Molar Conductance Measurements Research Articles

Synthesis, characterization, crystal structure and anticancer study of symmetrical binuclear bis-N-heterocyclic carbene silver(I) complexes

The synthesis of binuclear silver(I)-NHC complexes from bis-benzimidazolium salts and silver(I) ions has been carried out via an in-situ deprotonation (NHC = N-heterocyclic carbene). The reaction between 1,3-dibromopropane and two moles of N-substituted alkyl benzimidazole (R = methyl, hexyl, heptyl, octyl, and 4-methyl-benzyl) resulted in the formation of bis-benzimidazolium salts, H2L‧2Br- (1–5). Subsequent reactions of the respective salts with excess Ag2O yielded the formation of bis-NHC binuclear silver(I) complexes with the formula of [Ag2L2]·2PF6 (Ag1-Ag5). All compounds were characterized by 1H and 13C NMR, FTIR, elemental analysis, molar conductivity measurement, melting point analysis, and solubility tests. Single crystal X-ray crystallography data reveals that Ag2 exists as a dinuclear complex with no significant intramolecular argentophilic interactions. Anticancer studies of salts 1-5 and complexes Ag1-Ag5 were carried out by employing breast cancer cell lines (MCF-7). None of the salts showed antiproliferative activity, while all the complexes possessed significant anticancer properties in a dose-dependent manner. The complexes indicate better activity than a positive control except for Ag4.

Synthesis, spectroscopic, biological and structural characterizations for the gold(III), platinum(IV), and Ruthenium(III) ceftriaxone drug complexes

Three new metal complexes of ceftriaxone (cef), incorporating platinum(IV), gold(III), and ruthenium(III), were prepared. The complexes were prepared using a 1:2 molar ratio between ceftriaxone sodium salt (Na2cef) to AuCl3, PtCl4, and RuCl3 salts in methanol solvent. The as-synthesized complexes were characterized using microanalytical techniques for C, H, N, and S elements, magnetic and molar conductance measurements, as well as spectroscopic methods including FTIR, 1H NMR, and UV-Vis. The shape, morphology and size calculations have been examined using SEM, TEM, and X-ray diffraction data. The cef complexes were six-coordinate systems possessing a distorted octahedral geometry. Through the oxygen of both triazine and carboxylate moieties with the chemical formulae [Au(cef)2(Cl)(H2O)] (I), [Pt(cef)2(Cl)2] (II), and [Ru(cef)2(Cl)(H2O)] (III) the antibiotic cef acts as a bidentate ligand towards three metal ions. The newly created complexes demonstrated antibacterial activity showing efficacy in comparison to the cef sodium ligands. In vitro, antibacterial assays against specific microorganisms were evaluated to assess the antibacterial activities of the complexes. Cytotoxicity assays for cef complexes were conducted for HepG-2 and MCF-7 cell lines, representing human hepatocellular carcinoma and breast cancer, respectively. A value of 22.4 g and 26.2 g for 50% inhibitory concentration (IC50), respectively, for HepG-2 and MCF-7 were obtained for [Ru(cef)2(Cl)(H2O)] (III). KEY WORDS: Ceftriaxone sodium, Gold, Ruthenium, Platinum, Complexes, FTIR, IC50 Bull. Chem. Soc. Ethiop. 2024, 38(4), 937-948. DOI: https://dx.doi.org/10.4314/bcse.v38i4.10

Synthesis, Characterization and in vitro Antimicrobial Activity of Organotellurium Decorated 10-Membered Tetraazamacrocyclic Complexes of Cobalt(II)

Three novel organotellurium decorated 10-membered tetraazamacrocyclic complexes of Co(II) were synthesized using template condensation of 1,1-diiodo-1-telluracyclopentane, 1,1-diodo-2-methyl-1-telluracyclopentane and 1,1-diiodo-1,1-diethyltellurium(IV) with 1,2-diaminopropane and cobalt dichloride hexahydrate in dry methanol in 2:2:1 molar ratio. The characterization of the synthesized cobalt(II) complexes was carried out using elemental analysis, spectroscopic studies (IR, proton NMR & proton decoupled carbon NMR) and molar conductance measurements. The results of these studies suggested that the complexes may be formulated as [CoLCl2] where L = {C4H8Te-(NHCH2CH(CH3)NH)}2, {C4H7(CH3)Te(NHCH2CH(CH3)NH)}2 and {(C2H5)2Te(NHCH2CH(CH3)NH)}2. The synthesized complexes were also screened for antimicrobial activity using broth microdilution and agar disc diffusion methods.

