Preparation Of Metal Complexes Research Articles

Antimicrobial activity enhancement and acute toxicity lowering of benzamide through preparation of metal complexes

Two metal complexes [Mn(BZA)4Cl2] and [Cu2(BZA)2(CH3COO)4] (BZA - benzamide) have been synthesized and structurally characterized by element analysis, FT-IR, X-ray crystallography and Hirshfeld surface analysis. In silico (molecular docking) studies attest that biologically inactive compound BZA gains antimicrobial activity in result of metal complex formation. Antifungal activities of the metal complexes are higher than that of well-known compound fluconazole while antibacterial activities are comparable with biological action of standard drug levofloxacin. In vitro researches of antifungal activities confirm the results of the molecular docking studies whereas antibacterial activity of metal complexes is slightly higher than that of levofloxacin in silico activity. Moreover, in vivo determination of the metal complexes acute toxicity attests that LD50 of the initial compound (BZA ligand) is lowered more than two times in the metal complex, i.e. bioactivity and toxicity of BZA are enhanced through metal complex formation.

4-Aminopyridine containing metal-2,6-pyridine dicarboxylates and complex embedded hydrogels: Synthesis, characterization and antimicrobial applications

Hydrogels containing metal complexes with bioactive ligands have recently attracted great interest in biological applications due to good biocompatibility, water absorption, self-healing, and controlled release of drugs as well as structural diversity. Herein, to investigate the potential biological applicability of metal complex embedded hydrogels, three complexes including 2,6-pyridine dicarboxylic acid (dipicH2) and 4-aminopyridine (4-apy) were synthesized: (4-apyH)2[Mn(dipic)2]·3H2O (1), (4-apyH)2[Cu(dipic)2]·5H2O (2), (4-apyH)2[Zn(dipic)2]·3H2O (3). The complexes were characterized by X-ray single-crystal diffraction, elemental analysis, FT-IR, and thermogravimetric analysis (TGA). The complex embedded hydrogels (Mn-complex 1 hydrogel, Cu-complex 2 hydrogel, and Zn-complex 3 hydrogel) based on 2-hydroxyethyl methacrylate (HEMA) were prepared and characterized by FT-IR, thermogravimetric analysis (TGA) and Scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX). The prepared metal complexes and metal complex embedded hydrogels were tested for their antimicrobial activity against three fungal species Aspergillus brasiliensis, Saccharomyces cerevisiae, Candida albicans, and two bacteria strains a Gram-negative Escherichia coli, a Gram-positive Bacillus cereus by the in vitro agar diffusion method. The antimicrobial tests indicated that all metal complex embedded hydrogels exhibit antimicrobial activity against all tested strains better than that of the control hydrogel.

Anticancer acitivity of Schiff base ligand(E)-4-((5-chloro-2 hydroxybenzylidene) amino)-1, 5-dimethyl-2-phenyl-1H-pyrazol-3(2H)- one and its Co(II), Cu(II) and Zn(II) metal complexes

A series of transition metal complexes of Mn(II),Co(II), Ni(II), Cu(II), Zn(II) and VO(II) have been prepared by using the Schiff base ligand (L) derived from 4-aminoantipyrine and 5-chlorosalicylaldehyde. The structural properties of Schiff base ligand were characterized by mass, FT-IR, UV? ?Vis, 1H-NMR spectroscopy, etc. Also, metal complexes were studied by P- -XRD, elemental analysis, thermogravimetric studies along with various biological activities. The micro analytical data revealed that, the metal complexes have 1:1 stoichiometry composition of M:L. Generally, it is observed that prepared metal complexes show better antifungal, antibacterial and anticancer activities than its Schiff base ligand.

