Synthesis and characterization of mixed ligand complexes of cobalt(II) with some nitrogen and sulfur donors

Mixed ligand complexes of Co(II) with nitrogen and sulfur donors, Co(OPD)(S–S) · 2H₂O and Co(OPD)(S–S)L₂ [OPD = o-phenylenediamine; S–S = 1,1-dicyanoethylene-2,2-dithiolate (i-MNT^2?) or 1-cyano-1-carboethoxyethylene-2,2-dithiolate (CED^2?); L = pyridine (py), α-picoline (α-pic), β-picoline (β-pic), or γ-picoline (γ-pic)], have been isolated and characterized by analytical data, molar conductance, magnetic susceptibility, electronic, and infrared spectral studies. The molar conductance data reveal non-electrolytes in DMF. Magnetic moment values suggest low-spin and high-spin complexes. The electronic spectral studies suggest distorted octahedral stereochemistry around Co(II) in these complexes. Infrared spectral studies suggest bidentate chelating behavior of i-MNT^2?, CED^2?, or OPD while other ligands are unidentate in their complexes.     

Preparation of Schiff’s base complexes of Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) and their spectroscopic, magnetic, thermal, and antifungal studies

The potassium salt of salicylidene-DL-alanine (KHL), bis(benzylidene)ethylenediamine (A¹), thiophene-o-carboxaldene-p-toluidine (A²), and its metal complexes of the formula [(M^II(L)(A)(H₂O)] (M = Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II); A = A¹ or A²) are prepared. They are characterized by elemental analysis, magnetic susceptibility measurements, thermogravimetric analysis, and infrared and electronic spectral studies. The electronic spectral and magnetic moment data suggest an octahedral geometry for the complexes. All of these complexes, metal nitrates, fungicides (bavistin and emcarb), and ligands are screened for their antifungal activity against Aspergillus niger, Fusarium oxysporum, and Aspergillus flavus using a plate poison technique. The complexes show higher activity than those of the free ligands, metal nitrate, and the control (DMSO) and moderate activity against bavistin and emcarb. The text was submitted by the authors in English.     

Copper(II), cobalt(II), nickel(II) and mercury(II) complexes of 1,4-diphenylthiosemicarbazide

Summary The preparation and characterization of Cu^II, Co^II, Ni^II and Hg^II complexes containing 1,4-diphenylthiosemicarbazide (DPhTSC) of the type [Cu(DPhTSC-H)X.H₂O]nH₂O (X= Cl, Br or Ac; n=0 or 1) · [M(DPhTSC-H)₂yH₂O] (M=Co^II or Ni^II; y=0 or 1) and [Hg(DPhTSC)Cl₂]2 H₂O and [Cu(D-PhTSC)₂SO₄]H₂O are reported. The stereochemistry of the complexes have been studied with the help of magnetic and electronic measurements. The anomalous magnetic moments observed in all cases have been explained. The i.r. spectral studies have been used to determine the bonding sites in the complexes.     

Metal complexes of carbazic acids,part 2. Copper(II) complexes ofN-substituted carbazic acids

Summary Copper(II) complexes of N-substituted carhazic acids have been prepared and characterised by analytical, magnetic. electronic and i.r. spectral measurements. The complexes, which are of two types, CuL₂(H₂O), (where L = carhazic acid. methy1carbazic acid and phenylcarbazic acid) and CuL, (where L = 2,3-dimethylcarbazic acid, 3.3-dimethvlcarbazic acid and 3.3-methylphenylcarbazic acid), have distorted octahedral structures, bonded through one of the nitrogen atoms and carboxylate group.     

Manganese (II) complexes of some nitrogen-oxygen and nitrogen-sulphur donor ligands

Manganese(II) complexes of the general composition, Mn(L)₂X₂ (X = Cl or 1/2 SO₄,L = semicarbazones and thiosemicarbazones of acetone, ethyl methyl ketone and 2-methyl cyclohexanone) have been prepared and characterised by elemental analysis, magnetic moments, conductance measurements, IR, electronic and ESR spectral studies. All the complexes are six-coordinate octahedral.     