Enoxacin fluoroquinolone antibacterial agent complexes with Pt(IV), Ru(III) and Ir(III) ions: Synthesis, spectroscopic, physicochemical characterizations and biological studies

The synthesis, physicochemical characterizations, and biological investigations on the chelation of the antibiotic medication enoxacin (EXN) with certain vital metal ions, such as platinum(IV), ruthenium(III), and iridium(III) are discussed in this study. These compounds structures were interpreted based on elemental analysis and spectral measurements (FTIR, 1H-NMR, UV-Vis electronic, and XRD). The findings show that there is same coordination pathway for the chelation behavior of enoxacin complexes: a monodentate manner. The Pt(IV), Ru(III), and Ir(III) complexes are coordinated through the N atom of the piperazine ring, which is an unusual mode of coordination for this class of compounds. The dissolved complexes in DMSO were found to have non-electrolyte nature based on their molar conductance measurements. The formula for these complexes is [Pt(EXN)3(H2O)2Cl] (1), [Ru(EXN)3(H2O)3] (2), and [Ir(EXN)3(H2O)3] (3). Using scanning electron microscope (SEM) analysis and X-ray powder diffraction (XRD), the nano-scale range of the Pt(IV), Ru(III), and Ir(III) complexes has been determined. Results of in vitro cytotoxicity were examined using MCF-7 cells (human breast cancer cell line) and HepG-2 cells (human hepatocellular carcinoma) that had been grown. The cytotoxic activity of the metal complexes demonstrated a cytotoxic effect against the growth of human breast and liver cancer cell lines.
 KEY WORDS: Enoxacin, Platinum(IV), Complexity, Spectral analyses, Biological assessments
 Bull. Chem. Soc. Ethiop. 2024, 38(3), 685-699. 
 DOI: https://dx.doi.org/10.4314/bcse.v38i3.11

Oxovanadium (IV) Complexes of α-Amino Acid Schiff Bases and Polypyridyl Ligands: Synthesis, Characterization and Antimicrobial Activity

Oxovanadium(IV) complexes of the type [VO(L)(bpy)] (V-1 to V-5) have been synthesized and characterized by FTIR and UV-Vis spectra, molar conductance, melting points, and magnetic susceptibilities measurements, where L= N-salicylidene-β-alanine (sal-ala), N-salicylidene-glycine (sal-gly), N-salicylidene-DL-β-phenylalanine (sal-pheala), N-salicylidene-leucine (sal-leu), and N-salicylidene-DL-methionine (sal-met), and bpy is 2,2´-bipyridine. The infrared spectral data reveals that the tridentate nature of the amino acid-based Schiff base ligand and the coordination of the ligand through azomethine nitrogen, phenolic oxygen and carboxylate oxygen with vanadyl (VO2+) ion. All of these complexes were determined to be non-electrolyte in nature, according to conductivity measurements. The magnetic moment measurements have been attributed that these complexes are paramagnetic and have d1 configuration of vanadium (IV) ion. In Virto antimicrobial activity of the synthesized complexes was evaluated against two gram-positive (Bacillus subtilis and Staphylococcus aureus) and two gram-negative (Escherichia coli, Proteus vulgaris) bacterial strains.

