Enhanced photoelectrochemical performance of Bi2S3/Ag2S/ZnO novel ternary heterostructure nanorods

The current work investigates the morphology, crystallinity and photoelectrochemical (PEC) performance of bismuth sulfide/silver sulfide/zinc oxide nanorods (Bi₂S₃/Ag₂S/ZnO NRAs) photoelectrodes as prepared at different annealing temperature. ZnO NRAs was initially grown hydrothermally, deposited in sequence with Ag₂S and Bi₂S₃ via successive ionic layer adsorption and reaction (SILAR) method before undergoing the annealing treatment. The optimised photoelectrode (Bi₂S₃/Ag₂S/ZnO NRAs-400 °C) possesses an optical bandgap of 1.60 eV extending the absorption edge of ZnO to visible light spectrum. The current-voltage characterization of Bi₂S₃/Ag₂S/ZnO NRAs photoelectrodes revealed that the photocurrent density and photoconversion efficiency were strongly dependent on the annealing temperature. The PEC study shows that the photoelectrode annealed at 400 °C achieved impressive photocurrent density of 12.95 mA/cm² at +0.5 V (vs Ag/AgCl/saturated KCl) under 100 mW/cm² illumination with superior photoconversion efficiency of 12.63%. This improvement is due to the cascade-designed band structure alignment of Bi₂S₃/Ag₂S/ZnO/ITO and to the brilliant role of Ag₂S as an intermediate layer that reduced random chance of electron-hole (e⁻_-h⁺) pairs recombination and improved the electrons collection efficiency. This work is highly anticipated to give contribution on further utilisation of Bi₂S₃/Ag₂S/ZnO NRAs as a promising semiconductor material in PEC related applications.     

Microwave assisted metal-/oxidant-free cascade electrophilic sulfenylation/5-endo-dig cyclization of 2-alkynylanilines to generate diversified 3-sulfenylindoles

A metal-/oxidant-free sustainable protocol for the synthesis of 3-sulfenylindoles based on electrophilic cyclization of 2-alkynylanilines has been developed under microwave irradiation. Herein, catalytic amount of iodine and stoichiometric amount of sulfonyl hydrazides were employed as catalyst and electrophiles respectively to induce the 5-endo-dig cyclization of 2-alkynylanilines. This strategy allows a wide substrate scope, demonstrates good functional group tolerance, utilizes easily available reagents and overcome multistep synthesis.     

Microwave assisted synthesis of isothiazolo-, thiazolo-, imidazo-, and pyrimido-pyrimidinones as novel MCH1R antagonists

An efficient microwave assisted condensation of α-heteroarylamines with 3-dimethylamino-2-aryl-propenoates has been developed to synthesize various fused bi-heterocyclic compounds, including isothiazolo-, thiazolo-, imidazo-, and pyrimido-pyrimidinones as novel MCH1R antagonists.     

Boron and nitrogen-codoped TiO2 nanorods: Synthesis, characterization, and photoelectrochemical properties

Boron and nitrogen codoped TiO₂ nanorods (BNTRs) were synthesized via two-step hydrothermal reactions using TiN as a starting material. The as-prepared samples were characterized by X-ray diffraction, field-emission scanning electron microscope (SEM), transmission electron microscopy and X-ray photoelectron spectroscopy techniques. The results showed that TiO₂ nanorods with the diameter of approximately 50–100 nm and the length of several micrometers were doped by the interstitial N and B. The nanorods were firstly formed in the hydrothermal synthesis of nitrogen doped TiO₂. The growing process of nanorods was observed by SEM and a most probable formation mechanism of the trititanate nanorods was proposed. The BNTRs showed a higher photocatalytic activity and a bigger photocurrent response than N–TiO₂ nanorods under visible light irradiation.     

Synthesis,characterization and application of Cr2O3 nanoparticles as an efficient antibacterial agent

This study focuses on the microwave-assisted synthesis of Cr₂O₃ nanoparticles for the development of antibacterial materials. Characterization techniques including FT-IR spectroscopy, UV–vis spectroscopy, SEM-EDX, and XRD, were employed to analyze the nanoparticles' properties. The antibacterial efficacy against E. coli, S. aureus, B. subtilis, and P. aeruginosa was evaluated, with significant activity observed against all pathogens, highlighting their potential as antibacterial materials. The novelty of this study lies in the synthesis of Cr₂O₃ nanoparticles and their application as potent antibacterial agents against various pathogens. The results of XRD study concludes the average size of Cr₂O₃ nanoparticles as 49.96 nm. The synthesized Cr₂O₃ nanoparticles demonstrated a good zone of inhibition against E. coli (22 mm), S. aureus (19 mm), B. subtilis (18 mm), and P. aeruginosa (21 mm). The findings of the study suggest that Cr₂O₃NPs have potential as a novel antibacterial agent, and further research in this area could lead to the development of new and effective treatments for bacterial infections.     

