Non-electrolytes In Solution Research Articles

3D Series Metal Complexes Containing Schiff Base Ligand with 2,2'-Bipyridine: Synthesis, Characterization and Assessment of Antifungal Activity

The rapid increase in the number of multidrug-resistant of most pathogenic organisms is fast becoming a global concern, thus, the discovery of novel active pharmacological compounds against new targets is a matter of urgency. The incorporation of metal ions into organic ligands has introduced metal-organic drugs framework with synergistic effects for novel applications in the biological system. In this research work, metal(II) chloride complexes of copper, nickel and zinc containing methylphenylketone thiosemicarbazone (MPK-TSC) with 2,2’-bipyridine (bipy) were synthesized; they were further characterized by satisfactory microelemental analysis, Fourier Transform InfraRed (FTIR) spectra as well as electronic spectra study. The complexes are proposed to have the formulae [L1ML2(Cl2)] where M=metal ion, L1=methylphenylketone thiosemicarbazone L2=2,2’-bipyridine. The complexes are of 1:2 (metal:ligand) stoichiometry and non-electrolytes in solution, the bidentate nature of the two ligands was evident from the FTIR spectra. The compounds were screened for their antifungal activity against four pathogenic fungi: Aspergillus niger, Penicillium Species, Rizopus and Candida albicans using disc diffusion method. The activities of the complexes have been found to be greater than those of the metal salts and the uncoordinated ligands.

Synthesis, characterization, crystal structures and electrochemical properties of heteroleptic Cu(II), Mn(II) and Zn(II) complexes of metronidazole with benzoic acid derivatives

Cu(II), Mn(II) and Zn(II) complexes of metronidazole with benzoic acid derivatives formulated as [Cu2(met)4(4-nba)4] (1), [Mn(met)2(2bba)2(H2O)2] (2) and [Zn(met)2(3,5-dnba)2] (3) [met = metronidazole, 4-nba = 4-nitrobenzoic acid, 2-bba = 2-bromobenzoic acid and 3,5-dnba = 3,5-dinitrobenzoic acid] were synthesized and characterized by elemental analysis and spectroscopic techniques and two of them by single crystal X-ray crystallography. Single crystal X-ray crystallography revealed a five-coordinate, trigonal bipyramidal arrangement in compound 1, while compound 2 is six coordinate octahedral geometry. The molar conductance indicates the complexes are non-electrolytes in solution. The EPR spectra of 1 and 2 showed broad signals centered on g = 2.125, 2.116 and 1.970, 2.005. A hyperfine quartet was observed in the solid state for 1 typical of Cu(II) ion, I = 3/2; while a hyperfine sextet characteristic of 55Mn nucleus, I = 5/2 was observed for 2. Cyclic voltammetry revealed a one-step redox couple for 1 at a potential range of −0.4 to +0.1 V assigned to the reduction peak of Cu(II)/Cu(I). The linearity of Randles-Sevcik plot (R2 = 0.999) suggests a diffusion-controlled redox couple.

NOVEL ANTIMONY(III) HALIDE COMPLEXES WITH SOME N-ALKYL THIOUREAS: SYNTHESIS, CHARACTERIZATION AND STUDY OF THEIR EFFECT UPON THE CATALYTIC OXIDATION OF LINOLEIC ACID TO HYDROPEROXYLINOLEIC ACID BY LIPOXYGENASE

Four novel antimony(III) compounds (SbX 3 ; X = Cl or Br) of thiourea derivatives; N-methylthiourea (NMTU) and N-ethylthiourea (NETU) of formulae [SbCl 3 (NMTU) 3 ] ( 1 ), [SbBr 3 (NMTU) 3 ] ( 2 ), [SbCl 3 (NETU) 3 ] ( 3 ) and [SbBr 3 (NETU) 3 ] ( 4 ) were synthesized. These new antimony(III) halide compounds were characterized by melting point, elemental analysis, molar conductivity, FT-Infrared spectroscopy, FT-Raman spectroscopy, UV-Vis spectroscopy, NMR ( 1 H and 13 C) spectroscopy and TG-DTA analysis. The reactions of N-methylthiourea (NMTU) and N-ethylthiourea (NETU) with SbX 3 (X = Cl or Br) in a 2:1 ligand/metal rate but unexpectedly products were formed in a 3:1 ligand/metal rate. The compounds are non-electrolytes in solution and spectroscopic data of the compounds are appropriate with six coordinate octahedral geometry by three halide ions and three sulfur atoms from thiourea ligands. N-methythiourea and N-ethylthiourea ligands behave as monodentate in compounds 1 - 4 with the binding through sulfur. The influence of these compounds 1 – 4 , N-methythiourea and N-ethylthiourea upon the catalytic peroxidation of linoleic acid to hyperoxolinoleic acid by lipoxygenase was kinetically studied.