Synthesis, characterization and anticancer activity of Ni(II), Cu(II), Pd(II) and Au(III) complexes derived from novel Mannich base

AbstractNew four complexes of Ni(II), Cu(II), Pd(II), and Au(III) were derived from the tridentate ligand 3‐((3‐(4‐hydroxyphenyl)‐5‐mercapto‐4H‐1,2,4‐triazol‐4‐yl)(3‐oxobutyl)amino)naphtho[2,3‐b]furan‐2(3H)‐one (L), which synthesized using condensation reaction of formaldehyde, acetone, and secondary amine (Mannich reaction). The secondary amine is a heterocyclic compound possesses two rings, naphthafuran and triazole, both rings prepared through intermolecular cyclization reactions. Considering that naphthafuran‐2‐one derived from α‐amino nitrile. The α‐amino nitrile compound contains the other triazole ring which illustrated to the structure through successive steps. The compounds were characterized using elemental analysis (C.H.N.S), FT‐IR, ultraviolet–visble spectroscopy, thermal gravimetric analysis (TGA), flame atomic absorption, molar conductivity, and magnetic susceptibility measurements. Accordingly, the probable geometries of the complexes were suggested as square planner, and they have electrolytic nature. Thus, chemical formula; [NiLCl]Cl·6H2O, [CuLCl]Cl·2H2O, [PdLCl]Cl·2H2O, and [AuLCl]Cl2·3H2O. Cytotoxic effect was studied on brain cancer cell line (AMJM cell line) at different concentrations for L and complexes. The results showed that gold(III) complex has the highest cytotoxicity among all compounds.

Designing, DFT, biological, & molecular docking analysis of new Iron(III) & copper(II) complexes incorporating 1-{[-(2-Hydroxyphenyl)methylene]amino}−5,5-diphenylimidazolidine-2,4-dione (PHNS)

The exploration encompassed the synthesis and characterization of two innovative complexes, namely FePHNS and CuPHNS, employing a diverse array of analytical techniques such as elemental analysis, infrared and ultraviolet-visible spectroscopy, mass spectrometry, molar conductivity measurements, magnetic susceptibility assessments, and thermal analysis (TGA). In the spectral domain, infrared spectroscopy substantiated the tridentate ONS coordination of the PHNS ligand to the central metal atom. Thermal analysis offered valuable insights into the distribution and content of water molecules within the complexes. Density functional theory (DFT) calculations were harnessed to validate the molecular structures of both the PHNS ligand and its complex entities, providing an intricate comprehension of their quantum chemical parameters. The investigation extended to an evaluation of the in vitro antibacterial, antifungal, and antioxidant efficacy of the PHNS ligand and its complexes, revealing heightened biological activities for the complexes in comparison to the free PHNS ligand, notably with the CuPHNS complex demonstrating the highest activity, while the PHNS ligand exhibited the lowest. To delve into potential physiological activities, molecular docking studies were conducted, predicting the binding affinity of the compounds to proteins 2vf5 (Glucosamine-6-phosphate synthase in complex with glucosamine-6-phosphate) from Escherichia coli, 3cku (rate oxidase from Aspergillus flavus complexed with its inhibitor 8-azaxanthin and chloride) from Aspergillus flavus, and 5IJT (Crystal structure of Human Peroxiredoxin 2 Oxidized). The ensuing analysis of protein-ligand interactions and binding energies underscored the promising physiological activities of the investigated compounds, warranting further exploration for their potential in novel drug development.

Synthesis, spectral, DFT, and antibacterial studies of Nickel(II) and Cobalt(II) complexes with aminoantipyrine based Schiff base ligands

Schiff base complexes are a class of molecules that have sparked a great deal of attention due to their interesting chemical and physical properties, as well as their diverse applicability in a variety of scientific fields. Schiff bases and aminoantipyrine derivatives are continuously being investigated, despite their widespread use as medicines and bioactive compounds. In this study, we present the synthesis of new Ni(II) and Co(II) Schiff base complexes [M(L1-5)2Cl2] using the following ligands: 1,5-dimethyl-2-phenyl-4-((3,4,5-trimethoxy-benzylidene)amino)-1H-pyrazol-3(2H)-one (L1), 4-((4-methoxybenzylidene)amino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one (L2), 4-((3,4-dimethoxy-benzyli-dene)amino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one (L3), 4-((1-([1,1′-biphenyl]-4-yl)ethyli-dene)amino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one (L4), 4-((4-hydroxy-3-methoxy-benzylidene)amino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one (L5), derived from aminoantipyrine. Various approaches, including UV, IR, NMR (1H, 13C), DFT analyses, and molar conductance measurement, have been employed to characterise freshly synthesised compounds. The antimicrobial screening results indicate that the anti-bacterial activities of the metal complexes are more active than the free ligands. All the synthesized compounds were found to be active against both Gram positive and Gram negative bacteria. Compound [Ni(L4)2Cl2] was found to show best activity. According to the reactivity parameter factors, compound Co(L2)2Cl2 has a higher value of hardness (η = 1.677 eV) and a lower value of softness (σ = 0.596 eV), It suggests that compound [Co(L2)2Cl2] is less reactive and more stable.

