Study Of Mixed Ligand Complexes Research Articles

DNA binding/cleavage study of mixed ligand complexes of di-/triorganotin 4-fluroanthranilates with 1,10-phenanthroline/benzimidazole: Synthesis, characterization, X-ray structures of [Bu2Sn(FA)2.phen], [Me3Sn(FA).bz], and DFT calculations

The mixed ligand complexes of di-/tri-organotin 4-fluoroanthranilates with 1,10-phenanthroline (phen), viz. [R2Sn(FA)2.phen] {R=Bu (1), Oct (2), Me (3)} and benzimidazole (bz), viz. [R3Sn(FA).bz] {R=Me (4), Ph (5)} have been synthesized and satisfactorily characterized by analytical and spectroscopic techniques, especially FT-IR, NMR (1H, 13C, and 119Sn NMR) spectroscopy and ESI-MS spectrometry. Single crystal-Xray diffraction measurements (Sc-XRD) confirmed a distorted pentagonal-bipyramidal geometry for complex (1), where one carboxylate group is monodentate, and the second (–COO) group behaves as a bidentate, while complex (4) affirms trigonal–bipyramidal geometry around the tin centre. The bond angles, especially ∠C–Sn–C obtained by optimizing complexes’ gaseous phase geometry showed significant conformity with the data obtained from Sc-XRD and NMR. The Kb (binding constant) and Ksv (Stern-Volmer quenching constant) values, ranging from 103 to 107, have been obtained through UV–visible absorption and fluorescence titrations with CT-DNA. These results strongly indicate partial minor groove binding/electrostatic interactions between the complex and CT-DNA, which has also been evidenced by circular dichroism studies. The studied complexes cleaved efficiently pBR322 plasmid DNA in NC (nicked circular form), SC (supercoiled form), and linear form

Spectroscopic and biological studies of mixed ligand complexes of transition metal (II) ions with chloroquine and ketoprofen

To create fresh transition metal complexes of chloroquine and ketoprofen, we combined Ni(II), Co(II), Cu(II), and Zn(II). Metal analysis, IR, UV-vis, and X-ray diffraction (XRD) spectrum analyzes of the complexes were utilized to characterize them. The octahedral geometry was proposed for all compounds on the basis of the UV-vis and magnetic susceptibility data. The practical size of the ligands and complexes with crystallinity structure was in the nano range according to the XRD data. The antibacterial and antifungal activities of the ligands and their metal complexes have been examined.

Analyzing the Impact of the Substituent on the Quinazolinone Schiff Base and the Interaction of the Fe (III) and Cr (III) with Different Quinazolinone Schiff Base for Antioxidant and Anti-inflammatory Activity

Schiff base and their Fe (III), Cr (III) complexes stood vetted for Antioxidant, Anti-inflammatory activities and docking study. Mixed ligand complexes had strong antioxidant and anti-inflammatory properties. Docking study of mixed ligand complexes reveals substantial binding affinity for COX2 and STAT3 receptors. The experimental and computational anti-inflammatory and antioxidant activity results are more consistent.

Synthesis, characterization, molecular docking, DNA cleavage properties, and antimicrobial activity studies of mixed ligand complexes

AbstractCu (II), Ni (II), Co (II), and Mn (II) acetato in addition to Cu (II) chloro and nitrato mixed ligand complexes of 4‐([quinolin‐2‐yl]methyleneamino)‐1,2‐dihydro‐2,3‐dimethyl‐1‐phenylpyrazol‐5‐one (L), as a primary ligand and 2,4‐dihydroxy benzaldehyde (H2L), as a secondary ligand have been isolated. The structural features and geometrical arrangements of the synthesized mixed ligand complexes were identified by elemental analysis, Fourier transform infrared spectroscopy (FT‐IR), conductivity measurements, UV‐Vis spectra, magnetic moment measurements, X‐ray diffraction, and electron spin resonance (ESR) spectral and thermogravimetric techniques studies of the mixed ligand complexes confirming the molar ratio 1:1:1 (primary ligand: M: secondary ligand) for Cu (II), Co (II), Mn (II), and UO2(II) chelates. The spectral techniques also confirmed the metal chelates have the formulae (Cu[H2L][L][X]2), where X = Cl−(1); NO3−(2); and (M[L][HL][OAc])YH2O, where M = Cu (II) (3), Co (II) (4); Y = 1, Mn (II) (5); Y = 1 and UO2(II) (6); Y = 2. The kinetic and thermodynamics parameters of the mixed ligand complexes at different decomposition steps were calculated using Coast‐Redfern and Horowiz‐Metzger methods. Also, the antimicrobial activities of ligands and their mixed ligand complexes were screened by Disc Diffusion method. It was found that all mixed ligand complexes (1–6) have high antibacterial activity againstKlebsiella pneumoniaethan penicillin G. By studying the molecular docking between the quinoline‐2‐carbaldehyde, the ligand and the receptors (Escherichia coli(PDB code: 3t88),Staphylococcus aureus(PDB code: 3q8u), lung cancer (PDB code: 1x2j), and colon cancer (PDB code: 2hq6)), it was found that the ligand is efficient compound for all the receptors than the quinoline‐2‐carbaldehyde. The DNA cleavage properties of the two ligands and their complexes have been investigated by gel electrophoresis and the results showed that complex (1) without H2O2and complex (6) with H2O2exhibited a significant partial oxidative cleavage among other complexes.

