Synthesis and characterization of copper(II) metal(II) binuclear complexes of N,N′-bis(8-hydroxyquinoline-7-carboxaldene)-1,3-diaminopropane

Bio-Based Electrospun Fibers from Chitosan Schiff Base and Polylactide and Their Cu2+ and Fe3+ Complexes: Preparation and Antibacterial and Anticancer Activities

The Schiff base derivative (Ch-8Q) of chitosan (Ch) and 8-hydroxyquinoline-2-carboxaldehyde (8QCHO) was prepared and fibrous mats were obtained by the electrospinning of Ch-8Q/polylactide (PLA) blend solutions in trifluoroacetic acid (TFA). Complexes of the mats were prepared by immersing them in a solution of CuCl₂ or FeCl₃. Electron paramagnetic resonance (EPR) analysis was performed to examine the complexation of Cu²⁺(Fe³⁺) in the Ch-8Q/PLA mats complexes. The morphology of the novel materials and their surface chemical composition were studied by scanning electron microscopy (SEM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). The performed microbiological screening demonstrated that in contrast to the neat PLA mats, the Ch-8Q-containing mats and their complexes were able to kill all S. aureus bacteria within 3 h of contact. These fibrous materials had efficiency in suppressing the adhesion of pathogenic bacteria S. aureus. In addition, Ch-8Q/PLA mats and their complexes exerted good anticancer efficacy in vitro against human cervical HeLa cells and human breast MCF-7 cells. The Ch-8Q-containing fibrous materials had no cytotoxicity against non-cancer BALB/c 3T3 mouse fibroblast cells. These properties render the prepared materials promising as wound dressings as well as for application in local cancer treatment.

Synthesis and spectroscopic characterization of nickel(II) complexes of 1-benzotriazol-1-yl-[(p-X-phenyl)hydrazone]propan-2-one

The reaction of NiCl(2).H(2)O with 1-benzotriazol-1-yl-[(p-X-phenyl)hydrazone]propan-2-one, X=H (HL(1)), X=Cl (HL(2)), X=Br (HL(3)) and X=Me (HL(4)), gave the complexes [(HL)NiCl(2)] x nH(2)O and [LNi(OH)](2), where L is the monobasic anion of HL(2) or HL(3). The nature of the products is solvent and ligand dependent. The complexes are characterized by elemental analyses, molar conductivity, magnetic moments and spectroscopic (IR and UV/vis) measurements. The IR showed that the ligands act as neutral bidentate coordinated to the nickel(II) through the azomethine nitrogen and carbonyl oxygen atoms in case of [(HL)NiCl(2)] x nH(2)O. In case of [LNi(OH)](2), the ligands are monobasic bidentate bonded to the nickel(II) through the azomethine nitrogen and the enolato oxygen atoms. The room temperature magnetic moment values of 1.58-2.49 B.M. for [(HL)NiCl(2)] x nH(2)O and [LNi(OH)](2) and their electronic spectral data indicate that these complexes have square planar-tetrahedral equilibrium. The values of 1.61 and 1.58 B.M. for the hydroxo-complexes support their dimeric nature. The electronic spectral of [(HL)NiCl(2)] x nH(2)O and [LNi(OH)](2) in pyridine or alpha-picoline indicated the formation of six-coordinate adducts. The hydroxo-complexes reacted with different Lewis bases to give the complexes [L(2)Ni(L(s))(2)], where L(s)=Py, 2-Pic, 3-Pic, 4-Pic or n-PrNH(2). The relationship between the pK(b) of the Lewis base and the upsilon(Ni-O) of the ligand and upsilon(Ni-N) of the Lewis base was studied. The different ligand field parameters are calculated for the parent ligands in solutions and the solid mixed ligand complexes. The data showed that both are associated with a distorted octahedral ligand field around the nickel(II) and the ligand fields in solution are different from that in solid. The extent of distortion for the parent complexes is more than that in the solid adducts. Furthermore, the data showed that the nickel-ligand bonding in [LNi(OH)](2) is more covalent than in [L(2)Ni(L(s))(2)].

Synthesis and spectroscopic characterization of copper(II) complexes with the polydentate chelating ligand 4,4'-[1,4-phenylenedi(nitrilo)dipente-2-one

A new series of complexes of 4,4'-[1,4-phenylenenedi(nitilo)]dipenten-2-one, (H(2)L) with CuX(2) x nH(2)O, X = Cl, Br, ClO(4), NO(3) and OAc; n = 1-6 as well as their ethylenediamine adducts have been synthesized and characterized by different physical techniques. The formulation of the complexes is assumed based on their elemental analysis and the molar conductivity. The products are found to be pH-dependent. The IR data showed that the ligand acts as dibasic tetradentate coordinated to copper(II) ions through the enolato-oxygen and the azomethine nitrogen atoms. Electronic, ESR spectra and room temperature magnetic moments indicate that complexes 1-9 are square planar while complexes 10 and 11 are square based pyramidal. The different electronic spectral and ESR parameters are calculated and used to describe the nature of ligand-metal bonding (sigma and pi) as well as to estimate the extent of distortion. A macrocyclic containing copper(II) complex, 12 have been isolated by the reaction of Schiff-base with copper(II)-ethylenediamine mixture. The ligand (H(2)L) is designed as a building block for larger molecules and superamolecular assemblies.