The Synthesis,Characterization and DC Electrical Conductivity of Polypyrrole‐Zirconium Complex

Polypyrrole‐zirconium complex has been synthesized by reacting 2‐amino‐3,4‐dicyano‐5‐mercaptopyrrole with zirconium nitrate in absolute ethanol under reflux for 24 h. The product has been characterized by elemental analyses, FTIR spectroscopy, in addition to thermal analysis (TGA and DSC) and its solubility has been investigated. The DC electrical conductivity variation of polypyrrole‐zirconium complex has been studied in the temperature range 300–500 K after annealing for 24 h at 100°C and doping with I₂, FeCl₃ and CuCl₂ · H₂O for comparison. An attempt has been made to interpret the DC electrical conductivity behavior and thermal properties to chain length, dopant used, polymer structure and attached groups.     

The solid state reactions of o-aminobenzoic acid with Zn(Ⅱ), Cu(Ⅱ), Ni(Ⅱ), Mn(Ⅱ) acetate hydrate at room temperature

The solid-solid state reactions of o-aminobenzoic acid with Zn(OAc)2.2H2O, Cu(OAc)2 .H2O, Ni(OAc)2.4H2O and Mn(OAc)2.4H2O result in the formation of corresponding complexes M(OAB)2 (M = Zn(Ⅱ), Cu(Ⅱ), Ni(Ⅱ), Mn(IⅡ)). XRD, IR and elemental analysis methods have been used to characterize the solid products. The activation energies of these reactions, which are calculated from the kinetic data obtained by means of the isothermal electrical conductivity measurement method, have been found to increase in the order: Cu(OAc)2.H2O(37.7 kJ.mol-1)~Mn(OAc)2.4H2O (39.7kJ.mol-1) < Zn(OAc)2.2H2O (56.3 kJ.mol-1) < Ni(OAc)2.4H2O (85.2 kJ.mol-1). The trend is related to their crystal structures.     

Physicochemical processes involved in synthesis of thin films based on double oxides of the ZrO<Subscript>2</Subscript>-GeO<Subscript>2</Subscript> system

The major physicochemical processes underlying the preparation of thin films of the ZrO-GeO₂ system from film-forming solutions based on zirconium oxochloride (ZrOCl₂ · 8H₂O), germanium tetrachloride (GeCl₄), and ethanol were studied. The phase composition, structure, and physicochemical properties of the films were determined.     

Chemical deposition of zirconium doped tin silicate ion-exchanger and its characterization

Doping of inorganic ion-exchange material tin silicate with zirconium ion by sol-gel technique was conducted for the production of a novel ion-exchanger. Undoped and doped tin silicate has been characterized by elemental analysis (X-ray fluorescence), Fourier transform infrared spectroscopy (FT-IR), thermal analysis and X-ray diffraction studies. The structures of two ion-exchangers were identified and the empirical formulas found as SnSi₂O₆·6H₂O and SnZr₄Si₄O₁₂·16H₂O for tin silicate and zirconium doped tin silicate, respectively. The effect of zirconium ion concentration of the doped tin silicate on the crystalline size and strain of tin silicate was investigated. The probable structure of both materials was assessed by the ChemDraw Ultra program. Finally, application of these materials for the treatment of radionuclides in terms of capacity measurements was investigated.     

Tb(III) complexes with 1-phenyl-3-methyl-4-stearoyl-pyrazol-5-one as a material for luminescence Langmuir–Blodgett films

Abstract

Synthesis and properties of new luminescent amphiphilic Tb(III) complexes [TbL₃·2H₂O]·3H₂O, TbL₃·bipy, [H₃O][TbL₄]·6H₂O and [H₃O][TbL′₃L]·H₂O, where HL is 1-phenyl-3-methyl-4-stearoylpyrazolone-5 and HL′ is 1-phenyl-3-methyl-4-formylpyrazolone-5, are reported. The complexes have been characterized by elemental and thermal analysis, FTIR and luminescence spectroscopy methods. Formation and properties of Langmuir–Blodgett films of the complexes are described.     

