Series Of Transition Metal Complexes Research Articles

Zn(II), Mn(III), and Co(III) complexes of Schiff base derived from 2‐hydroxy‐1‐naphthaldehyde: Synthesis, spectral surveys, single crystal structure studies, Hirshfeld surface analysis, density functional theory calculation, molecular electrostatic potential, and molecular docking evaluations

A new series of transition metal complexes of bidentate Schiff base compound derived from 2‐hydroxy‐1‐(2‐methoxyethylimino)‐naphthalene (HL) were synthesized and characterized using elemental analysis, Fourier transform infrared spectroscopy (FT‐IR), and UV–vis spectroscopies. X‐ray single crystal structures of Zn(II), Mn(III), and Co(III) complexes (1–4) have also been determined, and it was indicated that these Zn(II) and Co(III) complexes (1, 4) are in an octahedral geometry. Whereas, it was found that the Zn complex (2) is in quite a regular tetrahedral environment. Also, the Mn center in complex (3) is ligated by two azomethine nitrogen atoms, two ligand oxygen atoms, and one Cl atom of metal salt forming five coordinated tetragonal pyramid geometry around the Mn atoms. The cyclic voltammetry of the complexes specifies an irreversible redox behavior for all complexes (1–4). Next, DFT/B3LYP theoretical method was used to determine the optimal geometrical configurations and comparison between experimental and theoretical data, as well as for calculations of molecular electrostatic potential, highest‐occupied molecular orbital (HOMO)‐lowest‐unoccupied molecular orbital (LUMO) energy values of selected compounds. The study of non‐covalent interactions was done by Hirshfeld surface analysis using CrystalExplorer program. Furthermore, molecular docking inspection was carried out to study the binding affinity of the tested complexes towards protein B‐cell lymphorna (PDB ID: 4LXD). Using the results obtained from the molecular docking and the summarized interaction of the binding processes, these structures show the validity of effective inhibition against liver cancer.

Investigation on Biological Activities of Thiosemicarbazide Derived Schiff Base-Metal Complexes

A Schiff base ligand was synthesized via the condensation reaction of thiosemicarbazide and salicylaldehyde. A series of transition metal complexes of VO(IV), Ni(II), Cu(II), and Zn(II) were obtained by the complexation reaction with the synthesized Schiff base ligand. The Schiff base ligand and its metal complexes were characterized by UV-Vis and FTIR spectroscopy, TGA-DTA, and some physical measurements. FTIR spectral studies showed that the NOS donor ligand coordinated to the metal ions through the N of azomethine group, S of thiolate, and O of deprotonated hydroxyl group. Molar conductance values indicated non electrolytic nature of the complexes. Magnetic moment values coupled with electronic spectral data exhibited the geometrical structure of the complexes. The Schiff base and its complexes were exposed to disinfectant studies tested by using the disc diffusion method. All the synthesized compounds exhibited moderate to strong antibacterial activity. The copper complexes showed more antibacterial activity than other complexes and Schiff bases. All the Synthesized complexes showed a good cytotoxic activity.

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.

Synthesis of New Series of Transition Metal Complexes with Poly (Pyrazolyl) Borates

In structuring catalysis enzyme and chemistry, tridentate ligands and Scorpionate ligands are of significant worth. This study presents the synthesis of a tris(pyrazolyl)borate ligand to be utilized in transition metal complexes as possible redox shuttles. Complexes of general formula [AgTp], [MIIITp (Cl2)] (M = Fe, Co), Tp = tri (1-pyrazolyl) borohydride and [AgTp*], [FeIIITp*(Cl2)], Tp* = tris (3, 5-dimethyl-1-pyrazolyl) borohydride were synthesized and characterized in solid state. The Tp ligands were considered triply coordinated with the metal center with two bounded chloride atoms as per the information gathered from spectroscopic information. Entire preparations and operations were performed under argon using common Schlenk procedures. Elemental analysis was performed using (the EURO EA instrument). Thermolysis shows that the Tp ligand decomposes around 100oC and above 300oC for some complexes. The composites were simple to compose, yielded high yields, and were reasonably air sensitive. This study has examined the synthesis of a tris(pyrazolyl)borohydride ligand to develop an iron complex. Further studies conducting electrochemical tests should be carried out to demonstrate the effectiveness of this likely redox mediator.

