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Sample records for acetylacetone

  1. Effect of sodium acetylacetonate on the sublimation of scandium and lutetium acetylacetonates

    By the methods of IR spectroscopy, X-ray phase and thermal analyses, as well as by vacuum sublimation, it has been shown that interaction between sodium acetylacetonate gives rise to formation of tetrakis - acetylacetonate of NaLu(Acac)4 composition, which can be congruently sublimated in vacuum. Ib the system with scandium there is no such effect. Transition to gaseous phase of sodium acetylacetonate within the tetrakis-complex of lutetium can be considered as synergism, as sodium acetylacetonate as such is not volatile

  2. Enhancement of thermal stability of silver(I) acetylacetonate by platinum(II) acetylacetonate

    Křenek, T.; Kovářík, T.; Pola, M.; Jakubec, Ivo; Bezdička, Petr; Bastl, Zdeněk; Pokorná, Dana; Urbanová, Markéta; Galíková, Anna; Pola, Josef

    2013-01-01

    Roč. 554, FEB (2013), s. 1-7. ISSN 0040-6031 Institutional support: RVO:61388980 ; RVO:61388955 ; RVO:67985858 Keywords : thermal gravimetric analysis * differential scanning calorimetry * silver (I) acetylacetonate * platinum(II) acetylacetonate * enhancement of thermal stability Subject RIV: CA - Inorganic Chemistry; CF - Physical ; Theoretical Chemistry (UFCH-W) Impact factor: 2.105, year: 2013

  3. Photochemical transformation of vanadium(5) acetylacetonate complexes

    Photochemical transformations of mixed vanadium (5) complex formed as a result of interaction between ethylorthovanadate and acetylacetone which includes in the first coordination sphere vanadyl oxygen, two enolate-ions and enthoxygroup are studied spectrophotometrically and using ESR method. During irradiation of ethanol solutions of the complex a successive reduction of central atom with formation of acetyl-acetonate complexes of vanadium (4) and (3) takes place. At that the solvent is oxidated. In CCl4 solution under the effect of UV irradiation ethoxygroup is replaced by chlorine ion with the formation of new mixed vanadium (5) complex, sensible to visible and UV radiation

  4. Enhancement of thermal stability of silver(I) acetylacetonate by platinum(II) acetylacetonate

    Highlights: ► Ag acetylacetonate increases thermal stability by mixing with of Pt acetylacetonate. ► Heated mixture of chelates yields a residue with Ag, Pt, O and C elements. ► Co-decomposition of metal chelates could yield novel metal structures and alloys. - Abstract: Thermal gravimetric analysis of equimolar silver(I) acetylacetonate–platinum(II) acetylacetonate mixture shows a significant increase in thermal stability of silver(I) acetylacetonate in the presence of the Pt counterpart. The heated mixture was examined by differential scanning calorimetry and complementary analyses of gaseous products, residues and sublimed fractions by Fourier transform infrared, Raman and X-ray-photoelectron spectroscopy, X-ray diffraction and scanning and high-resolution transmission electron microscopy. It is assumed that silver(I) acetylacetonate is thermally stabilized due to a week bonding with Pt chelate. An interaction between both chelates gets support from the structure of the residual powder which is composed of Ag, Pt, C and O elements and Pt oxides and contains silver nanoparticles whose decreased unit cell parameter can be due to substitution of silver by platinum

  5. MOCVD Nanoparticle Synthesis from Copper Acetylacetonate

    Moravec, Pavel; Smolík, Jiří; Klementová, Mariana; Levdansky, V.V.

    Thessaloniki : Hellenic Association for Aerosol Research, 2008, T01A058P. [European Aerosol Conference 2008. Thessaloniki (GR), 24.08.2008-29.08.2008] R&D Projects: GA ČR GA104/07/1093 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z40320502 Keywords : generation of nanoparticles * copper acetylacetonate * hot wall reactor Subject RIV: CF - Physical ; Theoretical Chemistry