Synthesis and characterization of some methylbismuth (III) O,O‐alkylenedithiophosphates: convenient transformation of and to pure Bi2S3

A series of methylbismuth(III)O,O‐alkylenedithiophosphates of the type [where G = CH₂CH(CH₃) ( 1 ), (CH₂)₄ ( 2 ), CH₂CH₂CH(CH₃) ( 3 ), CH(CH₃)CH(CH₃) ( 4 ), CH₂CHCH₂CH₃ ( 5 ), CH(CH₃)CH₂C(CH₃)₂ ( 6 ) and C(CH₃)₂C(CH₃)₂ ( 7 )] have been isolated by the reaction of methylbismuth(III) dichloride with potassium salt of O,O‐alkylenedithiophosphoric acids in 1:2 molar ratio in anhydrous benzene. These newly synthesized derivatives were characterized by elemental analyses, FT IR and multinuclear NMR (¹H, ¹³C and ³¹P) spectral studies. Thermogravimetric analysis of 6 has shown a single‐step decomposition of complex to Bi₂S₃ at 154.3 °C. Transformation of 2 and 6 to pure Bi₂S₃ was carried out successfully at refluxing xylene temperature (142 °C) as revealed by XRD and SEM analyses. Copyright © 2006 John Wiley & Sons, Ltd.     

Poly(N-vinyl-2-pyrrolidone-maleic anhydride-styrene) grafted terpolymer: Synthesis,characterization, and bactericidal property evaluation against E. coli and S. epidermidis

Poly(N-vinyl-2-pyrrolidone-maleic anhydride-styrene) terpolymer was prepared using AIBN initiator with acetone as solvent. The terpolymer was grafted with anti-bacterial agents para-aminobenzoic acid and 2,4-dichlorophenol to introduce bactericidal activity to the terpolymer. The terpolymer and the grafted polymers were characterized by FTIR, ¹H-NMR, and ¹³C-NMR spectroscopic methods. Thermal properties were determined by differential scanning calorimetric technique and thermogravimetric analysis. The glass transition temperature was found to be 111°C (terpolymer), 150°C (VMS-G-PABA) and 130°C (VMS-G-DCP). Terpolymer starts degradation at 288°C and grafted terpolymers at 104°C (VMS-G-PABA) and 129°C (VMS-G-DCP), respectively. The anti-bacterial activity of grafted terpolymers were evaluated by the shake flask method against gram positive and gram negative bacteria E. coli and S. epidermidis. The grafted terpolymers showed effective inhibition against both the bacteria, the minimum inhibition concentration was observed to be 75 µg/mL and 80 µg/mL for VMS-G-PABA and 50 µg/mL for VMS-G-DCP against E. coli and S. epidermidis, respectively. The new polymers showed 90% bacterial growth inhibition at 200 µg/mL.     

Enantioselective Allylation of (2E,4E)‐2,4‐Dimethylhexadienal: Synthesis of (5R,6S)‐(+)‐Pteroenone

Allylation, trans‐ and cis‐crotylation of (2E,4E)‐2,4‐dimethylhexadienal, a representative α,β,γ,δ‐unsaturated aldehyde, was carried out under different catalytic and stoichiometric conditions. The reactions catalyzed by organocatalysts TRIP‐PA and N,N′‐dioxides gave the best results with respect to yields, asymmetric induction, and catalyst load in comparison to other procedures. The developed methodology was applied in the enantioselective synthesis of (5R,6S)‐(+)‐pteroenone, a defensive metabolite (ichthyodeterrent) of the Antarctic pteropod Clione antarctica.     