Antibacterial, antifungal, DNA interactions, and antioxidant evaluation of Cu(II) Co(II), Ni(II), Mn(II) and UO2(II) mixed ligand metal complexes: Synthesis, characterization and molecular docking studies

The current work was designed to prepare novel 1:1:1 Metal (M): primary ligand (HL1): co-ligand (HL2) complexes; [Cu(L1)(L2)(OH2)2] (1), [Co(L1)(L2)]H2O (2), [Ni(L1)(L2)(OH2)2] 0·.75H2O (3) and [Mn(L1)(L2)(OH2)2] 4·.5H2O (4) and [UO2(L1)(L2)] (5) from ligands 7-Formyl-8-hydroxyquinoline (oxine) (HL1), 2-aminophenol (HL2) and characterized by analytical and spectroscopic techniques. FTIR, mass spectra, ESR techniques, elemental analysis, and thermal analysis were used to characterize the newly formed complexes. The results of the elemental analysis show the formation of [HL1:M:HL2] complexes. The ligands act as a mononegative bidentate chelating agent coordinating through C = O, NH2 and two OH groups by replacement of a proton from the latter groups. The molecular docking between the protein receptors and the ligand (HL1), ligand (HL2) and its mixed ligand metal complexes (1–5) was studied. The interface between HL2, complexes and calf thymus DNA (CT-DNA) displays hypochromism behavior. The binding value constant (Kb) are calculated and found to be 5.29 × 103, 8.49 × 104, 2.45 × 105, 2.96 × 104 and 1.16 × 104, 3.08 × 104 M−1 for HL2 and its mixed ligand metal complexes (1–5), respectively. Antimicrobial properties of ligands and the synthesized complexes were also screened versus G + ve bacteria (S. aureus and B. cereus), G-ve bacteria (K. pneumoniae, Pseudomonas sp. and E. coli, and fungi (F. oxysporum, A. niger, and C. albicans). The obtained results revealed the strong antimicrobial action of metal complexes with MIC, MBC and MFC values ranging from 5 to 45 µg/ml. HL1 showed higher antimicrobial and antioxidant activities than HL2 and major of the prepared metal complexes. All metal mixed ligand complexes inhibited the multidrug-resistant bacterium; Klebsiella pneumoniae compared to the standard antibiotic, penicillin G. Also, all metal mixed ligand complexes showed potent antifungal activities against both Aspergillus niger and Candida albicans.

Synthesis and Characterization of Novel Mn(II), Fe(II) and Fe(III) complex of 5-ethyl-4-[(E)- (phenylmethylidene) amino]-4H-1,2,4-triazole-3-thiol

Abstract: The synthesis and characterization of metal complexes with Triazole Schiff Base ligand is of great utility as these compounds possesses a wide variety of biological and medicinal properties. 1,2,4-triazole Schiff base ligand, 5-ethyl-4-[(E)- (phenylmethylidene) amino]-4H-1,2,4-triazole-3-thiol and its metal complexes with Mn(II), Fe(II) and Fe(III) were prepared. The ligand was characterized by micro analytical technique and FT-IR, 1H & 13C NMR spectroscopy. The IR spectra of the metal complex revealed that ligand is bidentate and donating to metal ion from deprotonated thiol group (S- ) and azomethine Natom. On the basis of elemental analysis data, octahedral geometry was proposed for the prepared metal complexes. Lattice water is also associated with all the prepared metal complexes.

Moxifloxacin and hydrazine mix ligand metal complexes of Cd(II), Cu(II), Co(II), and Zn(II); synthesis, characterization, and pharmacological activities, with molecular docking studies