  6. Photoelectron spectra of rare earth acetylacetonates

    By the method of gaseous photoelectron spectroscopy electron structure of rare earth acetylacetonates, prepared by means of thermolysis in spectrometer of the corresponding MA3·Q adducts (Q=DMSO, HMPA), has been studied. From yttrium series compounds only for Y, Dy, Ho, Er, Lu derivatives the spectra do not contain the bands of decomposition product-acetone. Out of three studied compounds of cerium groups (M=La, Sm, Nd) only for LaA3 the attempt to record photoelectron spectrum has failed. In the first three bands of all the compounds a-e-splitting is detected, which is caused by the contribution of metal AO to molecular orbital. The greatest splitting is characteristic for n--electrons of ScA3 and LuA3. Increase in ionization energy of Π3-- and n--electrons with an increase in rare earth ordinal number is caused by lanthanide compression and constitutes 0.2-0.3 eV

  7. Acetone and the precursor ligand acetylacetone : distinctly different electron beam induced decomposition?

    Warneke, Jonas; Van Dorp, Willem F.; Rudolf, Petra; Stano, Michal; Papp, Peter; Matejcik, Stefan; Borrmann, Tobias; Swiderek, Petra

    2015-01-01

    In focused electron beam induced deposition (FEBID) acetylacetone plays a role as a ligand in metal acetylacetonate complexes. As part of a larger effort to understand the chemical processes in FEBID, the electron-induced reactions of acetylacetone were studied both in condensed layers and in the ga

  8. The Electrochemical Synthesis of Transition-Metal Acetylacetonates

    Long, S. R.; Browning, S. R.; Lagowski, J. J.

    2008-01-01

    The electrochemical synthesis of transition-metal acetylacetonates described here can form the basis of assisting in the transformation of an entry-level laboratory course into a research-like environment where all members of a class are working on the same problem, but where each member has a personal responsibility for the synthesis and…

  9. Photochemical properties of acetyl-acetonate complex of vanadium (5)

    Photochemical properties of complex [VO(OH)(OCH3)(acac)] prepared by dissolving vanadium (5) acetylacetonate (acac) complex in methanol have been studied by spectrophotometric method. It has been ascertained that in the course of irradiation of methanol solution of the above-mentioned complex by UV photochemical reduction of vanadium (5) to vanadium (4) is observed. If irradiation is discontinued, the reaction occurs in the opposite direction

  10. Performance and Characterization for Blend Membrane of PES with Manganese(III) Acetylacetonate as Metalorganic Nanoparticles

    Abdallah, H.; Shalaby, M. S.; Shaban, A. M. H.

    2015-01-01

    This study describes the preparation, characterization, and evaluation of performance of blend Polyethersulfone (PES) with manganese(III) acetylacetonate Mn(acac)3 to produce reverse osmosis blend membrane. The manganese(III) acetylacetonate nanoparticles were prepared by a simple and environmentally benign route based on hydrolysis of KMnO4 followed by reaction with acetylacetone in rapid stirring rate. The prepared nanoparticle powder was dissolved in polymer solution mixture to produce RO ...

  11. Clinical applications of indium-111-acetylacetone-labelled blood cells

    A method permitting red-cell labelling with 111In-acetylacetone was reported in 1974 for evaluating intestinal blood loss, the liver-spleen ratio and the red-cell volume. White blood cells can be tagged similarly. In white-cell labelling, simultaneous red-cell or platelet tagging is avoided. Several procedures (dextran separation and gradient centrifugations) have been combined, to develop a highly selective cell separation. In osteomyelitis it may not be as advantageous to use 67Ga-citrate, as in inflammatory soft tissue processes. The detection of inflammatory processes with labelled leukocytes could be of great importance for the scintigraphic diagnosis of osteomyelitidies. A group of 97 patients with suspected osteomyelitis have been examined using 111In-acetylacetone-labelled leukocytes (111In-AAL) immediately following positive routine skeletal scintigraphy. Images obtained 24 h post injection usually were the most satisfactory. In the followup group of 70 patients 21 true positives, 43 true negatives, 21 false negatives and 3 false positives were observed. These findings result in a specificity of 92%, sensitivity of 50% and accuracy of 70% with 111In-AAL for osteomyelitis. Preliminary investigations using 111In-acetylacetone-labelled thrombocytes (111In-AAT) were carried out to detect rejection of transplanted kidneys. The platelets were separated by means of additional special density gradient centrifugations but no dextran from 15-20 ml of autologous whole blood. Scans have been obtained 15 min, 2.5 h and 24 h post injection in an initial group of 10 patients. In acute rejection, a high transplant uptake has been detected, whereas patients without acute rejection showed no or only a minimum activity accumulation. Patients with chronic rejection have intermediate uptakes

