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Schiff bases complexes of Co(II) and Ni(II) ions with diethyl 3,3'-(ethane-1,2-diylbis (azaneylylidene)) (3E, 3′E)-dibutyrate (H2L1) and (3E, 3′E)-3,3'-(ethane-1,2-diylbis (azanylylidene))bis (N-(pyridin-2-yl)butanamide) (H2L2) have been synthesized, characterized and analytically formulated as [Co2(L1)Cl2·2H2O]·H2O (1), [Ni2(L1)Cl2·6H2O]·2H2O (2), [Co2(H2L2)Cl4·2H2O]·H2O (3) and [Ni(H2L2)Cl2]·H2O (4). The IR spectral data revealed that H2L1 ligand behaves as a N2O2 binegative tetradentate in (1) and (2) through the oxygen of both enolized carbonyl (C O) groups and the nitrogen of two newly formed (C N)∗ groups. While H2L2 acts as neutral NNOONN hexadentate in (3) and as a neutral NNOO tetradentate in (4). The spectral and magnetic studies suggests a tetrahedral coordination geometry for complex (1) and octahedral geometry for other complexes. In addition, thermal degradation curves have been discussed for complexes in order to estimate their kinetic and thermodynamic parameters by two comparable methods. Various descriptors have been estimated using DFT calculations. Moreover, the anti-microbial activities and MTT cytotoxicity assay of the compounds have been examined.

Novel hydrazone 2-(2-((1E,2E)-2-(2-phenylhydrazineylidene)propylidene)hydrazineyl)pyridine and its nickel(II) and copper(II) complexes have been synthesized and characterized. The ligand (H2PGl) was prepared by the condensation reaction of 1-(2-phenylhydrazineylidene)propan-2-one and 2-hydrazinopyridine. The crystal structure of Ni(II) complex was determined. In both Ni(II) and Cu(II) complexes, H2PGl act as a neutral tridentate ligand forming two fused five-membered chelation rings through NNN set of donor atoms. Octahedral geometry is proposed for both chelates as illustrated in both magnetic and spectroscopic data. ESR spectroscopy was performed for Cu(II) complex which exhibited a considerable Cu–Cu interaction and harmonize directly with measured magnetic moment. The molecular modeling structures were optimized and showed the bond length, bond angle, reactivity, MEP and atomic charges for all the title frameworks. Hypothetical infrared intensities and 1H NMR of H2PGl was estimated on the basis of DFT scheme. A comparison of the experimental and theoretical data was very useful in creating correct assignments and understanding the basic chemical shift. Biological activity of the synthesized compounds were investigated versus some Gram positive, Gram negative bacteria and some fungal strains. Also, the antitumor activity was investigated.

In this work, Co2+, Ni2+, Cu2+, Pd2+, and UO22+ complexes of a carbohydrazone isatin ligand (H3L), are synthesized and structurally elucidated via various physic-chemical approaches (elemental analyses, magnetic, and molar conductance measurements, in addition to IR, NMR, UV–vis, PXRD, GC-MS, and ESR spectral studies). The low value of Ʌm suggested the non-electrolytic nature of the complexes. The proposed geometries were recognized using DFT optimization. Thermal degradation and kinetic parameters of the degradation stages were gauged. Optical bandgaps energies were assessed, and their values hinted at the photovoltaic features of the complexes. ESR spectrum of Cu2+ complex pointed out the existence of the last electron in dz2 ground orbital verifying its distorted (compressed) octahedral structure. A study of electrochemical behavior for Co2+ ions in the presence and absence of the ligand reinforced the successful condensation between Co2+ ions and the ligand. Pd2+ complex was investigated for its action in oxidative degradation of an organic azo-dye and exhibited encouraging activity. A new carbon paste electrode for Ni(II) ions determination based on Nˊ, 2-bis(Z)-2-oxoindolin-3-ylidene)hydrazine-1-carbohydrazide ionophore was investigated. The isolated compounds were assessed for their biological activity (antimicrobial activity, ABTS, and SOD-activity), and molecular docking studies were predestined against E. coli and S. aureus targets.