Elucidation for coordination features of N-(benzothiazol-2-yl)-3-oxo-3-(2-(3-phenylallylidene)hydrazineyl)propanamide on Co2+, Ni2+and Cu2+: Structural description, DFT geometry optimization, cyclic voltammetry and biological inspection

A series of transition metal complexes were prepared through a reaction of novel N-(benzothiazol-2-yl)-3-oxo-3-(2-(3-phenylallylidene)hydrazineyl)propanamide (H2BTOPP) ligand with divalent Co2+, Cu2+, and Ni2+ metal cations. The structures of the complexes were interpreted via several spectroscopic techniques including (FT-IR, UV–Visible, 1H/13C NMR, XRD, MS, EDX, and ESR), besides elemental analysis and magnetic measurements. SEM was subjected to the Schiff base ligand and its complexes to provide a microscopic approach to the surface or near-surface region of a specimen, in addition to clarifying the extent of the change in the ligand surface morphology as a result of the formation of metal complexes. Also, the thermal stability of the synthesized complexes was discussed through (TGA/DTA) techniques. Moreover, computational simulation through (DFT/GGA/RPBE) was applied to the molecular skeleton of all compounds associated with the evaluation of some characters (EHOMO, ELUMO, binding energy, dipole moment, MEP). Furthermore, electrochemical studies included in cyclic voltammetry were measured for Cu2+ in (absence-presence) of the ligand to realize the effect of complexation in solution, kinetic parameter (stability constant), and thermodynamic parameter (Gibbs free energy). Finally, all samples were screened for anti-bacterial against (Bacillus subtilis and Escherichia coli), anti-fungal against (Candida albicans), antioxidant, MTT cytotoxicity, and DNA binding studies to predict the biological activity of the synthesized compounds.

Synthesis, Characterization, Antioxidant and Antibacterial Activities of Six Metal Complexes Based Tetradentate Salen Type Bis-Schiff Base

Considering the importance of metal complexes in the development of medicinal chemistry, a series of transition metal complexes of Co(II), Fe(II), Zn(II), Cu(II), and Ni(II) has been synthesized from N,N'-bis(salicylidene)-2,2-dimethyl-1,3-diaminopropane H2L Schiff base ligand. The reaction of the H2L with the selected metal ions led to tetrahedral and octahedral coordinated complexes. The structural features of the obtained metal complexes were determined using analytical techniques such as FT-IR, NMR, UV-Vis, X-ray powder diffraction, mass spectrometry, and Thermogravimetry–differential thermal (TGA/DTA) analysis. The measured conductance for obtained compounds has shown the electrolytic behavior of all obtained complexes. The synthesized ligand and corresponding complexes were screened for their antioxidant and antibacterial activities. Indeed, Co(II) and Fe(II) complexes have shown excellent antioxidant activities for DPPH radical scavenging and FRAP assays, respectively. The results obtained from the disc diffusion assay showed that Co(II), Fe(II), Zn(II), and Cu(II) complexes had displayed promising antibacterial activity against Escherichia coli and Staphylococcus aureus, while no effect has been observed on both strains for ligand H2L and its corresponding Ni(II) complex.

New transition metal(II) complexes with naphthoate and aminoguanidine-based ligands: a combined spectroscopic and theoretical study with its applications

A new series of transition metal complexes of Mn(ΙΙ), Fe(ΙΙ), Co(ΙΙ) and Ni(ΙΙ) is synthesized from aminoguanidine and 3-hydroxy-2-naphthoic acid ligands with the formula (N4H7C)2[M{(C10H6(O)(COO)}2]·2H2O. The synthesized complexes were characterized by analytical, spectral and thermal studies. The elemental analysis confirms the composition of the complexes. The XRD studies show that all the complexes are isostructural in nature. The complexes were screened for antimicrobial activity against a Gram-positive, Bacillus subtilis (B. subtilis), and a Gram-negative, Escherichia coli (E. coli), bacterial species. The antibacterial results were concurrent with the output of the DFT investigation of metal complex, showing that the aminoguanidine moiety plays a key role in biological activity. Molecular docking studies have been carried out to identify the binding affinity and the mode of interaction of metal complexes with E. coli protein (2FUM). Further the synthesized complex is used as a single source precursor for preparation of nano metal oxides. The photocatalytic activity was carried out using the metal oxide as catalyst for degradation of dye materials. The metal oxide is found to be an efficient catalyst for degradation of methyl orange dye.

