N-heterocyclic carbene complexes comprise mesoionic carbenes (MICs) have emerged as a huge asset in the field of organometallic chemistry and particularly their applications in homogeneous catalysis. However, such complexes containing mixed chiral–MIC and phosphine donor ligands are rare and relatively less explored. In this manuscript, three new palladium(II) complexes with mixed MIC/Py/PPh3/PCy3 donor set ligands possessing chirality at MIC center are presented. Nuclear magnetic resonance (NMR) spectroscopy and electrospray ionisation (ESI) mass spectrometry analysis have been used to characterize these complexes. Single crystal X-ray diffraction (XRD) was also used to establish the structure of PdII complex possessing mixed MIC/PPh3 ligands. The new palladium(II) complexes with a combination of MIC and PR3 (R = Ph and Cy) ligands have been found as effective precatalysts and provided excellent yields in Suzuki–Miyaura coupling, Sonogashira coupling, and copper-free α-arylation reactions. It is observed that the PdII complexes with MIC/PR3 donor set of ligands show superior activity compared with the complexes with mixed MIC/Py set of ligands in α-arylation of amide and Sonogashira coupling reactions. The catalytic outcomes have also been supported with preliminary electrochemical measurements.

The measurement of Cd (II) ions in various matrices requires the development of sensors that are selective, sensitive, and simple to produce. The cadmium complex of a ligand prepared by the reaction of 2-pyridinecarbohydrazide with sodium 3-formyl-4-hydroxybenzenesulfonate, [Cd (NaPH)(H2O)].H2O, was synthesized, analyzed by elemental analysis, and structurally elucidated using various spectroscopic techniques. The infrared spectrum of Cd (II) complex suggests a bi-negative tri-dentate ONO behavior for the ligand via deprotonated form of both the enolic oxygen atom (C-O−) and the hydroxyl group of phenolic ring in addition to the azomethine group. The thermal behavior of this complex was revealed using TGA analysis. Applying Coast–Redfern and Horowitz–Metzger equations, we were able to calculate the kinetic and thermodynamic parameters to support the proposed fragmentation experiment for the Cd (II) complex. Cyclic voltammetry measurement was measured to estimate the electrochemical behavior of the Cd (II) ions as well as the impact of adding various NaH2PH ligand concentrations. The biological applications of [Cd (NaPH)(H2O)].H2O complex were assessed as antioxidant, anticancer, and antimicrobial. Based on the Cd (II) complex, we were able to modify Cd (II) ions carbon paste electrode (modified carbon paste electrode, MCPE) as a Cd (II) selective modifier. The created electrode displays a Nernstian slope in the linear range of 0.0001 to 10 mmol/L of 29.16 ± 0.03 mV decade−1, a quick reaction time of 6 s, and pH independence from 3–7. The suggested MCPE demonstrated strong selectivity to Cd (II) ions relative to many other cations and displayed negligible change in the slope or operating range if the experiment was achieved in a partially non-aqueous solution. This fabricated MCPE was used to determine Cd (II) ions in diverse water samples.

The tri-metallic magnetic nanoalloy synthesized via the eco-friendly procedure discussed here contains cobalt (Co), nickel (Ni), and zirconium (Zr) metals in a 3:1:1 M ratio (Co3O4.NiO.ZrO2 nanoalloy). Two different plant extracts which are rich in biologically active compounds from Spermacoce hispida and Vernonia cinereum were combined to get a multispecies nanoalloy with magnetic properties and medicinal values. The Fourier transform infrared, X-ray diffraction, and transmission and scanning electron microscopes analyses confirmed the spherical shape of the bioinspired Co3O4.NiO.ZrO2 nanoalloy. The average size of our nanoalloy was 32 nm, but the individual nanoparticles are between 21 and 73 nm in size. A vibrating sample magnetometer study of the magnetic characteristics of the nanoalloy reveals strong saturation magnetization (12.42 emu/g), low retentivity (Mr), and low coercivity (Hc) (282.36 Oe). The higher saturation magnetization in nanoalloy is attributed to their larger particle size, a high degree of crystalline structure, and slight external spinning deformation. The low coercive field (Hc) value reveals the unique soft nature of our nanoalloy. The disc diffusion study confirms that a 6.3 μg/mL solution of the nanoalloy kills almost 96% of the harmful bacteria like Bacillus subtilis (29 mm), Bacillus cereus (26 mm), and Escherichia coli (21 mm). It shows a moderate effect of 85% killing factor against Staphylococcus albus (17 mm), Pseudomonas aeruginosa (13 mm), and Klebsiella pneumoniae (15 mm) bacteria.