Synthesis and structural characterization of mixed ligand complexes of nickel(II) with 1-cyano-1-carboethoxyethylene-2,2-dithiolate and some nitrogen donors

Mixed ligand complexes of Ni^II ion with 1-cyano-1-carboethoxyethylene-2,2-dithiolate (CED²⁻[S₂C = C (CN)(COOC₂H₅)]²⁻) as a primary ligand and o-phenylenediamine (OPD), pyridine (py), α-picoline (α-pic), β-picoline (β-pic) or γ-picoline (γ-pic) as secondary ligands have been isolated and characterized on the basis of analytical data, molar conductance, magnetic susceptibility, electronic and infrared spectral studies. The molar conductance data reveal that the complexes have 1:1 electrolytic nature in DMF solution. Magnetic and electronic spectral studies suggest distorted octahedral stereochemistry around Ni^II ion in its complexes. Infrared spectral studies suggest bidentate chelating behaviour of CED²⁻ ion and OPD while other ligands show unidentate behaviour in their complexes.     

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.     

Studies on mixed ligand complexes,part 4. Cobalt(III) heterochelates containing trimethylenediamine and some bidentate NN,NO and OO donor ligands

Summary A series of new diamagnetic cobalt(Ill) mixed ligand complexes having general formula [Co(AA)(tn)₂]ⁿ⁺ (where AA = biguanide, picolinic acid, acetoacetanilide, benzoylacetanilide,m-nitrobenzoylacetanilide, acetylacetone,N-benzoylphenylhydroxylamine and malonic acid, tn = trimethylenediamine and n = 1–3) have been synthesized and characterized by elemental analysis, conductance measurements, electronic spectra, i.r. spectra, equivalent weight and magnetic measurements. The electronic spectra are typical of octahedral cobalt(III) complexes. The effect of cationic charge and the nature of the ligands on the R_f values of the complexes have been determined by paper chromatography.Author to whom all correspondence should be directed.     

Spectral,magnetic studies and molecular orbital calculations for (4,5-dimethyl-3-pyrazolyl)aldazine copper(II) complexes

Summary A new series of copper(II) complexes derived from (4,5-dimethyl-3-pyrazolyl) aldazine (DMPA), formulated as: (a) [LCuX₂]·nEtOH; (b) [LCu(H₂O)](ClO₄)₂; and (c) [LCuX]BF₄·nH₂O, where n = 1/2 or 1, X = Cl or Br and L = DMPA, have been synthesized. The formulations are based on elemental analyses and molar conductivity data. I.r., u.v.-vis., e.s.r. and magnetic data reveal that the complexes are trigonal bipyramidal, tetrahedral and stacked square-planar structures for (a), (b) and (c), respectively. The trigonal bipyramidal structure for class (a) compounds is confirmed using the atom superposition and electron delocalization-molecular orbital calculations, which agree with the experimental electronic spectral data. Variable temperature magnetic susceptibility data shows a ferromagnetic interaction within copper(II) complexes of class (c).     

Synthesis and chemical characterization of biologically important complexes of vanillin thiosemicarbazone with manganese(II), iron(II), cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II), and mercury(II)

Summary Vanillin thiosemicarbazone (VTSC) has been used to isolate the complexes of the types [M(VTSC)₂(H₂O)₂]X₂ (M=Mn^II, Fe^II, Co^II, or Ni^II and X=Cl) and [M(VTSC)X₂]H₂O (M=Cu^II, Zn^II, Cd^II or Hg^II and X=Cl). Probable structures of these complexes are suggested on the basis of elemental analysis, molar conductance, magnetic moment and electronic and i.r. spectral data. The fungicidal activity of VTSC and the isolated complexes has been evaluated on pathogenic fungi,Alternaria (Sp.),Paecilomyces (Sp.) andPestalotia (Sp.).On leave from the University of Myosore.     

Platinum(II) complexes ofN-alkylphenothiazines

Summary The synthesis and physical properties of eight square-planar platinum(II) complexes, [PtLCl₂] (L =N-alkylphenothiazine) are reported. Analytical, conductometric, spectral (electronic, i.r. and¹H n.m.r.) and thermal data for the complexes are discussed.     