DNA interaction, molecular dynamics simulation, molecular docking, biological, in vivo anti‐inflammatory and thermal studies of o‐hydroxyacetophenone and 2‐fluoroaniline Schiff base complexes

Series of transition metal complexes [Fe (HL)2Cl(H2O)](1), [Co (HL)2](2), [Ni (HL)2](3) and [Cu (HL)2](4) were derived on condensation of Schiff base ligand o‐hydroxyacetophenone with 2‐fluoroaniline in 1:1 ratio (HL) and characterized by spectral and analytical techniques. Based on the studies, complex 1 was found to be octahedral and complexes (2), (3) and (4) square planar. Coats–Redfern calculations suggest that all the complexes are non‐spontaneous and thermally stable. DNA binding studies revealed intercalation binding mode, while intrinsic binding constant (Kb) and Stern–Volmer quenching constant (Ksq) support high binding abilities. The nuclease activity using CT‐DNA was studied by gel electrophoresis. Docking studies were deduced using Accelry's Discovery Studio 2.1 program to understand binding affinities. The MD simulation, carried in order to analyse the stability of ligand and human topoisomerase I (PDB ID: 1T8I) complex for 100 ns using the Desmond 2020.1 from Schrödinger, LLC, revealed stable conformation of the ligand. In vivo, carrageenan induced inflammation studies in paw volume were carried out in rats, and results showed a higher rate of oedema inhibition for complex 4. Cytotoxicity and antimicrobial assay reveal that complex 4 exhibited higher cytotoxic and antimicrobial activity over other complexes and the ligand.

Dithiocarbazate Ligand-Based Cu(II), Ni(II), and Zn(II) Complexes: Synthesis, Structural Investigations, Cytotoxicity, DNA Binding, and Molecular Docking Studies.

S-4-methylbenzyl-β-N-(2-methoxybenzylmethylene)dithiocarbazate ligand, 1, prepared from S-(4-methylbenzyl)dithiocarbazate, was used to produce a novel series of transition metal complexes of the type, [M (L)2] [M = Cu(II) (2), Ni(II) (3), and Zn(II) (4), L = 1]. The ligand and its complexes were investigated by elemental analysis, FTIR, 1H and 13C-NMR, MS spectrometry, and molar conductivity. In addition, single X-ray crystallography was also performed for ligand, 1, and complex 3. The Hirshfeld surface analyses were also performed to know about various bonding interactions in the ligand, 1, and complex 3. The investigated compounds were also tested to evaluate their cytotoxic behaviour. However, complex 2 showed promising results against MCF-7 and MDA-MB-213 cancer cell lines. Furthermore, the interaction of CT-DNA with ligand, 1, and complex 2 was also studied using the electronic absorption method, revealing that the compounds have potential DNA-binding ability via hydrogen bonding and hydrophobic and van der Waals interactions. A molecular docking study of complex 2 was also carried out, which revealed that free binding free energy value was −7.39 kcal mol−1.

The Synthesis, Characterization, Molecular Docking and In Vitro Antitumor Activity of Benzothiazole Aniline (BTA) Conjugated Metal-Salen Complexes as Non-Platinum Chemotherapeutic Agents.