The synthesis and properties of thin films based on double oxide system SiO2-ZrO2

The main physical and chemical processes involved in the preparation of SiO₂-ZrO₂ thin films from film-forming solutions based on zirconium oxochloride ZrOCl₂·8H₂O, tetraethoxysilane Si(C₂H₅O)₄, and ethanol were studied. The phase composition, structure and physical and chemical properties of the films were determined and the diagram composition — property was constructed.     

Effect of collision gas pressure and collision energy on reactions between oxygen and the negative molecular ion of tetrachlorodibenzo-p-dioxins in the collision cell of a triple -quadrupole mass spectrometer

Low-energy reactive collisions between the negative molecular ion of a tetrachlorodibenzo-p-dioxin (TCDD) and oxygen inside the collision cell of a triple-stage quadrupole mass spectrometer produce a substitution ion [M ? Cl + O]^?, a phenoxide ion [C₆H_4-nO₂Cl_n]^?·, [M ? HCl]^?·, and Cl^? by which 1,2,3,4-, 1,2,3,6/1,2,3,7- and 2,3,7,8-TCDD isomers can be distinguished either directly or on the basis of intensity ratios. The collision conditions have an important effect on the relative abundances. Energy- and pressure-resolved curves show that the ions formed by a collisionally activated reaction (CAR) process, i.e. [M ? Cl + O]^? and [C₆H_4-n,O₂Cl_n]^?·, are favoured by a high pressure of oxygen (3-6 mTorr) (1 Torr = 133.3 Pa) and a low collision energy (0.1-7 eV), whereas the ions formed by a collisionally activated dissociation (CAD) process, i.e. [M ? HCl]^?· and Cl^?, are favoured by high pressure and high energy. By choosing a relatively low collision energy (5 eV) and high pressure (4 mTorr), the CAR and CAD ions can be clearly detected.     

Synthesis of rare earth ternary complexes using tryptophan and sodium citrate and their anticoagulant action

Using rare earth nitrates, tryptophan (L), and sodium citrate (NaL′), three new rare earth ternary complexes (Nd-L-L′· 4H₂O, Eu-L-L′ · 4H₂O, and La-L-L′ · 4H₂O) were prepared. The complexes were characterized by IR, molar conductivity, TG-DTA (thermo gravimetric-differential thermal analysis), ¹H NMR, and elemental analyses. TG and elemental analyses of the prepared complexes showed good agreement with their stoichiometry. Compared with two individual ligands, IR spectra of synthesized complexes showed dramatic shift and intensity changes; ¹H NMR also showed a slight downfield shift. All analytical results of complexes proved constant composition of M-L-L′ · 4H₂O (M = rare earth metal, namely Nd, Eu, or La). Animal tests were also performed to study the anti-coagulation time of these complexes considering also the different concentration of complex Nd-L-L′ · 4H₂O. PC-12 pheochromocytoma cells were used to study cell adhesion. Compared with ions of rare earth compounds, rare earth ternary complexes have lower cell toxicity, better cell adhesion, and better anticoagulant action.     

Thermochemistry of the complexes of some microelements and histidine

Solid complexes of M(His)₂Cl₂·nH₂O (M=Mn, Co, Ni, Cu) of MnCl₂·6H₂O, CoCl₂·6H₂O, NiCl₂·6H₂O, CuCl₂·2H₂O and L-α-histidine (His) have been prepared in 95% ethanol solution and characterized by elemental analyses, chemical analyses, IR and TG-DTG. The constant-volume combustion energies of the complexes have been determined by a rotating-bomb calorimeter. And the standard enthalpies of formation of the complexes have been calculated as well. This revised version was published online in August 2006 with corrections to the Cover Date.     

Synthesis,Characterization and Crystal Structures of new Coordination Polymers of Cerium(III) and Samarium(III) Containing 2,6‐Pyridinedicarboxylic Acid

The reaction of 2,6‐pyridinedicarboxylic acid ( 1 , LH₂) with CeCl₃·7H₂O and Sm(NO₃)₃·6H₂O in the presence of triethylamine led to the coordination polymer complexes [M(L)(LH)(H₂O)₂]·4H₂O [M = Ce ( 2 ) and Sm ( 3 )]. Both complexes were characterized by elemental analyses, IR spectroscopy and the crystal structures of 2 and 3 . Crystal data for 2 at ?80 °C: monoclinic, space group P2₁/c, a = 1404.6(1), b = 1122.1(1), c = 1296.1(1) pm, β = 102.09(1)°, Z = 4, R₁ = 0.0217 and for 3 at ?80 °C: monoclinic, space group P2₁/c, a = 1395.1(1), b = 1120.1(1), c = 1282.8(1) pm, β = 102.71(1)°, Z = 4, R₁ = 0.019.     