Acetate and malonate complexes of cobalt(II), nickel(II) and zinc(II) with hydrazinium cation

The hydrazinium(1+) metal acetates and malonate dihydrates of the molecular formula [(N₂H₅)₂M(CH₃COO)₄] and (N₂H₅)₂[M(OOCCH₂COO)₂(H₂O)₂] respectively, whereM=Co, Ni or Zn, have been prepared and characterized by chemical analyses, conductance, magnetic, spectral, thermal and X-ray powder diffraction studies. The magnetic moments and electronic spectra indicate that these complexes are of high-spin octahedral variety. The infrared spectra show that the hydrazinium ions are coordinated in the case of acetate complexes, whereas in the malonate complexes the hydrazinium ions are out side the coordination sphere. These complexes undergo exothermic decomposition in the temperature range 150–450°C to give the respective metal oxide as the final residue. The X-ray powder diffraction patterns of the malonate complexes indicate isomorphism among them.     

Complexes with N,S donor ligands. Nickel(II), copper(II), cobalt(II), iron(III) and palladium(II) complexes of biacetylbis(mercaptophenylimine) and their reactions with alkyl and aryl halides,leading to the formation of macrocycles

Summary Compounds of the type ML, where M is a divalent metal ion such as Ni, Cu and Co and H₂L=biacetylbis(mercaptophenylimine) and [MLCl], where M is iron(III) have been prepared and characterised by elemental analysis, molar conductances, magnetic susceptibilities and i.r. and electronic spectral data.A trinuclear complex of palladium(II), [Pd₃L₂]Cl₂, has also been isolated and characterised.¹H.n.m.r. spectroscopic data, along with other physico-chemical analytical results, support this trinuclear formulation.Reactions of these complexes, except for the palladium(II) complex, with difunctional alkylating agents produce macrocyclic derivatives with alkylation of the coordinated mercaptide groups.     

Cobalt(II), nickel(II), copper(II), zinc(II) and uranyl(VI) complexes of acetylacetone bis(4-phenylthiosemicarbazone)

Summary Reaction of one mole of acetylacetone with two moles of 4-phenylthiosemicarbazide yields the unusual Schiff base, MeC(=N-NHCSNHPh)CH₂C(=NNHCSNHPh)Me. APT = H₂L) acetylacetone bis(4-phenylthiosemicarbazone). The complexes of Co^II, Ni^II, Cu^II, Zn^II and U^VIO₂ have been prepared and characterized by analytical, i.r., electronic spectral and magnetic measurements. The Co^II, Ni^II and Cu^II complexes have been assigned square-planar stereochemistry on the basis of magnetic and spectroscopic studies. The ligand is a neutral or dibasic quadridentate SNNS donor as revealed by i.r. spectral studies.     

Cobalt(II), nickel(II) and copper(II) complexes of syn-2-picolyl phenyl and syn-2-quinaldyl phenyl ketoximes

Summary The syn-2-picolyl phenyl ketoxime (HL₁) and the syn-2-quinaldyl phenyl ketoxime (HL₂) give [M(HL)LX], [M(HL)₂X₂] and [ML] solid complexes (M=Co, Ni and Cu; X=Cl^–, Br^– and NO ₃ ^– which have been characterized by elemental analysis, room temperature magnetic moments and electronic and i.r. spectral measurements.     

Copper(II) and nickel(II) complexes of schiff bases

Summary The isolation of complexes of some nickel(II) and copper(II) salts with the Schiff base derived from 2-aminobenzimidazole and 4-methylbenzaldehyde (abimbz) is reported. They are of the general type M(abimbz)₂X₂ (M=Ni or Cu; X=Cl, Br, or ClO₄). The compounds have been characterized by elemental analyses, conductivity measurements, i.r., electronic and e.p.r. spectral studies and magnetic measurements. The i.r. spectra show that the ligand is bidentate through the tertiary nitrogen of the imidazole ring and the exocyclic imine nitrogen. Possible structures for the complexes are suggested.     

