Synthesis and Biological Activity of Ni(II), La(III), and Ce(IV) Complexes with 8-Hydroxy-7-iodo-6-((4-sulfophenyl)diazinyl)quinoline-5-sulfonic Acid Ligand

New mixed-ligand Co(II) and Ni(II) complexes with enrofloxacin and 1,10-phenanthroline/8-hydroxyquinoline have been synthesized. The metal complexes have been characterized by elemental analyses, molar conductance, FT-IR, solid reflectance, magnetic moment, thermal analyses, X-ray powder diffraction (XRD) and SEM analysis. Conductance measurements indicate that all the complexes are non-electrolytes. Spectral IR data showed that the deprotonated enrofloxacin is bidentately bound to the metal ion through the pyridone oxygen and the carboxylated oxygen; 1,10-phenanthroline acts as neutral bidentate ligand coordinated through two nitrogen donor atoms, and the deprotonated 8-hydroxyquinoline is coordinated through nitrogen and oxygen donor atoms. The geometry of the complexes was elucidated with solid reflectance UV and magnetic moments. Thermal analysis recorded that TG/DTG/DSC experiments revealed the thermal stability of metal complexes and confirmed their compositions suggested by the analytical data. In addition to experimental data, a molecular modelling study has been performed to establish the optimized geometries of metal complexes. The XRD analysis of powders evidences the nanocrystalline nature of all complexes. The results are in agreement with molecular modelling data. SEM images revealed highly agglomerated particles with irregular shape with sizes in the micrometre range. The ligand and their metal complexes were screened for their antimicrobial activity against Escherichia coli 25922, Staphylococcus aureus 25923, Pseudomonas aeruginosa 27853 and Candida albicans 10231. The metal complexes were also investigated for their cytotoxicity using an in vitro assay.

The dyes Azo have a lengthy history and are a vital part of our daily lives. There are numerous potentials uses for these substances and their derivatives in various industries and environmental and biological research. In this study conversion of various azo compounds into other derivatives, complexes, and polymers was accomplished. This review included examining the chemistry reactions, synthesis, and applications of azo dye ligands and their complexes, mentioned spectral, analytical, thermal, and morphology methods of investigation, and confirmed by mass fragment mechanisms for some azo dyes and metal complexes. One of the aims of this review is to explain the role of these azo dye derivatives and the effect of metal complexes on leather which exhibits high light fastness, wash fastness, and rubbing fastness. The interaction of DNA has also been achieved. New metal complexes (Co (II), Ni (II), Cu (II), and Zn (II) azo ligands derived from 4-amino antipyrine and 4-aminoacetophenone are reported. The nature of the compounds has been studied followed by methods of continuous contrast, Beer's law, and molar ratio. Analytical methods and spectra revealed the octahedral geometry of the complexes. The azo dye ligand and its metal (II) complexes possess appreciable microbial activities. Novel heterocyclic compounds and its complexes have been investigated. The relationship between the HOMO-LUMO gap and antibacterial activity was investigated computationally. Improved understanding of binding mechanisms was shown by the comparative molecular docking investigations. This review demonstrated the utilization of the polycrystalline Zn (II) metal complex as a sensitizer in organic dye-sensitized solar cells. Quinolinyl-azo-naphthol (HL) is a selective turn-on chemosensor for Al3+ in the presence of other ions, exhibiting a 750-fold rise in emission at 612 nm following activation at visible light (537 nm). The reported limit of detection (LOD) for the 3σ technique is 0.69 nM. During this review it was proven that the effective production of palladium nanoparticles with guar gum as a stabilizer and their use as a catalyst in reduction processes and azo dye degradation. The investigation describing and assessing thiazolyl azo ligand complexes with specific metal ions has been presented.( Zn (II), Cu (II), Co (II), and Ni (II) ) complexes with azo ligands generated from metoclopramide hydrochloride were examined for their industrial and biological applications in cotton fabric dyeing, as well as for light and cleaner firmness. Additionally, the evaluation of the ligand and their complexes' antimicrobial and antifungal capabilities revealed that the ZnL molecule had the strongest antibacterial activity. The application characteristics of thiophene-derived dispersion dyes complexed with Zn, Cu, and Co metal on (polyester and Nylon 6.6), showed good to excellent light fastness, good to excellent wash fastness, excellent fastness to perspiration and sublimation, and good levelness on both materials with varying shades of brown and violet. The azo benzoic acid ligand derived from 2,4-dimethylphenol and 4-aminobenzoic acid has been identified by several spectroscopic methods and has been used as dispersion dyes on cotton textiles to test the antibacterial properties of the chemicals generated against a range of bacteria and fungus. Each primed complex has been proposed to have a tetrahedral geometrical structure for the obtained datum. There have been reports on the use of azo dyes in combination with nickel and its uses in dye-sensitized solar cells. Ten complexes of metals including Zn (II), Cu (II), Cd (II), Ni (II), and Co (II) as well as Phloroglucinol and antipyrine were used to create two unique azo-colorants, which were isolated and examined using a variety of techniques, wool, polyamide, and poly acetate fibers exhibit coloristic activity toward H3L1 and H3L2 as well as their metal complexes, demonstrating their strong resistance to UV radiation. Both in static and dynamic settings, the H3L2 compound exhibited a good sorption activity towards heavy metal cations from aqueous solutions of trace concentrations. A particular combination of selected transition metal ions is complexed with the azo compound, which is obtained from the (2-hydroxy quinoline: synthesis, characterization, thermal analysis, and antioxidant activity). These compounds' reactive oxygen entity degradation was evaluated with the DPPH radical and subsequently compared to gallic acid, a standard naturally occurring antioxidant. Finally, this review explains the metal chelates of the azo dye derivative sulfafurazole through synthesis, structure confirmation, molecular docking simulation, antibacterial, anticancer, and application in bioinorganic chemistry.

