Coordination compounds of cobalt, nickel, copper and zinc with thiosemicarbazone and 3-phenylpropenal semicarbazone

Hydrates of 3-phenylpropenal thiosemicarbazone (HL·H₂O) and semicarbazone (HL′·H₂O) react in methanol with cobalt, nickel, copper, and zinc chlorides, nitrates, and acetates to form coordination compounds MX₂·2HL·nSolv [M = Co, Ni, Cu, Zn; X = Cl, NO₃; HL = C₆H₅CH=CH-CH=N-NHC(O)NH₂; n = 0–3; Solv = H₂O, CH₃OH], CuX₂·HL·nH₂O [M = Ni, Cu; n = 0, 1], ML₂·nH₂O and ML′·nH₂O [M = Co, Ni, Zn; HL′ = C₆H₅CH=CH-CH=N-NHC(O)NH₂; n = 0–3]. In the presence of amines (A = C₅H₅N, 2-CH₃C₅H₄N, 3-CH₃C₅H₄N, and 4-CH₃C₅H₄N) these reactions yield the complexes Cu(A)LCl·CH₃OH and M(A)LX·nH₂O [M = Cu, Ni; X = Cl, NO₃; n = 0–2]. The copper complexes with the amine ligands are of polynuclear structure, and other complexes are monomeric. Carbazones (HL and HL′) are included in the complexes as bidentate N,S-and N,O-ligands. The thermolysis of the complexes involves the stages of removing solvent crystallization molecules (70–90°C), deaquation (150–170°C), and full thermal decomposition (500–580°C).     

Coordination compounds of cobalt,nickel, copper,and zinc with 2-bromo-3-phenylpropenal benzoylhydrazone and thiosemicarbazone

By X-ray structural analysis the crystal structure of 2-bromo-3-phenylpropenal benzoylhydrazone (HL) was determined. The molecule is not flat. In the crystal the HL molecules form infinite chains with reciprocal van der Waals interaction. 2-Bromo-3-phenylpropenal hydrazone (HL) and thiosemicarbazone (HL′) react with cobalt, nickel, copper and zinc chlorides, nitrates and acetates to form coordination compounds of the composition Cu(HL)(L)₂ [HL = C₆H₅-CH=CBr-CH=N-NH-C(O)-C₆H₅], MX₂·2 HL′·nH₂O [M = Co, Ni, Cu, Zn; X = Cl, NO₃, HL′ = C₆H₅-CH=CBr-CH=N-NH-C(S)-NH₂; n = 0–3], MX₂·HL·n H₂O [M = Ni, Cu; n = 0, 1], and ML′₂·nH₂O [M = Co, Ni, Zn; n = 0–3]. The same reactions in the presence of amines (A = C₅H₅N, 2-CH₃C₅H₄N, 3-CH₃C₅H₄N, 4-CH₃C₅H₄N) afford complexes of the composition CuALCl and MALX·n H₂O [M = Cu, Ni; X = Cl, NO₃; n = 0–2]. Structure of the coordination node in the amine-containing copper derivatives is polynuclear, in complexes Cu(HL)(L)₂ is octahedral, in other compounds it is tetrahedral. The azomethines (HL and HL′) in these complexes behave as bidentate N,O and N,S ligands. Thermolysis of the complexes includes a step of dehydration (60–90°C) and complete thermal decomposition (430–590°C).     

Cobalt, nickel, and copper coordination compounds with 3-phenylpropenal benzoylhydrazone

3-Phenylpropenal benzoylhydrazone (HL) reacts with cobalt, nickel, and copper chlorides, nitrates, and acetates to give coordination compounds MX₂ · nH₂O [M = Co, Ni, Cu; X = Cl, NO₃, HL = C₆H₅CH=CHCH=NNHC(O)C₆H₅; n = 0, 2] and ML₂ · nH₂O (M = Co, Ni, Cu; n = 1–3). Complexes MALCI (M = Co, Ni, Cu) were obtained by these reactions in the presence of amines (A = C₅H₅N, 2-CH₃C₅H₄N, 3-CH₃C₅H₄N, 4-CH₃C₅H₄N). All the compounds have a monomeric structure. Azomethine (HL) in them behaves as a bidentate N,O-ligand. Thermolysis of the complexes involves the stages of dehydration (70–90°C), deaquation (145–155°C) or deamination (145–185°C), and complete thermal decomposition (330–490°C).     

