Synthesis, crystal structure, spectroscopic and biological properties of mixed ligand complexes of zinc(II) valproate with 1,10-phenanthroline and 2-aminomethylpyridine

Nano-[Fe3O4@SiO2/N-propyl-1-(thiophen-2-yl)ethanimine][ZnCl2] as a nano magnetite Schiff base complex and heterogeneous catalyst for the synthesis of pyrimido[4,5-b]quinolones

Nano-[Fe₃O₄@SiO₂/N-propyl-1-(thiophen-2-yl)ethanimine][ZnCl₂] as a nano magnetite Schiff base complex was designed and fully characterized by various analyses such as Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), differential thermal gravimetric analysis (DTA), vibrating sample magnetometry (VSM), scanning electron microscopy (SEM), and transmission electron micrographs (TEM). The presented nano magnetite Schiff base complex was used as a heterogeneous catalyst for the synthesis of pyrimido[4,5-b]quinolones by the reaction of aryl aldehyde, dimedone and 6-amino-1,3-dimethyluracil in EtOH : H₂O (7 : 3) as a solvent at 60 °C.

Nano-[Fe₃O₄@SiO₂/N-propyl-1-(thiophen-2-yl)ethanimine][ZnCl₂] as a nano magnetite Schiff base complex was designed and successfully tested for the synthesis of pyrimido[4,5-b]quinolones.

Combining valproate and bipyridyl ligands to construct a 0D core-shell Zn5(μ3-OH)2 cluster and a 2D layered coordination network with a [Zn3(μ3-OH)]2 SBU

Starting from the proposed zinc carboxylate cluster tetrakis(μ-2-propylpentanoato)dizinc(II), Zn₂(μ₂-valp)₄ (I), of valproic acid, a branched short-chain fatty acid, and bipyridine ligands, two new mixed-ligand coordination compounds, namely, bis(2,2'-bipyridine)di-μ₃-hydroxido-hexakis(μ-2-propylpentanoato)bis(2-propylpentanoato)pentazinc(II), [Zn₅(C₈H₁₅O₂)₈(OH)₂(C₁₀H₈N₂)₂] (II), and poly[[bis(μ-4,4'-bipyridine)di-μ₃-hydroxido-octakis(μ-2-propylpentanoato)bis(2-propylpentanoato)hexazinc(II)] dimethylformamide disolvate], {[Zn₆(C₈H₁₅O₂)₁₀(OH)₂(C₁₀H₈N₂)₂]·2C₃H₇NO}_n (III), were synthesized. Compound II is a core-shell-type zero-dimensional discrete Zn₅(μ₃-OH)₂ metal-organic cluster with Zn ions in double-triangle arrangements that share one Zn ion coincident with an inversion centre. The cluster contains three crystallographically non-equivalent Zn ions exhibiting three different coordination geometries (tetrahedral, square pyramidal and octahedral). The cluster cores are well separated and embedded in a protective shell of the aliphatic branched short chains of valproate. As a result, there is no specific interaction between the discrete clusters. Conversely, compound III, a 2D layered coordination network with a secondary building unit (SBU), is formed by Zn₆(μ₃-OH)₂ clusters exhibiting a chair-like hexagonal arrangement. This SBU is formed from two Zn₃(μ₃-OH) trimers related by inversion symmetry and connected by two syn-anti bridging carboxylate groups. Each SBU is connected by four 4,4'-bipyridine ligands producing a 6³-hcb net topology. 2D coordination layers are sandwiched within layers of dimethylformamide molecules that do not interact strongly with the network due to the hydrophobic protection provided by the valproate ligands.