Here, we describe the synthesis, characterization, and in vitro biological evaluation of a series of transition metal complexes containing benzothiazole aniline (BTA). We employed BTA, which is known for its selective anticancer activity, and a salen-type Schiff-based ligand to coordinate several transition metals to achieve selective and synergistic cytotoxicity. The compounds obtained were characterized by NMR spectroscopy, mass spectrometry, Fourier transform infrared spectroscopy, and elemental analysis. The compounds L, MnL, FeL, CoL, and ZnL showed promising in vitro cytotoxicity against cancer cells, and they had a lower IC50 than that of the clinically used cisplatin. In particular, MnL had synergistic cytotoxicity against liver, breast, and colon cancer cells. Moreover, MnL, CoL, and CuL promoted the production of reactive oxygen species in HepG2 tumor cell lines. The lead compound of this series, MnL, remained stable in physiological settings, and docking results showed that it interacted rationally with the minor groove of DNA. Therefore, MnL may serve as a viable alternative to platinum-based chemotherapy.

Molecular orbital projectors in non-empirical jmDFT recover exact conditions in transition-metal chemistry.

Low-cost, non-empirical corrections to semi-local density functional theory are essential for accurately modeling transition-metal chemistry. Here, we demonstrate the judiciously modified density functional theory (jmDFT) approach with non-empirical U and J parameters obtained directly from frontier orbital energetics on a series of transition-metal complexes. We curate a set of nine representative Ti(III) and V(IV) d1 transition-metal complexes and evaluate their flat-plane errors along the fractional spin and charge lines. We demonstrate that while jmDFT improves upon both DFT+U and semi-local DFT with the standard atomic orbital projectors (AOPs), it does so inefficiently. We rationalize these inefficiencies by quantifying hybridization in the relevant frontier orbitals. To overcome these limitations, we introduce a procedure for computing a molecular orbital projector (MOP) basis for use with jmDFT. We demonstrate this single set of d1 MOPs to be suitable for nearly eliminating all energetic delocalization and static correlation errors. In all cases, MOP jmDFT outperforms AOP jmDFT, and it eliminates most flat-plane errors at non-empirical values. Unlike DFT+U or hybrid functionals, jmDFT nearly eliminates energetic delocalization and static correlation errors within a non-empirical framework.

Thermal Behavior and Photovoltaic Application of NiII and CoIII Complexes with Substituted o‐Iminobenzoquinone Ligands

AbstractThe thermal properties and an opportunity for photovoltaic applications were studied for a series of transition metal complexes derived on functionalized o‐aminophenols ‐ mixed‐valent CoIII compounds and bis‐o‐iminobenzosemiquinonato NiII complexes. TGA and DSC explored the thermal behavior of compounds in the solid state. EI‐MS established the vapor phase composition. The temperature dependences of a saturated vapor pressure were measured by the Knudsen effusion method with the weight registration of the sublimated substance. Based on the volatility study data, the thermodynamic parameters of a sublimation process were calculated. A high absorptivity distinguishes metal complexes under investigation at visible and NIR regions (i. e., vis/NIR dyes) and, thus, were tested as photosensitizers in the fabricated dye‐sensitized solar cells. The photoelectric conversion efficiency (PCE) was estimated for devices with the NiII derivatives. The CoIII complexes demonstrated the absence of photovoltaic potential.

Synthesis, theoretical study, molecular docking and biological activity of nano tridentate (E)-2-((3-hydoxyphenyl)methyl)phenol metal complexes

A new series of transition metal complexes of Schiff base (E)-2-((3-hydoxyphenyl)methyl)phenol (H2L) with Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) have been synthesized and characterized using elemental analysis, IR, UV–Vis spectra, mass spectra, reflectance spectra, molar conductance measurements, magnetic susceptibility measurements, 1H NMR spectroscopy, thermal and X-ray diffraction analyses. The infrared spectral data showed that the chelation of the ligand towards transition metal ions occurs through two deprotonated phenolic oxygen atoms and azomethine nitrogen (ONO) in binegative tridentate manner. The XRD patterns of the complexes have sharp diffraction peaks indicating that these complexes are a mixture of crystalline and amorphous phases. The molecular structures of the Schiff base ligand and its metal complexes were optimized theoretically and the quantum chemical parameters were calculated. Molecular docking was used to predict the efficiency of binding between the Schiff base ligand and the receptors and found that the receptor of Staphylococcus aureus shows the best interaction than the receptor of Escherichia coli with Schiff base ligand. The synthesized ligand and its metal complexes were also screened for their antibacterial and antifungal activity against bacterial species and fungi. The activity data showed that the metal complexes are found to have antibacterial and antifungal activity higher than the parent ligand.