Studies of mixed ligand complexes of rubidium and caesium metal salts of some organic acids

The present study was aimed at synthesised and characterised complexes of Rb and Cs metal salts of some organic acids, viz. o-nitrophenol, 2, 4–dinitrophenol, 1–nitroso–2–naphthol & 8–hydroxy quino–line with o–aminothiophenol having a coordination sites N and S atoms.

Study of mixed ligand complexes in solution

Study of mixed ligand complexes in solution

Synthesis and spectral study of mixed ligand complexes of Chromium(III) dibasic tridentate schiff schiff bases as primary and naphthoic acid as co-ligand

The transition metal complexes of Schiff bases have been widely researched on account of their importance as biochemical,analytical and antimicrobial reagent. Herein, the transition metal ion complexes of Cr(III) with dibasic tridentae Schiff bases derived by condensation of thiosemicarbazide with acetoacetanilide as primary ligand and 1-hydroxy-2-naphthoic acid as co-ligand have been prepared. The mixed ligand complexes of the above mentioned metal ion were characterized by analytical, magnetic and electronic spectral study. The transition metal complexes were also evaluated for antifungal activity against Drechslera tetramera, Fusarium-oxysporum and Macrophomia phoseoli at different concentrations.

Synthesis spectroscopic (IR, UV- visible and E and P) and magnetic studies of mixed ligand complexes

Synthesis spectroscopic (IR, UV- visible and E and P) and magnetic studies of mixed ligand complexes

Synthesis, characterization and biological screening studies of mixed ligand complexes using flavonoids as precursors

Flavonoids are a group of plant phenolics that provide various health benefits through cell signalling pathways and antioxidant effects. In the present study, a new series of mixed ligand complexes of Co(II), Ni(II), Cu(II) and Zn(II) were synthesized by incorporating curcumin and quercetin flavonoid precursors. The structural features of the synthesized complexes were explored using elemental analysis, thermogravimetric analysis, UV–visible, infrared, NMR, mass and electron paramagnetic resonance spectral analyses and conductivity measurements. These data support an octahedral geometry of the synthesized complexes. In silico biological activity score for the ligand was predicted using PASS online software. ADMET properties were studied using VLS3D online software. Anti‐inflammatory and antioxidant activities were experimentally validated which prove that theoretical predictions are in agreement with the experimental results. Interestingly the synthesized complexes interact with calf thymus DNA through groove binding mode. Moreover, they have good potential to cleave pUC19 DNA. Minimum inhibitory concentration values of the synthesized complexes reveal that they have better antimicrobial efficacy than the ligands.

Synthesis, spectral, thermal and biological studies of mixed ligand complexes with newly prepared Schiff base and 1,10-phenanthroline ligands

A series of mixed ligand complexes were prepared from the Schiff base (L1) as a primary ligand, prepared by condensation of oxamide and furan-2-carbaldehyde, and 1,10-phenanthroline (1,10-phen) as a secondary ligand. The Schiff base ligand and its mixed ligand chelates were characterized based on elemental analysis, IR, 1H NMR, thermal analysis, UV–Visible, mass, molar conductance, magnetic moment. X-ray diffraction, solid reflectance and ESR also have been studied. The mixed ligand complexes were found to have the formulae of [M(L1) (1,10-phen)]Clm.nH2O (M = Cr(III) and Fe(III) (m = 3) (n = 0); M = Mn(II), Cu(II) and Cd(II) (m = 2) (n = 0); and M = Co(II) (m = 2) (n = 1), Ni(II) (m = 2) (n = 2) and Zn(II) (m = 2) (n = 3)) and that the geometrical structure of the complexes were octahedral. The parameters of thermodynamic using Coats–Redfern and Horowitz–Metzger equations were calculated. The synthesized Schiff base ligand, 1,10-phenanthroline ligand and Their mixed ligand complexes were also investigated for their antibacterial and antifungal activity against bacterial species (Gram−Ve bacteria: Pseudomonas aeruginosa and Escherichia coli) and (Gram + Ve bacteria: Bacillus subtilis and Streptococcus pneumonia) and fungi (Aspergillus fumigates and Candida albicans). The anticancer activity of the new compounds had been tested against breast (MFC7) and colon (HCT-116) cell lines. The results showed high activity for the synthesized compounds.