In the current study, four new mixed ligand metal complexes of Cd(II), Cu(II), Co(II), and Zn(II) with moxifloxacin (used as a primary ligand) and hydrazine (as an ancillary ligand) were synthesized. The newly prepared organometallic compounds were characterized by using conventional spectroscopic (UV–Vis, Atomic absorption, FTIR, and powder XRD), microscopic (SEM), elemental (CHN), and thermal (TGA) techniques. The synthesized chelates were evaluated for cytotoxicity (by hemolytic activity) and antimicrobial activity against different bacterial (S. aureus, B. subtilis, E. coli, and P. multocidia) and viral (A. flavus, A. niger, R. solani, and A. alternata) strains. The prepared metal complexes were also in vitro assayed for antidiabetic potential through α-amylase inhibition assay, and the results were further verified through molecular docking studies. This study demonstrates that half of the new metal complexes are good antibacterial agents, and complex 2 was significantly active against all four assayed bacterial strains. All the synthesized mixed ligand metal complexes proved to have significant fungicidal activity. Complex 3 has proved to be potentially active (24.3%) against Aspergillus flavus with a higher activity as compared to the reference standard, i.e., fluconazole (23.5%). The hemolytic values of 6.07%, 4.94%, and 12.05% for metal complexes 2, 3, and 4, respectively, were in acceptable range and comparable to moxifloxacin, while higher (19.05%) for complex 1. Present work reveals that all the bi-ligand complexes are significant antidiabetic agents, where complexes 3 and 4, with 62.45% and 54.25% α-amylase inhibition, have a similar effect as that of the standard drug, i.e., Acarbose having 64.12% α-amylase inhibition. The molecular docking studies correspondingly prove these two compounds as potent α-amylase inhibitors.

Novel Derivative For Dithiocarbamite Containing A New Sulphur-Azo Linkage And Its Complexes With Sn(II), Sn(IV), Co(II), Ni(II) And Cu(II) Ions; Synthesis, Characterization and Antibacterial Activity

The new ligand N-methyl-N-((((4-nitrophenyl)diazenyl)thio) carbonothioyl) aniline (LS2) was prepared by the reaction of 4-nitrobenzenediazonium salts with a (sodium N-methyl- N-phenyldithiocarbamate), a new ligand containing azo-sulphur linkage. A series of metal ions Sn(II), Sn(IV), Co(II), Ni(II), and Cu(II) were used to prepare metal complexes through reaction of two moles of LS2 ligand with one mole of appropriate metal chloride. The prepared compounds were characterized by CHNS elemental analysis, infrared spectroscopy (FT-IR), 1H NMR-spectroscopy, mass spectroscopy, UV-visible spectroscopy, magnetic susceptibility, and conductivity measurements. Stoichiometry was determined using analytical and spectroscopic information and it was found to be 1:2 (metal to a ligand) for all complexes. The spectral data confirm the coordination of the LS2 ligand with all metal ions through sulfur atoms of dithiocarbamate moiety. Molar conductivity of complexes was measured using DMF as a solvent and it was indicated that all prepared complexes were ionic. According to the results obtained from the elemental analysis and spectral measurements were complexes of Sn(II), Sn(IV) and Co(II) tetrahedral geometry, while the complexes with Ni(II) and Cu(II) had a square planar geometry. The ligand LS2 and its complexes were examined against Staphylococcus aurous bacteria and Escherichia coli bacteria.

Synthesis and characterization of Cu (II) complex derived from aniline based Schiff base ligand 4 – nitro-salicylidene aniline

In this manuscript, we report synthesis and characterization of Schiff base ligand 4 – nitro-salicylidene aniline and derived Cu (II) complex of this ligand. Structural and morphological properties of prepared metal complex were done using X-ray diffraction (XRD), Scanning Electron microscope (SEM) and Fourier-transform infrared spectroscopy (FTIR). From XRD, we identified the crystalline state and morphology of the complex was observed by SEM. FTIR elucidated information about functional groups, bonding types and nature of complex.

Novel Methodology for Synthesis and Computational Analysis of Zinc Complexes of Isatin Derivatives and Screening their Biological Activity