Synthesis, Characterization, and Antibacterial Studies of Some Metal Complexes of Dialkyl Thiourea: The X-Ray Single Crystal Structure of [CoCl2(detu)2

Co(II), Cu(II), and Zn(II) complexes of diethylthiourea and dimethylthiourea have been synthesized and characterized by elemental analysis, conductivity, magnetic susceptibility measurements, and FTIR UV-vis spectroscopy. The single-crystal X-ray structure of the Co(II) complex of diethylthiourea, [CoCl2(detu)2], is reported. The metal(II) complexes are four coordinated with two molecules of the alkyl thiourea and two molecules of either chloride or acetate ions. The compounds are nonelectrolytes in solution and the spectroscopic analysis is consistent with the proposed structures. The complexes were screened against six bacteria isolates to determine their antibacterial potentials.

Metal Complexes of Diisopropylthiourea: Synthesis, Characterization and Antibacterial Studies

Co(II), Cu(II), Zn(II) and Fe(III) complexes of diisopropylthiourea have been synthesized and characterized by elemental analyses, molar conductivity, magnetic susceptibility, FTIR and electronic spectroscopy. The compounds are non-electrolytes in solution and spectroscopic data of the complexes are consistent with 4-coordinate geometry for the metal(II) complexes and six coordinate octahedral for Fe(III) complex. The complexes were screened for their antibacterial activities against six bacteria: Escherichia coli, Pseudomonas auriginosa, Klebsiella pneumoniae, Bacillus cereus, Staphylococcus aureus and Bacillus pumilus. The complexes showed varied antibacterial activities and their minimum inhibitory concentrations (MICs) were determined.

Differential mutual diffusion coefficients of binary and ternary aqueous systems measured by the open ended conductometric capillary cell and by the Taylor technique

Binary and ternary mutual diffusion coefficients of aqueous solutions of electrolytes and non-electrolytes have been measured at different conditions (concentration, temperature, techniques, etc.), having in mind a contribution to a better understanding of the structure of these solutions, behaviour of electrolytes and non-electrolytes in solution, as well as supplying the scientific and technological communities with new data on these important parameters in solution transport processes. By using different techniques of the open ended capillary conductometric method and the Taylor dispersion technique we achieved, for different systems, experimental data of diffusion coefficients, presented and discussed in this review.

Synthesis and characterization of disubstituted arylcyanoximes and their several metal complexes

A series of new disubstituted halogenated arylcyanoximes was synthesized using nitrosation reaction of the respective phenylacetonitriles by CH 3–ONO at room temperature in isopropanol. Six synthesized colorless arylcyanoximes containing two F and/or Cl atoms at 2-, 4-, 5- and 6-positions were characterized by means of NMR, IR, UV–Vis spectroscopy and p K a studies. Crystal structures were determined for four cyanoximes and revealed the presence of only the syn-isomers for fluorinated compounds in a solid state, while the chlorinated arylcyanoxime exists as anti-isomer in the crystal. However, five out of the six protonated arylcyanoximes HL exist as a mixture of syn- and anti-isomers in solutions. Deprotonation of HL with NaOC 2H 5 in ether solutions leads to yellow NaL which were used as precursors for the synthesis of a series of monovalent Ag, Tl and bivalent Pd, Pt complexes. Seven palladium and platinum arylcyanoximates of [M(HL) 2Cl 2] composition were synthesized and characterized. Obtained colored compounds are non-electrolytes in solution. However, in EtOH and DMSO solutions Pt(II) cyanoximates undergo two consecutive solvolysis reactions. First order rate constants were measured at 294 K for complexes in both solvents. Binding modes of the cyanoxime ligands and the possible solid state structures of the obtained coordination compounds are suggested on a basis of their IR spectra and MM-2 calculations. Because of their structural resemblance to the cisplatin family of anticancer drugs, synthesized Pd/Pt arylcyanoximates were tested in vitro against human colon carcinoma WiDr cell line using cis-[Pt(NH 3) 2Cl 2] as positive control. Results showed that two Pd(II) and Pt(II) cyanoximates containing oximino(2,4-dichlorophenyl)acetonitrile exhibit cytotoxicity at 0.25 mM concentrations.

Lithium adsorption by acid and sodium amberlite

In this paper we used a previously reported model for examining the adsorption of nonelectrolytes in solution by solid adsorbents to study the adsorption of lithium(I) cations by acid and sodium amberlites, which is an ion-exchange process. Based on the results, both are equilibrium processes and obey a kinetic law with a unity partial order in the Li + concentration. The kinetic results were used to calculate the specific rate constants and thermodynamic activation functions involved. Also, equilibrium isotherms were used to determine the corresponding ion-exchange capacities, the individual equilibrium constants, and the thermodynamic functions for the overall process.