Leishmaniasis is a zoonotic disease prevalent in 83–92 countries. This disease's current treatments are unsatisfactory because of a variety of shortcomings, including serious toxicity, variable efficacy, painful administration, and the occurrence of parasite resistance to these antileishmanial agents. The abovementioned limitations have urged the development of novel, reliable, and affordable agents to treat leishmaniasis. Ferrocenylazine derivatives were therefore synthesized for activity screening against Leishmania major and Leishmania donovani cell cultures. This emphasizes the urgent need for new effective antileishmanial agents. In search for such therapeutics, we synthesized and evaluated in vitro the antileishmanial activity of a series of azine derivatives based on the organometallic compound ferrocene. Two ferrocenylaldazines, 2l and 2q, were uncovered as mammalian cell nontoxic antileishmanial early leads, expressing submicromolar activity with IC50 values of 0.78 ± 0.03 and 0.46 ± 0.03 μM, respectively, against amastigote of L. donovani. Ferrocenylazines may therefore act as potential new antileishmanial agents, and the next objective will be the identification of the involved biological targets.

A series of heterocyclic organobismuth (III) complexes based on bidentate C,O-coordinating ligands were designed and synthesized as antimicrobials. Antibacterial assays showed that complexes of this type are more effective for Gram-positive bacteria (Staphylococcus aureus, Staphylococcus epidermidis, and Enterococcus faecalis) than Gram-negative ones (Escherichia coli and Pseudomonas aeruginosa). Their activities are especially relevant to the synergism of lipophilicity, geometry, and stability, which depends on both the identity of coordinating ligands and the coordination number at the bismuth center. By comparison, the hypervalent 14-Bi-6 species diarylbismuth nitrate (8) was found to exhibit the most potent inhibitory effect, together with a high degree of selectivity, which gives an IC50(LO2)/MIC(Staphylococcus aureus) ratio of up to 23.08. Time–kill analysis demonstrated that complex 8 is bacteriostatic at low concentrations while displaying significant bactericidal activity at high doses. The results of drug resistance experiments suggested that complex 8 can inhibit the formation of bacterial biofilm and consequently delay or prevent the development of drug resistance. Furthermore, complex 8 also showed high inhibition efficiency against several drug-resistant Staphylococcus aureus, and the MIC values are within the range of 0.39–1.56 μM, thus indicating the lack of cross-resistance between this organometallic compound and commonly used antibiotics.

The main purpose of the current work is the design and synthesis of new Co(II), Ni(II), and Cu(II) mixed-ligand complexes derived from simple and easily synthesized azo-ligand, [2-(phenylthio)phenyl]diazenyl}-2-naphthol (HTe), with 8-hydroxyquinoline (HQ) to improve and understanding their action as an antimicrobial candidate and their therapeutic efficiency with the aid of density functional theory (DFT) calculations and molecular docking studies, which considered a hot topic of research. To access this target, and to explore the effect of changing metal ion type, the new Co(II), Ni(II), and Cu(II) mixed-ligand complexes were firstly synthesized and characterized via elemental analysis, Fourier transform infrared (FT-IR), mass spectrometry, ultraviolet–visible spectroscopy, magnetic susceptibility, thermogravimetric analysis (TGA), and stoichiometry analysis molar ratio method. Upon further inspection, the octahedral structures of the isolated metal complexes were found. The compounds' molecular structures were optimized using the DFT technique, and the quantum chemical parameters were evaluated. To determine whether or not these compounds are effective in preventing the spread of harmful bacteria and fungi, two of the most common environmental pollutants in the Arab world, a disc diffusion test was conducted. The prepared complexes were much more efficient against bacteria than the pristine ligands. Molecular docking experiments helped researchers learn which medicines inhibited the 1fj4 protein. All other tested compounds were found to have lower binding affinities than CuTeQ. This suggests that these compounds have the potential as starting points for the production of new classes of antibiotics. Finally, a correlation of the in vitro activity with the DFT and molecular docking data has been done and discussed.