  12. Saturated vapor pressure of lutetium tris-acetylacetonate

    By the statical method using 177Lu radioactive isotope the saturated vapor pressure of anhydrous lutetium acetylacetonate at 130 to 160 deg is determined. The calculations are carried out assuming the vapor to be monomolecular. The equation of lgP versus 1/T takes the form: lg Psub((mmHg))=(8.7+-1.6)-(4110+-690)/T. The thermodynamical characteristics of LuA3 sublimation are calculated to be ΔHsub(subl.)=79+-13 kJ/mol; ΔSsub(subl.)=111+-20 J/kxmol

  13. CuOx Nanoparticle Production from Copper Acetylacetonate

    Moravec, Pavel; Smolík, Jiří; Klementová, Mariana; Levdansky, V.V.

    Praha: Česká aerosolová společnost, 2008, s. 59-62. ISBN 978-80-86186-17-7. [konference České aerosolové společnosti /9./. Praha (CZ), 04.12.2008] R&D Projects: GA ČR GA104/07/1093 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z40320502 Keywords : generation of nanoparticles * copper acetylacetonate * hot wall reactor Subject RIV: CF - Physical ; Theoretical Chemistry http://cas.icpf.cas.cz/download/Sbornik_VKCAS_2008. pdf

  14. Proton transfer in acetylacetone and its α-halo derivatives.

    Dolati, Fatemeh; Tayyari, Sayyed Faramarz; Vakili, Mohammad; Wang, Yan Alexander

    2016-01-01

    A two-dimensional potential energy surface was utilized to treat the proton transfer in acetylacetone (AA) and its α-halo derivatives: α-fluoro-(FAA), α-chloro-(ClAA), and α-bromo-acetylacetone (BrAA). This potential energy function, which couples O-H stretching and in-plane bending vibrations, was acquired through ab initio calculations for a fixed skeleton geometry. The resulting potential energy surfaces were then used to calculate the proton tunneling frequencies and proton transfer barrier heights. The barrier heights (the energy difference between the saddle point and the minima) calculated at the MP2/6-31G(2d,p) level of theory for proton transfers in AA, FAA, ClAA, and BrAA are 7.2, 9.4, 6.3, and 5.9 kcal mol(-1), respectively. The theoretically predicted proton transfer barrier heights exhibit excellent linear correlations with geometrical, electronic structural, and topological parameters evaluated by the atoms-in-molecule (AIM) and natural bond orbital (NBO) analyses. PMID:26616236

  15. Solvents and supporting electrolytes for vanadium acetylacetonate flow batteries

    Shinkle, Aaron A.; Pomaville, Timothy J.; Sleightholme, Alice E. S.; Thompson, Levi T.; Monroe, Charles W.

    2014-02-01

    Properties of supporting electrolytes and solvents were examined for use with vanadium acetylacetonate - a member of the class of metal(β-diketonate) active species - in non-aqueous redox flow batteries. Twenty supporting-electrolyte/solvent combinations were screened for ionic conductivity and supporting-electrolyte solubility. Hexane, tetrahydrofuran, and dimethylcarbonate solvents did not meet minimal conductivity and solubility criteria for any of the electrolytes used, which included tetraethylammonium tetrafluoroborate, tetrabutylammonium tetrafluoroborate, tetrabutylammonium hexafluorophosphate, and (1-butyl, 3-methyl)imidazolium bis(trifluoromethanesulfonyl)imide. Ionic conductivities and solubilities for solutions of these electrolytes passed screening criteria in acetonitrile and dimethylformamide solvents, in which maximum supporting-electrolyte and active-species solubilities were determined. Active-species electrochemistry was found to be reversible in several solvent/support systems; for some systems the voltammetric signatures of unwanted side reactions were suppressed. Correlations between supporting-solution properties and performance metrics suggest that an optimal solvent for a vanadium acetylacetonate RFB should have a low solvent molar volume for active-species solubility, and a high Hansen polarity for conductivity.

