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Divalent Mn, Ni, Zn, and trivalent La complexes of H3L ligand [N’,2-bis((Z)-2-oxoindolin-3-ylidene)hydrazine-1 carbohydrazide] were synthesized and characterized via diverse spectroscopic methods (FT-IR, NMR, electronic, PXRD, and GC-MS), molar conductance and magnetic susceptibility measurements. The different ways of binding for the H3L ligand with metal ions were inferred, as the H3L ligand acted in mono-negative N2O tridentate, mono-negative N2O3 pentadentate, bi-negative N2O3 pentadentate, and tri-negative N2O3 pentadentate manners in coordination to Mn2+, Zn2+, La3+, and Ni2+ metal ions, respectively. DFT modeling was performed using the DMOL3/material studio software, and some of the experimental outcomes were interpreted and authenticated. Electrochemical performance of Mn2+ ions in the existence and absence of H3L ligand was considered via cyclic voltammetry. The corrosion effectiveness of the H3L ligand (inhibitor) to aluminum metal was evaluated, and the molecular dynamic (MD) simulations for adsorption of the H3L inhibitor on Al surface were performed via FORCITE quench code. The isolated compounds were inspected for their antimicrobial (against C. albicans fungi, G+ bacteria S. aureus and B. subtilis, and G− bacteria P. aeruginosa and E. coli), cytotoxic, and antioxidant (ABTS, and SOD) activities. A molecular docking study was performed to give the favorable binding sites for the ligand to E. coli, and S. aureus proteins.

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.

Cr(III), Mn(II), Fe(III), Cd(II), Zn(II) and Hg(II) complexes derived from carbohydrazone ligand were synthesized and characterized by spectroscopic methods, DFT calculations and TGA analysis. IR spectra together with DFT optimization revealed that the ligand uses its two (C N)azomthine in coordination with either Mn(II), Fe(III) or Zn(II) ions. While, Cd(II) and Hg(II) ions coordinates via the nitrogen atoms of the two pyridyl groups. On the other hand, the coordination takes place through the two (C N)azomthine and the (C O)carbonyl groups in Cr(III) complex. On the basis of the electronic spectra and as the magnetic measurements, an octahedral coordination geometry was proposed in case of Cr(III) and Fe(III) complexes and a tetrahedral geometry in case of Mn(II) complex. Kinetic and thermodynamic parameters of the isolated complexes were estimated using Coats-Redfern and Horowitz-Metzger models. The antioxidant (DDPH and ABTS methods), anti-hemolytic and cytotoxic activities of the compounds have been screened. The DDPH and ABTS antioxidant activity was investigated and indicated that Zn(II) complex exhibited the highest antioxidant activity. While, Fe(III) complex had significantly the same percentage of hemolysis as that of the positive control. With respect to antitumor activity, H2APEC and Zn(II) complex demonstrated the potent activity followed by Fe(III) complex.

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 copper (II) complexes of ligands H 2 L 1 and H 2 L 2 have been prepared and investigated. The ligands were prepared by the individually addition of picolinic acid hydrazide and 2-(2-aminothiazol-4-yl) acetohydrazide into benzoyl isothiocyanate. The results of analytical and spectroscopic equipments revealed that H 2 L 1 act as monobasic bidentate with square planner environment. While H 2 L 2 behaves as monobasic tetradentate with Oh geometry. The geometries of ligands and their complexes being carefully studied using Jaguar 9.1 program based on the density functional theory (DFT) to predict properties of materials performed by the hybrid density functional method B3LYP. Additionally, thermal degradation data were evaluated to determine the kinetic and thermodynamic parameters by different methods. Moreover, the anti-oxidant (using DPPH and SOD methods), and anti-bacterial activities of the compounds have been studied. Furthermore, the docking study of ligands and their complexes were applied against gram-positive S. Aureus , negative E. Coli bacterial and C. Albicans fungal strains by Schrodinger suite program using XP glide protocol.

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...

Four new mixed ligand metal(II) complexes with 1-methylpyrazole-3-aldehyde-4-(2-pyridyl)thiosemicarbazone (MPAPT) and 1,10-phenanthroline are reported. These complexes namely Cu(MPAPT)(1,10-phen)(Cl)] (1), [Ni(MPAPT)(1,10-phen)(Cl)] (2), [Mn(MPAPT)(1,10-phen)(Cl)].H 2 O (3) and [Co(MPAPT)(1,10-phen)(Cl)].H 2 O (4), were characterized by elemental analysis, spectral (IR, 1 H NMR and UV-Vis) and magnetic moment measurements. The magnetic and spectral data indicates octahedral structure for all complexes. Metal complexes have been modeled using parameterized PM3 semi-empirical method. The free ligand and its M(II) chelates have been screened for their antimicrobial activities. The antimicrobial screening demonstrated that, the Cu(II) complex have the maximum and broad activities among the investigated complexes.

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.

