Bis[n(chlorophenyl)dithiocarbamato] complexes of Cu(II), Zn(II), Cd(II) and Sn(II)

Ammonium[N(o-chlorophenyl)dithiocarbamate], NH₄(OCD), ammonium [N(m-chlorophenyl)dithiocarbamate], NH₄(MCD) and ammonium [N(p-chlorophenyl)dithiocarbamate], NH₄(PCD) and their complexes with Cu(II), Zn(II), Cd(II) and Sn(II) have been synthesised. These complexes have been characterised on the basis of chemical analyses, molecular weight determinations, conductance measurements, electronic and IR spectral studies. Thermal behaviour of the compounds has been studied with the aid of TG and DTA techniques in static air atmosphere. Heats of reaction for different decomposition steps have been calculated from the DTA curves. The end products obtained after thermal decomposition of the complexes were identified by elemental analyses and IR spectral data.     

Synthesis and characterization of Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes with N-salicydene-o-hydroxymethyleneaniline

The new Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes with tridentate Schiff base, the product of condensation of o-aminobenzyl alcohol with salicylaldehyde have been synthesized and characterized by elemental analysis, IR, electronic, EPR and Mössbauer spectra, thermal analysis, magnetic susceptibility and molecular weight measurements. Dimeric or polymeric structures for the investigated complexes were proposed. The interaction of the cobalt complex with dioxygen is also described.     

N-vinylcarbazole polymerization by 13X molecular sieve exchanged with Mn(II), Co(II), Ni(II), Cu(II) and Zn(II)

The polymerization of N-vinylcarbazole by 13X molecular sieves modified by five different transition metal ions, viz. Mn(II), Co(II), Ni(II), Cu(II) and Zn(II), has been studied under various conditions. The order of reactivity follows the trend: Mn(II) ≈ Cu(II) > Co(II) > Zn(II) > Ni(II) at pH ∼ 3.55 and an exchange level of 30% of the metal ion. The polymerizations are believed to occur by a dual-ion-initiation mechanism in which both metal ions and proton centres participate. The overall energy of activation (E_a) for each system decreases with decreasing pH of the exchanging salt solution. Average activation energy on proton centre (E_H) and that on metal ion centre (E_a) have been evaluated for each system. E_a, E_H and E_c have been shown to correlate with one another. The molecular weights and their distributions are affected by the nature of the metal ion and also by the protonic centres. The possibility of a correlation of the catalytic activity of the modified 13X with ionic radius, electronegativity and normal co-ordination number has been examined.     

Synthesis and spectroscopic studies of biologically active tetraazamacrocyclic complexes of Mn(II), Co(II), Ni(II), Pd(II) and Pt(II)

Complexes of Mn(II), Co(II), Ni(II), Pd(II) and Pt(II) were synthesized with the macrocyclic ligand, i.e., 2,3,9,10-tetraketo-1,4,8,11-tetraazacycoletradecane. The ligand was prepared by the [2 + 2] condensation of diethyloxalate and 1,3-diamino propane and characterized by elemental analysis, mass, IR and ¹H NMR spectral studies. All the complexes were characterized by elemental analysis, molar conductance, magnetic susceptibility measurements, IR, electronic and electron paramagnetic resonance spectral studies. The molar conductance measurements of Mn(II), Co(II) and Ni(II) complexes in DMF correspond to non electrolyte nature, whereas Pd(II) and Pt(II) complexes are 1:2 electrolyte. On the basis of spectral studies an octahedral geometry has been assigned for Mn(II), Co(II) and Ni(II) complexes, whereas square planar geometry assigned for Pd(II) and Pt(II). In vitro the ligand and its metal complexes were evaluated against plant pathogenic fungi (Fusarium odum, Aspergillus niger and Rhizoctonia bataticola) and some compounds found to be more active as commercially available fungicide like Chlorothalonil.     

Complexation en solution aqueuse des ions magnesium(II), manganese(II), nickel(II), cuivre(II) et plomb(II) avec la s-carboxymethyl-l-cysteine: Complex formation of magnesium(II), manganese(II), nickel(II), copper(II) and lead(II) with S-carboxymethyl-L-cysteine in aqueous solution

Complex formation of magnesium(II), manganese(II), nickel(II), copper(II) and lead(II) with S-carboxymethyl-L-cysteine in aqueous solution.The complex formation between Mg(II), Mn(II), Ni(II). Cu(II), Pb(II) ions and S-carboxy-methyl-l-cysteine (H₂A) has been studied by measurement of pH at 25°C and constant ionic strength (1 M NaClO₄). Although no interaction occurs with Mg(II), this work provides evidence for a variety of complexes: MnA; CuHA⁺; CuA; CuA₂^2-; NiHA⁺; NiA; NiA₂^2-; PbHA⁺; PbA et PbA(OH)^-. The overall formation constants of all these species are computed and refined. The results allow the determination of the distribution of the complexes as a function of pH; some structural features of the metal complexes in solution are indicated.     