Stereochemical applications of mass spectrometry. 3—Energy dependence of the fragmentation of stereoisomeric methylcyclohexanols

Breakdown graphs have been constructed from charge exchange data for the epimeric 2-methyl-, 3-methyl- and 4-methyl-cyclohexanols. Although the breakdown graphs for epimeric pairs are essentially identical above ～12 eV recombination energy, significant differences are observed for the epimeric 2-methyl- and 4-methyl-cyclohexanols at low internal energies. For the 2-methylcyclohexanols the ratio ([M? H₂O]^+·/[M]^+·)_cis/([M? H₂O]^+·/[M]^+·)_trans is 3.2 in the [C₆F₆]^+· charge exchange mass spectra. This is attributed to both energetic and conformational effects which favour the stereospecific cis-1,4-H₂O elimination for the cis epimer. The breakdown graph for trans-4-methylcyclohexanol shows a sharp peak in the abundance of the [M? H₂O]^+· ion at ～10 eV recombination energy which is absent from the breakdown graph for the cis epimer. This peak is attributed to the stereospecific cis-1,4-elimination of water from the molecular ion of the trans isomer; the reaction appears to have a low critical energy but a very unfavourable frequency factor, and alternative modes of water loss common to both epimers are observed at higher energies. As a result, in the [C₆F₆]^+· charge exchange mass spectra the ([M? H₂O]^+·/[M]^+·)_trans/([M? H₂O]^+·/[M]^+·)_cis ratio is ～24, compared to the value of 13 observed in the 70 eV EI mass spectra. No differences are observed in either the metastable ion abundances or the associated kinetic energy releases for epimeric molecules.     

An Efficient Solvent-free Synthetic Technique of 4,4’-Diaminotriarylmethane Leuco Materials

An efficient, versatile and solvent-free synthetic technique of diaminotriarylmethanes was reached by treating N,N-dimethylaniline with some arylaldehydes over zirconium(IV) oxide chloride (ZrOCl2•8H2O), in which ZrOCl2•8H2O has good activity, easy availability, recovery as well as reusability.     

Hexachloroplatinates of the Lanthanides: Syntheses and Thermal Decomposition of [M(NO3)2(H2O)6]2[PtCl6]·2H2O (M = La,Pr) and [M(NO3)(H2O)7][PtCl6]·4H2O (M = Gd,Dy)

The reaction of the nitrates M(NO₃)₃·6H₂O (M = La, Pr) and (H₃O)₂PtCl₆ led to yellow single crystals of [M(NO₃)₂(H₂O)₆]₂[PtCl₆]·2H₂O (M = La, Pr) (monoclinic, P2₁/c, Z = 2, La/Pr: a = 697.4(3)/695.5(1), b = 1654.5(1)/1652.5(2), c = 1317.7(6)/1318.5(3) pm, β = 93.97°(7)/93.93°(2), R_all = 0.0169/0.0659) while the reaction of M(NO₃)₃·5H₂O (M = Gd, Dy) and (H₃O)₂PtCl₆ yielded yellow single crystals of [M(NO₃)(H₂O)₇][PtCl₆]·4H₂O (monoclinic, P2₁/n, Z = 4, Gd/Dy: a = 838.72(3)/838.40(2), b = 2131.98(6)/2139.50(7), c = 1142.63(3)/1143.10(3) pm, β = 95.670(4)/95.698(3), R_all = 0.0475/0.0337). The crystal structures consist of octahedral [PtCl₆]^2? anions and complex [M(NO₃)₂(H₂O)₆]₂⁺ and [M(NO₃)(H₂O)₇]²⁺ cations, respectively. The thermal decomposition of both types of compounds leads via various steps to elemental platinum and the oxide chlorides MOCl (M = La, Pr, Gd, Dy).     

