Synthesis and Characterisation of Some Co(II), Cu(II) and Ni(II) Complexes with Nicotinoylhydrazine Derivatives and the Biological Role of Metals and Anions (SO4 2-, NO3 −, CzO4 2- and CH3CO− 2) on the Antibacterial Properties

Crystal structure of aqua-dichlorido-(4-(((3-ethoxy-2-oxidobenzylidene)hydrazono)(oxido)methyl)pyridin-1-ium-κ3 N,O,O′)iron(III), C15H16Cl2N3O4Fe

C15H16Cl2N3O4Fe, monoclinic, P21/n (no. 14), a = 8.7419(15) Å, b = 22.717(4) Å, c = 9.6256(16) Å, β = 112.546(2)°, V = 1765.4(5) Å3, Z = 4, R gt(F) = 0.0255, wR ref(F 2) = 0.0622, T = 298 K [1–3].

Anticancer Activities of Cu(II) Complex-Schiff Base and Low-Frequency Electromagnetic Fields and the Interaction Between Cu(II) Complex-Schiff Base with Bovine Serum Albumin by Spectroscopy

Cancer is the consequence of abnormal cell proliferation, which leads to the formation of abnormal mass. In this study, we aimed to determine the anticancer properties of Cu(II)-Schiff base complex and low-frequency electromagnetic field, and the interaction between BSA and Cu(II) complex. Firstly, Schiff base of the Cu(II) complex in the N,N'-dipyridoxyl(1,2 diaminobenzene) was originally synthesized. Following, the breast cancer was transplanted with the TUBO cells in vivo. Then, treatment of the cancerous mice was done by low-frequency electromagnetic field and the Cu(II)-Schiff base complex. In this project, antiproliferative activity on breast cancer cells was tested by TUBO cells using MTT assay and apoptosis properties were studied by flow cytometry. The interaction between the Cu(II)-Schiff base complex and bovine serum albumin (BSA) was checked by fluorescence and UV-vis absorbance spectroscopy. Tumor tissue investigation demonstrated that the low-frequency electromagnetic field and Cu(II)-Schiff base complex induce apoptosis and inhibit tumor growth. MTT results unveiled a cytotoxic impact on breast cancer cells. Flow cytometry analysis demonstrates that the anticancer effect of Cu(II)-Schiff base complex on breast cancer cells (MCF7) was associated with the cell cycle arrest. The results of fluorescence spectra and UV-vis absorption spectra showed that the conformation of bovine serum albumin has been changed in the presence of Cu(II)-Schiff base complex. Cu(II)-Schiff base complex and low-frequency electromagnetic field have anticancer properties. The spectroscopy method indicates the binding between Cu(II)-Schiff base complex and BSA.

Amalgamating 4′-substituted 4,2′:6′,4′′-terpyridine ligands with double-helical chains or ladder-like networks

Hg^II-mediated self-assembly of metal–organic coordination polymers based on 4,2′:6′,4′′-terpyridine derivatives is for the first time presented and the structural diversity dependent upon the use of 4′-substituents of ligand is revealed.

Azine or hydrazone? The dilemma in amidinohydrazones

Amidinohydrazone, an important class of biologically active molecules, is generally represented as a hydrazone. This moiety prefers to exist in its azine tautomeric state and hence, influences the physical, chemical and receptor binding properties.

Theoretical spectroscopic study of seven zinc(II) complex with macrocyclic Schiff-base ligand

Seven zinc complexes, which are [ZnL(1)](2+), [ZnL(2)](2+), [ZnL(3)](2+), [ZnL(4)](2+), [ZnL(5)](2+), [ZnL(6)](2+) and [ZnL(7)](2+), are studied as theoretically. Structural parameters, vibration frequencies, electronic absorption spectra and (1)H and (13)C NMR spectra are obtained for Zn(II) complexes of macrocyclic penta and heptaaza Schiff-base ligand. Vibration spectra of Zn(II) complexes are studied by using Density Functional Theory (DFT) calculations at the B3LYP/LANL2DZ. The UV-VIS and NMR spectra of the zinc complexes are obtained by using Time Dependent-Density Functional Theory (TD-DFT) method and Giao method, respectively. The agreements are found between experimental data of [ZnL(5)](2+), [ZnL(6)](2+) and [ZnL(7)](2+) complex ions and their calculated results. The geometries of complexes are found as distorted pentagonal planar for [ZnL(1)](2+), [ZnL(2)](2+) and [ZnL(3)](2+) complex ions, distorted tetrahedral for [ZnL(4)](2+) complex ion and distorted pentagonal bipyramidal for [ZnL(5)](2+), [ZnL(6)](2+) and [ZnL(7)](2+) complex ions. Ranking of biological activity is determined by using quantum chemical parameters and this ranking is found as: [ZnL(7)](2+)>[ZnL(6)](2+)>[ZnL(5)](2+)>[ZnL(3)](2+)>[ZnL(2)](2+)>[ZnL(1)](2+).