Thermal decomposition of mixed ligand complexes of manganese(II), nickel(II), copper(II), zinc(II) and cadmium(II) containing triethanolamine and oxalate

The kinetics of thermal decomposition of mixed ligand complexes of Mn(II), Ni(II), Cu(II), Zn(II) and Cd(II) containing triethanolamine and oxalate have been studied using thermogravimetry (TG) and differential scanning calorimetry (DSC). The decomposition reaction in which the complexes lose one molecule of triethanolamine was found to be first order and the activation energy and pre-exponential factors were calculated using established techniques. The values of E_a obtained for these reactions using a modified form of the Horowitz and Metzger equation were 27.75, 20.54, 18.33, 25.32 and 23.25 kcal mole^?1, respectively. Infrared spectral data of these complexes and the intermediates gave additional information about the coordinating nature of the ligands in these complexes.     

Coordination properties of N-(Thio)phosphorylated thioureas and thioamides with respect to Co(II), Ni(II), Zn(II), and Cd(II) ions in solution

The acid-base and coordination properties of N-(thio)phosphorylated thioureas and thioamides R¹C(X)NHP(Y)R ₂ ² , where X, Y = S, O (in various combinations); R¹ = t?Bu, i-Pr, PhNH, Ph; R² = (OPr?i), with respect to Co(II), Ni(II), Zn(II), and Cd(II) ions have been studied by pH-metry and UV spectrometry in an organic solvent. The pK values, the stability constants logβ and the maximum accumulated fractions of complex species in the solution have been calculated.     

Single crystal circular and linear dichroism spectra and absolute configuration of M(en)3(NO3)2 (M = Zn(II), Cu(II), Ni(II), Co(II), Mn(II) and Ru(II)

The isomorphous single crystals of M(ethylenediamine)₃(NO₃)₂, where M is Zn(II), Ni(II) and Co(II), exhibit macroscopic optical activity as predicted by their acentric space group. Axial circular dichroism measurements on these pure crystals show conclusively that spontaneous resolution has occurred. The axial circular dichroism and orthoaxial linear dichroism spectra of these pure crystals, and of Cu(II), Ni(II), Co(II), Mn(II) and Ru(II) doped into the Zn(en)₃(NO₃)₂ crystal have been measured at ambient and cryogenic temperatures in the range from 7 to 35 kK. The first NO₃^? transition at 32.5 kK is assigned as ¹A ← ¹A based on its linear polarization and sign of rotational strength. The d-d transitions are assigned in the context of D₃ symmetry and reveal a small negative crystal field parameter k, consistent with theoretical prediction. A positive R for all d-d transitions is found to be associated with the Λ configuration for all of the complex ions, by correlation with the crystal and solution circular dichroism of Ru(en)₃²⁺.     

Synthesis,characterization, antimicrobial and diuretic study of Mg(II), Mn(II), Fe(II) and VO(II) complexes of chemotherapeutic importance

The synthesis, characterization and diuretic activity of four new biologically active complexes of Mg(II) and VO(II) with bidentate Schiff base ligand acetazolamide–salicylaldimine (L) obtained from the inserted condensation of 5-acetamido-1,3,4-thiadiazole-2-sulphonamide (acetazolamide) with salicylaldehyde in a 1:1 molar ratio have been reported. Using this bidentate ligand complexes of Mg(II), Mn(II), Fe(II) and VO(II) with general formula ML₂ have been synthesized. The synthesized complexes were characterized by several techniques using elemental analysis, FT-IR, electronic spectra, TGA, mass, particle size analysis and molar conductance measurements. The elemental analysis data suggest the stoichiometry to be 1:2 [M:L]. The molar conductance measurements suggest non-electrolytic nature of the complexes. Infrared spectral data agreed with the coordination to the central metal ion through deprotonated phenolic oxygen and azomethine nitrogen atoms. On the basis of spectral studies, octahedral geometry is suggested for Mg(II), Mn(II), Fe(II) and square pyramidal geometry is suggested for VO(II) complexes. The pure drug, synthesized ligand and metal(II) complexes were screened for their antimicrobial activities against Eschericia coli, Bacillus subtilis, Aspergillus niger and Aspergillus flavous. The results show that the metal complexes were more active than the ligand and pure drug against these microbial species as expected. The ligand and its Mg(II) complexes was screened for their diuretic activity also.     

