Saurashtra University is a university in Gujarat state in India. This university was established on 23 May 1967, in Rajkot city, and the administrative headquarters are at Rajkot..
A series of hexahydroquinoline-3-carboxamide derivatives 4a–4j were prepared via an L-proline-catalyzed one-pot multicomponent reaction involving substituted aromatic aldehydes, dimedone, and N-aryl-3-oxobutanamides in ethanol, providing the target molecules in good yields (69–89
In the past few decades, electronic excitation-induced changes in BiFeO3 (BFO)-type systems have attracted a lot of attention due to their potential for modifying existing material properties and exploring applications. Dense electronic excitation led by Swift Heavy Ion (SHI) irradiation can modify the structural, optical, electrical, and magnetic properties of materials. In the present study, electronic excitation-induced modifications in the structural, microstructural, and resistive switching properties of Pulsed Laser Deposition (PLD)-grown 20% Ca-doped BFO-based heterostructures using a LaNiO3 (LNO) conducting buffer layer on LaAlO3 (LAO) (100) substrates have been studied by varying the ion fluences of 5 & times; 1010, 5 & times; 1011, 1 & times; 1012, and 5 & times; 1012 ions/cm2 of 150 MeV Ag11+ ions. X-ray diffraction confirms the single-phase nature of the heterostructure along with the modulation of the structural strain with ion fluences. Atomic force microscopy (AFM) measurements show changes in grain morphologies, including the formation of hillock-like and track-like defects after ion irradiation. Cross-sectional Scanning Electron Microscopy (SEM) and Rutherford Backscattering spectroscopy (RBS) measurements confirm the interface modifications due to ion irradiation, which play an important role in charge conduction. Interface modification, formation of oxygen vacancies, and structural defects due to SHI irradiation affect the resistive switching and charge conduction in the proposed system, which is also validated by theoretical fittings of the space charge-limited conduction mechanism. In addition, the impact of ion irradiation on the optical band gap has been understood using UV-visible spectroscopy and correlated with other results.
Abstract A novel series of disubstituted 1,2,3-triazolo-benzimidazole derivatives (8a-8 g) was efficiently synthesized via copper-catalyzed azide-alkyne cycloaddition (CuAAC) under ultrasonic irradiation, achieving up to 95% yields in 55 min at room temperature. This green sonochemical protocol significantly outperformed conventional methods, yielding high-purity products, as confirmed by FT-IR, 1H/13C NMR, and Mass spectrometry. In vitro antimicrobial assays revealed potent activity against Gram-positive (S. aureus, B. cereus) and Gram-negative (S. typhimurium, E. coli) strains, with compounds 8a, 8c and 8d outperforming tetracycline in several cases (zones up to 29 mm). Molecular docking against the Cro repressor (PDB: 1LMB) showed strong binding affinities (-5.07 to -5.67 kcal/mol), with 8a forming key H-bonds to DC29 and hydrophobic contacts to DG14. In silico ADME profiling confirmed drug-likeness (no Lipinski violations, bioavailability score 0.55) and low toxicity, whereas DFT analysis highlighted the high reactivity of 8c (ΔEgap = 1.998 eV). SAR studies underscored the role of 2,4-dimethyl/dinitro substitutions in enhancing broad-spectrum potency, positioning these hybrids as promising antimicrobial leads. Graphical Abstract
A new series of difluoro-substituted azo-cinnamate ester liquid crystals (C3-C16) was synthesized to investigate the influence of fluorine substitution on mesomor`phic behavior. Compounds C4, C6, and C8 exhibited monotropic nematic phases, while C10-C16 showed enantiotropic SmA phases. Mesomorphic properties and thermal transitions were studied using POM, DSC, and TGA, revealing smectic thermal stability up to 114.8 degrees C with mesophase ranges of 14.5-29.4 degrees C. Structures were confirmed by FT-IR, Mass, and NMR (1H and 13C). UV-Vis spectroscopy demonstrated the characteristic azo absorption and light-induced trans-cis photoisomerization. DFT calculations provided insights into optimized geometries, HOMO-LUMO energy gaps, and electrostatic potential distributions.
This study reports a new homologous series of azo-ester liquid crystalline compounds, 4-(4 '-n-alkoxy-3 '-methoxybenzoyloxy) phenyl azo-3 ''-chloro-4 ''-fluorobenzene, synthesized and characterized using spectroscopic techniques. Mesomorphic behavior was examined by polarized optical microscopy and differential scanning calorimetry. Lower homologues (C1-C4) were non-mesomorphic, while higher members (C5-C16) exhibited monotropic smectic phases on cooling. UV-Vis spectra showed bathochromic shifts with increasing alkoxy chain length, indicating enhanced pi-conjugation. Antimicrobial studies revealed that C8 and C10 derivatives displayed the highest activity. The results highlight the influence of terminal chain length and molecular architecture on mesomorphic and biological properties of azo-ester liquid crystalline materials.