Synthesis, Characterization, in silico DFT, Molecular docking, ADMET Profiling Studies and Toxicity Predictions of Ag(I) Complex Derived from 4‐Aminoacetophenone

AbstractThe reaction of the synthesized (E)‐1‐(4‐((2,4‐dihydroxy‐6‐methylphenyl)diazenyl)phenyl)ethan‐1‐one, (DMPDE) ligand with Ag(I) ion at room temperature resulted in the formation of the complex; [Ag(DMPDE)(H2O)2]. 1H NMR, 13C NMR, FTIR, UV‐Vis, mass spectra, elemental analyses, thermal analysis (TGA/DTA), and molar conductance measurements were done to elucidate the structure of synthetic compounds. The results revealed an interesting geometrical variation; tetrahedral for Ag(I) complex. FT‐IR spectra demonstrated that the ligand (DMPDE) under investigation behaves as a bidentate ligand (N,O) through the nitrogen atom of the azo group which is the farthest of the acetophenone moiety and oxygen phenolic for benzene moiety and forms a stable five‐membered chelating ring. The electronic structure, molecular electrostatic potential (MEP) and quantum chemical calculations of the newly synthesized compounds are investigated theoretically at the DFT/B3LYP level of theory. Additionally, the ligand (DMPDE) and Ag(I) complex were screened against the growth of pathogenic bacteria [Actinomycosis (G+), E. Escherichia Coli (G−)] and fungi (Penicillium spp.) compared with the reference antibiotics, Chloramphenicol and Nystatin. Furthermore, 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) was used to evaluate the antioxidant activities of the ligand and its complex, which showed they both possess significant antioxidant properties in comparison with L‐ascorbic acid (Vit. C) as standard. Based on docking studies, (DMPDE) and Ag(I) complex demonstrated a greater affinity for (PDB ID: 3T88), which corresponds to Escherichia coli protein (−6.7818 kcal/mol) and (−6.7928 kcal/mol), respectively. Interestingly, the most active Ag(I) complex inside the active site of cervical cancer receptor (PDB ID: 4XR8) demonstrated a higher binding energy (−6.2631 kcal/mol) than free ligand (−5.8561 kcal/mol). In silico, ADMET displayed that compounds obey the Lipinski rule and the “Veber's rule. Consequently, is likely to exhibit oral bioavailability with good LD50 and a safety profile that includes non‐cytotoxicity, non‐immunotoxicity, and non‐skin sensitization. Finally, the compounds synthesized showed significant anticancer activity in human cervical cancer cell lines HeLa and SiHa compared with positive controls (cisplatin) and normal human hepatic cells (WRL‐68). In the present study, all tested cancer cell lines showed promising activity against Ag(I) complex, whose IC50 value ranged from (61.02 to 71.09) μg/mL.

Synthesis, Biological and Medicinal Evaluation of New Boric Acid Ester Derived From Antibiotic Drug with Some of Its Metal Complexes

Synthesis of new ligand, namely [bis(2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethyl) hydrogen borate] (BIB), utilizing the reaction of metronidazole with boric acid in mole ratio (2:1), as well as the metal complexes with [Ni(II) and Cu(II)], were synthesized. All synthesized compounds were characterized by utilizing spectroscopic techniques such as FTIR, 1H-NMR, thermal analysis (T.G., UV-Vis), and atomic absorption (A.A.S.), as well as micro elemental analysis (C.H.N.), melting point (m.p), magnetic susceptibility, molar conductivity, and chloride content measurements. All complexes were paramagnetic, and the electrolyte and the suggested geometries were tetrahedral for nickel and octahedral for copper. In addition, all the transition metal complexes produced were shown to be antibacterial and antifungal against the bacteria Staphylococcus aureus, Escherichia coli, and the fungus Candida. Also, metronidazole and the ligand were evaluated as anticancer agents against human breast cancer (MCF-7). The results showed that ligand was more active as an anticancer than metronidazole.