In this study, hydroxycalix[4]arene, hydroxycalix[5]arene, hydroxycalix[6]arene, and their complexes with uranyl and thorium ions were analyzed by density functional theory. The coordination ability of hydroxycalixarene ligands to uranyl and thorium ions could be analyzed by simulating the infrared and ultraviolet–visible spectra, the Wiberg bond energy levels, the energy gaps, and the binding energies. We found that various hydroxycalixarene complexes with uranyl or thorium ions had significant differences in their properties, as well as in their infrared vibrational and ultraviolet absorption spectra. More importantly, different hydroxycalixarenes can be selected based on the adsorption requirements in environments with coexisting uranium and thorium ions. For example, hydroxycalix[4]arene and hydroxycalix[5]arene had a significantly higher binding capacities for thorium than uranyl ions, while hydroxycalix[6]arene showed less of a difference for the two ions but had a good binding ability for both uranyl and thorium ions at the same time. Thus, the use of hydroxycalixarene can achieve the removal of both uranyl and thorium ions in the environment, and the use of specific hydroxycalixarenes may be able to achieve the separation of these ions. These results provide important guidance for the future research of hydroxycalixarene without requiring the synthesis of hydrophilic derivatives, and they may be directly applied to the field of heavy metals.

Metal-porphyrin complexes with a well-defined M-N4 structure are a class of electrocatalyst materials that can be reasonably designed to exhibit high electrochemical carbon dioxide reduction (CO2RR) performance. The substituent effect of metal-porphyrin complexes plays an important role in CO2RR. Herein, Co-porphyrins with different substituents of -COOCH3, -OCH3, -COOH, and -OH (denoted as CoTCMePP, CoTOMePP, CoTCPP, and CoTOPP) were prepared and uniformly anchored on carbon nanotubes. CoTCMePP/CNTs exhibited a higher FE (CO) of 94.5% with a current density of 12.9 mA cm−2 and a TOF of 705 h−1 at −0.77 V versus RHE in 0.5 M KHCO3 than that of CoTCPP/CNTs. Meanwhile, the performance of CoTOMePP/CNTs was superior to CoTOPP/CNTs in FE (CO) and stability. The methylated derivatives exhibited enhanced electrocatalytic CO2 reduction performance, for the methylation of the hydroxyl and carboxyl might increase the solubility and suppress the aggregation of metal-porphyrin, helping Co-porphyrins disperse on the carbon nanotubes better.

In the present study, a nanomagnetic bisethylferrocene-containing ionic liquid (IL) supported on silica-coated Fe3O4, [Fe3O4@SiO2@{CH2}3-Imidazolium-Fc{H2PO4}], was designed and synthesized as a novel catalyst using a simple chemical co-precipitation procedure. The synthesized nanoparticles were identified by using EDX, FE-SEM, XRD, and FT-IR techniques. The catalytic activities of the novel magnetic nanoparticle were tested in the one-pot synthesis of hydroxycoumarin derivatives through the three-component reaction (t-CR) between 4-hydroxycoumarin, various aromatic aldehydes, and secondary amines at room temperature. Based on the obtained results, the prepared nano-catalyst has progressed through a t-CR due to the presence of acidic and basic segments in its structure. The short reaction time, high yield, eco-friendly properties, and easy work-up are some of the advantages of new synthesized nanomagnetic catalysts. The easy separation of the new magnetic catalyst from the reaction mixture makes it possible to reuse it after washing and drying.

The Fe2+-activated persulfate and H2O2 (Fe2+/persulfate/H2O2) system achieved 94% removal of four mixed sulfonamides with 300-s treatment and possessed excellent complementarity and stability over a wide pH (3–11) and temperature (5–65°C) range. The quenching and electron spin resonance spectroscopy results confirmed the coexistence of sulfate radicals and hydroxyl radicals in the coupled system, which were responsible for the elimination of sulfonamides under ambient conditions. The reaction rate constants of sulfate radicals and hydroxyl radicals at possible reactive sites distinguished the difference in removal ratios of four sulfonamides, according to experimental determination and density functional theory calculations. The removal ratio of sulfathiazole was higher than others because its calculated reaction rate constants of sulfate radicals and hydroxyl radicals were higher than those of sulfamerazine, sulfamethoxazole, and sulfamethazine. The finding provided a reference for investigating the removal mechanism of mixed organic pollutants in the presence of multiple free radicals.