Azo ligand as new corrosion inhibitor for copper metal: Spectral, thermal studies and electrical conductivity of its novel transition metal complexes

Synthesis, spectroscopic, structural characterization, thermal analysis, kinetics, biological evaluation of non-steroidal anti-inflammatory drug diclofenac zirconium (IV) solvates (L) (L = H2O, DMF, Py and Et3N)

An aqueous solution spectroscopic (Vis and EPR) study of the copper(II) complexes with the Ac-HGGG-NH2 and Ac-PHGGGWGQ-NH2 polypeptides (generically designated as L) suggests square base pyramids ascribable to [Cu(L)H(-2)] complex species, which contain three nitrogen donor atoms, arising from imidazole and peptide groups, in the equatorial plane and for a pseudo-octahedral geometry in the case of [CuLH-3]- and [Cu(L)H-4]2- which have four nitrogen donor atoms in their equatorial plane. The coordination sphere of the copper complex in the [Cu(L)H(-2)] species, which is present at neutral pH values, is completed by two oxygen donor atoms. ESI-MS spectra ascertained that water molecules are not present in the coordination equatorial plane of this latter species, in comparison with other copper(II) complexes with ligands bearing nitrogen and oxygen donor atoms and surely having equatorial water molecules. This indicates the coordination of a carbonyl oxygen atom in the equatorial plane has to be invoked. However, no direct proof about the involvement of a carbonyl group oxygen donor atom apically linked to copper was obtained, due to the flexibility of these structures at room temperature. Additionally, the low A(ll) value leads one to consider another oxygen atom of a carbonyl group being involved in the apical bond to copper in a fast exchange fashion. This apical interaction, which may also involve a water molecule, is more pronounced in the Cu-Ac-HGGG-NH2 than in the analogous Cu-Ac-PHGGGWGQ-NH2 system, probably because of the presence of tryptophan and proline in the polypeptide sequence.

The new Azo ligand and its metal complexes have been prepared and characterized The reaction of 4-nitroaniline and 2-hydroxy-1-naphthaldehyde in a 1:1 mole ratio resulted in the synthesis of ((E)-2-hydroxy-3-((4-nitrophenyl) diazenyl)-1-naphthaldehyde) (HL). The separation of monomeric complexes was accomplished by reacting ((E)-2-hydroxy-3-((4-nitrophenyl)diazenyl)-1-naphthaldehyde) (HL) with Cr, Mn II, Co II, Ni II, and Cu II metal ions in a mole ratio of 2:1 (L: M). Elemental microanalysis, magnetic susceptibility, conductance, FT-IR, electronic spectra, and 1HNMR, 13C-NMR, and mass spectra were among the analytical and spectroscopic techniques used to describe the products. Based on the data collected during the characterization process, six coordinates were determined. The ligand and its complexes were tested against certain bacteria and fungi. The findings acquired suggested that the metal complexes are more active against a variety of organisms have been studied as compared to the free ligand. Keywords: ((E)-2-hydroxy-3-((4-nitrophenyl) diazenyl)-1-naphthaldehyde); Azo ligand; Candida and Rhizopus porium; 2-hydroxy-1-naphthaldehyde; Metal Complexes.