Sodium(E)‑4‑hydroxy‑3‑((2‑(pyridin‑2‑ylcarbamothioyl)hydrazineylidene)methyl) benzenesulfonate (NaH3PyTSC) and its cobalt(II), nickel(II) and copper(II) chelates have been isolated. Different spectroscopic techniques have been utilized for elucidation of their structures. The 1HNMR spectrum of NaH3PyTSC illustrated the existence of three different isomers in DMSO solution; syn and anti-conformers of the thione form and the thiol form. The FTIR illustrated that NaH3PyTSC preforms as a bi-negative NOS tridentate in [CoH2PyTSC(H2O)]2.2H2O and [CuH2PyTSC(H2O)]2.H2O through the deprotonated thiol, (C N)azomethine and SO32− groups and also as binegative NNSO tetradentate in [NiH2PyTSC(H2O)]2.4H2O through deprotonated thiol, SO32−, (C N)azomethine and (C N)pyridyl groups. The spectral and magnetic studies proposes a tetrahedrally-coordinated Co(II) and Cu(II) complexes and interior bispin state originating from two distinct Oh and Td geometries for [NiH2PyTSC(H2O)]2.4H2O complex. The ESR data and its discussion coincide with the suggestion of distorted Td geometry for [CuH2PyTSC(H2O)]2.H2O complex. The ligand displayed maximum luminescent intensity at about 19,960 cm−1 whereas all complexes show an emission band at about 28,409 cm−1 and therefore they are photoactive compound. The cyclic voltammogram of copper complex indicates a reversible system including the transfer of one electron on every step in case of Cu(II) while that of Co(II) complex shows the transfer of two electrons in only one step. Kinetic and thermodynamic parameters of the isolated complexes for all decomposition steps are discussed. DFT optimization has been used to estimate different descriptors e.g. HOMO, LUMO, MEP and theoretical IR. DNA bioassay, antibacterial, antifungal, antioxidant and anticancer behaviors of the isolated frameworks have been studied.

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 major roadblock to fully realizing molecular electronic devices is the ability to control the properties of each molecule in the device. Herein we report the control of the magnetic properties of single-molecule magnets (SMMs), which can be used in memory devices, by using a photo-isomerizable diarthylenthene ligand. Photo-isomerization of the diarylethene ligand bridging two manganese salen complexes with visible light caused a significant change in the SMM behavior due to opening of the six-membered ring of diarylethene ligand, accompanied by reorganization of the entire molecule. The ring-opening activated the frequency-dependent magnetization of the complex. Our results are a major step towards the realization of molecular memory devices composed of SMMs because the SMM behaviour can be turned on and off simply by irradiating the molecule.

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.

The present work carried out a study on the ligational behavior of the new ligand, Vanillin- 4 N-(2-pyridyl) thiosemicarbazone (H 2 VPT) 1 towards some transition metal ions namely, Mn 2+ , Co 2+ , Ni 2+ , Cu 2+ , Zn 2+ ,Cd 2+ , Hg 2+ and U 6+ . These complexes namely [Mn(HVPT)Cl] 2 , [Co(VPT)(H 2 O)] 2 H 2 O 3 , [Ni(HVPT)Cl(H 2 O)] 4 , [Cu(HVPT)Cl(H 2 O)] 5 , [Zn(VPT)(H 2 O)]H 2 O 6 , [Cd(HVPT)Cl(H 2 O)] 7 , [Hg(VPT)(H 2 O)]H 2 O 8 and [UO 2 (H 2 VPT)(OAc) 2 ]H 2 O 9 , were characterized by elemental analysis, spectral (IR, 1 H NMR and UV–vis) and magnetic moment measurements. The suggested structures were confirmed by applying geometry optimization and conformational analysis. Thermal properties and decomposition kinetics of all compounds are investigated. The interpretation, mathematical analysis and evaluation of kinetic parameters ( E , A , Δ H , Δ S and Δ G ) of all thermal decomposition stages have been evaluated using Coats–Redfern equation. ESR spectra of [Cu(HVPT)Cl]H 2 O at room temperature show broad signal, indicating spin-exchange interactions between copper(II) ions.

A simple and rapid procedure is developed for the quantitative flotation of mercury(II) from aqueous solutions. Thiosemicarbazide derivatives such as: 1-(amino-N-phenylmethanethio)-4-(pyridine-2-yl)thio-semicarbazide (H2PPS), N-phenyl-2-(pyridine-2-ylcarbamothioyl) hydrazinecarboxamide (H2PBO), 1-(amino(thioformyl)-N-phenylform)-4-(pyridine-2-yl)thiosemicarbazide (H2APO), and 1-(amino-N-(pyri-dine-3-yl)methanethio)-4-(pyridine-2-yl)thiosemicarbazide (H2PPY) are used as organic chelating agents and oleic acid (HOL) as surfactant. The different parameters affecting the flotation process namely, metal ion, ligands and surfactant concentrations, foreign ions (which are normally present in fresh and saline waters), pH and temperature are examined. Nearly 100% of mercury ions are floated at a metal:ligand ratio of 1: 4, pH ~ 4 and at room temperature (~25°C). The procedure was successfully applied to recover Hg2+ ions spiked into some water samples. A flotation mechanism is suggested based on some physi...

Cr(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), Pd(II) and dioxouranium(VI), (UO2 2 +), complexes of 4‐(2‐pyridyl)‐1‐diacetylmonoxime‐3‐thiosemicarbazone (H2DMPT) have been synthes...

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 synthesis and characterization of Fe(III), Co(III), Co(II), Ni (II), Cu (II), Zn (II), Cd (II) and UOc complexes of bis(biacetylmonoxime) carbohydrazone (H3BMC) 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 tetradentate and/or pentadentate manner. The behaviour of the ligand towards any metal ion depends on the type of anion and the preparative conditions. An octahedral structure is proposed for the Fe (III), Co (III), Co (II) and the Ni (II) complexes which were prepared from the chloride, bromide, nitrate or sulphate salts. A square-planar structure is proposed for Cu (II) and the Ni (II) complexes derived from the acetate and thiocyanate salts on the basis of magnetic and spectral measurements. H3BMC acts as an oxidizing agent towards Co (II) chloride forming a diamagnetic Co (III) complex. All the complexes are no...

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.