The built-in electric field induced by piezoelectric effect for suppressing the electron–hole recombination has gained substantial attention recently. In this study, a novel Z-scheme ZnSnO3/Bi2WO6 (ZSO/BWO) piezo-photocatalyst with synergistic polarized electric field was synthesized by a simple impregnation method. The optimized 1% ZSO/BWO shows high piezo-photodegradation efficiency (99.9%, 60 min) and mineralization (42%, 60 min) of diclofenac (DCF) under the synergistic action of ultrasound and light, far exceeding that under sole ultrasound or illumination. The remarkable enhanced piezo-photocatalytic activity of ZSO/BWO composite was attributed to the increased absorption, improved charge transfer, Z-scheme heterojunction, and tight surface contact between ZSO and BWO. Moreover, the Z-scheme mechanism of ZSO/BWO composites is studied in depth and confirmed by the free radical capture experiment and electron spin resonance technology. In addition, the corresponding intermediates of DCF degradation and the possible degradation pathways that were proposed on ZSO/BWO composites were analyzed by liquid chromatography–mass spectrometry and DFT. This work offers an efficient approach for constructing and preparing the highly efficient piezo-photocatalysts for converting solar and mechanical vibration energies.

A novel Fe3O4@SiO2-Pr-Thiosemicarbazide-Cu(II) as a magnetically separable catalyst was synthesized and further confirmed by FT-IR, TGA, XRD, FE-SEM, EDX, ICP-AES, TEM, VSM, and XPS analyses. The catalytic efficiency of Fe3O4@SiO2-Pr-Thiosemicarbazide-Cu(II) was examined in the one-pot environmentally friendly synthesis of 1,2,3-triazoles by reacting terminal alkynes, alkyl halides, and sodium azide in ethanol at 55°C. The results revealed Fe3O4@SiO2-Pr-Thiosemicarbazide-Cu(II) nano–sizedcatalyst is advantageous in terms of excellent activity, high stability, and easily recoverable in the synthesis of 1,2,3-triazoles. The mechanistic study of Fe3O4@SiO2-Pr-Thiosemicarbazide-Cu(II) catalyzed synthesis of 1,2,3-triazole is also supported by DFT calculations. The significant advantages of this catalytic system are mild reaction conditions, easy work-up procedure, magnetic separation, heterogeneity, an excellent yield of the product, and recyclability without a notable decrease of catalytic potency for six runs. Further, histotoxicological assessment of synthesized 1,2,3-triazoles was done on the Indian major carp Labeo rohita.

A diformylphenol Schiff base of triazole-amine, 4-methyl-2, 6-bis-[(1H-[1,2,4] triazol-3-ylimino)-methyl]-phenol (PTR) has been synthesised and characterised by spectroscopic data (ESI-MS, UV-vis, FT-IR, NMR spectra). The probe, PTR, emits at 610 nm upon excitation at 380 nm and the emission is strongly intensified on interacting with Zn2+ ion in DMSO-water (99:1, v/v; HEPES buffer, pH, 7.2) solution even in the presence of 15 other cations (Cu2+, Mn2+, Co2+, Ni2+, Pd2+, Cd2+, Pb2+, Hg2+, Fe3+, Cr3+, Al3+, Na+, K+, Ba2+, Ca2+) and the emission band has been shifted to 530 nm. The limit of detection of Zn2+, 0.30 μM is much lower than WHO recommended value (76 μM). The binding constant (Kd) is 4.2585 × 104 M−1. Selective and sensitive chemosensing behaviour of PTR to Zn2+ has been explained by switching off ESIPT quenching of the keto-enol tautomerisation of the probe along with the chelation enhancement of fluorescence (CHEF) by binding with Zn2+. The Job's plot and NMR titration have been extended to measure the 1:1 M composition [PTR + Zn2+]. The energy calculation by the DFT computation of keto and enol isomers supports easy tautomerisation and helps ESIPT quenching by proton transfer. Intracellular Zn2+ ions in living cells of HEK293 (PBS: phosphate buffer saline; pH, 7.2) have also been identified by the probe, PTR, using fluorescence microscopic imaging technique.