Synthesis of new Fe(III), Co(II), Ni(II), and Cu(II) complexes of two azo ligands; 1-(phenyldiazenyl) naphthalene-2-ol (sudan orange R, HL1), and sodium 2-hydroxy-5-[(E)-(4-nitrophenyl) diazenyl]benzoate (alizarin yellow GG, HL2) have been reported. Stoichiometries of 1:2 and 1:3 (M:L) of the synthesized complexes were approved by total-reflection X-ray fluorescence technique (TXRF) and by elemental analyses. The geometry of complexes (octahedral and square planar) was typified by various spectroscopic, thermal, and magnetic techniques. The ESR spectroscopy showed that Cu(II) complexes are of different isotropic and rhombic symmetries with the existence of Cu–Cu ions interaction. TGA, DTA, and DSC analyses supported the multi-stage thermal decomposition mechanisms, where the thermal breakdown is ended by the formation of metal oxide in most cases. Moreover, chemical reactivity modeling using the density functional theory (DFT) method with the B3LYP/6–31 basis set, showed that metal complexes are more biologically active than their precursor ligands. The calculated lipophilicity character for metal complexes is in the range of 33.8–37.5 eV. Docking results revealed high scoring energy for [Fe(HL2)3].H2O complex and moderate inhibition strength of [Cu(L1)2].H2O complex versus 1bqb, 3t88, and 4esw proteins. Ultimately, the extent of biological effectiveness was endorsed experimentally against four microbial strains. The results are guidelines for toxicological investigations.Graphical

Contemporary pharmacology dating back to the late 19th/early 20th centuries has benefitted largely from the incorporation of metal complexes. Various biological attributes have been successfully realized using metal/metal complex-based drugs. Among anticancer, antimicrobial, and antiviral applications, anticancer applications have extracted the maximum benefit from the metal complex, Cisplatin. The following review has compiled the various antiviral benefits harnessed through inputs from metal complexes. As a result of exploiting the pharmacological aspects of metal complexes, the anti-COVID-19 deliverables have been summarized. The challenges ahead, the gaps in this research area, the need to improvise incorporating nanoaspects in metal complexes, and the need to test metal complex-based drugs in clinical trials have been discussed and deliberated. The pandemic shook the entire world and claimed quite a percentage of the global population. Metal complex-based drugs are already established for their antiviral property with respect to enveloped viruses and extrapolating them for COVID-19 can be an effective way to manipulate drug resistance and mutant issues that the current anti-COVID-19 drugs are facing.

Complex compounds of platinum (II) and (IV) with amino acids, peptides and their derivatives

Synthesis, structural characterization, computational studies, and anticancer evaluation of novel rufloxacin Schiff base metal complexes with involvement of Mcl-1 modulation in breast cancer cells.

BackgroundThe drug-metal complexes are used to control the growth of pathogens and parasites which are harmful to humans. Moxifloxacin (MOX) is a new fourth generation 8- methoxy fluoroquinolone. Its chemical name is [1-cyclopropyl-7-(S,S)-2,8-diazabicyclo(4.3.0)- non-8-yl-6-fluoro-8-methoxy-1,4-dihydro-4-oxo-3-quinoline carboxylic acid hydrochloride]. Many researchers have reported Moxifloxacin-metal complexes with transition metals and studied their biological applications. We have synthesized novel moxifloxacin- Au(III) and Ag(I) metal complexes ([Au(MOX) 2 (Cl) 2 ].2H 2 O and [Ag (MOX) 2 ].2H 2 O), characterized, and found their biological activities.MethodsMoxifloxacin- Au(III) and Ag(I) metal complexes were prepared by adding corresponding aqueous solutions of Au(III) and Ag(I) metal salts to methanolic solution of Moxifloxacin. These metal complexes were characterized by physio-chemical techniques like UV-Vis, 1 H- NMR, FTIR, XRD, DSC, TGA, SEM and microanalytical data. The disc diffusion method was used to study the antibacterial activity of the Moxifloxacin-metal complexes.ResultsThe structural assessment of these complexes has been carried out based on physio- chemical and spectroscopic methods. The powder X-ray diffraction data of the metal complexes revealed moderate crystallinity. SEM analysis confirms that [Ag(MOX) 2 ].2H 2 O complex has small rods like morphology whereas [Au(MOX) 2 (Cl) 2 ].2H 2 O has well crystalline rods like morphology. The results from DSC of moxifloxacin- Au(III) and Ag(I) metal complexes revealed the interaction between the drug and metals. Further, Au & Ag moxifloxacin metal complexes have shown significant antibacterial activity against gram-positive and gram-negative bacteria.ConclusionsThe spectral and analytical results clearly confirmed the coordination chemistry of Au (III) and Ag (I) Moxifloxacin metal complexes. The IR, electronic transition and elemental data led to the conclusion that the geometry of the complex of Au(III) is octahedral and that of Ag (I) complex is tetrahedral. The [Ag(MOX) 2 ].2H 2 O complex has showed good antibacterial activity compared to [Au (MOX) 2 (Cl) 2 ].2H 2 O metal complex. The antibacterial activity studies indicate the metal complexes have more biological activity than free ligand.