Synthesis, characterization, and biological and anticancer studies of mixed ligand complexes with Schiff base and 2,2′‐bipyridine

New mixed ligand complexes of transition metals were synthesized from a Schiff base (L1) obtained by the condensation reaction of oxamide and furfural as primary ligand and 2,2′‐bipyridine (L2) as secondary ligand. The ligands and their metal complexes were studied using various spectroscopic methods. Also thermal analyses were conducted. The mixed ligand complexes were found to have formulae [M(L1)(L2)]Clm⋅nH2O (M = Cr(III) and Fe(III): m = 3, n = 0; M = Cu(II) and Cd(II): m = 2, n = 1; M = Mn(II), Co(II), Ni(II) and Zn(II): m = 2, n = 0). The resultant data revealed that the metal complexes have octahedral structure. Also, the mixed ligand complexes are electrolytic. The biological and anticancer activities of the new compounds were tested against breast cancer (MCF‐7) and colon cancer (HCT‐116) cell lines. The results showed high activity for the synthesized compounds.

Synthesis, spectroscopic characterization, thermal stability and biological studies of mixed ligand complexes of gemifloxacin drug and 2,2′-bipyridine with some transition metals

The mixed ligand Zn(II), Zr(IV), Pd(II), Ce(IV), Th(IV), and U(VI) complexes of gemifloxacin and N-donor 2,2′-bipyridine have been prepared. These complexes have been characterized by elemental, infrared (IR), ultraviolet–visible (UV–Vis), 1H nuclear magnetic resonance (NMR), mass spectroscopy, thermal, molar conductance and magnetic susceptibility analyses. The infrared spectra indicate that gemifloxacin acts as a bidentate deprotonated ligand bound to the metal through the pyridone oxygen and one carboxylate oxygen, whereas the 2,2′-bipyridine coordinates through the two nitrogen atoms. The central metal in each complex is six-coordinate and a slightly distorted octahedral geometry is proposed. The calculated bond length and force constant, F(U=O), in the uranyl complex are 1.751 A and 641.04 N m−1, respectively. The thermodynamic parameters are calculated from the thermal analysis curves using the Coats–Redfern and Horowitz–Metzger methods. The antibacterial and antifungal activities of the ligand, metal salt and metal complexes have been tested. The data show that the complexes exhibit significant action against some of the four bacterial species but no effect on two species of fungi compared with gemifloxacin. The antitumor activity of the ligands and their complexes has been evaluated against breast (MCF-7) and colon (HCT-116) cancer cells.

Synthesis, Characterization and Antibacterial Activity of Mixed Ligand Complexes of Pd(II) Ions with Oxalic Acid and Heterocyclic Amines

The present work has been designed for the characterization and antibacterial studies of mixed ligand complexes of Pd(II) ions with phthalic acid and heterocyclic amines. The general formula of the complexes is (MLL/) [where, M = Pd(II); L = Oxalic acid, C2O4, L/ = Quinoline, C9H7N(1); iso-Quinoline, C9H7N(2)]. The complexes were prepared in the solid form and characterized by elemental analysis, conductivity & magnetic measurements and infrared & electronic spectroscopic studies. The infrared spectra of the complexes confirmed the coordination of metal ion with ligands. Their antibacterial activity has been evaluated by the disc diffusion method against seven pathogenic bacteria (three gram positive and four gram negative). The complexes were shown to exhibit mild to moderate antibacterial activity against the tested bacteria. DOI: http://dx.doi.org/10.3329/bpj.v17i1.22314 Bangladesh Pharmaceutical Journal 17(1): 46-50, 2014

Synthesis and Thermal Study of Co (II), Ni (II), Cu (II) Mixed Ligand Complexes Using Histidine As Tridentate Ligand