Synthesis, Structural, Morphological Characterization, and Cytotoxicity Assays of Metal Complexes Decorated SiO2 Nanoparticles Against Breast Cancer Cell Lines (MDA-MB-231)

This study examines the new synthesis of Pt (IV) and Au (III) Mannich base complexes derived from ciprofloxacin. The complexes were then used as precursors to prepare SiO2/PtO2 and SiO2/Au2O3 nanoparticles by depositing the synthesized complexes on porous silica nanoparticles. Elemental analysis, FT-IR, UV-vis, molar conductivity measurements, and melting point were used to characterize this ligand and its metal complexes. Elemental analysis data show that the general formula of the metal complexes formed is [M(L)2Cl2] nCl.H2O, where L = Mannich base ligand and M = Au(III) and Pt(IV), and n = 1,2 respectively with octahedral structure. The chemical structure and morphology of the metal oxide nanoparticles are investigated using FT-IR, XRD, AFM, TEM, and SEM. In the next step, the ligand and its complexes, SiO2/PtO2 and SiO2/Au2O3 nanoparticles were examined to investigate their toxicity (in vitro) as an anticancer agent to MDA-MB-231 cell lines by using different concentrations (50, 100, 200, and 400 µg /mL). Based on the results obtained from the cytotoxic activity, it can be concluded that the synthesized compounds are promising as new cancer candidates in the future, especially in high concentrations

Synthesis, characterization, antimicrobial, molecular docking simulation, and antitumor assays of nanometric complexes based on new thiazole Schiff base derivative

For further pharmaceutical applications, a novel Schiff base derivative of aminothiazole and its Co (II), Cu (II), Zn (II), and Th (IV) chelates were designed and prepared. For this purpose, 2‐aminothiazole and 2,4‐dihydroxybenzaldehyde have been coupled before the complexation reaction with the metal salts. Elemental analysis, FT‐IR, 1HNMR, UV–Vis spectra, transmission electron microscopy (TEM), X‐ray powder diffraction (XRD), molar conductance, and magnetic moment measurements were used to determine the structural formula of the ligand and its produced chelates. The acquired data pointed out that the ligand was chelated with metal through the nitrogen of azo group and deprotonated ortho phenolic oxygen atoms. In Cu (II) complex the copper ion chelated with two ligand molecules, whereas in other complexes the metal binds with one molecule only of ligand. It was shown by XRD patterns and high‐resolution TEM images that the complex particles had a uniform distribution across the chelates' surfaces and were nanometric in size. Extremely, antimicrobial and anticancer activity for the prepared ligand and complexes were investigated, which showed high activity, especially after complex formation. Docking studies have been performed to predict the compounds' efficacy as antitumor agents through their interaction with the co‐crystal structure of proteins for breast cancer cells (PDB ID: 3S7S) and protein of liver cancer 2 (PDB ID: 2JW2). The experimental results of the anticancer activity showed promising results, especially for Cu (II) compound which exhibited the greatest antitumor efficacy (IC50 = 12.81 μg/ml) contra HepG‐2 carcinoma and Mcf‐7 cells (IC50 = 18.92 ± 0.91 μg/ml). Antimicrobial activity against the strains Klebsiella pneumoniae (K. pneumoniae), Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), Bacillus subtilis (B. subtilis), C. albicans (C. albicans), and Aspergillus niger (A. niger) also gave very promising results when it is compared with the standard drugs.