We have synthesized novel cobalt(II) and nickel(II) pincer ligand complexes containing novel tridentate ligand precursors that coordinate via oxygen, nitrogen, and oxygen donor atoms. The novel tridentate ONO ligands, which are neutral, incorporate a carbonyl-substituted imidazole functionality and contain R groups of ethyl, isopropyl, or tert-butyl. The ligand precursors were thoroughly characterized using NMR spectroscopy, ESI-MS, and IR spectroscopy. The metal complexes were thoroughly characterized using single crystal X-ray diffraction, elemental analysis, ESI-MS, and cyclic voltammetry. The nickel(II) and cobalt(II) complexes with ethyl, isopropyl, and t-butyl wingtip groups had a pseudo-octahedral geometry about the metal center. The nickel(II) complex with R = isopropyl had a monoclinic lattice with C121 space group (a = 21.7639(8); b = 11.0649(5); c = 10.9225(4); alpha = 90.0 degrees; beta = 90.609(3) degrees; gamma = 90.0 degrees). The cobalt(II) complex with R = ethyl had a monoclinic lattice with P21/n space group (a = 17.7907(7); b = 21.5278(6); c = 21.8597(7); alpha = 90.0 degrees; beta = 95.063(3) degrees; gamma = 90.0 degrees). The cobalt(II) complexes were paramagnetic with μeff = 1.59 BM (R = ethyl) and 6.67 BM (R = t-butyl). The nickel(II) complex was paramagnetic with μeff = 2.59 BM. The ligand precursors and metal complexes are redox-active.

A string of novel coordination compounds of Cr(III) complexes have been derived and characterized from the macrocyclic ligands (L 1 -L 2 ) carried out by condensation reaction between ligands and the subsequent metal salt. The chemical composition of ligand was determined by analytical and spectral techniques i.e. elemental analysis, IR and Mass spectrocopy. Spectral techniques revealed tetradentate [N 4 ] the nature of ligand and its coordination mode to metal ion through nitrogen donor atoms. Metal complexes were characterized by elemental analyses, molar conductance, magnetic susceptibility measurements, IR, electronic spectra, ePR studies. The geometry of these complexes was ascertained by molecular modelling study by using Gaussian 09 program. All metal complexes were found to exhibit octahedral geometry around the metal ion. The newly synthesized macrocyclic ligands and metal complexes were subjected for antimicrobial screening to determine the inhibition and control against tested microorganisms, bacteria ( S.lutea , S.aureus, S.albus and E.coli ) and fungi ( A.fulviceps, U . hordei, A. niger and P.catinus ) by using disc diffusion method and agar plate technique, respectively. The experimental results suggest that metal complexes exhibit enhanced inhibition zone than free macrocyclic ligand.

In the present work, metal [Cu(II), Co(II), Ni(II) and Zn(II)] complexes have been synthesized by an azo ligand, 1-(6-chloro-1,3-benzothiazol-2-yl)-4-[(4-chlorophenyl)diazenyl]-5-methyl-1,2-dihydro-3H-pyrazol-3-one [HL] containing benzothiazole moiety. Newly prepared complexes were characterized by investigating various spectroscopic and analytical techniques such as FT-IR, 1H NMR, UV-Vis, ESR, Powder-XRD, TGA, EDAX, SEM, VSM (Vibrating Sample Magnetometer), and mass spectrometry. The azo ligand [HL] and its metal complexes have been evaluated for their biological studies such as antibacterial, antifungal and antituberculosis. From the results, some the compounds show moderated to good activity against tested pathogens.

New metal complexes [M(NNNS)X] (M = NiII, CuII, ZnII and CdII; NNNS− = anion of the quadridentate ligands formed from S-methyl-β-N-(2-aminophenyl)-methylenedithiocarbazate and pyridine-2-aldehyde or 6-methylpyridine-2-aldehyde; X = Cl, NCS, NO3 or I) and [Co(NNNS)Cl2]·2H2O have been prepared and characterized by elemental analysis and conductance measurements. Magnetic and spectroscopic evidence support a five-coordinate structure for [M(NNNS)X] (M = NiII, CuII, ZnII and CdII; X = Cl, NCS) and a squareplanar structure for [Ni(NNNS)]X (X = NO3 or I). The [Co(NNNS)Cl3]·2H2O complex is low-spin and octahedral. The Schiff bases and some of their metal complexes were tested against three pathogenic fungi, Alternaria alternata, Curvularia geniculata and Fusarium palidoroseum. The metal complexes are less fungitoxic than the free ligands.