  16. Reactions cyclopentadienylvanadium compounds with trifluoroacetic acid and acetylacetone

    Studied is the interaction of vanadocene (1) and vanadium cyclopentadienylcarboxylates Cp2 VOCOCF3 (2), CpV(OCOCF3)2 (3), CpV(OCOCH3)2 (4) and CpV(OCOC6H5)2 (5) with acidic reagents: trifluoroacetic acid (6) and acetylacetone (7). In interaction of (1) with (6), depending on the ratio of components, the Cp2V structure is either retained (1:1 ratio, reaction products (2) and H2) or one Cp ring is removed (ratio > 1:2) with formation of cyclopentadiene, hydrogen and (3). Interaction of (7) with (1) leads to complete rupture of V-Cp bonds and formation of V(C5H7O2)3 (8). (7) replaces Cp and acyloxy groups from all studied cyclopentadienylcarboxylate derivatives of vanadium (2, 3, 4, 5) with formation of 8, cyclopentadiene and the corresponding carboxylic acids

  17. An application of the coincidence Doppler spectroscopy for substances of chemical interest: phthalocyanine and acetylacetonate complexes

    Ito, Y

    2000-01-01

    Coincidence Doppler spectroscopy, which is particularly powerful when one is concerned with high momentum components of positron annihilation gamma-rays, has been applied to two different kinds of organo-metallic ligands: metal phthalocyanines and metal acetylacetonates. The energy (momentum) profiles of the annihilation gamma-rays were the same for metal phthalocyanines indicating that positron and/or positronium are not interacting with the metal ions. However, the profiles for the metal acetylacetonates evidently showed a dependence on the kind of metal ions. Discussion is made on the features of positron interaction which are different for phthalocyanines and acetylacetonates.

  18. Solvent extraction studies of lanthanide acetylacetonates. Part 3

    The complex formation of the heavier trivalent lanthanides (Ln) 65Tb, 67Ho, 69Tm and 71Lu with acetylacetone (HAa) has been studied at 25 ±0.1 deg. C by the liquid-liquid extraction technique in the system 0.02-3.5 M HAa in benzene/1.0 M Na(H)ClO4 using trace amounts of radioactive lanthanides. The stepwise formation constants, Kn=[LnAan][LnAan-1]-1[Aa-]-1 (n=2 to 4), the distribution constant of the neutral complex LnAa3 between the phases (P3), and the self-adduct formation of LnAa3 x HAa in the organic phase (Kadd1) have been evaluated. To obtain the necessary data for a precise evaluation of the lower formation constants, distribution values as low as 0.0001 had to be measured with high accuracy in the pH range 3-9. To make this possible the investigation was made by the recently developed AKUFVE-LISOL technique. A survey of the results on all the lanthanides studied in this series is also given. (author)

  19. Halomethyl-cobalt(bis-acetylacetonate) for the controlled synthesis of functional polymers.

    Demarteau, Jérémy; Kermagoret, Anthony; German, Ian; Cordella, Daniela; Robeyns, Koen; De Winter, Julien; Gerbaux, Pascal; Jérôme, Christine; Debuigne, Antoine; Detrembleur, Christophe

    2015-10-01

    Novel organocobalt complexes featuring weak C-CoL2 bonds (L = acetylacetonate) are prepared and used as sources of halomethyl radicals. They permit the precision synthesis of α-halide functionalized and telechelic polymers in organic media or in water. Substitution of halide by azide allows derivatization of polymers using the CuAAC click reaction. PMID:26273709

  20. Nanoparticle Formation by Thermal Decomposition and Oxidation of Manganese(II) Acetylacetonate

    Moravec, Pavel

    2012-01-01

    Over the last decade, Mn and MnOx nanoparticles has been extensively investigated due to their great importance in catalysis, electrochemistry, ion exchange materials, batteries and other areas (Si et al., 2005; Han et al., 2006). This work describes preliminary experiments producing manganese nanoparticles by metal organic chemical vapor deposition (MOCVD) using manganese(II) acetylacetonate (MnAA) as a precursor.

