T. purpurea leaf extract has been utilized to synthesize facile and non-toxic silver nanoparticles. Analytical techniques were used to characterize the TP-AgNPs, including FE-SEM, EDX, UV–visible spectroscopy, FTIR spectroscopy, XRD, and zeta potential. Further, the biological activities of TP-AgNPs were examined, which advanced their applications for futuristic research purposes.

Tephrosia purpurea silver nanoparticles (TP-AgNPs) were synthesized with water-based leaf extract of the plant T. purpurea. UV–Vis characterization had shown the maximum absorbance at 436 nm. The surface morphology was examined via electron microscopy (FE-SEM) analysis (average size: ~100 nm, shape: spherical). The zeta potential (ZP) of TP-AgNPs revealed values of −41.72 mV suggesting appropriate physical stability. Besides, an X-ray crystallography (XRD) study had shown the crystalline size of 20 nm approximately having 2θ values of 32°, 38°, 44°, 64°, and 77° for the silver crystals. The energy dispersive (EDAX) study manifests the absorption peak at 2.983 keV for TP-AgNPs. Infrared spectroscopy analysis (Fourier-transform infrared spectroscopy) indicated the presence of alcoholic as well as aromatic groups in the extract that took part in the stability and silver reduction mechanisms. Biologically, TP-AgNPs had shown prominent anti-oxidant activities against 2,2-diphenyl-1-picrylhydrazyl radicals (IC₅₀ 50 μg/mL) and H₂O₂ radicals (IC₅₀ 106 μg/mL). It had also inhibited the proliferation of breast cell lines (MCF 7) showing total growth inhibition (TGI) at 8.2 μg/mL with the LC₅₀ of 44 μg/mL for TP-AgNPs. Further, hemolysis analysis revealed that TP-AgNPs are non-toxic to human erythrocyte cells (RBCs) as they do not cause the breakdown of RBCs. Thus, TP-AgNPs were found to be an effective agent to be studied further for chemotherapeutic mechanisms.

We reported the synthesis, electrochemical, and antiparasitic properties and the structure–activity relationship (SAR) study of new organometallic N-acylhydrazones of general formula [R¹-CH=N-NH-C(O)-(R²)] with (R¹ = ferrocenyl or cyrhetrenyl; R² = 5-nitrofuryl or 5-nitrothienyl).

In searching for new therapeutic agents for treating American trypanosomiasis and Human African trypanosomiasis, four nitroheterocyclic acylhydrazones of general formulae [R¹-CH=N-NH-C(O)-(5-C₄H₂X)] (where R¹ = ferrocenyl or cyrhetrenyl, and X = O or S) have been synthesized and characterized by spectroscopic techniques. Comparative studies of their stability by ¹H-NMR and UV–Vis experiments were reported. Single-crystal X-ray diffraction confirmed the molecular structures of NF-1 and NT-2. Their X-ray crystal structures reveal that both adopt an E-configuration on the C=N moiety. Regarding the -NH-C(O)- bond, the structure of NF-1 confirmed a trans conformation, while NT-2 exhibited a cis-amide conformation. The cyclic voltammetry and electron spin resonance (ESR) experiments were conducted to study the electrochemical behavior of N-acylhydrazones. The antiparasitic activities of compounds against Trypanosoma cruzi (epimastigotes) and Trypanosoma brucei (trypomastigotes) revealed that cyrhetrenyl complexes were more effective than their ferrocenyl analogs. The cyrhetrenyl derivative NT-2 (EC₅₀ = 2.25 μM) showed activity against T. brucei comparable to the standard drug nifurtimox (Nfx, EC₅₀ = 3.56 μM). The ferrocenyl compound NT-1 (>200 μM) was at least two times less cytotoxic than the Nfx (88.7 μM) against the L₆ rat skeletal myoblast cell line and exhibited a selectivity like Nfx toward T. brucei. Density functional theory (DFT) calculations were utilized as an approximation to explain the impact of organometallic and heterocyclic rings on antiparasitic activities. This study supported the experimental results, confirming that the cyrhetrenyl fragment in N-acylhydrazone derivatives plays a significant role in the antitrypanosomal activity, which can be attributed to an increase in positive charge on the metal.

Synthesis routes and molecular structure of the PNSiP ligand.