Synthesis, Characterization, Fluorescence and Antibacterial Activities Studies of Transition Metals Complexes with a Macro Acyclic Schiff Base Ligand

The reactions of the Schiff base 2,2’-[(2-hydroxypropane-1,3-diyl) bis-(imino-methane diyl)] bis-(4-bromophenol) (H3L), with metal transition ions (Mn(II), Ni(II), Cu(II), Zn(II), and Cd(II),) afforded one type of complex formulated as [M(HL)(H2O)2].nH2O. These compounds have been characterized by elemental analysis, UV–Vis, FTIR, 1H and 13C NMR spectroscopies, molar conductivity and room temperature magnetic measurements. The structure of nickel (II) complex has been determined by X-ray crystallography. The complex crystallizes in the orthorhombic space group Pnma with a = 7.7702(4) Å, b = 23.1921(15) Å, c = 10.6853(5) Å, V = 1925.57(15) Å3, Z = 8, R1 = 0.043 and wR2 = 0.107, Dcalc = 1.893 Mg m−3. The ligand acts in tetradentate fashion in its di-deprotonated form. Two coordinated water molecules complete the coordination sphere. The environment around the Ni(II) center is best described as an octahedral geometry. In the crystal structure of the Schiff base ligand, the existence of a strong intramolecular O-H•••O hydrogen bonding [O2W-H2W 0.80(3) Å, H2W •••O1 1.915(3) Å, O2W••• O1 2.6258(19) Å, O2W-H2W•••O1 148(3)°] and [O1W-H1W 0.73(3), H1W•••O1 2.15(4) Å, O1W•••O1 2.836(2)Å, O1W-H1W•••O1 156(4)°] are observed. Antibacterial activity study shows that the cadmium (II) complex is more active than the free ligand on.

DESIGN, SYNTHESIS, SPECTRAL ANALYSIS, ANTIMICROBIAL EVALUATION AND TOXICOLOGICAL ASPECTS OF BIVALENT TIN COMPLEXES WITH MACROCYCLIC MOIETY

The novel complexes Sn(II), were synthesized of macrocyclic ligands derived from various diamine and dicarboxylic acids in the ratio of 2:2 and characterized by elemental analysis, molar conductance measurements, mass, NMR, FT-IR, and electronic spectra. The interactions of macrocyclic ligands (MLn) with SnCl2 in a 1:1 molar ratio in methanol produced the ensuing physiologically active [Sn(MLn)Cl2] type complexes, where n = 1 or 2. The complexes were initially identified using conductivity tests, molecular weight calculations, and elemental investigations. The bonding mode was determined using spectral data from the IR, 1H NMR, and 119Sn NMR. The complexes exhibit hexacoordinated octahedral geometry. The positive findings of Brine shrimp lethality of the ligands and their complexes have been discussed. The antimicrobial effects of each complex on several types of harmful fungus and bacteria have been assessed. The research focused on investigating and analyzing various aspects related to male fertility. It specifically investigated cauda epididymal spermatozoa density, sperm motility, testicular sperm density, fertility, and biological constraints of propagative tissues. The findings and discussions about these factors were presented in the study.

Influence of proline and hydroxyproline as antimicrobial and anticancer peptide components on the silver(I) ion activity: structural and biological evaluation with a new theoretical and experimental SAR approach.

