Synthesis, characterization and spectral studies of mononuclear and binuclear Fe(II), Co (II), Ni (II), Zn(II) complexes with 2,4-dinitrophenylhydrazine dithiocarbamate

New complexes of dithiocarbamate of the general formula [M(2,4-dinitrphenhydra - dtc)2], [MM’(2,4-dinithrphenhydra-dtc)4] where: M=Fe (II), Co(II), Ni(II), M’=Zn(II), 2,4- dinitrphenhydra-dtc=2,4- di nitro phenyl hydrazine dithiocarbamate and [M(l,10-phen)3][M’(2,4 – dinitrphenhydra-dtc)4], [M(1,10- phen)3][M’2(2,4-dinitrphenhydra - dtc)6] Where: M=Co(II), Ni(II), M’=Zn(II), (1,10-phen)= 1,10-phenanthroline monohydrate. Have been prepared and characterized by atomic absorption spectroscopy infrared, conductance measurements, electronic absorption spectra, nuclear magnetic resonance and magnetic susceptibility measurements. Magnetic moments and electronic spectra indicate that the complexes of the type [M(2,-dinitrphenhydra-dtc)2], [MM’(2,4-dinitrphenhydra - dtc)4] are of square planner geometry while the complexes of the type [M(1,10-phen)3][M’(2,4-dinitrphenhydra-dtc)4] and [M(1,10 phen)3][M’2(2,4-dinitrphenhydra-dtc)6] have octahedral geometry.

Synthesis and Spectral studies of Ru (II) complexes with Macrocyclic Ligands

Fifteen Ru (II) complexes of the type [RuCl2(L)] (where L= N4 donor macrocyclic ligands) have been synthesised by reaction of [(RuCl2(DMSO)4] with fifteen macrocyclic Schiff base ligands containing N4 donors groups. The prepared fifteen [RuCl2(L)] complexes were characterised by elemental analysis, molar conductivity, UV-visible, IR, X- ray photoelectron spectra (XPS) and magnetic susceptibility measurementsand an octahedral geometry was proposed for all these complexes.

Synthesis, Identification, and Biological Study for Some Complexes of Azo Dye Having Theophylline

This article includes the synthesis of heterocyclic azo dye of theophylline by coupling diazonium salt of 4-chloroaniline with theophylline which is, namely, 8-(1-(4-chlorophenyl)azo)theophylline (CPAT). The complexes of cobalt and nickel were prepared by reacting their ions with CPAT ligand in ethanol under 1 : 2 ratio metal-ligand. The CPAT ligand and its complexes were characterized by elemental analysis, infrared spectrometry, electronic absorption spectroscopy, molar conductivity, and magnetic moment. The cobalt and nickel complexes show octahedral geometry having general formula [M(CPAT)2Cl2]. This article addresses the properties of CPAT dye such as photochromic properties. The CPAT dye exhibited obvious and desired changes under irradiation with visible light (405 nm), high sensitive for pH changes which refer to its ability to be analysis indicator. CPAT dye exhibited solvatochromic properties presenting red shift with polar solvent. The CPAT and its complexes show interesting antibiological activities towards Staph. aureus and E. coli bacteria and Aspergillus fungi.

Synthesis, Structure and Electrochemical Properties of Acetamide- and Caprolactam-Containing Silicon Catecholates

Hexacoordinated heteroligand silicon catecholates, although being prospective as easily soluble compounds with high hydrolytic stability and diverse redox properties, have been insufficiently studied. The transesterification of 1-(trimethoxysilylmethyl)-2-oxohexahydroaze or N-methyl-N-(trimethoxysilylmethyl)acetamide by two equivalents of catechol derivatives in the presence of dicyclohexylamine afforded a series of target compounds in good yield. The complexes were characterized using elemental analysis, FTIR, 1H, 13C and 29Si NMR spectra, X-ray crystallography and cyclic voltammetry. X-ray diffraction confirmed that the silicon atom possesses the octahedral geometry of the SiCO5 polyhedron that remains unchanged in solution as it follows from 29Si NMR data. The compounds demonstrated up to three oxidation waves; and the reduction profile strongly depended on the nature of the substituents on a catecholate anion.

catena-Poly[[bis(1H-indole-5-carboxylato-κ2 O,O′)zinc(II)]-μ-4,4′-azobipyridine-κ2 N 1:N 1′]

The asymmetric unit of the title coordination polymer [Zn(C9H6NO2)2(C10H8N4)] n , consists of one ZnII cation, one bidentate 1H-indole-5-carboxylate (I5C) anion and half of a 4,4′-azobipyridine (Abpy) neutral ligand. In the coordination polyhedron, the ZnII ion adopts a distorted octahedral geometry. The coordination polymer is stabilized by a combination of N—H...O and C—H...π interactions, which leads to the formation of wave-like two-dimensional coordination polymeric layers.

