Structural and characterization of novel copper(II) azodye complexes

Synthesis, structural characterization, antioxidant, cytotoxic activities and docking studies of schiff base Cu(II) complexes

By combining hydrazide with 2-Acetylpyridine, a hydrazone ligand (HL) was successfully created. Several copper (II) salts have been used to create three copper (II) hydrazone complexes (acetate, sulphate, and chloride). The hydrazide ligand and its copper (II) complexes (1-3) were studied via variety of analytical techniques, including elemental analysis, electronic, infrared, UV-vis Spectrum, XRD study, thermal analysis, also molar conductivity amounts. The spectrum results indicate that in all complexes, the ligand exhibits monobasic tridentate behavior. Octahedral geometries were present in all metal complexes. The Coats-Redfern equations were used to compute and describe the dynamics properties of several steps of TGA (Ea, A, ΔH*, ΔS*, and ΔG*). Calculations using the density functional theory (DFT) were done at the molecular studio software toward examine ligands agent's and its complexes' best structures. The MCF-7 in addition to HepG-2 cell lines was resistant to tumor-inducing effects of the copper (II) chelates. The in vitro antioxidant capacities of all complexes have been estimated via DPPH free radical scavenger assays. Furthermore, zones of inhibition length accustomed to test antimicrobial effect of particular complexes in vitro towards Staphylococcus aureus (Gram positive bacteria) E. coli (Gram negative bacteria). Both absorption spectra and viscosity measurements in calf thymus DNA binding have been used to study the complexes. In order to explore docking research of copper (II) chelates, the crystallographic construction of the SARS-active CoV-2's site protein (PDB ID:6XBH) was used (COVID-19) and breast cancer distorted (PDB ID: 3hb5).

Synthesis, Structural Characterization, Molecular Modeling and DNA Binding Ability of CoII, NiII, CuII, ZnII, PdII and CdII Complexes of Benzocycloheptenone Thiosemicarbazone Ligand

Background & Objective:

Six novel complexes of transition metal namely, [CoLCl2(H2O)2]0.5H2O, [NiLCl2(H2O)2]0.5H2O, [CuLCl2]0.5H2O, [ZnLCl2], [PdLCl2]H2O and [CdLCl2]H2O, where L is benzocycloheptenone thiosemicarbazone ligand, have been obtained. The confirmation of the structures of the obtained metal chelates depends on the different spectral and physicochemical techniques including CHN analysis, infrared spectra, molar conductivity measurement, UV-vis, thermogravimetric analysis and magnetic moment. The infrared spectral results ascertained that the ligand behaved as neutral bidentate connecting the metal centers via N and S atoms of C=N and C=S groups, respectively.

Methods:

The UV-Vis, molar conductivity and magnetic susceptibility results implied that the geometrical structures of the metal chelates are octahedral for Co(II) & Ni(II) complexes, tetrahedral for Zn(II) & Cd(II) complexes and square planar for Cu(II) & Pd(II) complexes which have been confirmed by molecular modeling studies.

Conclusion:

Moreover, the mode of interaction between some chosen metal complexes towards SSDNA has been thoughtful by UV-Vis spectra and viscosity measurements. The value of the intrinsic binding constant (Kb) for the examined compounds has been found to be lower than the binding affinity of the classical intercalator ethedium bromide. Also, the viscosity measurements of the complexes proved that they bind to DNA, most likely, by a non-intercalative mode like H-bonding or electrostatic interactions.

Correlation between ionic radii of metal azodye complexes and electrical conductivity

5-(2,3-Dimethyl-1-phenylpyrazol-5-one azo)-2-thioxo-4-thiazolidinone (HL) and its metal complexes with copper(II) (1), cobalt(II) (2) and nickel(II) (3) are synthesized and characterized by physico-chemical techniques. The thermal properties of the ligand (HL) and its metal complexes (1-3) are discussed. The thermal activation energies of decomposition (Ea) of HL and its metal complexes with Cu(II), Co(II) and Ni(II) are found to be 48.76, 36.83, 30.59 and 40.45 kJ/mol, respectively. The frequency and temperature dependence of ac conductivity, dielectric constants for HL and its complexes (1-3) are investigated in the temperature range 300-356 K and frequency range 0.1-100 kHz. Both of the ac conductivity and the values of the thermal activation energy for conduction, as well as the dielectric properties of the complexes of HL are found to depend on the nature of the metallic ions. The values of the thermal activation energies of electrical conductivity decrease with increasing the value of test frequency. The small polarons tunneling (SPT) is the dominant conduction mechanism for the ligand (HL), while for complex (2) the overlapping large tunneling model (OLPT) is the dominant conduction mechanism. The correlated barrier hopping (CBH) is the dominant conduction mechanism for both of the complexes (1) and (3).