Silver(I) complexes with proline and hydroxyproline were synthesized and structurally characterized and crystal structure analysis shows that the formulas of the compounds are {[Ag2(Pro)2(NO3)]NO3}n (AgPro) (Pro = L-proline) and {[Ag2(Hyp)2(NO3)]NO3}n (AgHyp) (Hyp = trans-4-hydroxy-L-proline). Both complexes crystallize in the monoclinic lattice with space group P21 with a carboxylate bidentate-bridging coordination mode of the organic ligands Pro and Hyp (with NH2+ and COO- groups in zwitterionic form). Both complexes have a distorted seesaw (C2v) geometry around one silver(I) ion with τ4 values of 58% (AgPro) and 51% (AgHyp). Moreover, the results of spectral and thermal analyses correlate with the structural ones. 1H and 13C NMR spectra confirm the complexes species' presence in the DMSO biological testing medium and their stability in the time range of the bioassays. In addition, molar conductivity measurements indicate complexes' behaviour like 1 : 1 electrolytes. Both complexes showed higher or the same antibacterial activity against Bacillus cereus, Pseudomonas aeruginosa and Staphylococcus aureus as AgNO3 (MIC = 0.063 mM) and higher than silver(I) sulfadiazine (AgSD) (MIC > 0.5 mM) against Pseudomonas aeruginosa. In addition, complex AgPro exerted a strong cytotoxic effect against the tested MDA-MB-231 and Jurkat cancer cell lines (IC50 values equal to 3.7 and 3.0 μM, respectively) compared with AgNO3 (IC50 = 6.1 (5.7) μM) and even significantly higher selectivity than cisplatin (cisPt) against MDA-MB-231 cancer cell lines (SI = 3.05 (AgPro); 1.16 (cisPt), SI - selectivity index). The binding constants and the number of binding sites (n) of AgPro and AgHyp complexes with bovine serum albumin (BSA) were determined at four different temperatures, and the zeta potential of BSA in the presence of silver(I) complexes was also measured. The in ovo method shows the safety of the topical and intravenous application of AgPro and AgHyp. Moreover, the complexes' bioavailability was verified by lipophilicity evaluation from the experimental and theoretical points of view.

Palladium(ii), platinum(ii), and silver(i) complexes with 3-acetylcoumarin benzoylhydrazone Schiff base: Synthesis, characterization, biomolecular interactions, cytotoxic activity, and computational studies.

New Pd(ii) (C1), Pt(ii) (C2), and Ag(i) (C3) complexes derived from 3-acetylcoumarin benzoylhydrazone (HL) Schiff base were synthesized and characterized by FTIR, 1H NMR, UV-visible spectroscopies along with elemental analysis (C, H, N), magnetic, molar conductivity measurements, and DFT calculations. The obtained results suggested that the ligand had different behaviors in the complexes: mono-negative tridentate (C1) and neutral tridentate (C2) as an ONO-donor and neutral bidentate (C3) as an ON-donor. Quantum chemistry calculations were performed to validate the stability of the suggested geometries and indicated that all the complexes possess tetra-coordinated metal ions. The binding affinity of all the compounds toward calf thymus (ctDNA), yeast (tRNA), and bovine serum albumin (BSA) was evaluated by absorption/emission spectral titration studies, which revealed the intercalative binding to ctDNA and tRNA and static binding upon complex formation with BSA. Molecular insights into the binding affinity of the characterized complexes were provided through conducting molecular docking analysis. Moreover, the cytotoxic activity (in vitro) of the compounds was screened against human cancerous cell lines and a non-cancerous lung fibroblast (WI38) one using cis-platin as a reference drug. The IC50 and selective index (SI) values indicated the higher cytotoxic activity of all the metal complexes compared to their parent ligand. Among all the compounds, the complex C2 showed the highest activity. These results confirmed the improvement of the anticancer activity of the ligand by incorporating the metal ions. In addition, flow cytometry results showed that complexes C1 and C2 induced cell cycle arrest at S and G1/S, respectively.

Synthesis and Structural Views on New Azo Ligand and Its Metal Complexes with Some of their Application

In this work, we presented a study of the structural formula for a new series of complexes with Ag(I), Cu(II), Zn(II), and Cd(II) derived from the guanine azo dye ligand 2-amino-8-((3-hydroxyphenyl)diazinyl)-1,7-dihydro-6H-purin-6-one (HAG), which is investigated using various physicochemical analyses, spectroscopic techniques (FT-IR, U.V-VIS, and 1H NMR), thermogravimetric analysis (TGA). In addition, elemental analyses, magnetic susceptibility, and molar conductance measurements were all stabilized. As well as the mole ratio, stability constant, and Gibbs free energy were studied for all complexes, where they showed high stability and spontaneous synthesis. The Cu(II) complex was suggested to have octahedral stereochemistry, while the Ag(I), Zn(II), and Cd(II) complexes were suggested to have tetrahedral stereochemistry. The ligand has been demonstrated to be a useful acid-base indicator, and it has been shown that the ligand (HAG) and its complexes exhibit high photostability and have various colors that can be used to dye wool materials.