A series of manganese(I) tricarbonyl complexes formulated as [Mn(8-HQ)(CO)3Imd] (HQ = hydroxyquinoline and Imd = imidazole derivatives) was synthesized and fully characterized. These structures could be easily accessed from a common dimeric edifice formulated as [Mn2(8-HQ)2(CO)6]. The structure of this complex has been confirmed by X-ray diffraction studies. Its reaction with a range of imidazole derivatives (Imd) yielded the monomeric complexes [Mn(8-hydroxyquinoline)(CO)3Imd] with various functional groups as an anchoring point for a vector. Photoactivation of all these complexes by blue-light irradiation led to the liberation of 3 mol of CO per mol of complex as determined experimentally. Spectroscopic and computational methods were employed to explore the mechanism of CO release. Finally, a manganese complex including the more elaborate imidazole ligand N- and C-di-protected histidine was successfully synthesized, opening the way to its direct incorporation in peptides.

Utilizing sunlight as a driving force in chemical reactions is a great benefit for a sustainable future. Metal-based composites are basic components in various catalytic reactions. However, few researches reported carbon nitride-supported Pd nanoparticles in photocatalytic coupling reactions. This study reports the preparation of a graphitic-carbon nitride system (C3N5) followed by modification with various amounts of Pd nanoparticles. The C3N5 was synthesized by thermal deammoniation of melem hydrazine precursor and then modified by Pd cations to create a metallic composite. Regarding the N-rich surface of C3N5, Pd2+ cations are rapidly reduced to Pd nanoparticles in mild conditions, which is strongly supported by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analyses. Moreover, field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM) analyses clearly depicted the formation of 20 nm Pd nanoparticles on the surface of C3N5. The obtained Pd/C3N5 composite exhibited prominent photocatalytic performance for Suzuki-Miyaura coupling reactions (91% during 25 min at room temperature). This study also compares the effect of various amounts of Pd cation in the progress of Suzuki-Miyaura coupling reactions.

The Ag(I) and Cu(II) complexes of the ligand, 2,2′-(1,2,4-oxadiazole-3,5-diyl) dianiline, (L; 4) were synthesized and characterized using different spectroscopic techniques. Their anticancer activities against three types of cancer cell lines were explored. The [AgL (NO3)]n complex (5) has 1D polymeric structure whereas the [CuL (NO3)2] (6) and [CuLCl2] (7) are monomeric complexes. The Ag(I) in 5 is tetra-coordinated and has AgN2O2 coordination sphere where both L and NO3¯ are bridging the Ag(I) sites along the polymer array. In 6 and 7, the coordination environments are CuN3O3 and CuN3Cl2, respectively. In both cases, the oxadiazole ligand is a tridentate chelate via two N-atoms from both amino groups and one N-atom from the oxadiazole moiety. Hirshfeld analysis revealed the importance of O … H (23.5%), H … H (24.8%), and C … C (6.6%) non-covalent interactions in the molecular packing of 5. In 6, the O … H (40.7%), N … H (4.9%), O … O (5.9%), N … O (3.2%), and C … N (2.2%) contacts are the most important. Regarding safety on normal human fibroblasts Wi-38, MTT assay for all metal complexes especially the Ag(I) complex 5 exhibited higher safety profiles than the free oxadiazole ligand as well as the standard chemotherapeutic drug 5-fluroruracil (5-FU). The cytotoxic activities of complexes 5–7 surpassed 5-FU against A549, Caco-2, and MDA-MB231 cell lines. 5 has the best anticancer activity (IC50 = 0.074, 0.085, and 0.533 μM, respectively) and exhibiting pronounced selectivity index up to 44.3. Quantitative PCR analysis of BAX and BCL-2 revealed their apoptotic induction mechanism and showed that the metal complexes can repress the main oncogene BCL-2 and enhance the expression of proapoptotic gene BAX. Again, 5 is the most potent with 14.28 folds BCL-2 downregulation and 4.86 folds BAX upregulation.

