donating and withdrawing substituents. These electronic factors correlate directly with the predicted biological activities of the compounds. Notably, compounds 5 g and 6 g emerged as the most promising candidates for biological applications, displaying narrow energy gaps, high electrophilicity indices, and balanced chemical hardness, indicating the importance of tuning electronic properties to optimize biological efficacy.