Two new coordination assemblies were prepared by combining the open and close forms of 1,2-bis(5-carboxyl-2-methyl-3-thienyl)perfluorocyclopentene (H2dae) with [Mn2(saltmen)2(H2O)2](PF6)2, where H2saltmen = 2,2′-((1E,1′E)-((2,3-dimethylbutane-2,3-diyl)bis(azaneylylidene)) bis(methaneylylidene))diphenol. From X-ray diffraction analyses, the complexes had the following formula: [Mn2(saltmen)2(dae-open)] (1open) and [Mn(saltmen)(dae-close)]·H2O·Et3N (1close). Both complexes crystallized in the C2/c monoclinic space group. In 1open, dae-o2– behaves as a bidentate ligand attached to the outer Mn-saltmen monomer via the oxygen atom of carboxylato groups, whereas in 1close, the dae-c2– ligand behaves as a monodentate ligand attached to the external Mn-saltmen dimer by only one carboxylato group of the photochromic ligand. The complexes showed reversible photochromic responses to UV/vis light and showed single-molecule magnet-like behavior. The relaxation times and energy barriers of the metal complexes are clear...

Hg(II), Cd(II) and binuclear Zn(II) complexes derived from the tetradentate N(1)-ethyl-N(2)-(pyridine-2-yl) hydrazine-1, 2-bis (carbothioamide) ligand (H2PET) have been prepared and characterized by conventional techniques. The isolated complexes acquired the formulas, [Hg(HPET)(H2O)2Cl]⋅H2O, [Cd(HPET)Cl] and [Zn2(HPET)(PET)(OAc)]⋅H2O, respectively. IR data revealed that the ligand behaves as monobasic tridentate through (CN)py, (C-S) and new (NC)azomethine(∗) groups in both Hg(II) and Cd(II) complexes. In the binuclear Zn(II) complex, the behavior of ligand contains two types, where H2PET acts as dibasic tetradentate via (CN)py, both deprotonated (C-SH) and the new (NC)azomethine(∗) towards two Zn atoms and also it acts as monobasic tridentate via (CS), deprotonated (C-SH) and (CN)py towards the same Zn atoms. An octahedral geometry for Hg(II) complex and tetrahedral geometry for both Cd(II) and Zn(II) complexes were proposed. The bond lengths, bond angles, HOMO, LUMO and dipole moment have been calculated by DFT using materials studio program to confirm the geometry of ligand and its metal complexes. The association constant of the ligand and the stability constants of its complexes as well as the thermodynamic parameters were calculated by pH metric measurements at 298, 308 and 318K in 50% dioxane-water mixture, respectively. Also, the kinetic and thermodynamic parameters for the different thermal degradation steps of the complexes were determined by Coats-Redfern and Horowitz-Metzger methods. Moreover, the anti-oxidant (using ABTS and DPPH methods), anti-hemolytic, and cytotoxic activities of the compounds have been tested.

Cr(III), Mn(II) and Fe(III) complexes derived from the quadruple potential dithione heterocyclic thiosemicarbazide ligand (H 2 PET) have been prepared and characterized by conventional techniques. The isolated complexes were assigned the formulae, [Cr(HPET)(H 2 O) 2 Cl 2 ]·3H 2 O, [Mn(HPET)(H 2 O)Cl] 2 and [Fe(HPET)(H 2 O) 2 Cl 2 ]·H 2 O, respectively. IR data revealed that the ligand behaves as monobasic bidentate through (C N) py and (C S) groups in both Cr(III) and Fe(III) complexes. In the binuclear Mn(II) complex, H 2 PET acts as NSNS monobasic tetradente via (C N) py , (C S), (C S) and the new azomethine, (N C) * groups. An octahedral geometry for all complexes was proposed. The bond lengths, bond angles, HOMO, LUMO and dipole moment have been calculated by DFT using materials studio program to confirm the geometry of H 2 PET and its metal complexes. The ligand association constant and the stability constants of its complexes in addition to the thermodynamic parameters were calculated from pH metrically at 298, 308 and 318°K in 50% dioxane–water mixture, respectively. Also, the kinetic and thermodynamic parameters for the different thermal degradation steps of the complexes were determined by Coats–Redfern and Horowitz–Metzger methods. Moreover, the anti-oxidant (using ABTS and DPPH methods), anti-hemolytic, and cytotoxic activities of the compounds have been tested.