Background: Due to arising threats of microbial infectious diseases in the human population, and the development of resistance against therapeutics, novel medicinal agents are required to counteract antimicrobial resistance. Heterocyclic rings such as indole or pyrrole, have been acknowledged to possess various biological properties like antimicrobial, anticancer, antiviral, antitubercular, etc and metals such as platinum, vanadium, zinc, selenium, etc. also show therapeutic actions. Thus, this work focuses to turn heterocyclic ring compound (isatin) and metal (zinc) into a drug having antimicrobial potential. Objective: The objective of the study was to synthesize zinc complexes of isatin Schiff bases and evaluate for antibacterial and antifungal activity. Methods: Herein, the conventional method was used for the synthesis of isatin Schiff bases from isatin and different monosubstituted amines. Then, zinc complexes were prepared by using isatin Schiff bases and zinc acetate. Physicochemical characteristics such as Rf value and melting point were determined by TLC and decibel melting point apparatus respectively. All the complexes were characterized by FT-IR and 1H NMR techniques. Further, the final zinc complexes were screened for antimicrobial potential by the serial dilution method. Some computational studies were also done with the help of MOPAC 2016. Result: In the present work, 14 complexes of zinc are obtained in harmonious yield from isatin Schiff bases using zinc acetate. Amongst the studied complexes, Z-3, Z-4, and Z-12 depicted maximum antimicrobial activity. Conclusion: 14 complexes of zinc were prepared by using 14 isatin Schiff bases which were in turn prepared by isatin and different mono-substituted amines. Characterization of these complexes was done by using FT-IR and 1H NMR. All prepared metal complexes were obtained in appropriate yield. The synthesized complexes were screened for their antimicrobial potential.

Synthesis of nano-oxides by preparing metal complexes based on dithiocarbamate derivatives

Metal oxide nanoparticles are a branch of nanoparticles that have high optical properties. Dithiocarbamites are organic sulfur bonds that form stable complexes with metals. There are two types of dithiocarbamate: mono- and di-alkyl dithiocarbamate. In this study, two Schiff bases were prepared, the first Schiff base: [(E)-N-(2-ethylhexyl)-1-Phenyl methanimine] and the second Schiff base: [(E)-N-benzyl-1-Phenyl methanimine ]. From these two bases, the first secondary amine was prepared: N-Benzyl-2-ethylhexyl-1-amine, and the second secondary amine, Di Benzylamine. This was followed by the preparation of ligands from the two prepared secondary amines, which are Potasium benzyl(2-ethyl) Carbamadithioate, and the second ligand: Potasium di benzyl Carbamodithioate. These two ligands were employed in the interaction with the ions: Mn, Cu, Zn. each separately to form the macrocyclic complexes.

Synthesis, crystal structures and electrocatalytic water oxidation by Mn(II), Co(II) and Ni(II) complexes of thiophene-2-carbohydrazide

Electrocatalytic water oxidation by molecular electrocatalyst has emerged very rapidly. Here, metal complexes of Mn(II), Co(II), and Ni(II) containing Thiophene-2-carbohydrazide were synthesized and characterized by spectroscopic and single crystal X-ray techniques. The complexes 1, 2, and 3 crystallize in monoclinic, orthorhombic, and monoclinic systems with space groups P21/c, Pca21, and P21/c, respectively. The crystal structure of complexes is stabilized via various intermolecular hydrogen bonding including N-H···Cl, O-H···Cl, O-H···O, N-H···O, C-H···S etc. providing supramolecular architectures. The prepared metal complexes [Mn(tphch)3]2+ (1), [Co(tphch)3]2+(2), and [Ni(tphch)3]2+(3) were coated on glassy carbon electrodes (GCE). Nafion (Nf) solutions were used during the immobilization process to provide an electroactive surface on GCE (GCE/Nf). Electrochemical characterizations of modified electrodes were achieved from the results of cyclic voltammetry and linear sweep voltammetry techniques. GCE modified GCE/Nf/Complex-1, GCE/Nf/Complex-2, and GCE/Nf/Complex-3 show efficient electrocatalytic activity for oxygen evolution reaction (OER). Tafel slope of GCE/Nf/Complex-2 and GCE/Nf/Complex-3 was found lower than commercial benchmark electrocatalyst RuO2 and IrO2.