Crystal structures of pyridine-4-aldehyde thiosemicarbazone perchlorate and trifluoromethane sulfonate

The new salts of pyridine-4-aldehyde thiosemicarbazone: perchlorate (I) and trifluoromethane sulfonate (II) HN⁺C₅H₄-CH=N-NH-C(S)-NH₂·X^? (X = ClO₄, CF₃SO₃) were synthesized and studied by IR and NMR spectroscopy and X-ray diffraction analysis. The compounds were synthesized by a reaction of pyridine-4-aldehyde thiosemicarbazone with chloric or trifluoromethane sulfonic acid, respectively. Compound I crystallized in the triclinic crystal system, space group P-1, a = 6.8691(2) Å, b = 9.5406(4) Å, c = 9.6348(4) Å, α = 78.838(1)°, β = 77.618(1)°, γ = 69.661(1)°, Z = 2. Compound II crystallized in the monoclinic crystal system, space group P2₁/c, a = 7.3149(8) Å, b = 11.9830(16) Å, c = 15.143(2) Å, β= 96.949(4)°, Z = 4. The structures are formed by hydrogen-bonded ions. Moreover, the cations are linked in “dimmers” due to the weak N-H...S hydrogen bonds.     

Solution studies on chelates of nickel, zinc and cadmium with 2-thiopicolinanilide

The protonation constants of 2-thiopicolinanilide (TPA) and the stability constants of its complexes with Ni, Zn and Cd have been determined potentiometrically in 50% w/w ethanol-water medium, at 25 degrees and 0.100M ionic strength (LiClO(4)). Co-ordination centres in TPA are suggested.     

High-performance liquid chromatographic determination of nickel,copper and zinc as their tetraphenylporphine chelates

Nickel(II), copper(II) and zinc(II) ions are extracted from an aqueous solution into carbon tetrachloride as their diethyldithiocarbamate (DDC) chelates. The extract, after removal of the solvent, is treated with meso-tetraphenylporphine (TPP) in benzyl alcohol at 140°C for 60 min. Quantitative conversion of the DDC chelate to the TPP chelate is obtained over the range 0.25–4.5 μg of each metal by use of 3 μgmol of TPP. The reaction mixture is analysed by reversed-phase high-performance liquid chromatography with spectrophotometric detection at 412 nm. Simultaneous determination of Cu and Zn in NBS bovine liver is possible by this procedure.     

Versatile chelating behavior of benzil bis(thiosemicarbazone) in zinc, cadmium, and nickel complexes

Reactions of benzil bis(thiosemicarbazone), LH(6), with M(NO(3))(2).nH(2)O (M = Zn, Cd, and Ni), in the presence of LiOH.H(2)O, show the versatile behavior of this molecule. The structure of the ligand, with the thiosemicarbazone moieties on opposite sides of the carbon backbone, changes to form complexes by acting as a chelating molecule. Complexes of these metal ions with empirical formula [MLH(4)] were obtained, although they show different molecular structures depending on their coordinating preferences. The zinc complex is the first example of a crystalline coordination polymer in which a bis(thiosemicarbazone) acts as bridging ligand, through a nitrogen atom, giving a 1D polymeric structure. The coordination sphere is formed by the imine nitrogen and sulfur atoms, and the remaining position, in a square-based pyramid, is occupied by an amine group of another ligand. The cadmium derivative shows the same geometry around the metal ion but consists of a dinuclear structure with sulfur atoms acting as a bridge between the metal ions. However, in the nickel complex LH(6) acts as a N(2)S(2) ligand yielding a planar structure for the nickel atom. The ligand and its complexes have been characterized by X-ray crystallography, microanalysis, mass spectrometry, IR, (1)H, and (13)C NMR spectroscopies and for the cadmium complex by (113)Cd NMR in solution and in the solid state.     

Synthesis,characterization and antitumour studies of metal chelates of acetoacetanilide thiosemicarbazone

Summary Complexes of transition metals with acetoacetanilide thiosemicarbazone, AatH₂, have been prepared and characterized. The complexes were found to have the following stoichiometries: [Mn(Aat)(H₂O)₂]_n; [Zn(Aat)(H₂O)₂]; [M(Aat)(H₂O)], where M = Cd^II or Hg^II; [Cu(Aat)]_n; [Ag(AatH)]; [M(AatH)₂], where M = Co^II or Ni^II, and [Fe(Aat)Cl(H₂O)]_n. The compounds have been studied for their possible antitumour activity against Ehrlich Ascites tumour cells in vitro.     