Cobalt(II), nickel(II), copper(II) and zinc(II) complexes of thiadiazole based Schiff base ligands: Synthesis, structural characterization, DFT, antidiabetic and molecular docking studies

A new series of transition metal complexes of type [M(L1-3)(H2O)(CH3COO)] where, M = Co(II), Ni(II), Cu(II) & Zn(II), and L1 = 2-(((1,3,4-thiadiazol-2-yl)imino)methyl)-6-ethoxyphenol; L2 = 2-ethoxy-6-(((5-methyl-1,3,4-thiadiazol-2-yl)imino)methyl)phenol; L3 = 2-ethoxy-6-(((5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl)imino)methyl)phenol; were synthesized and characterized by various spectral and physico-analytical techniques such as 1H, 13CNMR , FTIR, HRMS, XRD, ESR, TGA, SEM and EDAX. The studies envisaged a penta-coordinated geometry for the complexes, where the Schiff base ligands act in a tridentate manner via the azomethine nitrogen, deprotonated oxygen and one of the nitrogen atom of thiadiazole heterocycle. DFT/B3LYP theoretical method was utilised for calculations of molecular electrostatic potential, HUMO-LUMO energy values of selected compounds. In an in-vitro experiment, the antidiabetic effects of the synthesized compounds were assessed on α-amylase and α-glucosidase enzymes. It was found that compounds 14 and 15 revealed good biological potency with IC50 value close to Acarbose (standard). In-silico study of the synthesized compounds was carried out to check the drug-likeness and it was observed that compounds can be used as orally active drugs. Additionally, molecular docking studies of the potent compounds i.e. 14 and 15, were carried out in the active site of human pancreatic α-amylase (PDB code: 1BSI) and α-glucosidase (PDB code: 5ZCC).

DNA binding, cleavage, docking, biological and kinetic studies of Cr(III), Fe(III), Co(II) and Cu(II) complexes with ortho‐vanillin Schiff base derivative

Abstract2‐((4‐Hydroxyphenylimino)methyl)‐6‐methoxyphenol ligand was synthesized by refluxing 2‐hydroxy‐3‐methoxybenzaldehyde with p‐aminophenol in 1:1 molar ratio. A series of transition metal complexes with the synthesized ligand OVAP, [Cr(OVAP)2] (1), [Fe(OVAP)2] (2), [Co(OVAP)2] (3) and [Cu(OVAP)2] (4) is reported. Characterisation of the complexes by sophisticated analytical techniques revealed the geometry around central metal ion to be octahedral for 1, 2 and 3 complexes and complex 4 with square planar geometry. Kinetic parameters of the complexes were estimated by Coats–Redfern method, and the complexes were found to be thermally stable. DNA binding affinity of these metal complexes was explored by means of fluorescence, ultraviolet (UV)–visible and viscosity studies and the studies suggested intercalative mode. The Kb values from the absorption studies are 2.98 × 105, 2.16 × 105, 4.66 × 105 and 5.46 × 105 M−1 and Ksv values from fluorescence studies are 3.79 × 104, 2.14 × 104, 4.92 × 104 and 6.47 × 104 M−1 for 1, 2, 3 and 4 complexes, respectively. Nuclease studies in the presence of H2O2 were performed using pUC19 supercoiled DNA. Docking studies were done using human DNA topoisomerase‐I (DNA topoI) receptor protein. Biological studies revealed higher activity for complexes than the ligand, and in vitro antitumour studies showed that complexes 3 and 4 possess potential inhibitory efficiency with an IC50 of 42.32 ± 0.5 and 38.12 ± 1.2 μg/ml correspondingly.

