Development of Novel DNA Cleavage Systems Based on Copper Complexes. Synthesis and Characterisation of Cu(II) Complexes of Hydroxyflavones

Copper(II) complexes of several hydroxyflavones were prepared and characterised through their physico-chemical properties. The nuclease activity of three synthesised complexes is reported. These copper(II) complexes present more nuclease activity than the ligands and the copper(II) ion

Copper(II) complexes with a flexible oxamato ligand

We report on a convenient synthesis of the ligand precursor, diethylethylene-1,2-bis(oxamate), (Et2H2oeo, 1), and show how a partial and preferential hydrolysis of the ester group can give rise to the dianionic ligand, (H2oeo)2−. Reaction of this ligand with Cu(II) affords the neutral dimeric species, [Cu2(H2oeo)2], which has a low aqueous solubility. We describe the crystal structure of the hydrate Cu2(H2oeo)2(H2O)4 (2) and report magnetic studies that show a weak exchange interaction in the solid. Under more basic conditions and in the presence of Cu(II) ions, we are able to avoid amide cleavage and yet deprotonate the amide group, resulting in the formation of the highly soluble [Cu(Hoeo)2]4− complex anion. The structure of (NBu4)4[Cu(Hoeo)2](H2O)4 (3) is described and compared with the recently reported anhydrous phase

Copper(II) complexes with different diamines as inhibitors of bacterial quorum sensing activity

Three copper(II) complexes, trans-[Cu(1,3-pd)(2)Cl-2]center dot H2O (Cu1; 1,3-pd is 1,3-propanediamine), trans-[Cu(2,2-diMe-1,3-pd)(2)Cl-2] (Cu2; 2,2-diMe-1,3-pd is 2,2-dimethyl-1,3-propanediamine) and trans-[Cu(1,3-pnd)(2)Cl-2]center dot H2O (Cu3; 1,3-pnd is (+/-)-1,3-pentanediamine), were synthesized and structurally characterized by elemental microanalyses, IR, electronic absorption and reflectance spectroscopy and molar conductivity measurements. The antimicrobial efficiency of the complexes against four clinically relevant microorganisms and their antiproliferative effect on the normal human lung fibroblast cell line MRC-5 were evaluated. Since in many bacteria, pathogenicity is regulated by an intercellular communication process called quorum sensing (QS), the effect of the copper(II) complexes Cu1-3 on bacterial QS was examined. The obtained results showed that these complexes inhibited violacein production in Chromobacterium violaceum CV026, indicating their anti-QS activity via the homoserine lactone (HSL) pathway. Two biosensor strains were used to determine which pathway, C4-HSL (N-butanoylhomoserine lactone) or 3OC12-HSL (N-(3-oxododecanoyl) homoserine lactone), was affected by the copper(II) complexes. The biological activities of the copper(II) complexes were compared with those for the nickel(II) complexes of the general formula trans-[Ni(L)(2)(H2O)(2)]Cl-2 (L = 1,3-pd, 2,2-diMe-1,3-pd and 1,3-pnd)

Reduction Data Obtained from Cyclic Voltammetry of Benzophenones and Copper-2-Hydroxyphenone Complexes

This article provides detailed redox data on nine differently substituted benzophenones and ten square planar copper(II) complexes containing 2-hydroxyphenones obtained by cyclic voltammetry (CV) experiments. The information provided is related to the published full research articles “An electrochemical and computational chemistry study of substituted benzophenones” (Electrochim. Acta 2021, 373, 137894) and “Electrochemical behaviour of copper(II) complexes containing 2-hydroxyphenones” (Electrochim. Acta 2022, 424, 140629), where the CVs and electrochemical data at mainly one scan rate, namely at 0.100 Vs−1 , are reported. CVs and the related peak current and voltage values, not reported in the related research article, are provided in this article for nine differently substituted benzophenones and ten differently substituted copper-2-hydroxyphenone complexes at various scan rates over more than two orders of magnitude. The redox data presented are the first reported complete set of electrochemical data of nine 2-hydroxyphenones and ten copper(II) complexes containing 2-hydroxyphenone ligands

Investigation of synthesis and some properties of the copper complexes containing imidazole ligand

The copper(II) complexes bearing tetrasubstituted imidazole derivatives containing oxygen donor as ligands (L1-6) were synthesized and characterized by spectroscopic methods, magnetic measurements, elemental and thermogravimetric analyses. The fluorescence efficiency of the ligands (L1-6) and their copper(II) complexes were investigated at r.t. in DMF solution. Theoretical calculations were performed for the copper(II) complex of L4 ligand, in this study. The molecular geometry, bond lengths, bond angles and vibrational wave numbers were calculated by using ab initio calculations based on the Hartree-Fock{HF/6-31G(d)} and the density functional theory {B3LYP/6-31G(d)} in the ground state

DNA CLEAVAGE ACTIVITY OF NOVEL SCHIFF BASE COPPER(II) COMPLEXES WITH SULFUR CONTAINING-LIGANDS: (2-(2-METHYLTHIO)PHENYLIMINO)METHYLPHENOL, N-BENZYLIDINE-2-METHYLTHIOANILINE