Crystal structure of benzoylformic acid thiosemicarbazone

Institute of Applied Physics, Academy of Sciences of the Moldavian SSR. Institute of Chemistry, Academy of Sciences of the Moldavian SSR. Burevestnik [Stormy Petrel] Scientific-Industrial Association, Leningrad. Translated from Zhurnal Strukturnoi Khimii, Vol. 29, No. 5, pp. 166–169, September–October, 1988.     

Crystal structures of deoxyvasicinone and its salts

The structures of the alkaloid deoxyvasicinone and of its complexes with HCl and CoCl₂·2HCl have been established by the method of x-ray structural investigation. The formation of complex salts of deoxyvasicinone differs from that of alkaloids with similar structures - peganine and deoxypeganine.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 849–854, November-December, 1995. Original article submitted April 17, 1995.     

Polymerization of acrylonitrile catalyzed by methoxo-β-diketone nickel chelates

The polymerization of acrylonitrile initiated by methoxo-β-diketone nickel chelates of the [Ni(L)(CH₃O)(CH₃OH)]_n type and pyridine was studied. Chelating agents L employed included acetylacetone, ethylacetoacetate, and salicylaldehyde. These systems could initiate the polymerization of acrylonitrile at ?40°C. The polymerization is thought to occur by an anionic coordination mechanism.     

Crystal structures of 2- and 3-cyanopyridine

The crystals of 2- and 3-cyanopyridine isomers have been obtained by a sublimation method. The crystal structures of both isomers have been determined on the basis of low-temperature X-ray single crystal experiments and compared, also in relation to 4-cyanopyridine. In 2-cyanopyridine the nitrogen atom of the CN group, whereas in 3- the N-ring atom, is involved in the shortest intermolecular contact. In both cases, the hydrogen bond type interactions are rather of a weak nature, but they are important for developing of the polymeric chains.     

Determination of isotope ratios of chromium nickel,zinc and copper by gas chromatography-mass spectrometry by using volatile metal chelates

A gas chromatographic-mass spectrometric (GC-MS) method involving thermally stable, volatile chelates was investigated for measurements of isotope ratios of chromium, nickel, zinc and copper. The chelating agents acetylacetone, trifluoroacetylacetone, sodium diethyldithiocarbamate and lithium bis (trifluoroethyl)dithiocarbamate [Li(FDEDTC])] were used. Experimental conditions for the preparation of chelates and the mass spectrometric operating parameters for precise and accurate measurement of isotope ratios were optimized using a general-purpose mass spectrometer. Imprecision values of 1–4% were obtained for measurements of different isotope ratios using chelates containing about 10 ng of metal. The capability of this technique for the accurate determination of natural and altered isotope ratios was also evaluated for these elements using Li(FDEDTC) as a chelating agent. This GC-MS method obviates the need for a more specialized mass spectrometer such as a thermal ionization or inductively coupled plasma mass spectrometer for trace metal determination. The technique gives detection limits down to parts per 10⁹ levels and offers considerable potential for isotope dilution measurements.     

Crystal structures and DNA cleavage activities of two mononuclear nickel(II) complexes

Two new nickel complexes, [Ni(L₁)₂]?·?2(CH₃OH) (1) and [Ni(L₂)₂]?·?2(CH₃OH) (2), where HL₁ is 4-chloro-2-((2-hydroxy-ethylimino)methyl)phenol and HL₂ is 4-fluoro-2-((2-hydroxy-ethylimino)methyl)phenol, have been synthesized and characterized by single-crystal X-ray diffraction and UV-Vis absorption spectra. The coordination polyhedron of nickel(II) in each complex can be described as distorted octahedral. The interactions between the complexes and calf thymus (CT)-DNA/DNA were investigated by UV-Vis spectra and agarose gel electrophoresis. The results show that the complex transforms supercoiled to nicked form and exhibits effective DNA cleavage activity via hydrolytic cleavage mechanism.     

Electrochemical arylation of cobalt and nickel chelates with diphenyliodonium salts

Electrochemical arylation of cobalt chelates with diphenyliodonium salts occurs at low cathodic potentials (viz., potential of the first reduction wave of the diphenyliodonium salt) and affords the phenyl derivatives of Co^III chelates containing the -Co—C(sp²) bond. Nickel complexes should be arylated at higher cathodic potentials because it is necessary to generate paramagnetic Ni^I complexes.