Bioactive Mixed Ligand Metal Complexes Of Cu(II), Ni(II), And Zn(II) Ions: Synthesis, Characterization, Antimicrobial And Antioxidant Properties

A series of transition metal complexes having general formula [M(Lb)(L1)](NO3)2, (where, M = Cu(II), Ni(II), and Zn(II)) of mixed ligands, Lb = N-Isonicotinamido-Thiophene-2-Carbaldimine, L1 = 1, 10-phenanthroline, were synthesized. The obtained compounds were successfully characterized by different spectroscopic techniques. Conductivity measurements indicated that all complexes were 1:2 electrolytes in nature. IR spectra indicated that ligands coordinated to metals via the carbonyl oxygen atom and the azomethine nitrogen atom. Magnetic moment values and UV-Visible spectra confirmed square planar structure around the Cu(II), and Ni(II) ions, and a tetrahedral geometry around the Zn(II) ion. The metal complexes of Lb and L1 were tested against Escherichia coli and Pseudomonas sp. Among the tested compounds, Zn(II)complex showed higher antibacterial activity over both bacterial strains against reference drug Kanamycin. Moreover, synthesized metal complexes exhibited moderate antioxidant activity than the Schiff base. Cu(II) complexes were found to be most active whereas, Zn(II) complexes showed the lowest antioxidant activity comparable to the BHT.

Can One Novel Series of Transition Metal Complexes of Oxy-dianiline Schiff Base Afford Advances in Both Biological Inorganic Chemistry and Materials Science?

ABSTRACT This paper provides a manifestation of a new tradition by which Comments on Inorganic Chemistry starts publishing original research content that, nonetheless, preserves the Journal’s identity as a niche for a critical discussion of contemporary literature in inorganic chemistry; for previous manifestations, see Comments Inorg. Chem. 2020, 40, 277-303 and references cited in the abstract thereof as Yaseen W. K.; Sanders S. F.; Almotawa R. M.; Otten B. M.; Bhat S.; Alamo D. C.; Marpu S. B.; Golden T. D.; Omary M. A. “Are Metal Complexes” Organic, Inorganic, Organometallic, or Metal-Organic Materials? A case Study for the Use of Trinuclear Coinage Metal Complexes as “Metal-Organic Coatings” for Corrosion Suppression on Aluminum Substrates Comments Inorg. Chem. 2019, 39, 1-26 and also, Mohapatra R. K.; Das P. K.; Pradhan M. K.; El-Ajaily M. M.; Das D.; Salem H. F.; Mahanta U.; Badhei G.; Parhi P. K.; Maihub A. A.; Kudrat -E-Zahan Md. “Recent Advances in Urea- and Thiourea-Based Metal Complexes: Biological, Sensor, Optical, and Corrosion Inhibition Studies” Comments Inorg. Chem. 2019, 39, 127-147). In this work, the Schiff base 1-(6-(1-((4-(4-aminophenoxy)phenyl)imino)ethyl)-pyridin-2-yl)ethan-1-one (L) and eight transition metal complexes were synthesized. The reaction of 4,4-oxy-dianiline with 2,6-diacetylpyridine in 1:1 molar ratio affords to the ligand which was employed in the synthesis of the corresponding metal complexes by reacting with the Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) chlorides in 1:1 molar ratio. All the compounds were characterized by using different analytical methods. Structures of complexes were found to be octahedral as deduced from the spectroscopic and magnetic moment measurements. The ligand behaves as a neutral tridentate ligand where it coordinated to metal ions through N-azomethine, N-pyridine, and O-carbonyl group. Besides, experimental investigations for their antibacterial activity against different bacteria species were studied, molecular docking studies were reported with receptors 4ME7, 4K3V, 3T88 and 4WJ3. Density functional theory (DFT) calculations for ligand were reported. Finally, the evaluation of corrosion inhibition efficiency was measured by using different techniques such as electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and electrochemical frequency modulation (EFM). Scanning electron microscope (SEM) and energy dispersive X-Ray analysis (EDX) were measured to affirm the presence of barrier film on the carbon steel surface by inspecting the surface morphologies and elemental composition of corrosion products.