Synthesis, crystallographic, spectroscopic studies and biological activity of new cobalt(II) complexes with bioactive mixed sulindac and nitrogen-donor ligands

Four novel complexes [Co(H2O)4(sul)2] 1, [Co(2-ampy)2(sul)2] 2, [Co(H2O)2(1,10-phen) (sul)2] 3 and [Co(2,9-dimephen)(sul)2] 4 (sul = sulindac, 2-ampy = 2-amino pyridine, 1,10-phen = 1,10-phenanthroline and 2,9-dimeph = 2,9-dimethyl-1,10-phenanthroline) were prepared and characterized by IR, UV-Visible spectroscopy and magnetic properties. The crystal structures of complexes 1 and 4 were determined by single-crystal X-ray diffraction. In-vitro anti-bacterial activity for the prepared complexes against Gram-positive (Staphylococcus epidermidis, Staphylococcus aureus) and Gram-negative (Bordetella, Escherichia coli) bacteria and Yeast species (Saccharomyces and Candida) were performed using agar well-diffusion method. Only complex 4 showed reasonable activity against yeast. All compounds showed more anti-bacterial activity against Gram-positive bacteria than Gram-negative. Graphical abstract This work reports synthesis, crystallographic, spectroscopic studies and biological activity of new cobalt(II) complexes with bioactive mixed sulindac and nitrogen-donor ligands. The crystal structures of complexes 1 and 4 were determined using single-crystal X-ray diffraction. In-vitro anti-bacterial activity of the prepared complexes and their parent ligands were investigated against different Gram-positive and Gram-negative bacteria using agar diffusion method.

Synthesis, structure and characterization of a layered coordination polymer based on Zn(ii) and 6-(methylmercapto)purine

A layered coordination polymer was synthesized from Zn(ii) and 6-(methylmercapto)purine (mMP-H) in N,N-dimethylformamide (DMF). Its structure and formula [Zn₂(μ₂-mMP)₃(NO₃)(DMF)(H₂O)]_n·nDMF were determined by single crystal X-ray diffraction.

New mixed ligand palladium(II) complexes based on the antiepileptic drug sodium valproate and bioactive nitrogen-donor ligands: synthesis, structural characterization, binding interactions with DNA and BSA, in vitro cytotoxicity studies and DFT calculations

The complexes [Pd(valp)2(imidazole)2] (1), [Pd(valp)2(pyrazine)2] (2) (valp is sodium valproate) have been synthesized and characterized using IR, (1)H NMR, (13)C{(1)H} NMR and UV-Vis spectrometry. The interaction of complexes with CT-DNA has been investigated using spectroscopic tools and viscosity measurement. In each case, the association constant (Kb) was deduced from the absorption spectral study and the number of binding sites (n) and the binding constant (K) were calculated from relevant fluorescence quenching data. As a result, a non-covalent interaction between the metal complex and DNA was suggested, which could be assigned to an intercalative binding. In addition, the interaction of 1 and 2 was ventured with bovine serum albumin (BSA) with the help of absorption and fluorescence spectroscopy measurements. Through these techniques, the apparent association constant (Kapp) and the binding constant (K) could be calculated for each complex. Evaluation of cytotoxic activity of the complexes against four different cancer cell lines proved that the complexes exhibited cytotoxic specificity and significant cancer cell inhibitory rate. Moreover, density functional theory (DFT) calculations were employed to provide more evidence about the observed data. The majority of trans isomers were supported not only by energies, but also by the similarity of its calculated IR frequencies, UV adsorptions and NMR chemical shifts to the experimental values.

Synthesis, spectroscopic characterization, biological screenings, DNA binding study and POM analyses of transition metal carboxylates

This article contains the synthesis of a novel carboxylic acid derivative, its transition metal complexes and evaluation of biological applications. Six carboxylate complexes of transition metals, Zn(II) and Hg(II), have been successfully synthesized and characterized by FT-IR and NMR (1H, 13C). The ligand, HL, (4-[(2,6-Diethylphenyl)amino]-4-oxobutanoic acid) was also characterized by single crystal X-ray analysis. The complexation occurs via oxygen atoms of the carboxylate moiety. FT-IR date show the bidentate nature of the carboxylate moiety of the ligand as the Δν value in all complexes is less than that of the free ligand. The ligand and its complexes were screened for antifungal and antileishmanial activities. The results showed that the ligand and its complexes are active with few exceptions. UV-visible spectroscopy and viscometry results reveal that the ligand and its complexes interact with the DNA via intercalative mode of interaction. A new and efficient strategy to identify the pharmacophores and anti-pharmacophores sites in carboxylate derivatives for the antibacterial/antifungal activity using Petra, Osiris and Molinspiration (POM) analyses was also carried out.