The extensive use of azo dyes in textile and pharmaceutical industries pose significant environmental and health risks. This problem requires to be tackled forthwith through a cheap, environmentally friendly and viable approach to mitigate water pollution. In this context, the green synthesis method was used for synthesis of ZnO NPs. These biogenic ZnO NPs were characterized by UV–Vis and Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), high-resolution transmission electron microscopy (HR-TEM) coupled with energy-dispersive X-ray (EDX), dynamic light scattering (DLS) and Zeta potential (ZP) analysis. The characteristic bandgap energy (3.02 eV), crystallite size (18.6 nm), particle size (84 nm), hydrodynamic diameter (101 nm) and ZP (−31.5 mV) all indicated the successful synthesis of the stabilized NPs, which have an absorption edge at 373 nm. Based on the responsive energy band gap to visible light, these NPs demonstrated promising photocatalytic activity for the degradation of toxic dyes with efficiencies of 82.2 and 87.5 % for of methylene blue (MB) and methyl orange (MO), respectively, in only 2 h of sunlight exposure. To evaluate the reaction kinetics and thermodynamic parameters including the activation energy and rate constant, the degradation process was conducted at various temperatures. The effect of temperature showed the highest rate constant values of 0.022 and 0.025 min⁻¹ at 90 °C, and activation energies of 4.1 and 3.8 kJ mol⁻¹ for MO and MB, respectively. A possible degradation mechanism was proposed based on results of the radical scavenging experiments. The photocatalyst showed recyclability for five consecutive cycles with a simple regeneration. CMFE@ZnO NPs have also exhibited great antibacterial potential by inhibiting the growth of Gram-positive (S. aureus (13 mm) and B. subtilis (14 mm)) and Gram-negative (E. coli (17 mm) and P. multosida (15 mm)) bacterial strains. As a result, these CMFE@NPs may have great commercial importance in reducing the concentration of azo dyes and drug-resistant bacteria in textile and pharmaceutical industry effluents.

C. macrocarpa fruit extract-based synthesis of NiO NPs for improved photocatalytic degradation of Crystal Violet dye, antibacterial efficacy, and antioxidant applications.

The present investigation deals with the synthesis, characterization and pharmacological evaluation of four cadmium complexes (1–4) with Schiff bases (¹L-⁴L) derived from the substituted amines and aryl aldehydes. Amantadine is reacted with different aryl aldehydes (salicylaldehyde, 3-ethoxysalicylaldehyde and 4-(diethylamino) salicylaldehyde) to prepare Schiff base ligands ¹L-³L, while ⁴L was prepared using 4-methylaniline. The complexes were characterized by elemental analysis, spectroscopic techniques and thermal analysis, and the structure of one of the ligands, ³L was determined by X-ray crystallography. The spectroscopic data indicate that the ligands coordinate with Cd(II) in a bidentate fashion to give octahedral geometry. Single crystal XRD analysis shows that ³L is orthorhombic with the space group P2₁2₁2₁. The ligands and their Cd(II) complexes were evaluated for antimicrobial activities, while the complexes were also investigated for inhibition effects towards an enzyme, alkaline phosphatase. The anti-microbial screening results showed that cadmium complex 1 exhibited significant antibacterial potential, particularly against Staphylococcus aureus with respect to the corresponding ligand suggesting that the complexes are more effective than their ligands for antimicrobial activity. In case of alkaline phosphatase inhibition screening, the synthesized cadmium complex 1 was found to maximally inhibit the activity of alkaline phosphatase in comparison to rest of three complexes.

A Schiff base ligand HL, (E)-2-((adamantan-1-ylimino)methyl)-6-allylphenol, was synthesized by condensation of amantadine with 3-allyl-2-hydroxybenzaldehyde, followed by the synthesis of its Zn(II), Co(II), Cr(III), and VO(IV) complexes under reflux conditions. The synthesized compounds were comprehensively elucidated by using different spectroscopic and analytical techniques: UV-Vis, ¹H and ¹³C-NMR, FT-IR, ESI-MS, thermal, and single-crystal XRD analysis. The chemical composition of the synthesized compounds was also verified by molar conductance and elemental analysis. An octahedral geometry for Cr(III) and Co(II) complexes, tetrahedral for Zn(II) complex, and square pyramidal geometry have been proposed for VO(IV) complexes. The antidiabetic activities of the synthesized compounds were also evaluated by performing in vitro α-amylase and α-glucosidase inhibition studies. The Co(II) complex exhibited the highest α-glucosidase inhibitory activity, whereas oxovanadium(IV) and zinc(II) complexes were also found to be effective against α-amylase. In alkaline phosphatase (ALP) inhibition studies, the HL was found to be inactive, while the complexes showed remarkable enzyme inhibition in the following order: VO > Zn > Co, in a concentration-dependent manner.

Herein, a one-pot synthesis of tetra-substituted imidazole, 4-chloro-2-(1-(4-methoxyphenyl)-4,5-diphenyl-1H-imidazol-2-yl)phenol (HL), is reported by the reaction of benzil, 5-chlorosalicylaldehyde, ammonium acetate and anisidine.