Synthesis and characterization of Co (II), Ni (II) and Cu (II) complexes with unsymmetrical tetradentate Schiff base ligand

A novel series of cobalt (II), nickel (II) and copper (II) complexes of unsymmetrical Schiff base ligand 1-(2-hydroxynaphthalideneimino)-2-(5 methoxysalicylidene imino)-4 chlorobenzene-1,2-diamine was synthesised by condensation reaction of 1:1:1 molar ratio of 2-hydroxynaphthalene-1-carbaldehyde, 4-chlorobenzene -1,2-diamine and 5-methoxysalicyidehyde in alcoholic medium. The synthesised ligand and its metal complexes were characterised by elemental analysis, molar conductance measurements, magnetic susceptibility measurements, UV-Vis and infrared spectral data. The molar conductance of synthesised metal complexes in DMSO solution indicates their non-electrolytic nature. The analytical data show the general formula for the complexes to be [M(L)2] where L = Schiff base ligand and M = Co (II), Ni (II) and Cu (II). The spectral data and magnetic moment suggested that Schiff base behaves as a tetradentate ligand, coordinating through azomethine nitrogen and phenolic oxygen atoms to the metal ion. Magnetic susceptibility measurements, UV-Vis and infrared spectral data geometry of metal complexes were proposed to be square planar.

Azo-imine based Nickel(II), Copper(II), and Zinc(II) complexes: Synthesis, physicochemical and spectral investigations, quantum chemical calculations, molecular docking studies, and antibacterial investigations

Three new complexes of Nickel(II), Copper(II), and Zinc(II) derived from Azo-imine ligand, namely, 2-((E)-(2-(1H-indol-3-yl) ethylimino) methyl)-4-((E)-(2-nitrophenyl) diazenyl) phenol (L), were prepared with the stoichiometric ratio of 1: 2 as metal: ligand. These structures were examined by CHN, FT-IR, 1HNMR, and UV–Vis spectroscopy, powder XRD, thermal analysis, and molar conductivity measurement. Based on the experimental findings, complexation with ligands occurs through the N imino and O phenolic atoms. In infrared spectra of complexes, two weak and new bands were formed at 583–598 cm−1 and 449–520 cm−1, which correspond to ν (M-O) and ν (M-N), respectively. The amorphous nature of [Zn(L)2] and the nanocrystalline nature of [Ni(L)2], and [Cu(L)2] were revealed. Also, the quantum chemical calculations were accomplished via DFT approach. The nature of the metal–ligand bonds was checked by NBO and EDA analysis, and it was found that the nature of L → M bonding is mainly covalent. Molecular docking simulations predict significant antitumor properties for the three complexes. Eventually, the antibacterial activity was investigated against two Gram-positive and two Gram-negative bacteria.

Synthesis, characterization, crystal structure, hirshfeld surface analysis and chromotropic properties of halo- bridged copper(II) complexes

In this study, two novel chromotropic binuclear copper(II) complexes were introduced. The complexes were denoted as [LCu(μ-Cl)Cl]2, 1 and [LCu(μ-Br)Br]2, 2 with L representing the chelating ligand N,N-dimethyl-N'-(9-methylanthracenyl)ethylenediamine. To investigate the structures of these complexes, various analytical techniques were employed, including FT-IR, EPR, UV–Vis spectroscopy, TG-DTA, molar conductivity measurements, and elemental analysis. The geometrical property of [LCu(μ-Br)Br]2 was determined using X-ray crystallography, while the intermolecular interactions were studied through Hirshfeld surface analysis. The characterization data provided strong evidence supporting the proposed binuclear structure, wherein two copper (II) centers are connected by two halogen bridges. Remarkably, these complexes exhibit solvatochromism and thermochromism properties, displaying a diverse range of colors in solutions with varying polarities and/or temperatures. Experimental findings suggest that the observed chromotropism can be attributed to the substitution of solvent molecules with the coordinated halogens in the complexes.