Structural and characterization of novel copper(II) azodye complexes

The synthetic methods of novel Cu(II) and adduct complexes, with selective azodyes containing nitrogen and oxygen donor ligands have been developed, characterized and presented. The prepared complexes fall into the stoichiometric formulae of [Cu(L(n))(2)](A) and [Cu(L(n))(2)(Py)(2)](B), where two types of complexes were expected and described. In type [(A) (1:2)] the chelate rings are six-membered/four coordinate, whereas in type [(B) (1:2:2)] they are six-membered/six coordinate. The important bands in the IR spectra and main (1)H NMR signals are tentatively assigned and discussed in relation to the predicted assembly of the molecular structure. The IR data of the azodye ligands suggested the existing of a bidentate binding involving azodye nitrogen and C-O oxygen atom of enolic group. They also showed the presence of Py coordinating with the metal ion. The coordination geometries and electronic structures are determined from the framework of the proposed modeling of the formed novel complexes. The complexes (1-5) exist in trans-isomeric [N,O] solid form, while adduct complexes (6-10) exist in trans isomeric (Py) form. The square planar/octahedral coordination geometry of Cu(II)/adduct is made up of an N-atom of azodye, the deprotonated enolic O-atom and two Py. The azo group was involved in chelation for all the prepared complexes. ESR spectra show the simultaneous presence of a planar trans and a nearly planar cis isomers in the 1:2 ratio for all N,O complexes [Cu(L(n))(2)]. The ligands in the dimmer are stacked over one another. In the solid state of azo-rhodanine, the dimmers have inter- and intramolecular hydrogen bonds. Interactions between the ligands and Cu(II) are also discussed.

N'-(2,3-Dihy-droxy-benzyl-idene)isonicotinohydrazide

The title compound, C₁₃H₁₁N₃O₃, crystallized with two independent mol­ecules in the asymmetric unit. One of the mol­ecules is twisted while the other is almost planar, with dihedral angles of 28.02 (6) and 2.42 (9)°, respectively, between the benzene and pyridine rings. Intra­molecular O—H⋯O and O—H⋯N hydrogen bonds are present in both mol­ecules. The two independent mol­ecules are linked by pairs of O—H⋯O hydrogen bonds. The crystal structure is further stabilized by inter­molecular N—H⋯N hydrogen bonds and C—H⋯N and C—H⋯O inter­actions.

Transition metal complexes of isonicotinic acid (2-hydroxybenzylidene)hydrazide

A new series of transition metal complexes of Schiff base isonicotinic acid (2-hydroxybenzylidene)hydrazide, HL, have been synthesized. The Schiff base reacted with Cu(II), Ni(II), Co(II), Mn(II), Fe(III) and UO2(II) ions as monobasic tridentate ligand to yield mononuclear complexes of 1:2 (metal:ligand) except that of Cu(II) which form complex of 1:1 (metal:ligand). The ligand and its metal complexes were characterized by elemental analyses, IR, UV-vis, mass and 1H NMR spectra, as well as magnetic moment, conductance measurements, and thermal analyses. All complexes have octahedral configurations except Cu(II) complex which has an extra square planar geometry distorted towards tetrahedral. While, the UO2(II) complex has its favour hepta-coordination. The ligand and its metal complexes were tested against one strain Gram +ve bacteria (Staphylococcus aureus), Gram -ve bacteria (Escherichia coli), and Fungi (Candida albicans). The tested compounds exhibited higher antibacterial activities.