Ternary metal complexes of guaifenesin drug: Synthesis, spectroscopic characterization and in vitro anticancer activity of the metal complexes

The coordination behavior of a series of transition metal ions named Cr(III), Fe(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) with a mono negative tridentate guaifenesin ligand (GFS) (OOO donation sites) and 1,10-phenanthroline (Phen) is reported. The metal complexes are characterized based on elemental analyses, IR, (1)H NMR, solid reflectance, magnetic moment, molar conductance, UV-vis spectral studies, mass spectroscopy, ESR, XRD and thermal analysis (TG and DTG). The ternary metal complexes were found to have the formulae of [M(GFS)(Phen)Cl]Cl·nH2O (M=Cr(III) (n=1) and Fe(III) (n=0)), [M(GFS)(Phen)Cl]·nH2O (M=Mn(II) (n=0), Zn(II) (n=0) and Cu(II) (n=3)) and [M(GFS)(Phen)(H2O)]Cl·nH2O (M=Co(II) (n=0), Ni(II) (n=0) and Cd(II) (n=4)). All the chelates are found to have octahedral geometrical structures. The ligand and its ternary chelates are subjected to thermal analyses (TG and DTG). The GFS ligand, in comparison to its ternary metal complexes also was screened for their antibacterial activity on gram positive bacteria (Bacillus subtilis and Staphylococcus aureus), gram negative bacteria (Escherichia coli and Neisseria gonorrhoeae) and for in vitro antifungal activity against (Candida albicans). The activity data show that the metal complexes have antibacterial and antifungal activity more than the parent GFS ligand. The complexes were also screened for its in vitro anticancer activity against the Breast cell line (MFC7) and the results obtained show that they exhibit a considerable anticancer activity.

Thermal, dielectric characteristics and conduction mechanism of azodyes derived from quinoline and their copper complexes

A novel series of (5-(4'-derivatives phenyl azo)-8-hydroxy-7-quinolinecarboxaldehyde) (AQLn) (n=1, p-OCH3; n=2, R=H; and n=3; p-NO2) and their complexes [Cu(AQLn)2]·5H2O are synthesized and investigated. The optimized bond lengths, bond angles and the calculated quantum chemical parameters for AQLn are investigated. HOMO-LUMO energy gap, absolute electronegativities, chemical potentials, and absolute hardness are also calculated. The thermal properties, dielectric properties, alternating current conductivity (σac) and conduction mechanism are investigated in the frequency range 0.1-100kHz and temperature range 293-568K for AQL1-3 and 318-693K for [Cu(AQL1-3)2]·5H2O complexes. The thermal properties are of ligands (AQLn) and their Cu(II) complexes investigated by thermogravimetric analysis (TGA). The temperature and frequency dependence of the real and the imaginary part of the dielectric constant are studied. The values of the thermal activation energy of conduction mechanism for AQLn and their complexes [Cu(AQLn)2]·5H2O under investigation are calculated at different test frequencies. The values of thermal activation energies ΔE1 and ΔE2 for AQLn and [Cu(AQLn)2]·5H2O decrease with increasing the values of frequency. The ac conductivity is found to be depending on the chemical structure of the compounds. Different conduction mechanisms have been proposed to explain the obtained experimental data. The small polaron tunneling (SPT) is the dominant conduction mechanism for AQL1 and its complex [Cu(AQL1)2]·5H2O. The quantum mechanical tunneling (QMT) is the dominant conduction mechanism for AQL2 and its complex [Cu(AQL2)2]·5H2O. The correlated barrier hopping (CBH) is the dominant conduction mechanism for AQL3 and its complex [Cu(AQL3)2]·5H2O, and the values of the maximum barrier height (Wm) are calculated.