Silicon-bridged/N, P (PNSiP) ligand/Cr (III) catalyst system based on different fluorinated hydrocarbons as modifiers have been explored for ethylene selective tri-/tetramerization. Modifiers like 1H-Perfluorohexane (1H-PFH), Hexafluorobenzene (HFB), and Perfluorobiphenyl (PFB) have been proven to show a significant influence on ethylene oligomerization toward 1-hexene and 1-octene of the catalytic system. Among them, 1H-PFH showed the most significant promotion effect in improving activity from 0.95 × 10⁶ g·(mol Cr·h)⁻¹ to as much as 5.66 × 10⁶ g·(mol Cr·h)⁻¹ at high temperature 90°C. Through the analysis of nuclear magnetic resonance (NMR) spectroscopy and ultraviolet visible diffuse reflectance spectroscopy (UV–vis DRS) results, we concluded that 1H-PFH can react with an amount of trimethylaluminum (TMA) contained in the cocatalyst modified methylaluminoxane (MMAO) and the solubility of Cr (III) in solvent can be increased after adding 1H-PFH. Furthermore, the possible reaction routes of 1H-PFH with TMA and MMAO were proposed.

Dinuclear piano-stool ruthenium (II) complexes anchored on pyrazine-based carboxylic carboxamide ligands catalyse transfer hydrogenation of a wide of ketones at low catalyst loadings.

Reactions of ligand pyrazine-2-carboxylic acid (HL1) with [Ru(η⁶-p-cymene)Cl₂]₂ precursor gave the dinuclear piano-stool ruthenium (II) complex [{Ru(η⁶-p-cymene)Cl₂}-μ-(L1)-{Ru(p-cymene)Cl}] (Ru1). Separately, reactions of N-(quinolin-8-yl) pyrazine-2-carboxamide (HL2), 5-methyl-N-(−(quinolin-8-yl) pyridine-2-carboxamide (HL3) and 5-chloro-N-(quinolin-8-yl) pyridine-2-carboxamide (HL4) with [Ru(η⁶-p-cymene)Cl₂]₂ dimer in the presence of KPF₆ afforded the cationic dinuclear complexes [{Ru(η⁶-p-cymene)Cl}₂-μ-(L2)][PF₆] (Ru2), [{Ru(η⁶-p-cymene)Cl}₂-μ-(L3)][Ru(L3)Cl₃] (Ru3) and [{Ru(η⁶-p-cymene)Cl}₂-μ-(L4)][PF₆] (Ru4). The Ru (II) complexes were analysed using FT-IR, ¹H, ¹³C{¹H}, ³¹P{¹H} (Ru2 and Ru4) and ¹⁹F (Ru2 and Ru4) NMR spectroscopic techniques, micro-analyses and mass spectrometry. Molecular structures of complexes Ru1 and Ru3 were confirmed to display piano-stool coordination nature using single-crystal X-ray crystallography analyses. All the complexes (Ru1–Ru4) mediated the transfer hydrogenation (TH) of a broad spectrum of ketones in isopropanol in the presence of a base and demonstrated high catalytic activities (TON of 24,000) at catalyst concentrations of 0.002 mol%. In general, the catalytic performance of these Ru (II) complexes depended on the identity of the ligands, coordination chemistry and ketone substrates.

This study was done into these chelate catalytic performances for the environmentally friendly synthesis of 7-amino-4.5-dihydro-tetrazolo[1.5-a]pyrimidine-6-carbonitrile derivatives utilizing aromatic aldehyde, malononitrile, and 5 aminotetrazole as reactants.