Application of a Single Model to Study the Adsorption Equilibrium of Prednisolone on Six Carbonaceous Materials

The knowledge of sorption processes of nonelectrolytes in solution by solid adsorbents implies the study of kinetics, equilibrium, and thermodynamic functions. However, quite frequently the equilibrium isotherms are studied by comparing them with those corresponding to the Giles et al. classification (1); these isotherms are also analyzed by fitting them to equations based on thermodynamic or kinetic criteria, and even to empirical equations. Nevertheless, information obtained is more coherent and satisfactory if the adsorption isotherms are fitted by using an equation describing the equilibrium isotherms according to the kinetic laws. These mentioned laws would determine each one of the unitary processes (one or more) which condition the global process. In this paper, an adsorption process of prednisolone in solution by six carbonaceous materials is explained according to a previously proposed single model, which allows to establish a kinetic law which fits satisfactorily most of C vs t isotherms (2). According to the above-mentioned kinetic law, equations describing sorption equilibrium processes have been deducted, and experimental data points have been fitted to these equations; such a fitting yields to different values of adsorption capacity and kinetic equilibrium constants for the different processes at several temperatures. However, in spite of their practical interest, these constants have no thermodynamic signification. Thus, the thermodynamic equilibrium constant (K) has been calculated by using a modified expression of the Gaines et al. equation (3). Global average values of the thermodynamic functions have also been calculated from the K values. Information related to variations of ΔH and ΔS with the surface coverage fraction was obtained by using the corresponding Clausius–Clapeyron equations.

Palladium(II)-phenothiazine complexes: synthesis and characterization

Palladium(II) chloride or nitrate complexes of phenothiazine and its derivatives have been prepared. The new complexes were characterized by their elemental analyses, molar conductivity, magnetic susceptibility and spectroscopic data. The molecular formulae of the complexes were found to be: [C 12H 9NS) 2PdCl 2]·H 2O where C 12H 9NS = phenothiazine (PTZ); [C 12H 8ClNS) 2PdCl 2] where C 12H 8ClNS = 2-chlorophenothiazine (CPTZ); [(C 21H 27N 2S 2)Pd 2Cl 5].2H 2O where (C 21H 27N 2S 2) + = protonated thioridazine (TRH +); and [(C 17H 21N 2S) 2Pd 2Cl 5]NO 3 where (C 17H 21N 2S) + = protonated promethazine (PMH +). The PM complex behaves as an electrolyte whereas the other complexes act as nonelectrolytes in solution. All the complexes are diamagnetic species. Tentative structures have been proposed.

Interhalogen Derivatives of Thallium(III) Complexes With 1-Ethylimidazole

Abstract The following compounds: TlCl3.L3, TlBrCl2.L3, TlBr3.L3, TlBr2Cl.L3, TlIBr2.L2, TlI3.L2, TlI2Br.L2, TlI2Cl L2and TlIBrCl.L2(where L = 1-ethylimidazole) have been prepared and characterized by elemental analyses. All the solids are monomers and they behave as non-electrolytes in solution. Their 1H NMR and IR spectra were studied, with particular attention on the Tl-X stretching vibration modes, and possible molecular structures for the complexes are proposed.

Interhaloderivatives of Thallium(III) Complexes with 1-Methyl-2-Phenylimidazole

Abstract The following compounds: TlBrCl2.2L, TlICl2.3L, TlBr2Cl.2L, TlIBr2.2L, TlI2C1.2L, TlI2Br.2L, TlI2Br.3L, and TlIBrCl.2L (where L = 1-methyl-2-phenylimidazole) have been prepared and characterized by elemental analyses. All the solids are monomers and they behave as non-electrolytes in solution. Their 1H NMR and IR spectra are discussed, especially the Tl-X stretching vibration modes, and possible molecular structures for the complexes are proposed. Referee I: R. J. Williams Referee II: M. Denk

Complexes of TlClI2with Aromatic Amine Oxides

Abstract The following compounds: TlClI2 (PyO)2; TlClI2(2-PicO)2; TlClI2(3-PicO)2; TlClI2(4-PicO)2; TlClI2(4-Cl-PyO)2; TlClI2 (4-CN-PyO)2; TlClI2(4-NO2-PyO)2 and TlClI2 (4-CH3O-PyO)2 have been prepared and characterized by elemental analysis. The solids behave as monomers and non-electrolytes in solution. Possible molecular structures are given on the basis of 1H NMR and lR spectra, with particular attention on the νTl-X and νTl-O strectching modes.

Biologically active bimetallic complexes formed from acetylacetonates of copper, cobalt and nickel

A few binuclear complexes of either copper, cobalt or nickel acetylacetonates with silicon, tin, selenium and tellurium chloride were synthesized and characterized by elemental analyses, conductivity measurements, magnetic and spectral data. The binuclear complexes are 1:1 adducts and nonelectrolytes in solution. The complexes are biologically active as demonstrated by bacteriostatic, mammalian acute toxicity, and antialgal activity tests.