The mixed ligand complexes of Co (II), Ni (II) and Cu (II) with histidine (His.) and 8- hydroxyquinoline (Qui.) have been synthesized and characterized.The resulting complexes were characterized by vibrational and electronic spectral data, thermogravimetric studies , metal analysis and molar conductance measurements. The histidine acts as tridentate ligand, coordinating through the two nitrogen atoms of imidazole ring and the amino group and carboxylate oxygen whereas 8-hydroxyquinoline shows a bidentate nature and the coordination occurs through nitrogen of imine group and oxygen of phenol group. The experimental data suggest that a mononuclear octahedral structure with general formula (M (His.)(Qui.) H2O ) where M= Co (II), Ni (II) and (Cu (His.)(Qui.)H2O) .H2O, thermo gravimetric studies reveal the presence of coordinated water molecules in all complexes. The molar conductance measurements reveal non-electrolytic nature of complexes. Mixed ligand complexes of 8-hydroxyquinoline and o-hydroxybenzylidene-1-phenyl-2, 3-dimethyl-4-amino-3- pyrazolin-5-on with Fe (II), Co (II), Ni (II) and Cu (II) ions were synthesized , the molar conductivity of the complexes in DMF solution have non-electrolyte behavior and 8-hydroxyquinoline coordinate through the nitrogen and oxygen atoms. therefore, the complexes have tetrahedral configuration. (12) Several mixed ligand Ni(II),Cu(II) and Zn(II) complexes of 2- amino-3-hydroxypyridine(AHP) and imidazoles viz.,, imidazole (him), benzimidazole (bim), histamine(hist) and L- histidine(his) have been synthesized and characterized, the geometry becomes tetrahedral when mixed ligand complexes are fomed with him, bim and hist for Cu(II) and Zn(II). All Ni (II) and Cu (II) / Zn (II) histidine mixed ligand complexes have octahedral geometry.The complexes exhibited considerable amount of antibacterial activity and Cu (II) complexes cleave DNA yielding scission of the sugar- phosphate backbone . (13) Mixed ligand Zr(IV) complexes prepared with 8-hydroxyquinoline as a primary ligand and amino acids such as L-alanine/L - serine/glycine as a secondary ligand. Zr(II) was used due to its high coordination number and ability to form stable complexes. These complexes were characterized and screened for their antibacterial, antifungal and cytotoxic properties . (14) Kinetics and mechanism of thermal decomposition of o-vanilline-L-histidine complexes of some transition metal ions in which histidine acts as a tridentate ligand and an octahedral structure for the complexes has been reported . (15) Synthesis, structural, coordination and thermal stability studies of mixed ligand complexes of histidine with other ligands (adenine/guanine/ethylenediamine, diethylenetriamine or N,N,N , N ,, ,N ,,, -pentamethyldiethylenetriamine, glycine or L-alanine, histamine and diethylglyoxime) have been carried out .

Metal-Based Molecular Design Tuning Biochemical Behavior: Synthesis, Characterization, and Biochemical Studies of Mixed Ligand Complexes Derived From 4-Aminoantipyrine Derivatives

ABSTRACT Biosensitive mixed ligand complexes of metals (Fe(III), Co(II), Ni(II), Cu(II), and Zn(II)) with the Schiff bases of L1 and HL2 (L1: obtained through the condensation of 4-aminoantipyrine with furfuraldehyde; HL2: derived from 2-aminophenol and 3-nitrobenzaldehyde) were synthesized. They were characterized using elemental analysis, magnetic susceptibility, molar conductance, proton nuclear magnetic resonance spectroscopy, ultraviolet–visible spectroscopy, infrared, and electron spin resonance techniques. Cyclic voltammogram of the complexes in dimethylsulfoxide solution at 300 K was recorded and their salient features were summarized. The X-band electron spin resonance spectrum of the copper complex in dimethylsulfoxide solution at 300 and 77 K was recorded. The in vitro biological screening effects of the investigated compounds were tested against the bacterial species Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, and Pseudomonas aeruginosa and the fungal species Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola, and Candida albicans by disc diffusion method. Comparative study of inhibition values of the Schiff bases and their complexes indicates that the complexes exhibit higher antimicrobial activity than the free ligands. DNA binding studies of metal complexes using ultra-violet-visible spectroscopy and cyclic voltammetry paved the way to probe their DNA binding abilities. The solvatochromism and superoxide dismutase activity of these complexes have also been examined.