Novel Self-assembly Pd(II)-Schiff Base Complex Modified Glassy Carbon Electrode for Electrochemical Detection of Paracetamol

A self-assembly Pd-Schiff base complex was synthesized and used as an electrochemical sensor in phosphate buffer solution, where it enhanced the electrocatalytic activity toward the paracetamol detection. The Schiff base {(HL) = (4-(((Z)-3-(hydroxyimino) butan-2-ylidene) amino)-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one)} was selected to prepare Pd-based complexes due to its high antimicrobial activity. A linear calibration curve was constructed using GC/Pd-SB in paracetamol concentration range of 1–50 μM and its detection limit was calculated as 0.067 μM. The modified electrode, GC/Pd-SB, could successfully determine the paracetamol concentration in human blood serum and commercial drug tablets with high sensitivity. The prepared metal complex was characterized using techniques, namely, X-ray diffraction (XRD) and scanning electron microscope (SEM). In addition, electrochemical studies were performed using different electrochemical techniques like cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). DFT calculations were used to estimate the equilibrium geometry, molecular orbital, ground-state properties, and interaction energy between paracetamol and palladium.Graphical

Mechanochemistry - A Promising Tool on the Synthesis of Organometallic Pincer Compounds: Current State and Future Perspectives

Abstract: Among the different synthethic proceedures available where the reactivity of substances is exploited using solid–state chemistry, such as microwave irradiation, ultrasound (sonochemistry), photochemistry, and mechanochemistry, the latter stands out as a synthetic tool on various areas of chemistry and materials sciences, acquiring great relevance in recent years. Thus, mechanochemistry has been applied in different areas such as organic synthesis, preparation of metal complexes, multicomponent pharmaceutical solid forms, catalysis, polymers, etc. However, despite the attractiveness of this sustainable technique, its application in the synthesis of coordination and organometallic compounds has been very incipient. On the other hand, pincer compounds have been a privileged ligand platform that has been profusely used for the synthesis of organometallic and coordination compounds for the last 20 years, finding applications on a large number of areas of chemistry, this being particularly true in the case of catalysis, being able to activate bonds difficult to activate such as C-H bonds, due in part to their characteristic thermal robustness. In this sense, on this perspective paper we present the current state of mechanochemistry in the preparation of organometallic pincer compounds and discuss future perspectives for the synthesis of these foremost interesting species via mechanochemistry.

Synthesis, structural elucidation, DNA binding, cleavage, AChE and BuChE cholinesterase efficiencies of metal complexes with 1,10-phenanthroline scaffold

A series of metal complexes containing a 1,10-phenanthroline scaffold [ML] (L-1,10-Phenanthroline derivative comprises conjugated aromatic core and electron withdrawing –NO2 group); M = Cu(II), Zn(II), Co(II), and Zn(II) ions were designed and synthesized to obtain effective anti-cholinesterase efficiencies of metal chelates. Analytical and spectroscopic studies were used to determine the structural features. An octahedral structure with moderate distortion was attributed to the above metal chelates based on spectroscopic data. S. aureus, A. niger, C. albicans, B.subtilis, A. flavus, and E. coli were used to test the antibacterial efficacy of the synthesized ligands and metal complexes. Using agarose gel electrophoresis, the DNA fragmentation proficiency of prepared metal complexes was tested on pUC 18 DNA. The distorted octahedral geometry of the copper(II) complex to DNA (K b = 4.11 × 105 M−1) is stronger than that of ethidium bromide (EB) to DNA (K b = 3.3 × 105 M−1) and other metal complexes, respectively. The synthesized 1,10-phenanthroline derivative had the best inhibitory effects against acetylcholinesterase and butyrylcholinesterase, with IC50 values of 0.45 and 3.6 M, respectively, which were lower than the reference molecules. Our experimental results may contribute to the development of new drug molecules particularly in the treatment of neurological disorders including glaucoma, Alzheimer’s disease and diabetes. The actions of inhibitors on the glycosidase enzyme help to delay the breakdown and release of sugar molecules into the bloodstream, and they can be used as therapeutic factors in the treatment of diabetes.

