Applied Organometallic Chemistry最新文献

In the present article, a selective and efficient sensor based on organosilane functionalized graphene oxide nanocomposites has been synthesized for the fluorometric detection of tyrosine (Tyr). The 1,2,3-triazole functionalized organosilane has been synthesized by a condensation reaction between 4-(methylthio) aniline and alkylated benzaldehyde followed by azide-alkyne cycloaddition reaction using Cu (I) catalyst. The synthesized organosilane has been fabricated on graphene oxide nanoparticles and the obtained graphene-functionalized organosilane (GO-Silane) was characterized by FTIR and XRD. The morphology of the nanocomposite film was analyzed using scanning electron microscopy. The photophysical properties of GO-Silane were studied which established its selective sensor for tyrosine with the limit of detection values of 1.04 × 10⁻⁸ M with a response time of 8 s. The strong coordinated interactions of GO-Silane for the Tyr have been confirmed from FTIR spectra of the GO-Silane-Tyr complex. The competitive amino acid interference assay successfully demonstrated the selectivity of the nanocomposite sensor.

The current work aims to synthesize calcium nanostructure (Ca NS) using a green approach, given the growing trend of Ca NS in various sciences. We present the synthesis of Ca NS utilizing aloe vera extract and pectin extracted from citrus for the first time. Through the use of several analytical techniques, including ultraviolet–visible (UV-Vis), dynamic light scattering (DLS), Fourier transform infrared (FT-IR), x-ray diffraction (XRD), Raman, transmission electron microscopy (TEM), and scanning electron microscopy (SEM), the Ca nanostructures were verified and characterized. According to UV-Vis spectrum, a peak in the blue area of 204 nm for pectin–Ca NS indicated a small size nanoparticle. But for aloe vera/Ca NS, the presence of two blue and red peaks, at 227 and 401 nm, showed that nanoparticles with larger size than pectin/Ca NS. The results of the zeta potential showed that the synthesis of Ca NS with both pectin and aloe vera extracts is very stable. But pectin/Ca NS is more stable. In FT-IR and Raman spectrum, the presence of more peaks in pectin/Ca NS indicates a more complex structure and more agent groups than Aloe vera/Ca NS. In the XRD spectrum, in pectin/Ca NS and Aloe vera/Ca NS, calcium peak was well identified and showed that complete calcium synthesis has been performed. The SEM and TEM pictures of pectin/Ca NP and Aloe vera/Ca NS show the spherical shapes and average size around 4–18 nm for nanoparticles. In addition, the antioxidant capacity of Ca NSs was taken into account. The outcomes demonstrated that pectin has superior qualities and is a promising candidate for synthesizing Ca NSs. It was discovered that the Ca NSs had a very powerful anti-DPPH free radical effect.

Three Co(II) complexes of terephthalate anion containing 1,10-phenanthroline (phen) or 2,2′-bipyridine (2,2′-bipy), are prepared. The structures of dimeric [Co₂(H₂O)₄(μ-H₂O)₂(phen)₂]⁴⁺·2(C₈H₄O₄²⁻), 1, and the polymeric [Co₂(H₂O)₂(phen)₂(μ-C₈H₄O₄)₂]_n, 2, complexes were confirmed by single crystal structure determination. Both complexes have CoN₂O₄ core in a distorted octahedral arrangement. Extensive hydrogen bonding and π–π stacking interactions consolidate 3-D structures in 1 and 2. Complex 3, [Co(μ-C₈H₄O₄)(2,2′-bipy)]_n, was previously reported. It has CoN₂O₄ core in a distorted trigonal prismatic environment. Complexes 1, 2 and 3 exhibited good inhibition efficiencies for corrosion of carbon steel in 0.25-M sulfuric acid solution. The order of corrosion inhibiting effect of the complexes was 2 (94.6%) > 1 (90.5%) > 3 (79.5%). The increase in R_p value and the decrease in C_dl were in parallel with the increase in the concentration of complexes. Tafel plot indicated that complex 1 behaved as a cathodic-type corrosion inhibitor, whereas complexes 2 and 3 as anodic inhibitors for C-steel in sulfuric acid medium. Weight loss measurement of steel samples in 1-M HCl showed more inhibition of corrosion by complexes 1 and 2 than by complex 3. The adsorption mechanism of inhibitors on C-steel followed Langmuir isotherm. The free energy changes indicated comprehensive physical and chemical adsorption for the three complexes on the surface of the C-steel. SEM analysis of steel samples in 1-M HCl proved the efficiency of complexes in retarding corrosion as the steel surface showed smoothness compared to the blank. Quantum chemical DFT study declared that the highest corrosion inhibition efficiency is observed for complex 2, which was strongly supported by the electrochemical anticorrosion studies. The results of the TGA analysis support the X-ray crystal structures of the complexes.