Polymer complexes. LX. Supramolecular coordination and structures of N(4-(acrylamido)-2-hydroxybenzoic acid) polymer complexes

A number of novel polymer complexes of various anions of copper(II), cobalt(II), nickel(II) and uranyl(II) with N(4-(acrylamido)-2-hydroxy benzoic acid) (ABH) have been synthesized and characterized by elemental analysis, IR, 1H NMR, magnetic susceptibility measurements, electronic spin resonance, vibrational spectra and thermal analysis. The molecular structures of the ligand are optimized theoretically and the quantum chemical parameters are calculated. Tentative structures for the polymeric metal complexes due to their potential application are also suggested. The IR data exhibit the coordination of ONO2/OAc/SO4 with the metal ions in the polymeric metal complex. Vibrational spectra indicate coordination of carboxylate oxygen and phenolic OH of the ligand giving a MO4 square planar chromophore. Ligand field ESR spectra support square planar geometry around Cu(II). The thermal decomposition of the polymer complexes were discussed in relation to structure, and the thermodynamic parameters of the decomposition stages were evaluated applying Coast-Redfern and Horowitz-Metzger methods.

Correlation between ionic radii of metals and thermal decomposition of supramolecular structure of azodye complexes

An interesting azodye heterocyclic ligand of copper(II), cobalt(II), nickel(II) and uranyl(II) complexes have been synthesized by the reaction of metal salts with 5-(2,3-dimethyl-1-phenylpyrazol-5-one azo)-2-thioxo-4-thiazolidinone (HL) yields 1:1 and 1:2 (M:L) complexes depending on the reaction conditions. The elemental analysis, magnetic moments, spectral (UV-Vis, IR, (1)H and (13)C NMR and ESR) and thermal studies were used to characterize the isolated complexes. The molecular structures of the ligand tautomers are optimized theoretically and the quantum chemical parameters are calculated. The IR spectra showed that the ligand (HL) act as monobasic tridentate/neutral bidentate through the (-N=N), enolic (C-O)(-) and/or oxygen keto moiety groups forming a five/six-membered structures. According to intramolecular hydrogen bond leads to increasing of the complexes stability. The molar conductivities show that all the complexes are non-electrolytes. The ESR spectra indicate that the free electron is in dxy orbital. The calculated bonding parameter indicates that in-plane σ-bonding is more covalent than in-plane π-bonding. The coordination geometry is five/six-coordinated trigonal bipyramidal for complex (1) and octahedral for complexes (2-6). The value of covalency factor β1(2) and orbital reduction factor K accounts for the covalent nature of the complexes. The activation thermodynamic parameters are calculated using Coats-Redfern and Horowitz-Metzger methods. The synthesized ligand (HL) and its Cu(II) complexes (1, 2 and 4) are screened for their biological activity against bacterial and fungal species. The ligand (HL) showed antimicrobial activities against Escherichia coli. The ligand (HL) and its Cu(II) complexes (2 and 4) have very high antifungal activity against Penicillium italicum. The inhibitive action of ligand (HL), against the corrosion of C-steel in 2M HCl solution has been investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS).

Investigation of in vitro anticancer and DNA strap interactions in live cells using carboplatin type Cu(II) and Zn(II) metalloinsertors

A series of carboplatin type Cu(II) and Zn(II) metalloinsertors (1-8) having β-diketone analogues and biologically significant cyclobutane-1,1-dicarboxylic acid have been synthesized and characterized by spectral and analytical methods. The binding and cleavage propensity of these metalloinsertors on DNA and their cytotoxic effects in live cells have been explored. From the gel electrophoresis study, it is observed that the complexes 1-8 cleave pBR322 DNA via a hydrolytic mechanism induced by hydroxyl radical scavengers, DMSO and EtOH as the reactive oxygen species (ROS). In vivo antitumor efficacy has been studied on EAC tumor bearing mice which is assessed by mean survival time, effect on hematological parameters and solid tumor volume. The results strongly support that complex 1 shows potent antitumor effect against EAC and higher than the standard drug carboplatin. Moreover, the cytotoxicity of the complexes, screened on a panel of human cancerous cell lines viz., human cervical cancer cells (HeLa), human breast adenocarcinoma cells (MCF-7), human laryngeal epithelial carcinoma cells (HEp-2), human liver carcinoma cells (Hep G2) and non-cancerous NIH 3T3 mouse embryonic fibroblasts cell lines, reveals that complex 1 exhibits a better anticancer activity than other complexes and standards.