Characterization of the adducts of bis(O-isoamyldithiocarbonato)nickel(II) with heterocyclic amines and X-ray structure of bis(O-isoamyldithiocarbonato)-bis(3-bromopyridine)nickel(II)

A series of six-coordinated Ni(II) complexes, with the general formula Ni(Xan)L₂ (where Xan = = isoamyldithiocarbonato and L = 2-bromopyridine, 3-bromopyridine, 4-acetylpyridine, 3-hydroxypyridine and 2-methoxypyridine) are synthesized and characterized by the elemental analysis and various physicochemical techniques such as magnetic susceptibility and conductivity measurements, UV-visible and infrared spectral data. Based on the electronic spectra and magnetic susceptibility measurements, an octahedral geometry is proposed for all the complexes. IR spectral data show that in all these complexes substituted pyridines coordinate to the metal ion through nitrogen atoms occupying the fifth and sixth axial positions, whereas O-alkyldithiocarbonate acts as a monoanion bidentate ligand and occupies the planar positions of octahedral structures. The structure of the adduct with 3-bromopyridine is elucidated by the single crystal X-ray diffraction method. The complex crystallizes in the triclinic space group P-1 with unit cell parameters a = 6.5855(4) Å, b = 9.4984(6) Å, c = 12.4518(8) Å, α = 87.944(5)°, β = 78.843(5)°, γ = 77.794(5)°. The crystal structure of the molecule is stabilized by intermolecular C–H…S and C–H…π interactions.     

Synthesis of copper(II) and nickel(II) triazacycloalkane complexes

Summary Copper(II) and nickel(II) complexes of triazacycloalkanes (pqr-cy), with p, q, r = 2–6, have been prepared and characterized by means of electronic and i.r. spectroscopy, and by magnetic measurements. With nickel(II) mononuclear octahedral complexes [Ni(pgr-cy)₂](CI0₄)₂ are formed, but for copper(II) mononuclear octahedral complexes were obtained only for 222-cy and 223-cy. The other ligands gave copper(II) complexes of the type [Cu(pgr-cy)CI]CIO₄, [Cu(pgr-cy)OH]ClO₄, Or [Cu(pgr-cy)CI_1/2OH_1/2]ClO₄. The hydroxy complexes have low magnetic moments and binuclear hydroxy bridged structures are proposed.Ligand names: e.g. p = q = r = 2 is 1,4,7-triazacvclononane     

Interaction of manganese(II), iron(II), cobalt(II), nickel(II), copper(II) and zinc(II) with acetylhydrazine, formed in situ; first crystal structure of tris(acetylhydrazine) nickel(II) perchlorate

A series of transition metal complexes of the type [M(ah)₃](ClO₄)₂ (1–6) [M = Mn^II, Fe^II, Co^II, Ni^II, Cu^II and Zn^II, ah = acetylhydrazine] have been prepared by the reaction of M(ClO₄)₂ · 6H₂O with acetylhydrazine formed in situ by the reaction of hydrazine hydrate and acetylsalicylic acid methyl ester. The chelating behaviour of acetylhydrazine and overall geometry of these complexes have been spectroscopically investigated by means of FT-IR, ¹H-n.m.r. and electronic spectral techniques, as well as by elemental analysis data, molar conductance values and magnetic susceptibility measurements. Single X-ray structure determination of complex (4) revealed three acetylhydrazine ligands coordinated to nickel ion in a bidentate manner maintaining an octahedral environment. In all other complexes too, an octahedral geometry has been proposed on the basis of results obtained by various physico-chemical studies.     

Six-coordinate dinuclear hexaazamacrocyclic complexes of nickel(II), copper(II) and zinc(II) with tetraamide group ligands

Summary A series of 20–24 membered macrocyclic dinuclear transition metal complexes [M₂L¹X₄]-[M₂L⁴X₄] (M = Ni^II, Cu^II or Zn^II; X = Cl or NO₃) have been synthesized by template condensation of diethylenetriamine with dicarboxylic acids. The bonding and stereochemistry of the complexes have been characterized by i.r.,¹H-n.m.r., e.p.r. and electronic spectral studies, magnetic susceptibility and conductivity measurements. The Ni and Zn complexes exhibit octahedral geometry around the metal ion, whereas the Cu complexes possess a distorted octahedral geometry. Each metal ion is coordinated by two amide nitrogens and two secondary nitrogens of the diethylenetriamine moiety; the fifth and sixth coordination sites are occupied by the anions.