A high-performance catalyst, RuO4@C, was safely generated in situ from a safety mask Ru@C, which was recyclable and commercially available. The catalyst could selectively oxidize thioethers to sulfones in 95%–99% yields and alkynyl sulfurs to alkynylsulfones in 93%–98% yields. This safe, non-toxic, inexpensive, and readily available catalyst is potentially promising for industrial applications in the production of sulfones from sulfur oxidation.

In this research, we synthesized ferrocenyl-grafted polymethylhydrosiloxane (PMHS) through a hydrosilylation reaction between 3-butenylferrocene and PMHS. The incorporation of the ferrocenyl derivative into the polymer backbone imparted electrochemical properties to the modified polymer. The modification of the polymer was confirmed by various techniques, including FT-IR, 1H NMR, and UV–Vis spectroscopy. To prepare the new ferrocenyl polymer, we utilized cross-linking agents, namely terephthaldehyde (TPA) and fresh egg white (FEW). The resulting polymer was drop-coated onto a glassy carbon electrode (GCE) surface (5 μL). Electrochemical impedance spectroscopy (EIS) analysis confirmed the successful immobilization of the polymer on the GCE surface. Under physiological pH conditions (pH = 7), the Fc/Fc + couple facilitated the oxidation of folic acid (FA) at a potential of 0.40 V vs. the Ag/AgCl reference electrode. The GC/PMHS-Fc/(TPA + FEW) electrode exhibited excellent stability, retaining 89% and 90% of its electrocatalytic activity after 500 cycles and 30 days of storage in a refrigerator, respectively. Thus, it shows promising potential for the determination of FA in biological fluids. The ferrocene-modified electroactive polymer demonstrated satisfactory linear ranges for FA determination (5–150 μM) and a low limit of detection (LOD = 36 nM). These results highlight the effectiveness of the new polymer in detecting FA in biological samples.

Aiming to design unique metallic drugs with significant therapeutic activity, in this work, mixed ligand Cu (II) complex involving 2,2′-bipyridine and phenylalanine [Cu (bpy) (phenala.)Cl].2H2O has been fabricated and characterized using IR spectroscopy. The interaction of Cu (II) complex with CT-DNA molecules was examined through UV–vis absorption titration plots, thermal denaturation experiments, viscosity measurements, and electrochemical studies. Cyclic voltammetry, electrochemical impedance spectroscopy, and chronoamperometry measurements have been exploited to elucidate their binding style. The negative potential shift in ΔE and E1/2 values as well as the increased current density of Cu (II)/Cu(I) redox couple suggested the promoted rate of electron transfer process in presence of CT-DNA molecules in the examined solution. Some kinetic parameters were also estimated such as the diffusion coefficient, the exchange current density, and Tafel slope values. Based on the results of these binding experiments, a groove and/or electrostatic interaction mode was expected. The antimicrobial activity of the studied Cu (II) complex was screened against a series of bacteria and fungi. An outstanding performance was shown when treating different Gram-positive and Gram-negative bacteria types. Moreover, an enhanced cytotoxicity behavior toward some human tumor cell lines, including MCF7, HEPG2, and HFB4, was detected with respective IC50 values of 43.02, 51.21, and >200 μM when incubated with Cu (II) complex for 72 h. These results suggest the application of [Cu (bpy) (phenala.)Cl].2H2O complex as a chemotherapeutic agent with a promising output in the drug discovery field.

New Pd (II) and Pt (II) complexes (C1/C2) with a O,N,N donor pincer ligand, 4-hydroxy-3-((E)-1-(((Z)-phenyl (pyridin-2-yl)methylene)hydrazono)ethyl)-2H-chromen-2-one (HL) were synthesized and methodically characterized by several spectroscopic and XRD techniques. Absorption and fluorescence techniques were used to assess the mechanism of interaction of the complexes with bovine serum albumin protein. MTT assay was executed to investigate the antiproliferative activity of the complexes with several cancer cell lines (MCF-7, HCT116, A549, and HepG2) along with a normal cell line (PBMC). Both C1 and C2 showed better antiproliferative activity with HepG2 cell line (IC50 value of 15.3 and 5.1 μM, respectively). A cytotoxicity study was performed, and complex C2 exhibited a better antiproliferative activity as compared to C1. The morphological changes were also examined by staining methods, and fragmented DNA unveiled that the cell death took place through apoptosis.