Supramolecular spectroscopic and thermal studies of azodye complexes

A series of heterocyclic ligand of copper(II) complexes have been synthesized by the reaction of copper(II) acetate with 5-(4'-derivatives phenylazo)-2-thioxothiazolidin-4-one (HLn) yields 1:1 and 1:2 (M:L) complexes depending on the reaction conditions. The elemental analysis, spectral (IR and ESR), conductance, magnetic measurements, and thermogravimetric analysis (TGA) are used to characterize the isolated complexes. It is found that the change of substituent affects the thermal properties of azodye rhodanine derivatives and their Cu(II) complexes. The molecular and electronic structures of the investigated compounds (HLn) were also studied using quantum chemical calculations. According to intramolecular hydrogen bond leads to increasing of the complexes stability. The data revealed that the coordination geometry around Cu(II) in all complexes (1-4) exhibit a trans square planar by NO monobasic bidentate and the two monobasic bidentate in octahedral complexes (5-7). Electronic, magnetic data and ESR spectra proposed the square planar structure for all complexes (1-4) under investigation. The value of covalency factor [Formula: see text] and orbital reduction factor K accounts for the covalent nature of the complexes. The activation thermodynamic parameters, such as activation energy (Ea), enthalpy (ΔH(*)), entropy (ΔS(*)), and Gibbs free energy change of the decomposition (ΔG(*)) are calculated using Coats-Redfern and Horowitz-Metzger methods.

Conformation of azo-bridge in 3,3'-dinitro-2,2'-azobipyridine and its 4,4'(or 5,5' or 6,6')-dimethyl-derivatives: vibrational studies and DFT quantum chemical calculations

Syntheses of 3,3'-dinitro-2,2'-azobipyridine and 4,4' (or 5,5' or 6,6')-dimethyl-3,3'-dinitro-2,2'-azobipyridine have been described. Molecular structures of these compounds have been determined and compared, to the basic compound, azobipyridine, reported by us earlier. The conformation of the azo-bond and other structural data are discussed in terms of substitution place of methyl chromophore. Fourier transform IR and Raman spectra of these compounds have been measured and analysed. The 6-311G (2d,2p) basis set with the B3LYP functional have been used to discuss the space conformation and dynamics of the studied compounds.

Supramolecular spectral studies on metal-ligand bonding of novel quinoline azodyes

A series of novel bidentate azodye quinoline ligands were synthesized with various p-aromatic amines like p-(OCH3, CH3, H, Cl and NO2). All ligands and their complexes have been characterized on the basis of elemental analysis, IR, (1)H and (13)C NMR data and spectroscopic studies. IR and (1)H NMR studies reveal that the ligands (HLn) exists in the tautomeric azo/hydrazo form in both states with intramolecular hydrogen bonding. The ligands obtained contain NN and phenolic functional groups in different positions with respect to the quinoline group. IR spectra show that the azo compounds (HLn) act as monobasic bidentate ligand by coordinating via the azodye (NN) and oxygen atom of the phenolic group. The ESR (g|| and g ) and bonding α(2) parameters of the copper ion were greatly affected by substituting several groups position of ring of quinoline and p-aromatic ring. The ESR spectra of copper complexes in powder form show a broad signal with values in order g|| >g > ge > 2.0023. The value of covalency factor β and orbital reduction factor K accounts for the covalent nature of the complexes. All complexes possessed an octahedral and square planar geometry. The thermal properties of the complexes were investigated using TGA and DSC. It is found that the change of substituent affects the thermal properties of complexes.

Synthesis and characterization of Cu(II), Co(II) and Ni(II) complexes of a number of sulfadrug azodyes and their application for wastewater treatment

The azodye ligand (HL(1)) was synthesized from the coupling of sulfaguanidine diazonium salt with 2,4-dihydroxy-benzaldehyde while the two ligands, HL(2) and HL(3), were prepared by the coupling of sulfadiazine diazonium salt with salicylaldehyde (HL(2)) and 2,4-dihydroxy-benzaldehyde (HL(3)). The prepared ligands were characterized by elemental analysis, IR, (1)H NMR and mass spectra. Cu(II), Co(II) and Ni(II) complexes of the prepared ligands have been synthesized and characterized by various spectroscopic techniques like IR, UV-Visible as well as magnetic and thermal (TG and DTA) measurements. It was found that all the ligands behave as a monobasic bidentate which coordinated to the metal center through the azo nitrogen and α-hydroxy oxygen atoms in the case of HL(1) and HL(3). HL(2) coordinated to the metal center through sulfonamide oxygen and pyrimidine nitrogen. The applications of the prepared complexes in the oxidative degradation of indigo carmine dye exhibited good catalytic activity in the presence of H2O2 as an oxidant. The reactions followed first-order kinetics and the rate constants were determined. The degradation reaction involved the catalytic action of the azo-dye complexes toward H2O2 decomposition, which can lead to the generation of HO radicals as a highly efficient oxidant attacking the target dye. The detailed kinetic studies and the mechanism of these catalytic reactions are under consideration in our group.