A new series of metal complexes formed by the reaction of 2-oxo-N′-((4-oxo-4H-chromen-3-yl)methylene)-2-(phenylamino)acetohydrazide(H2L) and Cu(II), Co(II), Ni(II), Cd(II), Zn(II), Hg(II) and U(VI) O 2 2 + ions. The isolated complexes have been characterized by elemental analyses, spectral (IR, UV–visible and 1H NMR) as well as magnetic and thermal measurements. The data revealed that the ligand acts as neutral ON or ONO as well as mononegative ONO. On the basis of magnetic and electronic spectral data an octahedral geometry for the Co(II), Cu(II) and U(VI)O2 complexes, a tetrahedral structure for the Ni(II), Cd(II), Zn(II) and Hg(II) complexes have been proposed. The bond length, bond angle, HOMO, LUMO, dipole moment and charges on the atoms have been calculated to confirm the geometry of the ligand and the investigated complexes. Also, kinetic parameters were determined for each thermal degradation stage of some complexes using Coats–Redfern and Horowitz-Metzger methods. Moreover, the ligand and its complexes were screened against Bacillus thuringiensis (Bt) as Gram positive bacteria and Pseudomonas aeuroginosa (Pa) Gram negative bacteria using the inhibitory zone diameter.

Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), Pd(II) and dioxouranium(VI), (UO:2 2 +), complexes of 4-(2-pyridyl)-1-salicyldehyde-3-thiosemicarbazone (H2SBT) have been synthesized and characterised by elemental analyses, molar conductance, spectral (IR, visible and NMR) and magnetic moment measurement. IR spectral data show that the ligand behaves in a bi-, tri- and/or tetradentatc manner. An octahedral structure is proposed for Cr(HSBT)2Cl.H2O. Mn(HSBT)2, Fe(HSBT)Cl2·H2O, Ni(SBT)·2H2O and Co(HSBT)2Cl·H2O, while a square-planar structure is found for Ni(H2SBT)2Cl2·2H2O, Pd(HSBT)2, Cu3(HSBT)2Cl·2H2O and Cu2(SBT)(OAc)2·2H2O.

The synthesis and characterization of CrIII, MnII, FeIII, CoII, NiII, CuII, ZnII, CdII and UOinf2sup2+complexes of N-isonicotinamido-N′-benzoylthiocarbamide (H2IBTC) are reported. I.r. spectral data show that the ligand behaves in a bidentate, tridentate and/or tetradentate manner. Different stereochemistries are proposed for CrIII, MnII, FeIII, CoII, NiII and CuII complexes on the basis of spectral and magnetic studies. The i.r. data indicate that the carbonyl oxygen of the benzoyl moiety is the backbone of chelation in most complexes.

Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and UO2 2+complexes of isatin 4(2-pyridyl)-3-hiosemicarbazone, H2IPT, have been synthesed and characterized by elemental analyses, molar conductance, spectral (i.r., visible and n. m. r.) and magnetic moment measurements. I. r. spectra show that H2IPT behaves as a bidentate (ON or SN) end a tridentate ONS in a neutral or anionic form. An octahedral structure is proposed Co(HIPT)Cl.3H2O, Co(HIPT)2. 2H2 O, Si(HIPT)Ac.2H2 0 and Cu(H2IPT)2 (Ac)2 complexes and square-planar structure for the Cu(HIPT)Cl.2H2O complex on the basis of spectra and magnetic studies. The molar conductivities for all complexes were in the range of non-electrolytes.

The complexes of MnII, CoII, NiII, CuII, ZnII, CdII, HgII, CoIII and UO 2 2+ ions with 2-hydroxyimino-3-(2′-hydrazonopyridyl)-butane (HL) have been synthesised and characterized by elemental analyses, molar conductivities, magnetic measurements and spectral (i.r., visible, n.m.r.) studies. I.r. spectra show that HL behaves as a neutral or mononegative ligand and binds in a bidentate and/or tridentate manner. Also, HL behaves as oxidizing agent towards CoII forming diamagnetic CoIII complexes depending on the preparative conditions. Different stereochemistries are proposed for MnII, CoIII, CoII, NiII and CuII on the basis of spectral and magnetic studies.

The synthesis and characterization of CrII, MnII, FeII, CoII, NiII, PdII, CuII, ZnII, CdII and UO22+ complexes of 1-meotinoyl-4-phenyl-3-thiosemicarbazide (H2NTS) are reported. I.r. spectral data show that the ligand behaves in a bidentate and/or tetradentate manner. An octahedral structure is proposed for the CrII, FeII and NiII complexes; a tetrahedral structure for the MnII, CoII and Cu(NTS)·2H2O complexes; and a square planar structure for the PdII and Cu(HNTS)Cl·H2O complexes. The i.r. data suggest that the FeII complex contains a hydroxo bridge.