Bioactive Co(II), Ni(II), and Cu(II) Complexes Containing a Tridentate Sulfathiazole-Based (ONN) Schiff Base

New Co(II), Ni(II), and Cu(II) complexes were synthesized with the Schiff base ligand obtained by the condensation of sulfathiazole with salicylaldehyde. Their characterization was performed by elemental analysis, molar conductance, spectroscopic techniques (IR, diffuse reflectance and UV–Vis–NIR), magnetic moments, thermal analysis, and calorimetry (thermogravimetry/derivative thermogravimetry/differential scanning calorimetry), while their morphological and crystal systems were explained on the basis of powder X-ray diffraction results. The IR data indicated that the Schiff base ligand is tridentate coordinated to the metallic ion with two N atoms from azomethine group and thiazole ring and one O atom from phenolic group. The composition of the complexes was found to be of the [ML2]∙nH2O (M = Co, n = 1.5 (1); M = Ni, n = 1 (2); M = Cu, n = 4.5 (3)) type, having an octahedral geometry for the Co(II) and Ni(II) complexes and a tetragonally distorted octahedral geometry for the Cu(II) complex. The presence of lattice water molecules was confirmed by thermal analysis. XRD analysis evidenced the polycrystalline nature of the powders, with a monoclinic structure. The unit cell volume of the complexes was found to increase in the order of (2) < (1) < (3). SEM evidenced hard agglomerates with micrometric-range sizes for all the investigated samples (ligand and complexes). EDS analysis showed that the N:S and N:M atomic ratios were close to the theoretical ones (1.5 and 6.0, respectively). The geometric and electronic structures of the Schiff base ligand 4-((2-hydroxybenzylidene) amino)-N-(thiazol-2-yl) benzenesulfonamide (HL) was computationally investigated by the density functional theory (DFT) method. The predictive molecular properties of the chemical reactivity of the HL and Cu(II) complex were determined by a DFT calculation. The Schiff base and its metal complexes were tested against some bacterial strains (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtilis). The results indicated that the antibacterial activity of all metal complexes is better than that of the Schiff base.

Structural elucidation, thermal studies and antimicrobial screening of mixed ligans complexes of 4-benzylimino-2,3-dimethyl-1-phenylpyrazal-5-one and L-Lysine

The mixed ligand complexes involving Fe(II), Co(II) and Ni(II) ions, Schiff base 4 phenylpyrazal-5-one (L1) and L-lysine (Lys) were synthesized. The complexes were characterized on the basis of their elemental analysis, conductivity measurements, FT-IR, MS,1H-NMR and 13C-NMR spectral studies. All the synthesized complexes were subjected to simultaneous thermogravimetric analysis to study their decomposition mechanism and thermal stability. The mixed ligand complexes were screened against some strains of bacteria and fungi to study their antimicrobial activity. The complexes were found to be non-electrolytes and possessed octahedral geometry. The results showed that the metal complexes possessed better antimicrobial activity than the free ligands.

A half-salamo-based pyridine-containing ligand and its novel NiII complexes including different auxiliary ligands: syntheses, structures, fluorescence properties, DFT calculations and Hirshfeld surface analysis

Three novel multinuclear NiII complexes, namely, bis{μ-2-methoxy-6-[8-(pyridin-2-yl)-3,6-dioxa-2,7-diazaocta-1,7-dien-1-yl]phenolato}bis[thiocyanatonickel(II)], [Ni2(L)2(NCS)2], 1, bis{μ-2-methoxy-6-[8-(pyridin-2-yl)-3,6-dioxa-2,7-diazaocta-1,7-dien-1-yl]phenolato}bis[azidonickel(II)], [Ni2(L)2(N3)2], 2, and catena-poly[[{2-methoxy-6-[8-(pyridin-2-yl)-3,6-dioxa-2,7-diazaocta-1,7-dien-1-yl]phenolato}nickel(II)]-μ-dicyanamidato], [Ni(L)(dca)] n , 3 {dca is dicyanamide, C2N3, and HL is 2-methoxy-6-[8-(pyridin-2-yl)-3,6-dioxa-2,7-diazaocta-1,7-dien-1-yl]phenol, C16H17N3O4}, with a half-salamo-based pyridine-containing HL ligand have been synthesized and characterized by FT–IR, UV–Vis absorption spectroscopy, X-ray crystallography, Hirshfeld surface analysis and density functional theory (DFT) calculations. The central NiII ions in complexes 1–3 are hosted in the half-salamo-based N3O-donor cavity of the organic ligand. Complex 1 is a centrosymmetric dimer and two [Ni(L)(NCS)] units form a centrosymmetric dimeric structure, which is bridged by two phenolate O atoms. The two N atoms at the axial ends are provided by two NCS− ligands. In complex 1, each NiII ion has a six-coordinated octahedral geometry. Complex 2 is similar to 1, but they differ in that the auxiliary NCS− ligand is replaced by N3 −. However, complex 3 is a one-dimensional coordination polymer constructed from [Ni(L)(dca)] units, which are connected by the auxiliary bidentate dca ligand via N-donor atoms. As with complexes 1 and 2, the NiII ion in 3 has a six-coordinated octahedral geometry.

Crystal structure of bis{2-hydroxy-N′-[1-(pyrazin-2-yl)ethylidene]benzohydrazidato}cadmium(II)

In the title complex molecule, [Cd(C13H11N4O2)2], the Cd atom is coordinated in a distorted octahedral geometry by two tridentate ligands synthesized from 2-hydroxybenzohydrazide and 1-(pyrazin-2-yl)ethan-1-one. The molecule has twofold crystallographic symmetry and is isomorphous to its Mn, Co, Ni, Cu and Zn counterparts.