Preparation,characterization and biological activity of novel metal-NNNN donor Schiff base complexes

Novel Schiff base (H₂L) ligand is prepared via condensation of benzil and triethylenetetraamine. The ligand is characterized based on elemental analysis, mass, IR and ¹H NMR spectra. Metal complexes are reported and characterized based on elemental analyses, IR, ¹H NMR, solid reflectance, magnetic moment, molar conductance, and thermal analyses (TG, DTG and DTA). 1:1 [M]:[H₂L] complexes are found from the elemental analyses data having the formulae [M(H₂L)Cl₂]·yH₂O (M = Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II)), [Fe(H₂L)Cl₂]Cl·H₂O, [Th(H₂L)Cl₂]Cl₂·3H₂O and [UO₂(H₂L)](CH₃COO)₂·2H₂O. The metal chelates are found to be non-electrolytes except Fe(III), Th(IV) and UO₂(II) complexes are electrolytes. IR spectra show that H₂L is coordinated to the metal ions in a neutral tetradentate manner with 4Ns donor sites of the two azomethine N and two NH groups. The geometrical structures of these complexes are found to be octahedral. The thermal behaviour of these chelates is studied where the hydrated complexes lose water molecules of hydration in the first step followed immediately by decomposition of the anions and ligand molecules in the subsequent steps. The activation thermodynamic parameters are calculated using Coats–Redfern method. The ligand (H₂L), in comparison to its metal complexes, is screened for its antibacterial activity. The activity data show that the metal complexes have antibacterial activity more than the parent Schiff base ligand and cefepime standard against one or more bacterial species.     

Synthesis and characterization of cerium,thorium, and uranyl complexes with ( E )-4-(4-methoxyphenoxy)-4- oxobut-2-enoic acid

(E)-4-(4-Methoxyphenoxy)-4-oxobut-2-enoic acid and its Ce(IV), Th(IV), and UO₂(II) complexes were synthesized and characterized by MS, elemental analysis, IR, UV, TG-DTA, and NMR. The complexes have composition [CeL₂(OH)₂ · 2H₂O] · H₂O, [ThL₂(OH)₂ · 2H₂O] · H₂O, and [UO₂L₂ · 2H₂O] · H₂O. Molar conductance data confirm that the three complexes are nonelectrolytes. The IR and NMR results show that the carboxylates coordinate to the metal ions bidentate, and the ester carboxylic groups do not take part in coordination. Luminescence spectra of the ligand and complexes in DMSO at room temperature were also studied showing strong luminescence of the metal ions.     

Structure and Optical Properties of 0.1BiFeO3-0.9SrBi2Nb2O9 Thin Films Using a Modified Sol-Gel Technique

Fe-doped SrBi₂Nb₂O₉ precursor solution was synthesized using bismuth nitrate Bi(NO₃)₃·5H₂O, strontium nitrate Sr(NO₃)₂, iron nitrate Fe(NO₃)₃·9H₂O, and niobium ethoxide Nb(OC₂H₅)₅ as starting materials, ethylene glycol monomethyl ether (C₃H₈O₂) as the solvent. 0.1BiFeO₃-0.9SrBi₂Nb₂O₉ thin films were prepared on fused quartz substrates using sol-gel processing. The surface morphology and crystal structure and optical properties of the thin films were investigated. The thin film annealing at 400°C were found to be amorphous, and the thin films crystallize to a perovskite structure after a post-deposition annealing at 600°C for 1 h in air. The grain of thin film was evenly distributed. The thin films exhibit the designed optical transmission, while the optical transition is indirect in nature. Their optical band gap is about 2.5 eV.     

Benzotriazol-based structure assemble directed by transition metals

Two coordination polymers, namely [Mn(L)₂(H₂O)₂]_n (1) and [Cd₂(L)₄(H₂O)₄]_n (2) {HL?=?(benzotriazol-1-yloxy)-acetic acid}, have been synthesized and characterized by single-crystal X-ray diffraction as well as with infrared spectroscopy and elemental analysis. The results reveal that CP1 has 1D double chain structure, while CP2 features a 1D infinite chain structure. Additionally, there both exist O–H···O and O–H···N hydrogen bonds in CP1 and CP2, forming 3D supramolecular structures, respectively. UV-vis absorption spectra of CP1, and photoluminescence property of CP2, have been examined in solid state at room temperature. The result on optical energy gap of 2.80 eV indicates that CP1 is a potential semiconductive material.