Thermodynamic study of the complexation processes between 6,7-dihydro-3(H)-6-methyl-5-methoxy-7-oxo-vic-triazolo (4,5-d) pyrimidine and Cu(II), Zn(II), Cd(II) and Hg(II)

The compound 6,7-dihydro-3(H)-6-methyl-5-methoxy-7-oxo-vic-triazolo (4,5-d) pyrimidine (LH) has been characterized by IR, ¹H-NMR and UV-visible spectroscopy. Furthermore, its acid behaviour in aqueous solutions at variable temperatures and ionic strengths have been studied.The stability constants of the complexes formed by LH with Cu(II), Zn(II), Cd(II) and Hg(II) metal ions at different ionic strengths and temperatures have been calculated by the method of Chabereck and Martell. From these data, the thermodynamic functions for the corresponding complexation processes have been obtained.     

Synthesis and Spectral Properties of Ni(II), Pd(II), Pt(II), and Pt(IV) Tetraphenyltetrabenzoporphyrinates

Complexation reactions of 5,10,15,20-tetraphenyltetrabenzoporphyrin and transmetallation of its cadmium complex with nickel(II) acetate, Ni(II), Pd(II), and Pt(II) chlorides in dimethylformamide and phenol have been studied. The corresponding Ni(II), Pd(II), and Pt(II) porphyrinates have been synthesized. Pt^IVBr₂ porphyrinate has been obtained by the treatment of Pt(II) 5,10,15,20-tetraphenyltetrabenzoporphyrinate with bromine in chloroform. The obtained compounds have been characterized by elemental analysis, electronic absorption and ¹H NMR spectroscopy and mass spectrometry.     

Organic acid solutions in the chromatography of inorganic ions. VII. Cation exchange of Mg(II), Ca(II), Sr(II), Ba(II), Mn(II), Cd(II), Co(II), Ni(II), Zn(II), Cu(II) and Fe(III) in succinate media

Summary The cation-exchange behaviour of Mg(II), Ca(II), Sr(II), Ba(II), Mn(II), Cd(II), Co(II), Ni(II), Zn(II), Cu(II) and Fe(III) in succinate media at various concentrations and pH, was studied with Dowex 50 WX8 resin (200–400 mesh) in the NH ₄ ⁺ form. As examples separations of Cd(II)/Co(II), Cd (II)/Ni(II), Fe(III)/Cu(II)/Ni(II) and Mg(II)/Ca(II)/Sr(II)/Ba(II) have been achieved.This work was supported by C.N.R. of Italy.     

Synthesis,characterization and biological studies of Co(II), Ni(II), Cu(II) and Zn(II) complexes with pyrral-l-histidinate

The Schiff base ligand, pyrral-l-histidinate(L) and its Co(II), Ni(II), Cu(II) and Zn(II) complexes were synthesized and characterized by elemental analysis, mass, molar conductance, IR, electronic, magnetic measurements, EPR, redox properties, thermal studies, XRD and SEM. Conductance measurements indicate that the above complexes are 1:1 electrolytes. IR data show that the ligand is tridentate and the binding sites are azomethine nitrogen, imidazole nitrogen and carboxylato oxygen atoms. Electronic spectral and magnetic measurements indicate tetrahedral geometry for Co(II) and octahedral geometry for Ni(II) and Cu(II) complexes, respectively. The observed anisotropic g values indicate the presence of Cu(II) in a tetragonally distorted octahedral environment. The redox properties of the ligand and its complexes have been investigated by cyclic voltammetry. Thermal decomposition profiles are consistent with the proposed formulations. The powder XRD and SEM studies show that all the complexes are nanocrystalline. The in vitro biological screening effects of the synthesized compounds were tested against the bacterial species, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa and Staphylococcus aureus; fungal species, Aspergillus niger, Aspergillus flavus and Candida albicans by the disc diffusion method. The results indicate that complexes exhibit more activity than the ligand. The nuclease activity of the ligand and its complexes were assayed on CT DNA using gel electrophoresis in the presence and absence of H₂O₂.     

Synthesis, spectroscopic and cyclic voltammetry studies of novel azacrown ether containing vic-dioxime ligand and its Ni(II), Cu(II), Co(II), Cd(II) and Zn(II) complexes

In this study, the novel vic-dioxime ligand (3) and its Ni(II), Cu(II), Co(II), Cd(II) and Zn(II) complexes (4–8) were synthesized for the first time by condensation reactions of N-(4-aminophenyl)aza-15-crown-5 (1) and anti-chlorophenylchloroglyoxime (2). All of these new compounds were characterized by the elemental analysis, Fourier transform infrared, ultraviolet–visible, mass spectrometry, ¹H NMR, ¹³C NMR and magnetic susceptibility measurements. The electrochemical properties of the ligand and its complexes have been investigated by cyclic voltammetry at the glassy carbon electrode in 0.1 M TBATFB in DMSO.     