Complexes of Uranium(IV) Acetate with Hydrazones

Abstract A few uranium(IV) acetate complexes with aroyl hydrazones have been synthesized and characterized by infrared, conductivity and magnetic measurements. All the complexes are colored, amorphous, soluble in DMF and DMSO and are insoluble in common organic solvents. Conductivity data indicated that the complexes behave as non-electrolytes in solution.

Studies of glycine acetophenone complexes of copper(II), cobalt(II) and oxovanadium(IV)

Complexes of copper(II), cobalt(II) and oxovanadium(IV) with glycine acetophenone Schiff bases were synthesized and characterized by elemental analyses, conductivity measurements, magnetic and spectral data. The complexes were shown to have 1:2 (metal:ligand) stoichiometry and were found to be non-electrolytes in solution.

Ligand function and substrate effect on metal-oxygen stretching frequencies in somecis-dioxomolybdenum(VI) complexes of bivalent tridentate Schiff bases

New dioxomolybdenum(VI) complexes [MoO2LD] (LH2=Schiff base derived from isonicotinylhydrazide and salicylaldehyde, 2-hydroxynaphthaldehyde and 2-hydroxyacetophenone and benzoylhydrazide and 2-hydroxyacetophenone; D=H2O, HCONMe2, C5H5NO, C4H8O or Me2SO) have been synthesized and characterized. The complexes contain acis-MoO2 moiety. The difference betweenvsym andvasymm of MoO2 is related to the basicity and ligand repulsion of the ligand (L) and the donor power of D. All the complexes decompose before melting and their thermal stability is in the order: C4H8O < HCONMe2 < Me2SO < C5H5NO < H2O. The complexes are monomeric, non-electrolytes in solution in MeOH, MeCN and PhNO2 and are diamagnetic.

Cobalt(II) and zinc(II) complexes of 1,1,5,5,-tetramethylcarbohydrazide

1,1,5,5,-Tetramethylcarbohydrazide (Me 2NNH) 2CO(tmc) was synthesized via the thermal decomposition of the carbamate Me 2NNHC(O)OSiMe 3. The complexes Co(tmc)Cl 2(III), Co(tmc) 2Cl 2(IV), Zn(tmc)Cl 2(V) and Zn(tmc) 2Cl 2(VI) were prepared. These compounds are non-electrolytes in solution in acetone and nitromethane. The complexes III and V have pseudo tetrahedral structures in the solid state and in solution in acetone, in which they are monomeric. The most likely solid state structure for the M(tmc) 2Cl 2 complexes IV and VI is octahedral. In solution, however, complexes IV and VI are extensively dissociated, via loss of one tmc ligand, giving equilibrium mixtures containing the four-coordinate complexes III and V, respectively. In all four complexes, the tmc ligand chelates to the metal centre via the carbonyl oxygen and one of the terminal dimethylamino groups. The ligand in Zn(tmc)Cl 2 is non-fluxional. Exchange among tmc ligands in solutions of Zn(tmc) 2Cl 2(VI) is rapid on the nmr time scale at temperatures above O °C.

Trinuclear complexes of dimethylsilane and cobalt schiff-base complexes

A few trinuclear complexes of cobalt and silicon were synthesized and characterized by elemental analyses, conductivity measurements, magnetic and spectral data. The complexes were shown to have a 1:2 (cobaltSchiff base:dimethyldichlorosilane) stoichiometry. The complexes were nonelectrolytes in solution, and the stereochemistry around the cobalt changed from square planar to octahedral after the reaction between dimethyldichlorosilane and the Schiff-base cobalt complex.

Isoelectric focusing of proteins using a pH gradient created by a concentration gradient of nonelectrolytes in solution

A new method of producing a stable pH gradient in buffer solutions is suggested, obtained by the concentration gradient of a nonelectrolyte in buffer solutions as a result of the gradual change in the dielectric properties of the solution. The maximal concentrations of nonelectrolyte which do not influence the protein configuration allow a pH gradient with a range of two pH units to be produced. It is suggested that the properties of some polyols (i.e. glycerol or mannitol) be used to change the pH of the borate buffer for the production of greater pH gradient with a range of up to 4–5 pH units. Creating the gradient of concentration of polyols, one can obtain a pH gradient in borate buffer solutions. Though the polylydroxyl compound-borate complexes possess mobility in an electric field, a stable pH gradient can be achieved during 12 days of electrophoresis. The isoelectric focusing of haemoglobin, human serum albumin and immunoglobulins was carried out in both systems suggested. These findings were compared with isoelectric focusing in Ampholines. There was a good agreement between the methods compared. The possible differences are discussed.