     

Spectroscopic studies and biological evaluation of some transition metal complexes of Schiff-base ligands derived from 5-arylazo-salicylaldehyde and thiosemicarbazide

Synthesis and spectroscopic characterization of Schiff-base complexes of Cu(II), Ni(II), and Mn(II) resulting from condensation of salicylaldehyde derivatives with thiosemicarbazide [PHBT = 1-(5-(2-phenyldiazenyl)-2-hydroxybenzylidene)thiosemicarbazide, CHBT = 1-(5-(2-(2-chlorophenyl)diazenyl)-2-hydroxybenzylidene)thiosemicarbazide, and MHBT = 1-(5-(2-p-tolyldiazenyl)-2-hydroxybenzylidene)thiosemicarbazide] are discussed. The solid complexes were confirmed by elemental analysis (CHN), molar conductance, and mass spectra. Important infrared (IR) spectral bands corresponding to the active groups in the three ligands, ¹H-NMR and UV-Vis spectra and thermogravimetric analysis were performed. The dehydration and decomposition of [Cu(PHBT)(H₂O)], [Ni(PHBT)(H₂O)] · 2H₂O, [Mn(PHBT)(H₂O)] · H₂O, [Cu(CHBT)(H₂O)], [Ni(CHBT)(H₂O)] · H₂O, [Mn(CHBT)(H₂O)] · H₂O, [Cu(MHBT)(H₂O)], [Ni(MHBT)(H₂O)] · 2H₂O, and [Mn(MHBT)(H₂O)] · 2H₂O complexes were studied. The ligands are tridentate forming chelates with 1 : 1 (metal : ligand) stoichiometry. The molar conductance measurements of the complexes in DMSO indicate non-electrolytes. The biological activities of the metal complexes have been studied against different gram positive and gram negative bacteria.     

Synthesis,Crystal Structures,and Thermal Analyses of ­Copper(II) and Manganese(II) Mixed‐Ligand Coordination Polymers Constructed from Benzimidazole‐5, 6‐dicarboxylic Acid and N‐Donor Ligands

The coordination polymers, {[Cu(Hbidc)(2, 2′‐bpy)(H₂O)] · 2H₂O}_n ( 1 ) and {[Mn(Hbidc)(2, 2′‐bpy) (H₂O)₂] · 2H₂O}_n ( 2 ) (H₃bidc = benzimidazole‐5, 6‐dicarboxylic acid, 2, 2′‐bpy = 2, 2′‐bipyridine), were synthesized in solution and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis (TGA), and single‐crystal X‐ray diffraction. Complexes 1 and 2 consist of different 1D chain structures. In both compounds, 2, 2′‐bpy is chelating in a bidentate manner, whereas the Hbidc ligands in complexes 1 and 2 display chelating‐bridging tridentate and bridging bidentate coordination modes. The two complexes are further extended into 3D supramolecular structures through O–H ··· O and N–H ··· O hydrogen bonds. The thermal stabilities of complexes 1 and 2 were studied by thermogravimetric analyses (TGA).     

Synthesis and anticancer property of one Ce(III) compound based on 5-(2-pyrazinyl)tetrazole-2-acetic acid

Mononuclear [Ce(pztza)₂(H₂O)₆](pztza)·H₂O (1) (pztza = 5-(2-pyrazinyl)tetrazole-2-acetato) has been prepared and characterized by IR, elemental analysis and single-crystal X-ray diffraction. PEG_-5000 (poly(ethyleneglycol_-5000)) coated [Ce(pztza)₂(H₂O)₆](pztza)·H₂O nanoparticles (NPs) can disperse into distilled water. In vitro study on Hela cells shows that Hpztza is nontoxic while [Ce(pztza)₂(H₂O)₆](pztza)·H₂O NPs show high toxicity with half-maximal inhibitory concentration (IC₅₀) of 17 μg/mL (1.93 × 10^?5 M). In addition, such NPs can inhibit the migration of Hela cells effectively.