  1. Preparation of ferric acetylacetonate, bonzonate and caprate labelled with Fe-55 and tests of application to liquid scintillation measurements

    The methods of preparation of ferric acetylacetonate, benzoate and caprate labelled with 55Fe are described. The quenching effect, the spectral baehaviour and the count rate stability are studied by liquid scintillation measurements in toluene, INSTAGEL and HISAFE II, for two different values of the sample concentration. The ferric acetylaceton-ate is stable for all the three scintillators but shows a strong quench, while the ferric benzoate and caprate are stable only for INSTAGEL and HISAFE II showing no significant quench at the concentrat-ions of interest in habitual measurements. (Author)

  2. Preparation and Biodistribution Studies of a Radiogallium-Acetylacetonate Bis (Thiosemicarbazone) Complex in Tumor-Bearing Rodents

    Jalilian, Amir Reza; Yousefnia, Hassan; SHAFAII, KAMALEDDIN; Novinrouz, Aytak; Rajamand, Amir Abbas

    2012-01-01

    Various radiometal complexes have been developed for tumor imaging, especially Ga-68 tracer. In the present study, the development of a radiogallium bis-thiosemicarbazone complex has been reported. [67Ga] acetylacetonate bis(thiosemicarbazone) complex ([67Ga] AATS) was prepared starting [67Ga]Gallium acetate and freshly prepared acetylacetonate bis (thiosemicarbazone) (AATS) in 30 min at 90°C. The partition co-efficient and the stability of the tracer were determined in final solution (25°C) ...

  3. Extraction of carrier-free 144Ce with acetylacetone and 8-hydroxyquinoline

    The extraction of carrier-free 144Ce with 3.25 to 0.65 M solutions of acetylacetone in carbon tetrachloride and with 1.0 to 0.01 M solutions of 8-hydroxyquinoline in chloroform at a constant as well as variable pH was investigated. On the basis of the analysis of distribution curves it may be presumed that in both extraction systems the oxidation of cerium(III) to cerium(IV) microamounts takes place. The distribution curves of extraction and reextraction in the systems with 8-hydroxyquinoline show a considerable complexity. In the extraction system with acetylacetone constants were found which satisfactorily express the distribution of 144Ce in this system. (author)

  4. Mechanism of recoil implantation reactions of technetium and ruthenium in metal acetylacetonates

    Recoil implantation of Tc and Ru in metal acetylacetonates were performed using ruthenium metal as a source and MIII(acac)3 and MII(acac)2 complexes as catchers. The recoil atoms were obtained by 100Ru(γ,p)99mTc and 98Ru(γ,n)97Ru reactions. The yields of Tc(acac)3 and Ru(acac)3 were clearly dependent on the force constant of the bond between the central metal atom and oxygen in acetylacetone K(M-O). A plot of the yield vs. 1/K(M-O) showed a linear relationship. However, the yield of Tc(acac)2 implanted in M(acac)2 did not show such a dependence on the force constant. The difference of the mechanism of complex formation between Tc(acac)3 and Tc(acac)2 was discussed. (author)

  5. 1,3-Dioxolane, tetrahydrofuran, acetylacetone and dimethyl sulfoxide as solvents for non-aqueous vanadium acetylacetonate redox-flow-batteries

    Highlights: • Four solvents were employed in a non-aqueous redox flow battery system. • Coulombic efficiencies of 85.9–98.5% and energy efficiencies of 26.6–43.6% were achieved. • Discharge power density was enhanced up to 0.080 mW cm−2. • Solubility of V(acac)3 was increased to 0.8 M compared to the acetonitrile system. -- Abstract: A non-aqueous vanadium acetylacetonate redox flow battery with different organic solvents and tetrabutylammonium hexafluorophosphate has been investigated. Cyclic voltammograms show three redox couples in 1,3-dioxolane, tetrahydrofuran, acetylacetone and two redox couples in dimethyl sulfoxide. Cell potentials between 2.21 and 2.61 V are measured, depending on the solvent used. Impedance Spectroscopy has been used to determine rate limiting step in the non-aqueous redox flow battery. Experiments in a charge–discharge test cell yielded coulombic and energy efficiencies of 85.9–98.5% and 26.6–43.6%, respectively

  6. Sensing properties of tin acetylacetonate-based thin films doped with platinum

    Fitl, P.; Myslík, V.; Vrňata, M.; Náhlík, J.; Kopecký, D.; Vlček, J.; Hofmann, J.; Lančok, Ján