A new complex of type [Nd (HL) (NO₃)₂] has been synthesized with a Schiff base ligand H₂L derived from 2-hydroxy-3-methoxybenzaldehyde and L-histidine. The structure of the synthesized complex was established using elemental analysis, molar conductivities, FT-IR, ¹HNMR, SEM, and x-ray diffraction (XRD) spectroscopy. FT-IR data revealed that H₂L acts as a tetradentate ligand through the carboxylic acid, azomethine nitrogen, methoxy oxygen, and hydroxyl groups. Based on the electronic spectra, an octahedral configuration was hypothesized for the complex. The TGA method was employed to study the thermal behavior of ligand and its complex, and thermodynamic parameters were determined using Coats–Redfern equations. The XRD analysis revealed that the synthesized compounds possess nanoscale dimensions, with their crystallinity significantly enhanced by the coordination of the Nd(III) ion with H₂L. DFT calculations were performed to optimize the geometry of the proposed structures, indicating improved thermodynamic and electronic stabilities. The reduced HOMO–LUMO gap in the Nd(III) complex further highlights its remarkable conductive and electronic properties. The surface morphology of the Nd(III) complex was analyzed using SEM to investigate its structural characteristics. The SEM images reveal a variety of particle shapes, including elongated, prismatic, and irregular blocky particles with sharp edges, suggesting a crystalline nature. The ligand and its Nd(III) complex were evaluated for their anticancer activity against prostate carcinoma, breast carcinoma, and lung carcinoma cell lines. The inhibition rate of Nd(III) complex was 92.81%, 93.25%, and 94.58%, respectively. The results demonstrated that the Nd(III) complex exhibited significantly enhanced anticancer activity compared to the ligand alone, likely due to its improved structural and electronic properties. These findings suggest that the Nd(III) complex holds promise as a potent anticancer agent.

The complexes of [Zn (DAP)(SA)] (1) and [Zn (bpy)(DAP)]Cl₂ (2) (where DAP is 3,4-diaminobenzophenone, SA is a dianion of salicylate, and bpy is 2,2′-bipyridine) were synthesized and characterized using various techniques such as ¹H NMR, ESI-Mass, ¹³C NMR, FT-IR, thermal gravimetric analysis (TGA), and UV–Vis. The formation of these complexes was supported by theoretical DFT approach. It reveals that these complexes have tetrahedral geometry. The interaction of these complexes with CT-DNA was studied by different methods. The UV–Vis titration revealed a bathochromic shift and significant hypochromicity at 260 nm for the absorption band of CT-DNA in the presence of these complexes. The studies in this work showed that the intercalative interaction between these complexes and CT-DNA is not the main or strongest mode, but other modes such as groove binding play role in their interactions. The achieved results from viscosity and electrochemical measurement confirmed this finding. The fluorescence studies showed that the proposed mechanism of fluorescence quenching for both complexes is static quenching. The thermodynamic parameters (ΔH° and ΔS°) revealed that the interaction of complex (1) with DNA occurs through hydrophobic forces and for complex (2) via hydrogen bonding and van der Waals interaction. The antioxidant activity of these complexes was investigated by DPPH (2,2-Diphenyl-1-picrylhydrazyl) assay. According to this test, the antioxidant activity compared to the standard sample (vitamin C) is as follows: vitamin C > 2 > 1. Furthermore, the docking result proposed the binding of these complexes to the groove of DNA.

In this research, we designed phthalocyanine compounds that are thought to be used as potential acetyl/butyrylcholinesterase inhibitors in the treatment of Alzheimer's disease. First, phthalonitrile compound (PNM-CN), which is the precursor compound for phthalocyanines, was synthesized. Then, by cyclotetramerizing this compound, pyridine-substituted peripheral cobalt (PNM-CoPc), copper (PNM-CuPc), and manganese (PNM-MnClPc) phthalocyanine compounds were synthesized, and their structures were described using mass, NMR (except phthalocyanines), FT-IR, and UV–Vis (except phthalonitrile) spectroscopic techniques. Investigations were carried out into the new pyridine-substituted peripheral (PNM-Cu/Co/MnClPcs) phthalocyanines' in vitro inhibitory properties against butyrylcholinesterase (BuChE) and acetylcholinesterase (AChE). With an IC₅₀ of 5.95 ± 2.12 μM (AChE) and 0.74 ± 0.01 μM (BuChE), PNM-CuPc showed the most potent inhibitory effect against AChE and BuChE among all compounds.