Synthesis, characterization and photoluminescent studies of zinc complexes with heterocyclic ligands comprising N, O donor atoms

In the present work, preparation as well as photophysical characteristics of zinc(II) complexes containing pyridine-N-oxide (PNO) and 2-pyridinol-N-oxide (PHNO) along with 8-hydroxyquinoline (q) were reported. Synthesized materials [Zn(PNO)(q)] and [Zn(PHNO)(q)] revealed good thermal and electrochemical stability. Via the combination of theoretical and experimental approaches, photophysical characteristics of prepared materials were investigated. Gaussian 03 suites of programmes were used to perform all the theoretical calculations. Mixed ligand-based zinc (II) complexes were found to exhibit green emissions with wavelength of 507 and 504 nm, respectively. Temperature-dependent emission profiles of prepared metal complexes was also illustrated. Prepared materials exhibited better quantum efficiency in comparison to Alq3 and thus can be efficiently used in electroluminescent devices.

Synthesis and in vitro biochemical properties, DNA binding and DNA cleavage ability of copper complexes of hydroxyflavone derivatives of novel organosulfur compounds as therapeutic agent

Novel and synthetically essential flavonoids compounds containing the organosulfur moiety from Schiff bases, as well as their copper complexes, were synthesized from chrysin and 2-(phenylthio)aniline. These complexes were characterized using elemental analysis, mass spectrometry, electronic absorption spectroscopy, IR, 1H, and 13C NMR spectroscopy techniques. All the Cu(II) complexes exhibit square planar geometry. The in vitro antimicrobial activities of the investigated compounds were tested against the bacterial species, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus epidermidis, and Klebsiella pneumoniae and fungal species, Aspergillus niger, Fusarium solani, Culvularia lunata, Rhizoctonia bataicola, and Candida albicans by serial dilution method. The DNA binding and DNA cleavage properties of copper complexes were studied. Free radical scavenging, superoxide dismutase, glutathione peroxidase, and antioxidant activities of the copper complexes have also been studied. In addition, using the egg albumin process, the in vitro anti-inflammatory efficacy of metal chelates was examined. Anti-tuberculosis and α-glucosidase inhibition activity were carried out from the prepared metal complexes. The flavonoid compounds containing the organosulfur moiety of Cu(II) complexes (1–8) exhibited better therapeutic agent.

Synthesis, Characterization and Antibacterial Activity Study of Cobalt(II), Nickel(II), Copper(II), Palladium(II), Cadmium(II) and Platinum(IV) Complexes with 4-Amino-5-(3,4,5-trimethoxyphenyl)-4<i>H</i>-1,2,4-triazole-3-thione

New transition metal complexes of cobalt(II), nickel(II), copper(II), palladium(II), cadmium(II), and platinum(IV) with bidentate ligand 4-amino-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazole-3-thiol were synthesized and characterized by microelemental analyses (CHNS), Fourier-transform infrared (FT-IR), UV-Visible spectra, molar conductance, magnetic susceptibility and thermal analyses (TG-DSC). The ligand was synthesized by ring closure of potassium-2-(3,4,5-trimethoxybenzoyl) hydrazine carbodithioate with an excess amount of hydrazine, and then was acidified using hydrochloric acid. The ligand was used as Lewis bases to prepare metal complexes through the reaction of ratio (1:2) metal:ligand. The ligand was characterized by 1H-NMR and 13C-NMR and the previously described methods to identify the complexes. The results obtained from spectra and elemental analyses indicated the tetrahedral geometry around Cd(II) ion, square-planar for Cu(II) and Pd(II), and octahedral geometry around Co(II), Ni(II), and Pt(IV). All the metal complexes showed significant antibacterial activity in comparison with the free ligand. The antibacterial test of the platinum(IV) complex showed higher activity than other metal complexes against bacteria Staphylococcus aureus (G-positive) and Escherichia coli (G-negative).