Solvothermal Synthesis and Crystal Structure of the New Layered Thioantimonate(III) [Ni(C4H13N3)2]9Sb22S42 · 0.5H2O: Interconnection of the SbS3, SbS4, and SbS5 Primary Building Units Yielding the Very Large Sb30S30 Heteroring

The novel thioantimonate(III) [Ni(dien)₂]₉Sb₂₂S₄₂ · 0.5H₂O was synthesised under solvothermal conditions by reacting elemental Ni, Sb and S in an aqueous solution of diethylenetriamine (dien) (80%). The compound crystallises in the triclinic space group P1¯, a = 8.997(2) Å, b = 15.293(3) Å, c = 34.434(7) Å, α = 85.51(3)°, β = 84.16(3)°, γ = 83.54(3)°, V = 4672.7 (16) ų, Z = 1. The layered [Sb₂₂S₄₂^18—] anion in [Ni(dien)₂]₉Sb₂₂S₄₂ · 0.5H₂O is composed of nine SbS₃ trigonal pyramids, one SbS₄ and one SbS₅ unit. The interconnection of these units by sharing common S atoms yields Sb‐S heterorings of different sizes. Besides the smaller Sb₂S₂ and Sb₃S₃ rings a very large Sb₃₀S₃₀ heteroring is observed. The structure directing effect of the [Ni(dien)₂]²⁺ cations is obvious as they are located above and below the pores of the anion. The nine [Ni(dien)₂]²⁺ cations exhibit different conformations. All Ni²⁺ cations are in an octahedral environment of six N atoms of two dien ligands. The anions and cations are stacked perpendicular to [100] in an alternating fashion.     

A novel series of M(II) complexes of 6‐methylpyridine‐2‐carboxylic acid with 4(5)methylimidazole: Synthesis,crystal structures, α‐glucosidase activity,density functional theory calculations and molecular docking

Novel complexes of 6‐methylpyridine‐2‐carboxylic acid and 4(5)methylimidazole, namely [Mn(6‐mpa)₂(4(5)MeI)₂] ( 1 ), [Zn(6‐mpa)₂(4(5)MeI)₂] ( 2 ), [Cd(6‐mpa)₂(4(5)MeI)₂] ( 3 ), [Co(6‐mpa)₂(4(5)MeI)₂] ( 4 ), [Ni(6‐mpa)₂(4(5)MeI)(OAc)] ( 5 ) and [Cu(6‐mpa)₂(4(5)MeI)] ( 6 ), were synthesized for the first time. The structures of complexes 1 – 4 and complexes 5 and 6 were determined using X‐ray diffraction and mass spectrometric techniques, respectively. The experimental spectral analyses for these complexes were performed using Fourier transform infrared and UV–visible techniques. The α‐glucosidase inhibition activity values (IC₅₀) of complexes 1 – 6 were identified in view of genistein reference compound. Moreover, the DFT/HSEh1PBE/6‐311G(d,p)/LanL2DZ level was used to obtain optimal molecular geometry and vibrational wavenumbers for complexes 1 – 6 . Electronic spectral behaviours and major contributions to the electronic transitions were investigated using TD‐DFT/HSEh1PBE/6‐311G(d,p)/LanL2DZ level with conductor‐like polarizable continuum model and SWizard program. Finally, in order to investigate interactions between the synthesized complexes ( 1 – 6 ) and target protein (template structure S. cerevisiae isomaltase), a molecular docking study was carried out.     

Synthesis and spectroscopic,magnetic and cyclic voltammetric characterization of some metal complexes of methionine: [(C5H10NO2S)2MII]; MII = Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II)

Some metal complexes of DL–methionine were prepared in aqueous medium and characterized by different physico-chemical methods. Methionine forms 1:2 complexes with metal, M(II). The general empirical formula of the complexes is proposed as [(C₅H₁₀NO₂S)₂M^II]; where M^II = Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II). All the complexes are extremely stable in light and air and optically inactive. Magnetic susceptibility data of the complexes demonstrate that they are high spin paramagnetic complex except Zn(II), Cd(II) and Hg(II) complexes. The bonding pattern in the complexes are similar to each other as indicated by electronic absorption spectra and FTIR spectral analysis. The current potential data, peak separation (AE) and the peak current ratio (i_pa/i_pc) of the (Mn, Cu and Cd) complexes indicate that the charge transfer processes are irreversible, the systems are diffusion controlled and also adsorptive controlled. The charge transfer rate constant of metals in their complexes are less than those in their metal salts at identical experimental conditions due to the coordination of metal with methionine.