Three GUBZCu, GUBZVO, and GUBZPd chelates have been prepared from 2-guanidino benzimidazole (GUBZ ligand) by a bidentate coordinating approach. FT-IR, mass, and NMR spectra; magnetic moment; CHN analysis; UV–Vis spectra; molar conductance; and TGA were studied to describe and estimate the molecular formulae of tested molecules. The stability constant for GUBZ complexes was estimated in the solution. Also, the pH profile displays the extra stability of tested complexes. Structure elucidation of the studied complexes had been supported by density functional theory (DFT) along with calculated electronic and vibrational spectra. Electronic absorption spectra were estimated practically through UV–Vis spectra and theoretically performed using the time-dependent TD-DFT/B3LYP, for computing the absorption maximum, oscillator strength, and excitation energy of the tested compounds. This study was done into these chelates' catalytic performances for the environmentally friendly synthesis of 7-amino-4,5-dihydro-tetrazolo[1,5-a]pyrimidine-6-carbonitrile derivatives utilizing aromatic aldehyde, malononitrile, and 5-amino tetrazole as reactants. The used reactions have been directed in a concerned environment through a green solvent. The obtained results verified the promising catalytic activity and selectivity of the tested complexes. All tested reaction conditions have been enhanced between variable Lewis acid catalysts in associating to our studied complexes. GUBZPd catalyst presented an advantage in overall tests through high yield, green conditions, and short time. Also, the regaining of hetero-catalyst has prospered as well as recycled through the same effectiveness up to four or five times, and then the performance has been reduced. The mechanism of action has been recommended depending on the capability of the Pd (II) complex for totaling extra bonds above the z-axis as well as reinforced with theoretical study. This strategy's simplicity, safety, commercially accessible catalyst, stability, fast reaction time, and outstanding yields may be used in the industry in the future.

In this study, nPd/Fes were dispersed on peanut shells-derived alkali-modified biochar (BC_alk) to obtain BC_alk-nPd/Fe composite for overcoming the instability, agglomeration, and oxidation of nPd/Fes. Results demonstrated that the dispersion stability and thermal stability of nPd/Fes were improved and the surface passivation layer was thinned by nanoparticles loading onto the alkalized biochar. Characterization analyses revealed of the improved 2,4-D dichlorination by BC_alk-nPd/Fe. After biochar alkalization, more Si-O-Si sites on BC_alk responsible for supporting nZVI particles were formed and coupled with nZVI to generate Si-O-Fe. Hence, nPd/Fes were immobilized on BC_alk, while the increased oxygen-containing surface functional groups promoted electron transport between nPd/Fes and 2,4-D. Therefore, the BC_alk-nPd/Fe exhibited higher dechlorination efficiency toward 2,4-D than that of nPd/Fe and BC_raw-nPd/Fe. About 99.25% and 89.11% of the 2,4-D removal and dechlorination, respectively, were achieved after 150 min. Kinetic studies revealed that the removal of 2,4-D using nPd/Fe, BC_raw-nPd/Fe, and BC_alk-nPd/Fe fitted well in the Langmuir–Hinshelwood kinetic model, and the order of rate constants was as follows: BC_alk-nPd/Fe > BC_raw-nPd/Fe > nPd/Fe. This study suggested that the prepared composites promoted detoxification and harmlessness of 2,4-D contaminated wastewater and exhibited promising prospect in the efficient treatment of wastewater containing chlorinated organics.

Three hydroxyl functionalized crystalline K-doped g-C₃N₄ were designed and synthesized, which exhibited high photocatalytic activity for production H₂O₂ directly from natural seawater. Under optimized conditions, the highest H₂O₂ production rate of 1622 μmol g⁻¹ h⁻¹ for duration of 10 h was obtained.

Three hydroxyl functionalized crystalline K-doped g-C₃N₄ were synthesized from dicyandiamide, melamine, ammonium chloride, ammonium oxalate, and ammonium citrate via ionothermal polycondensation using KCl as molten salt under N₂ atmosphere, which served as efficient recyclable photocatalysis realized that generating H₂O₂ directly from seawater with air by 2e⁻ ORR pathway under stimulated solar irradiation in ambient conditions. Under optimized conditions, the highest H₂O₂ production rate of 1622 μmol g⁻¹ h⁻¹ for duration of 10 h was obtained. The cycling performances of HPCN-2 displayed reusable for five times without noticeably loss of its catalytic activity. This work presents a real safer, sustainable, and economical approach for production of H₂O₂ directly from abundant natural seawater.

The proposed mechanism on the ODN and ODS.