Objective: To study the DNA cleavage activity of all copper(II) complexes using supercoiled pUC19 DNA by agarose gel electrophoresis.Methods: In this study, six new schiff base mixed ligand copper(II) complexes containing [Cu(L1)(8Hq)Cl2], [Cu(L2)(8Hq)Cl],[Cu(L2)(phen)Cl2], [Cu(L1)(Bpy)Cl2], and [Cu(L2)(Bpy)Cl] (where, phen=1,10-phenanthroline, Bpy=2, 2'-bipyridyl, 8Hq=8-hydroxy quinoline, ligandL1=(2-(2-methylthio)phenylimino)methylphenol, ligand L2=N-benzylidine-2-methylthioaniline) were synthesized. The six novel schiff base ligandswere characterized by molar conductance, ultraviolet, infrared (IR), and cyclic voltammetry (CV) measurements. Low molar conductance values ofcopper(II) complexes showed non-electrolyte in nature. The IR spectral data indicate that nitrogen, sulfur, and azomethine nitrogen coordinate to thecentral metal ion. The electrochemical properties such as anodic, cathodic peak potential, and electron transfer process of the complexes were studiedusing CV measurements. Based on these spectral data, octahedral geometry was proposed to all copper(II) complexes.Results: The result confirmed that binding constant value of 13.95 × 1023 M for complex (VI) suggested good intercalative binding with calf thymus(CT) DNA. When DNA (pUC19) cleavage analyses was performed, copper(II) complexes - I, II, V, VI showed cleavage activity.−1Conclusion: The complexes - III and IV did not exhibit DNA binding as well as DNA cleavage potential which may be due to the presence ofO-phenanthroline.Keywords: (2-(2-methylthio)phenylimino)methylphenol, N-benzylidine-2-methylthioaniline, Copper(II) complexes, Calf thymus DNA, pUC19 DNA,DNA binding and cleavage activity.2], [Cu(L1)(phen)Cl

Coordination properties of vic-isonitrosoimines in their copper (II) and palladium (II) complexes

Preparation and structural characterization of palladium (II) complexes of ligands III-V and copper (II) complexes of III are reported. The elemental analyses of the complexes show that the metal: ligand ratio is 1:2. The electrical conductance in acetone shows the non-electrolytic nature of the complexes. The diamagnetic character suggests a gross square-planar geometry for the palladium (II) complexes. Copper (II) complexes are paramagnetic with μeff.~1·90 B.M. Spectral data suggest that in all the complexes the ligand coordinates to the metal (II) symmetrically through isonitroso-nitrogen and imine-nitrogen, forming a five membered chelate ring. Amine-exchange reactions of the complexes are discussed and compared on the basis of their structures

Ruthenium and Copper Complexes for Anti-Cancer and Catalytic Applications

Abstract This thesis details the synthesis, characterisation and evaluation of novel β-bis-ketoiminate ruthenium(II) and β-bis-ketoiminate copper(II) complexes for their biological and chemical applications. The anti-cancer, anti-bacterial and anti-fungal and catalytic activity of these complexes was investigated, with lead complexes undergoing further mechanistic investigations. Chapter 1 contains the background introduction to the project, through literature research of similar work as well as the aims of this project. Chapter 2 presents the synthesis and characterisation of novel β-bis-ketoiminate ruthenium(II) dicarbonyl complexes. 1H NMR, 13C {1H} NMR and detailed X-ray crystallographic data are given for this series of complexes. Chapter 3 introduces novel β-bis-ketoiminate copper(II) complexes, their synthesis and characterisation, with X-ray crystallographic data discussed. Chapter 4 introduces the MTT technique for assessing cytotoxicity, and discusses the anti-cancer activities of the series of complexes synthesised in Chapters 2 and 3. In addition, the chapter gives a brief literature review to anti-bacterial and anti-microbial studies, and the results of anti-bacterial and anti-fungal investigations on the β-bis-ketoiminate ruthenium(II) and copper(II) complexes. Chapter 5 presents the results of chemical investigations, hydrolysis and biomembrane, conducted on the two libraries of complexes. Chapter 6 contains a brief literature review on catalysis, and the results for transfer hydrogenation and Ullmann catalytic reactions on β-bis-ketoiminate ruthenium(II) complexes and β-bis-ketoiminate copper(II) complexes respectively. Chapter 7 contains experimental details and characterisation data for all the complexes synthesised within this thesis, and protocols for all the biological and chemical studies. Appendix presents a summary of X-ray crystallographic structure analysis for all the crystal structures reported within this thesis

Simple Model of the Dynamic Jahn‐Teller Effect in Six‐Coordinated Copper(II) Complexes

A model potential is assumed for describing the vibrational degrees of freedom associated with the Jahn‐Teller effect in six‐coordinated copper (II) complexes. The pseudorotational limit is characterized by a potential that is constant in the region between two concentric cylinders, but becomes infinite elsewhere. The energy spectrum is obtained for both angular and radial excitations. A square‐well periodic angular potential is applied as a perturbation, yielding a localization of states. The results are used to describe the temperature dependence of the electron spin resonance spectra of copper (II) complexes with emphasis on the system NaCl:Cu(II) containing the hexachlorocuprate (II) complex.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70781/2/JCPSA6-57-2-702-1.pd