Cobalt(II), copper(II), zinc(II)—Amino and thiosalicylic acids ternary complexes

A series of Co(II), Cu(II), Zn(II)-thiosalicylic-amino acids of the molecular formula (M-TSA-a.a.) · 2 H₂O has been synthesized and characterized by chemical analyses, molar conductance, electronic and i.r. spectral measurements.     

Mn(II), Co(II), Ni(II) and Cu(II) complexes of a tertraaza macrocyclic ligand: Synthesis, characterization and biological screening

Manganese(II), cobalt(II), nickel(II) and copper(II) complexes with 1,5,11,15-tetraaza-21,22-dioxo-tricyclo [19,3,1,I^6,10]-5,10,15-20-dicosatetraene (L), as a new macrocyclicligand, have been synthesized with and characterized by elemental analysis, molar conductance measurements, magnetic susceptibility measurements, mass, IR, electronic and EPR spectral studies. The molar conductance measurements of the complexes in DMF correspond to non-electrolytic nature of Mn(II), Co(II) and Cu(II) complexes, while showing a 1:2 electrolyte for thew Ni(II) complexe. Thus, these complexes may be formulated as [M(L)X₂] and [Ni(L)]X₂ (where M = Mn(II), Co(II) and Cu(II) and X = Cl^- and NO₃ ^-). On the basis of IR, electronic and EPR spectral studies, an octahedral geometry has been assigned for Mn(II) and Co(II), a square planar for Ni(II) and tetragonal for Cu(II) complexes. In vitro ligand and its metal complexes were also screened against the growth of some fungal and bacterial species in order to assess their antimicrobial properties.     

Polarographic analytical determination of Hg(II), Cu(II), Cd(II), As(III), Sb(III), Ti(IV) and U(VI) in the presence of Fe(III)

The analytical determination of Hg(II), Cu(II), Cd(II), As(III), Sb(III), Ti(IV) and U(VI) in the presence of Fe(III) and 1 M H₂SO₄ are investigated using the polarographic technique. The wave corresponding to the reduction of Fe(III) to Fe(II) was found to be completely suppressed by the addition of 1% pyrogallol. Thus, different mixtures of these elements, viz. Hg(II), Cu(II), Cd(II), As(III) and Fe(III)-mixture (A), Cu(II), Cd(II), Sb(III), As(III) and Fe(III)-mixture (B), and Cu(II), Cd(II), Ti(IV), U(VI) and Fe(III)-mixture (C), were quantitatively determined using 1% pyrogallol and 1 M H₂SO₄ as supporting electrolyte. The i₁/c results give excellent correlations in each case, as indicated from the results of leastsquares regression analysis.     

BisN(chlorophenyl)dithiocarbamato complexes of cobalt(II), nickel(II), palladium(II) and platinum(II)

Summary Cobalt(II), nickel(II), palladium(II) and platinum(II) complexes witho-(OCD),m-(MCD) andp-chlorophenyldithiocarbamate (PCD) ligands have been synthesised and characterised by chemical analyses, molecular weight determinations, conductance measurements, electronic and i.r. spectral studies. The thermal behaviour of the complexes has been studied by t.g. and d.t.a. techniques in a static air atmosphere and heats of reaction of different decomposition steps have been calculated from the d.t.a. curves. The thermal decomposition products of the complexes were identified by elemental analyses and i.r. spectra.     

Cation-Induced dimerization of nickel(II), platinum(II), and palladium(II) meso-tetra(benzo-15-crown-5)porphyrinates

Cation-induced dimerization of nickel(II), platinum(II), and palladium(II) meso-tetra(benzo-15-crown-5)porphyrinates (Ni(II)TCP, Pd(II)TCP, and Pt(II)TCP) on treatment with potassium thiocyanate in a chloroform-methanol solution has been studied by electronic absorption spectroscopy. The formation of [{MTCP}₂(K⁺)₄](SCN^?)₄ in solution induces a hypsochromic shift of the Soret band and a bathochromic shift of the β-band with respect to their positions in the spectrum of MTCP. The equilibrium constants (K) for the 2MTCP + 4K⁺ = [{MTCP}₂(K⁺)₄] processes at 20°C are determined to be as follows: log K _Ni(II)TCP = 27.31 ± 1.67, logK _Pd(II)TCP = 27.16 ± 1.43, and logK _Pt(II)TCP = 26.15 ± 1.56.     

Synthesis and spectroscopic characterization of Zn(II), Cd(II), and Hg(II) ciprofloxacin complexes

Ciprofloxacin metal co mplexes with general for mula [M(CPF)₂]X₂·nH₂O [M = Zn(II), Cd(II), and Hg(II)] have been synthesised and characterized using elemental analysis (CHN), spectroscopic (UV-Vis, IR, MS, and ¹H NMR) and ther mogravimetric (TG and DTA) data. Using the Coats-Redfern and Horowitz-Metzeger methods, kinetic analysis of the thermogravimetric data had been performed.