In this work, the effect of different parameters on catalyst efficiency in the catalytic oxidative desulfurization (ODS) and denitrogenation (ODN) process is studied. A series of samples with different metal compounds, including Ni, Cu, Co, CoNi, CoCu, and CuNi on a reduced graphene oxide (GO) were prepared by an impregnation method. The synthesized samples were carefully characterized by Fourier transform infrared (FTIR), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) analysis, and X-ray powder diffraction (XRD) techniques. The potential of this methodology was illustrated by the oxidation of 84.11% carbazole (CBZ) and 88.36% dibenzothiophene (DBT) in model fuel containing 500 ppmw sulfur and nitrogen. The effect of DBT and CBZ initial concentration and oxidant type on the oxidation process was investigated. The initial concentration of 250 ppmw for DBT and 100 ppmw for CBZ showed more efficiency than other initial concentrations (1,000, 750, 500, 250 ppmw) for DBT and (500, 400, 250, 100 ppmw) for CBZ, and NaClO as an oxidant showed higher performance than H₂O₂, formic acid, and oxygen. The results indicated that the Co-Cu/rGO catalyst shows higher activity than other prepared catalysts in the oxidation of DBT and CBZ. Moreover, the catalyst could be regenerated three times with no discernible decrease in its catalytic activity. Lastly, the catalytic oxidation of CBZ and DBT was the proposed reaction mechanism.

A porphyrin-based porous organic polymer H₂Pp-TAPM containing flexible chains has been synthesized successfully. The H₂Pp-TAPM has demonstrated the ability to facilitate the transfer and separation of photogenerated electron–hole pairs and delivered superior activity in the selective aerobic oxidation of sulfides to sulfoxides.

Porphyrin-based porous organic polymers (Por-POPs) are attracting increasing attention because of their potential in visible light photocatalysis. The distinctive attributes of Por-POPs have been elucidated by investigating their response to specific reactions, such as the aerobic oxidation of sulfides. However, most researchers choose porphyrin molecules with relatively short peripheral substituent chains and strong stiffness to construct porphyrin-based materials, especially Por-POPS. Herein, we designed and prepared a flexible POP material H₂Pp-TAPM by incorporating extra π-conjugated rigid units TAPM into a relatively flexible porphyrin monomer H₂Pp through imine linkages. The POP synthesized in this study has demonstrated the ability to facilitate the transfer and dissociation of photogenerated electron–hole pairs, leading to the production of singlet oxygen ¹O₂ and superoxide radical anions O₂˙⁻. These anions act as effective mediators for the selective aerobic oxidation of sulfides, resulting in the conversion of 99% and the selectivity more than 99%. Furthermore, the H₂Pp-TAPM has excellent stability and recyclability, indicating its attractiveness as heterogeneous photocatalyst for the transformation of organic compounds. This makes it a promising candidate for visible-light-driven reactions.

In this work, novel Ni (II) complexes, namely, [Ni₂(L)₂(OAc)₂(EtOH)₂] (1a), [Ni₂(L)₂(OAc)₂(H₂O)₂] (1b-1) and [Ni₂(L)₂(OAc)₂(EtOH)₂] (1b-2) as co-crystal were synthesized by the 1:1 condensation (https://www.sciencedirect.com/topics/chemistry/condensation) of Ni (CH₃COO)₂·4H₂O and Schiff base ligand (H₂L) (2-hydroxy-4-methoxybenzaldehyde and 2-amino-2-methylpropanol). The ligand based on Schiff base and fabricated complexes (1a) and (1b-1 and 1b-2) were successfully identified by CHN assessment, FT-IR, UV–Vis spectra, melting point and CV voltammogram. The electrochemical behavior investigation shows that the nickel complexes exhibited irreversible oxidation processes in methanol solution. Additionally, the crystal structures of complexes (1a) and (1b) have been recognized by single-crystal X-ray diffraction investigation. It turned out that the complexes (1b-1) and (1b-2) crystallize together, making a co-crystal 1b with an additional EtOH solvent molecule in the crystal structure. A detailed study of intermolecular exchanges was performed using attractive graphical analysis tools such as three-dimensional Hirshfeld surfaces analysis, two-dimensional fingerprint plots (FPs), and enrichment ratios (E), which make C-H … C, C-H … O hydrogen bond, C … O, H … H, and O … O short contacts on Hirshfeld surfaces with color code are observed. Moreover, an appraisement of the inhibitory trace against coronavirus (main protease SARS-CoV-2, PDB ID: 6Y2F) and molecular targets of human angiotensin-converting enzyme-2 (ACE-2) was performed by a molecular docking study in which two nickel complexes performed best for PDB protein ID: 6M0J and all three complexes for PDB protein ID: 6Y2F.