DNA-binding and Kinetics AChE Inhibition studies of Cobalt(II) and Copper(II) Complexes Derived from 5-[4-(dimethylamino) phenyl]-3-(2-oxo-2H-chromen-3-yl)-1H-pyrazole-1-carbothioamide

A series of transition metal complexes of the general formula [MLCl(H2O)2] ,M=Co(II) and Cu(II) and L=3-(pyridine-2-yl)-4,5-dihydro-1H-pyrazole-1-thiocarboxamides (L) have been synthesized by a two steps reaction sequence starting from substituted Benz aldehydes and 2-acetyl pyridine. The cobalt(II) and copper(II) complexes were isolated in their solid state by the direct reactions of ligand ,L with CoCl2.6H2O and CuCl2•2H2O solutions. The structure and geometry of the metal complexes were determined their chemical structures on the basis of (CHNS) elemental analyses, FT-IR,LC-MS and UV-Visible spectra beside the measurements of magnetic susceptibility at room temperature and molar conductance in DMSO solvent. The application part of the recent paper was the screening of the new poly dentate-based pyrazoline ligand and its CoL and CuL complexes with thymus DNA act as powerful sequence-specific gene modulators, by exerting their effect from transcription regulation to gene modification. The DNA binding abilities of the 5-[4-(dimethylamino)phenyl]-3-(2-oxo-2H-chromen-3-yl)-1H-pyrazole-1-carbithioamide and it Cu , Co complexes was evaluated by UV–Vis titration experiments, which was a useful method to calculate the DNA binding constants in vitro. After Calf Thymus DNA (CT DNA) was added to the phosphate buffer solution containing constant ligand and complexes concentrations, all of the solutions exhibited a slight hypochromic without any significant spectral shift. The binding constants of the compounds were calculated by using a plot of D/∆Ɛapp versus D. Close ,Cu and Co showed the largest binding constant (7.8 * 104 , 8 * 108 , 6.1* 103 ) M for binding with DNA respectively . Specifically, both compounds showed hypochromicity upon increasing DNA concentration, indicating that both compounds interacted with the DNA helix. However, a weak hypochromic effect is indeed observed, and no red shift is apparent. In a third part of study ,a series of chromene and its complexes with Co and Cu were synthesized and their acetyl cholinesterase enzyme (AChE) inhibitory effects were investigated. All carben were synthesized from the corresponding carboxylic acids via of the acids with diphenyl phosphoryl azide followed by addition of benzyl alcohol. The chromene and its complexes with Co and Cu were determined to be very good inhibitors against for AChE with different type of inhibition (mix and non-competitive) inhibition.

SYNTHESIS, COMPLEXATION AND SPECTRAL STUDY OF NOVEL 2-BROMOBENZALDEHYDE DERIVED BENZILMONOXIMEHYDRAZONE

In this newly approached method a novel series of Transition metal complexes were synthesized by the reaction of 2- bromobenzaldehyde react with benzilmonoximehydrazone in ethanolic solution at refluxed condition. Mononuclear complexes were synthesized by reaction with Cu(II), Ni(II) and Co(II) chloride salts. The ligand and its complexes were characterized by elemental analysis, UV, FTIR and PMR spectral studies.

Synthesis, Characterization and Biological Activity of Transition Metals Schiff Base Complexes Derived from 4,6-Diacetylresorcinol and 1,8-Naphthalenediamine

The tridentate Schiff base ligand was prepared via condensation of 4,6-diacetylresorcinol and 1,8-naphthalenediamine in 1:1 molar ratio using conventional method. Additionally, a new series of transition metal complexes of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) metal ions were prepared and fully characterized by elemental analysis, FT-IR, 1H NMR, UV–vis, conductivity and magnetic susceptibility measurements and theoretically through density function theory (DFT). Spectral studies suggested that, the Schiff base coordinated to the metal ions through the azomethine N, N-amine and phenolic oxygen atoms. From the elemental, magnetic susceptibility and spectroscopic data, the complexes were suggested to have octahedral geometry. The Schiff base and its metal complexes were screened for their in vitro antimicrobial activities and showed that Cd(II), Cu(II) and Cr(III) complexes have high activity against Escherichia coli, while Ni(II) and Cd(II) complexes have the highest activity against Bacillus Subtilis, Co(II) complex has the highest activity against Staphylococcus aureus and Cd(II) complex has the highest activity against Pseudomonas aeruginosa. In addition, the molecular docking study was performed to explore the possible ways for binding to crystal structure of Staphylococcus aureus nucleoside diphosphate kinase complexed with ADP (PDB ID: 3Q8U).