Synthesis, characterization, luminescent properties and biological activity studies of mixed ligand complexes of nickei(II) with sulphur and some nitrogen donors

Synthesis, characterization, luminescent properties and biological activity studies of mixed ligand complexes of nickei(II) with sulphur and some nitrogen donors

Potentiometric studies of mixed ligand complexes of Sc(III), Y(III) and La(III)

In this study, the composition and stability constants of a mixed ligand complex of Sc(III), Y(III) and La(III) ion by using NTA (H3B) (Nitrilotriacetic acid) and HEDTA (H3B) (N-(2-hydroxyethyl)ethylenedinitrilotriacetic acid) as a primary ligand and 2,3-DHBA (H3A) (2,3-dihydroxybenzoic acid) as secondary ligand have been determined by using a potentiometric method and the BEST computer programme at 25◦C, in a 0.1 M NaCl ionic medium. The complex stability was found to follow the trend Sc(III) > Y(III) > La(III) based on the ionic radius of the metal ions.

Complex formation reactions and equilibrium studies of mixed ligand complexes of diaqua (1-Phenyl piperazine)(Palladium)(II) with some biologically relevant ligands.

With the purpose of the search of new antitumor metal complexes, the complex-formation reactions of [Pd(Phenpip)(H2O)2] 2+ (Phenpip = 1-Phenylpiperazine) with some selected bio-relevant ligands, containing different functional groups (amino acids, peptides, DNA constituents and dicarboxylic acids) were investigated. Stoichiometry and stability constants for the complexes formed are reported. The results show the formation of 1 : 1 complexes with amino acids and dicarboxylic acids. The effect of chelate ring size of the dicarboxylic acid complexes on their stability constants was examined. Peptides form both 1 : 1 complexes and the corresponding deprotonated amide species. Structural effects of the peptide on the amide deprotonation were investigated. DNA pyrimidinic constituents, such as uracil, uridine, thymidine and thymine, form 1 : 1 and 1 : 2 complexes, whereas purinic constituents, such as inosine, inosine 5´-monophosphate (5-IMP) form only 1 : 1 complexes. The stability constant of the complexes formed in solution were determined and the binding centers of the ligands were assigned. The concentration distribution diagrams of the complexes were evaluated

Synthesis and thermal studies of mixed ligand complexes of Cu(II), Co(II), Ni(II) and Cd(II) with mercaptotriazoles and dehydroacetic acid

A series of new mixed ligand complexes of cobalt(II), nickel(II), copper(II) and cadmium(II) have been synthesized with 3benzyl1H4[(2 methoxybenzylidine) amino]1, 2, 4triazole5 thione (MBT), 3bezyl1H4[(4chlorobenzylidine) amino]1, 2, 4triazole5thione (CBT), 3benzyl 1H4[(4nitrobenzylidine)amino]1, 2, 4triazole 5thione (NBT) and dehydroacetic acid sodium salt (Nadha). The mixed ligand complexes have been characterized by elemental analysis, spec troscopic spectral measurements (IR, UVVis.), molar conductance, magnetic measurements and thermal studies. The stoichiometry of these com plexes is M:L1:L2 = 1:1:1, 1:2:1 or 1:1:2 where L1 = NBT, CBT and MBT and L2 = Nadha. Tetrahedral structure was proposed for all Cd(II) mixed ligand complexes while the square planar geometry was proposed for Cu(II) mixed ligand complex with NBT. Octahedral structure was proposed for Ni(II), Co(II) mixed ligand complexes and Cu(II) mixed ligand complexes with CBT and MBT ligands. The thermal decomposition study of the prepared complexes was monitored by TG, DTG and DTA analysis in dynamic nitrogen atmosphere. TG, DTG and DTA studies confirmed the chemical formulations of theses complexes. The kinetic parameters were determined from the the thermal decomposition data using the graphical methods of CoatsRedfern and HorwitzMetzger. Thermodynamic parameters were calculated using standard relations.

Synthesis and spectroscopic studies of mixed-ligand complexes of lead(II) hexafluoroacetylacetonate including the crystal structure of [Pb2(phen)4(hfa)2(𝛍-NO3)2

Four new mixed-ligand complexes of lead(II) hexafluoroacetylacetonate (hfa) were synthesized and characterized by elemental analyses, IR, 1H and 13C NMR spectroscopy. The single-crystal structure of [Pb2(phen)4(hfa)2(μ-NO3)2] (1) shows the complex to be a dimeric unit as a result of nitrate bridging. The coordination number of Pb(II) is eight with four N-donors from a “phen” and four O-donors from the hexafluoroacetylacetonate and nitrate ligands. This dimeric complex is the first fluorine β-diketonate and nitrate mixed-ligand lead(II) complex that has been characterized by X-ray structural analysis. The supramolecular features in this complex are controlled by weak directional intermolecular interactions and aromatic π–π stacking interactions.