Macro‐ and nano‐oligomers ternary metal complexes preparation, structural elucidation: Antimicrobial, anticancer activities, and mechanistic study of Cu nanocomplexes on liver carcinoma

A new binuclear transition metal complexes of Co (II) and Cu (II) have been synthesized in both bulk and nanosized formations. The complexes were synthesized by the reaction between equimolar quantities of the metal sulfate with nitrilotriacetic acid and creatine. The nanosized forms are controlled by using (CTAB). Characterization of the nanocomplexes has been done using a transmission electron microscope (TEM) and X‐ray diffraction. This technique is considered a novel approach to the synthesis of the nanoternary complexes. The Co (II) and Cu (II) complexes displayed distorted dimeric octahedral and tetrahedral structures, respectively. The prepared metal complexes were investigated by electronic spectral analysis, magnetic susceptibility measurement, infrared spectra, thermal gravimetric analysis (TGA), UV–visible spectra, and mass spectra. The molecular weights of the dimer complexes are measured by GPC (Gel Permeation Chromatography). Characterization of the obtained complexes showed that the NTA ligand coordinates with metal ions in tridentate mode (one N and two COO−) after deprotonation, the creatine molecule coordinates through the carboxylate group, while the dimeric structure of these complexes formed with one of the sulfate groups which coordinates as a bridged bidentate ligand. Investigation of the biological activity of these complexes, as well as their hepatocellular carcinoma (HepG2) cell line inhibitory, has also been achieved.

Synthesis, spectral characterization, SC-XRD, HSA, DFT and catalytic activity of a dioxidomolybdenum complex with aminosalicyl-hydrazone Schiff base ligand: An experimental and theoretical approach

A new dioxidomolybdenum(VI) complex has been successfully prepared by the reaction of an ONO donor Schiff base, derived by condensing 4-amino-2-hydroxybenzohydrazide and 3-methoxysalicylaldehyde, with MoO2(acac)2. The structures of synthesized products were explored spectroscopically through FT-IR, 1H &13C NMR and by elemental composition (CHN) through combustion analysis. The structural investigations of the dioxidomolybdenum(VI) complex were accomplished by taking its diffraction data through X-ray crystallography. The tridentate Schiff base ligand is bonded to the central metal through its deprotonated enolic and phenolic oxygen atoms and by the nitrogen of the azomethine group. The interpretation of the data obtained through diffraction analysis validates the distorted octahedral geometry of the prepared metal complex. QTAIM, MEP and NCI calculations and Hirshfeld surface analysis were performed to investigate the nature and types of non-covalent linkages present among the sample molecules. The theoretical calculations, performed by DFT using the B3LYP/Def2-TZVP level of theory, direct that the intended outcomes are in compliance with the actual consequences. Furthermore, the catalytic potential of the molybdenum complex was explored for the selective oxidation of benzylic alcohols to the desirable aryl aldehydes at room temperature in the presence of 70% aqueous tert-butyl hydroperoxide (TBHP) under solvent-free conditions. The main advantage of the present catalytic work is the accomplishment of reaction in a short period of time, high percentage yield and easy work-out procedure.

Synthesis, spectra (FT-IR, NMR) investigations, DFT, FMO, MEP, NBO analysis and catalytic activity of MoO2(VI) complex with ONO tridentate hydrazone Schiff base ligand

A new dioxomolybdenum(VI) complex has been successfully prepared by the reaction of an ONO donor Schiff base, derived by condensing 4-amino-2-hydroxybenzohydrazide and 3-ethoxysalicylaldehyde, with MoO2(acac)2. The structures of synthesized products were explored spectroscopically through FT-IR, 1H & 13C NMR and by elemental composition (CHN) through combustion analysis. The tridentate Schiff base ligand is bonded to the central metal through its deprotonated enolic and phenolic oxygen atoms and by the nitrogen of the azomethine group. The interpretation of the data obtained through diffraction analysis validates the distorted octahedral geometry for the prepared metal complex. Furthermore, the catalytic potential of the molybdenum complex was explored for the selective oxidation of the aryl and alkyl sulfides to the corresponding sulfones in the presence of 30% aqueous H2O2 in ethanol. The main edge of the present catalytic work is the accomplishment of reaction in a short period of time, high percentage yield and easy work-up procedure.