Supramolecular coordination and antimicrobial activities of constructed mixed ligand complexes

A novel series of copper(II) and palladium(II) with 4-derivatives benzaldehyde pyrazolone (L(n)) were synthesized. The mixed ligand complexes were prepared by using 1,10-phenanthroline (Phen) as second ligand. The structure of these complexes was identified and confirm by elemental analysis, molar conductivity, UV-Vis, IR and (1)H NMR spectroscopy and magnetic moment measurements as well as thermal analysis. The ligand behaves as a neutral bidentate ligand through ON donor sites. ESR spectra show the simultaneous presence of a planar trans and a nearly planar cis isomers in the 1:2 ratio for all N,O complexes [Cu(L(n))(2)]Cl(2)⋅2H(2)O. Schiff bases (L(n)) were tested against bacterial species; namely two Gram positive bacteria (Staphylococcus aureus and Bacillus cereus) and two Gram negative bacteria (Escherichia coli and Klebsiella pneumoniae) and fungal species (Aspergillus niger, Fusarium oxysporium, Penicillium italicum and Alternaria alternata). The tested compounds have antibacterial activity against S. aureus, B. cereus and K. pneumoniae.

Supramolecular structure and spectral studies on mixed-ligand complexes derived from β-diketone with azodye rhodanine derivatives

A novel method to synthesize some mononuclear ternary palladium(II) complexes of the general formula [Pd(L(n))L] (where LH=diketone=acetylacetone, HL(n)=azorhodanine) has been synthesize. The structure of the new mononuclear ternary palladium(II) complexes was characterized using elemental analysis, spectral (electronic, infrared and (1)H &(13)C NMR) studies, magnetic susceptibility measurements and thermal studies. The IR showed that the ligands (HL(n) & LH) act as monobasic bidentate through the azodye nitrogen, oxygen keto moiety and two enolato oxygen atoms. The molar conductivities show that all the complexes are non-electrolytes. Bidentate chelating nature of β-diketone and azorhodanine anions in the complexes was characterized by (electronic, infrared and (1)H &(13)C NMR) spectra. Square planar geometry around palladium has been assigned in all complexes. Various ligand and nephelouxetic parameter have been calculated for the complexes. The thermal decomposition for complexes was studied.

Supramolecular structure, mixed ligands and substituents effect on the spectral studies of oxovanadium(IV) complexes of bioinorganic and medicinal relevance

An interesting series of heterocyclic mixed ligand of oxovanadium(IV) complexes have been synthesized by the reaction of vanadium(IV) sulfate with rhodanine azo (HL(n)) in the presence of β-diketon (LH). The elemental analysis, magnetic moments, spectral (UV-Vis, IR, (1)HNMR and ESR) with thermal studies were used to characterize the isolated complexes. The IR showed that the ligands (HL(n) and LH) act as a monobasic bidentate through the (NN), oxygen keto moiety and oxygen atom of the two enolate groups thereby forming a six-membered. The molar conductivities show that all the complexes are non-electrolytes. The ESR spectra indicate that the free electron is in d(xy) orbital. The calculated bonding parameter indicates that in-plane σ-bonding is more covalent than in-plane π-bonding. The coordination geometry around oxovanadium(IV) in all complexes is a hex-coordinated trans octahedral, with one bidentate ligand (L(n)), and one bidentate ligand (L). Electronic and magnetic data proposed the octahedral structure for all complexes under investigation. ESR spectra of VO(2+) reveal data that confirmed the proposed structure. The value of covalency factor (β(1)(∗))(2) and orbital reduction factor K accounts for the covalent nature of the complexes. All electronic transitions were assigned. The Hammett's constant is also discussed.