Reconnoitre the use of earth-abundant metals for an essential organic reaction was extremely provocative from an industrial vantage point. In this study, the fundamental and energy-efficient co-precipitation approach was employed to aid the Cu₂O cubed nanostructured catalyst in the generation of benzimidazole and quinoxaline derivatives. The developed Cu₂O cubed nanostructured catalyst was thoroughly evaluated by world-class analytical and spectroscopic techniques. The Cu₂O cube catalyst exhibited exceptional crystallinity, a cubic shape, a large specific surface area and uniformly distributed active sites on its surface. The obtained astounding structural and physico-chemical characteristics successfully enabled the catalytic activity for the synthesis of benzimidazole and quinoxaline. The recognised vital structural and physical attributes substantially improved the catalytic activity for the production of benzimidazole and quinoxaline derivatives over mild reaction conditions. Employing a cubic Cu₂O catalyst, diverse reaction parameters have been examined, encompassing the effects of catalyst dosage, temperature, time, solvent, yield and substrate scope. As a result, the designed catalyst was used to synthesise heterocyclic 2-substituted benzimidazole and quinoxaline derivatives via the condensation of o-phenylenediamine, aldehydes and 1,2-diketone. The reported results showed 100% conversion in both aimed products, with 90% selectivity for 2-substituted benzimidazole and 95% selectivity for quinoxaline derivatives, respectively. The obtained yield for 2-substituted benzimidazole and quinoxaline derivatives was 85 and 98 at 60°C for 3 and 4 h, individually. The catalytic activity was fully based on the inherent properties of cubic Cu₂O. On top of that, all synthesised compounds were structurally validated by ¹H NMR, ¹³C NMR and mass spectrum data. Remarkably, the efficient cubic Cu₂O catalyst demonstrated impressive recyclability for up to six consecutive cycles with minimal loss of its initial catalytic activity. The spent cubic Cu₂O catalyst's characteristic results revealed evidence for its stable structural and physico-chemical features. In addition, we endeavoured to propose and describe a plausible reaction mechanism utilizing the developed nanostructured Cu₂O cubes for the synthesis of benzimidazole and quinoxaline derivatives.

A novel quinolinyl hydrazone ligand (NaphHQino) has been synthesized by condensation of 2-hydrazinyl-4,7-dimethylquinoline with 2-hydroxy-1-naphthaldehyde. Reactions of NaphHQino with copper(II), nickel(II), and cobalt(II)-chlorides yielded a series of novel complexes. Structures of the NaphHQino ligand, Cu-NaphHQino, Ni-NaphHQino, and Co-NaphHQino complexes have been inspected with the help of elemental and thermal analyses, magnetic susceptibility and molar conductivity measurements, infrared, electron spin resonance (ESR), proton nuclear magnetic resonance (¹H NMR), mass, and electronic spectra. The studied NaphHQino ligand acts either as a neutral NN-donor or as a dibasic tridentate NNO-donor, forming square-planar complexes. Molar conductivity measurements demonstrate a neutral character of the NaphHQino complexes. The ESR spectrum of the Cu-NaphHQino complex confirmed the proposed square-planar geometry with values of α² and β², demonstrating that the in-plane π-bonding character is less prominent than the covalent in-plane σ-bonding character. Implementing density functional theory at the B3LYP/6-311G(d,p) and LanL2dz levels, the molecular fundamental properties of NaphHQino and NaphHQino-complexes were assessed. NaphHQino ligand exhibited antineoplastic activity towards Ehrlich ascites carcinoma, and metal-NaphHQino complexes showed higher activity than NaphHQino. Molecular docking simulations were carried out, which supported the obtained results for antineoplastic activity.

The reactions of two equivalents of monoanionic bidentate [PN]-type ligand characterized by a dibenzophosphole-backbone with M (NR₂)₄ (M = Ti, R = Me; M = Zr, R = Et) afforded titanium and zirconium complexes. Two signals appeared in the solution, as evidenced by the presence of a minimum of two diastereomers in the corresponding ³¹P NMR spectrum. The X-ray crystallographic studies of the molecular structures of one of the two diastereomers complexes revealed distorted octahedral structures with phosphorus atoms coordinated to titanium and zirconium centers and the pyrrolido group coordinated to the metal center in the η¹-coordination, and the two dibenzophosphole rings exhibited π-π stacking interactions. Ethylene polymerization at 0.4 MPa using these complexes with dried modified methylaluminoxane (dMMAO) as a cocatalyst produced linear polyethylene (PE) with a melting point of 128°C–136°C. The polymerization activity for ethylene attained values of up to 276 kg/mol (Ti)·h and 223 kg/mol (Zr)·h at 50°C.