Structurally diverse copper(II)-carboxylato complexes: neutral and ionic mononuclear structures and a novel binuclear structure

Modulatingp-hydroxycinnamate behavior as a ditopic linker or photoacid in copper(ii) complexes with an auxiliary pyridine ligand

p-Hydroxycinnamate behaves either as a ditopic linker or as a photoacid in copper(ii) complexes with a suitable auxiliary pyridine ligand.

Anion-controlled photochromism of two bipyridinium-based coordination polymers and nondestructive luminescence readout

The first Zn-based coordination polymer constructed with a bipyridinium-functionalized m-benzenedicarboxyl ligand has been synthesized, which can show dual luminescence responses to light in different spectral regions to render nondestructive luminescence readout.

Copper complexes as catalyst precursors in the electrochemical hydrogen evolution reaction

Two copper complexes were investigated with respect to their activity in the electrocatalysed hydrogen evolution reaction. The complexes are precursors for highly active copper(0) and Cu₂O deposits.

Ternary copper(II) complexes with amino acid chains and heterocyclic bases: DNA binding, cytotoxic and cell apoptosis induction properties

Nowadays, chemotherapy is a common means of oncology. However, it is difficult to find excellent chemotherapy drugs. Here we reported three new ternary copper(II) complexes which have potential chemotherapy characteristics with reduced Schiff base ligand and heterocyclic bases (TBHP), [Cu(phen)(TBHP)]H2O (1), [Cu(dpz)(TBHP)]H2O (2) and [Cu(dppz)(TBHP)]H2O (3) (phen=1,10-phenanthroline, dpz=dipyrido [3,2:2',3'-f]quinoxaline, dppz=dipyrido [3,2-a:2',3'-c]phenazine, H2TBHP=2-(3,5-di-tert-butyl-2-hydroxybenzylamino)-2-benzyl-acetic acid). The DNA-binding properties of the complexes were investigated by spectrometric titrations, ethidium bromide displacement experiments and viscosity measurements. The results indicated that the three complexes, especially the complex 13, can strongly bind to calf-thymus DNA (CT-DNA). The intrinsic binding constants Kb of the ternary copper(II) complexes with CT-DNA were 1.37×10(5), 1.81×10(5) and 3.21×10(5) for 1, 2 and 3 respectively. Comparative cytotoxic activities of the copper(II) complexes were also determined by 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results showed that the ternary copper(II) complexes had significant cytotoxic activity against the human lung cancer (A549), human esophageal cancer (Eca109) and human gastric cancer (SGC7901) cell lines. Cell apoptosis were detected by AnnexinV/PI flow cytometry and by Western blotting with the protein expression of p53, Bax and Bcl-2. All the three copper complexes can effectively induce apoptosis of the three human tumor cells.

A homochiral luminescent compound with four-fold symmetry as a potential chemosensor for nitroanilines

Crystal structure of the first homochiral luminescent compound of a dansylated amino acid (tyrosine) of Cu(ii), [Cu₂(HTyr-N-Dan)₄(H₂O)₂]·2H₂O (1) (H₂Tyr-N-Dan = N-dansyltyrosine), and selective sensing of nitroanilines by both the ligand and 1 are reported.

Structural features of mono- and tri-nuclear Zn(II) complexes with a non-steroidal anti-inflammatory drug as ligand

The interaction of Zn(II) with the non-steroidal anti-inflammatory drug tolfenamic acid leads to the formation of the structurally characterized trinuclear [Zn(3)(tolfenamato)(6)(CH(3)OH)(2)] complex. In the presence of the N,N'-donor heterocyclic ligands 1,10-phenanthroline and 2,2'-bipyridine at a range of ratios, the mononuclear Zn complexes of the general formulae [Zn(tolfenamato)(N,N'-donor)Cl] and [Zn(tolfenamato)(2)(N,N'-donor)] have been isolated and structurally characterized by X-ray crystallography. The deprotonated tolfenamato ligands are coordinated to the Zn(II) ion through carboxylato oxygen atoms. Tolfenamic acid and its complexes exhibit good binding propensity to human or bovine serum albumin protein having relatively high binding constant values.

Copper(II) complexes with antimicrobial drug flumequine: structure and biological evaluation

The copper(II) complexes with the first-generation quinolone antibacterial agent flumequine(Hflmq) in the presence or absence of the nitrogen donor heterocyclic ligands 2,2'-bipyridylamine(bipyam), 2,2'-bipyridine(bipy), 1,10-phenanthroline(phen) or pyridine(py) have been synthesized and characterized. Flumequine acts as bidentate ligand coordinated to Cu(II) atom through the pyridone oxygen and a carboxylato oxygen. The crystal structures of the complexes [Cu(flmq)(bipyam)Cl], [Cu(flmq)(bipy)Cl] and [Cu(flmq)(phen)Cl] have been determined by X-ray crystallography revealing a distorted square pyramidal geometry for Cu(II) atom. The interaction of the complexes with bovine or human serum albumin proteins has been studied by fluorescence spectroscopy revealing their good binding propensity to the proteins with relatively high binding constant values. UV study of the interaction of the complexes with calf-thymus DNA (CT DNA) has shown that they bind to CT DNA and [Cu(flmq)(2)(py)(2)] exhibits the highest binding constant to CT DNA. The cyclic voltammograms of the complexes have shown that in the presence of CT DNA the complexes can bind to CT DNA by the intercalative binding mode which has also been verified by DNA solution viscosity measurements. Competitive study with ethidium bromide(EB) has shown that the complexes can displace the DNA-bound EB indicating that they bind to DNA in strong competition with EB.

Non-steroidal antiinflammatory drug-copper(II) complexes: structure and biological perspectives

Copper(II) complexes with the non-steroidal antiinflammatory drug mefenamic acid in the presence of aqua or nitrogen donor heterocyclic ligands (2,2'-bipyridine, 1,10-phenanthroline, 2,2'-bipyridylamine or pyridine) have been synthesized and characterized. The crystal structures of [(2,2'-bipyridine)bis(mefenamato)copper(II)], 2, [(2,2'-bipyridylamine)bis(mefenamato)copper(II)], 4, and [bis(pyridine)bis(methanol)bis(mefenamato)copper(II)], 5, have been determined by X-ray crystallography. UV study of the interaction of the complexes with calf-thymus DNA (CT DNA) has shown that the complexes can bind to CT DNA and [bis(aqua)tetrakis(mefenamato)dicopper(II)] exhibits the highest binding constant to CT DNA. The cyclic voltammograms of the complexes in the presence of CT DNA solution have shown that the complexes can bind to CT DNA by the intercalative binding mode verified also by DNA solution viscosity measurements. Competitive studies with ethidium bromide (EB) indicate that the complexes can displace the DNA-bound EB suggesting strong competition with EB. Mefenamic acid and its complexes exhibit good binding propensity to human or bovine serum albumin protein having relatively high binding constant values. All the compounds have been tested for their antioxidant and free radical scavenging activity as well as for their in vitro inhibitory activity against soybean lipoxygenase showing significant activity.