The synthesis and characterization of Co(III), Ni(II), Cu(II), Zn(II), Cd(II) and UO2 2+ complexes of biacetylmonoxime-hydrazine-S-benzyldithiocarbazate (H2BTC) are reported. Elemental analyses, molar conductance, magnetic moment and spectral (i.r., visible and n.m.r.) measurements have been used to characterize the complexes. I.R. spectral data show that the ligand behaves in a bidentate and/or tridentate manner. An octahedral structure is proposed for the Co(III) complex while a square-planar structure is proposed for both Ni(II) and Cu(II) complexes on the basis of magnetic and spectral measurements.

A new series of thiocarbamides was prepared by the reaction of benzoylisothiocyanate with various amines namely 2-aminopyridine (H2LI), 3-aminopyridine (H2LII), 2,3-diaminopyridine (H2LIII), 2,6-diaminopyridine (H2LIV), o-phenylene diamine (H2LV), p-phenylenediamine (H2LVI) and ethylene diamine (H2LVII). The copper(II) complexes of these ligands were isolated and have been characterized by elemental analyses, molar conductivities, magnetic moments and spectral (visible, i.r.) measurements. I.r. spectra show that the ligands behave as dianionic or neutral tetradentates or as monoanionic or neutral bidentates. The [Cu(HLI)Cl]2 and Cu(H2LIV)Cl2 complexes are diamagnetic and the other complexes have normal magnetic moment at room temperature. Electronic spectral analyses show that Cu2(LIV)Ac2 is planar and the other complexes are tetragonally distorted octahedral. All the complexes are non-electrolytes.

The synthesis and characterization of MnII, CoII, NiII, CuII, ZnII, CdII UO 2 2+ , CrIII and FeIII complexes of biacetylmonoxime nicotinoyl hydrazone (H2BMNH) are reported. Elemental analysis, molar conductance, magnetic moment and spectral (i.r., visible and n.m.r.) measurements have been used to characterize the complexes. I.r. spectral data show that the ligand behaves in a bidentate and/or tridentate manner. An octahedral structure is proposed for the MnII, NiII, CrIII and FeIII complexes, while a square-planar structure is proposed for both CoII and CuII complexes on the basis of magnetic and spectral measurements.

Complexes ofN-benzamido-N′-benzoyl-thiocarbamide (HBBTC) with CoII, NiII, CuII, ZnII, CdII and UO22+ have been prepared and characterized on the basis of elemental analyses, molar conductance, magnetic moment and spectral (visible, i.r.) studies. I.r. spectra show that HBBTC behaves in a bidentate and/or tridentate manner. Different stereochemistries are proposed for CoII, NiII and CuII complexes on the basis of spectral and magnetic studies.

Complexes of CuII, NiII, CoII, ZnII, CdII and HgII with 4-benzamido-1-o-aminoacetophenone-3-thiosemicarbazone (H2BATS) are reported and have been characterized by elemental analyses, molar conductivities, magnetic moments, spectral (visible, i.r.) and thermal (d.t.a., t.g., d.t.g.) measurements. I.r. spectra show that H2BATS behaves as a dianionic, monoanionic or neutral tetradentate ligand or as a monoanionic tridentate ligand. [Cu2(H2BATS)Cl2]·2H2O and [Cu2(H2BATS)Ac2]·2H2O complexes are diamagnetic while [Co(HBATS)OH]·2H2O and [Ni(HBATS)OH]·2H2O are octahedral. All the complexes are non-electrolytes. Generally, the solid metal acetate complexes have a unique decomposition exotherm profile which can be used as a rapid and sensitive tool for the detection of acetate-containing complexes.

3-Isonicotinamido-rhodanine (HINRd) reacts with metal ions to yield complexes of the types M(INRd)OH·nH2O (where M=CoII, NiII, ZnII or CdII and n=1 or 2), Cu(HINRd)X·2H2O (where X=Cl or Br), Pd(HINRd)Cl2 and Cd(HINRd)X2·H2O (where X=Cl or Br), depending on the metal salt used and the reaction conditions. The metal complexes have been characterized by elemental analysis, molar conductivities, molecular weights, magnetic susceptibility, visible, and i.r. studies. The i.r. spectra show that HINRd binds in a bidentate or monodentate manner. The spectral and magnetic studies suggest a tetrahedral arrangement for CoII, octahedral for NiII and square-planar for PdII. HINRd behaves as a reducing agent towards CuII chloride or bromide forming diamagnetic CuI complexes.