Antimicrobial activity and spectral, magnetic and thermal studies of some transition metal complexes of a Schiff base hydrazone containing a quinoline moiety

A series of new copper(II), cobalt(II), nickel(II), manganese(II), iron(III), and uranyl(VI) complexes of the Schiff base hydrazone 7-chloro-4-(benzylidene-hydrazo)quinoline (HL) were prepared and characterized. The Schiff base behaves as a monobasic bidentate ligand. Mononuclear complexes with the general composition [ML2(Cl)m(H2O)2(OEt)n] x xEtOH (M = Cu(II), Co(II), Ni(II), Mn(II), Fe(III) or UO2(VI); m and n = 0-1; x = 1-3) were obtained in the presence of Li(OH) as a deprotonating agent. The nature of bonding and the stereochemistry of the complexes have been deduced from elemental analyses, infrared, electronic spectra, magnetic susceptibility and conductivity measurements. An octahedral geometry was suggested for all the complexes except the Cu(II) and UO2(VI) ones. The Cu(II) complex has a square-planar geometry distorted towards tetrahedral, while the UO2(VI) complex displays its favored heptacoordination. The Schiff base ligand, HL, and its complexes were tested against one strain gram +ve bacteria (Staphylococcus aureus), gram -ve bacteria (Escherichia coli), and Fungi (Candida albicans). The prepared metal complexes exhibited higher antibacterial activities than the parent ligand and their biopotency is discussed.

Synthesis, magnetic, spectral, and antimicrobial studies of Cu(II), Ni(II) Co(II), Fe(III), and UO2(II) complexes of a new Schiff base hydrazone derived from 7-chloro-4-hydrazinoquinoline

A new hydrazone ligand, HL, was prepared by the reaction of 7-chloro-4-hydrazinoquinoline with o-hydroxybenzaldehyde. The ligand behaves as monoprotic bidentate. This was accounted for as the ligand contains a phenolic group and its hydrogen atom is reluctant to be replaced by a metal ion. The ligand reacted with Cu(II), Ni(II), Co(II), Fe(III), and UO2(II) ions to yield mononuclear complexes. In the case of Fe(III) ion two complexes, mono- and binuclear complexes, were obtained in the absence and presence of LiOH, respectively. Also, mixed ligand complexes were obtained from the reaction of the metal cations Cu(II), Ni(II) and Fe(III) with the ligand (HL) and 8-hydroxyquinoline (8-OHqu) in the presence of LiOH, in the molar ratio 1:1:1:1. It is clear that 8-OHqu behaves as monoprotic bidentate ligand in such mixed ligand complexes. The ligand, HL, and its metal complexes were characterized by elemental analyses, IR, UV-vis, mass, and 1H NMR spectra, as well as magnetic moment, conductance measurements, and thermal analyses. All complexes have octahedral configurations except Cu(II) complex which has an extra square-planar geometry, while Ni(II) mixed complex has also formed a tetrahedral configuration and UO2(II) complex which formed a favorable pentagonal biprymidial geometry. Magnetic moment of the binuclear Fe(III) complex is quite low compared to calculated value for two iron ions complex and thus shows antiferromagnetic interactions between the two adjacent ferric ions. The HL and metal complexes were tested against one stain Gram positive bacteria (Staphylococcus aureus), Gram negative bacteria (Escherichia coli), and fungi (Candida albicans). The tested compounds exhibited higher antibacterial acivities.

Co(II), Ce(III) and UO2VI) bis-salicylatothiosemicarbazide complexes: binary and ternary complexes, thermal studies and antimicrobial activity

A series of new metal complexes of Co(II), Ce(III) and UO(2)(VI), with the Schiff base ligand, H2L, bis-salicylatothiosemicarbazide have been prepared in presence of different molar ratios of LiOH.H2O as a deprotonating agent. Also, the ternary complexes were prepared by using 2-aminopyridine (2-Ampy) or oxalic acid (Ox) as a secondary ligand. All synthesized compounds were identified and confirmed by elemental analyses, molar conductivities, spectral (UV-Vis, IR, 1H NMR, mass) and magnetic moment measurements as well as TG-DSC technique. The changes in the selected vibrational absorption bands in IR and NMR spectra of the Schiff base ligand upon coordination indicate that, the ligand behaves as a neutral, monoanionic and/or dianionic tetradentate manner with ONNO donor sites. Conductance measurements suggest the non-electrolytic and 1:1 electrolytic nature of the metal complexes. Thermal studies suggest a mechanism for degradation of the metal complexes as function of temperature supporting the chelation modes, moreover, show the possibility of obtaining new complexes pyrolytically in the solid state which cannot be synthesized from solution. Antimicrobial screening of the free ligand and its binary complexes showed that, the free ligand and some metal complexes possess antimicrobial activities towards four type of bacteria and five types of fungi and these results were compared with eleven type of known antibiotics.