    2012-01-01

    Roč. 24, č. 2 (2012), s. 75-86. ISSN 0914-4935 R&D Projects: GA ČR(CZ) GAP108/11/1298 Institutional research plan: CEZ:AV0Z10100522 Keywords : gas sensing * tin acetylacetonate * pulsed laser deposition (PLD) method * selectivity tunable by temperature Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.288, year: 2012 http://122.249.91.209/myukk/Journal/Download.php?fn=SM0870.pdf

  7. Performance and Characterization for Blend Membrane of PES with Manganese(III Acetylacetonate as Metalorganic Nanoparticles

    H. Abdallah

    2015-01-01

    Full Text Available This study describes the preparation, characterization, and evaluation of performance of blend Polyethersulfone (PES with manganese(III acetylacetonate Mn(acac3 to produce reverse osmosis blend membrane. The manganese(III acetylacetonate nanoparticles were prepared by a simple and environmentally benign route based on hydrolysis of KMnO4 followed by reaction with acetylacetone in rapid stirring rate. The prepared nanoparticle powder was dissolved in polymer solution mixture to produce RO PES/Mn(acac3 blend membrane, without any treatment of Polyethersulfone membrane surface. The membrane morphology, mechanical properties, and performance were presented. The scanning electron microscopy (SEM images have displayed a typical asymmetric membrane structure with a dense top layer due to the migration of Mn(acac3 nanoparticles to membrane surface during the phase inversion process. Contact angle measurements have indicated that the hydrophilicity of the membrane was improved by adding Mn(acac3. AFM images have proved excellent pores size distribution of blend membrane and lower surface roughness compared with bare PES. The desalination test was applied to blend membrane, where the blend membrane provided good performance; particularly, permeate flux was 24.2 Kg/m2·h and salt rejection was 99.5%.

  8. Double deuterated acetylacetone in neon matrices: infrared spectroscopy, photoreactivity and the tunneling process.

    Gutiérrez-Quintanilla, Alejandro; Chevalier, Michèle; Crépin, Claudine

    2016-07-27

    The effect of deuteration of acetylacetone (C5O2H8) is explored by means of IR spectroscopy of its single and double deuterated isotopologues trapped in neon matrices. The whole vibrational spectra of chelated enols are very sensitive to the H-D exchange of the hydrogen atom involved in the internal hydrogen bond. UV excitation of double deuterated acetylacetone isolated in neon matrices induces the formation of four open enol isomers which can be divided into two groups of two conformers, depending on their formation kinetics. Within each group, one conformer is more stable than the other: slow conformer interconversion due to a tunneling process is observed in the dark at low temperature. Moreover, IR laser irradiation at the OD stretching overtone frequency is used to induce interconversion either from the most stable to the less stable conformer or the opposite, depending on the excitation wavelength. The interconversion process is of great help to assign conformers which are definitively identified by comparison between experimental and calculated IR spectra. Kinetic constants of the tunneling process at play are theoretically estimated and agree perfectly with experiments, including previous experiments with the totally hydrogenated acetylacetone [Lozada García et al., Phys. Chem. Chem. Phys., 2012, 14, 3450]. PMID:27412624

  9. Statistical modeling for Toluene Diisocyanate and Polypropylene Glycol Polymerization with Ferric Acetylacetonate as Catalyst

    Polyurethane elastomer was synthesized with propylene glycol and toluene diisocyanate with ferric acetylacetonate catalyst. This polymerization was modeled using the kinetic equations. The number and weight average degrees of polymerization (DPw and DPn), the number and weight average molecular weights (Mw and Mn) and the polydispersity index parameters were found and tested as function of time and conversion and they were finally compared with GPC laboratory and experimental results. The effect of concentration of the catalyst and the addition sequence of starting materials and catalyst on Mn, Mw, DPI and Mz/Mn are reported and discussed

  10. Effect of γ-radiation on the degradation of the M-O bond of some trivalent acetylacetonate complexes

    The effect of γ-radiation on the degradation of the M-O bond of seven trivalent acetylacetonate complexes was followed by IR spectrophotometry. The rate of degradation, K(M-O)afor K(M-O), obeyed a first order kinetics. The obtained K(M-O) and Go(M-O) for the different acetylacetonates are found to be linearly increased by the increase in the atomic radii of the chelated cations. A mechanism for the irradiation process is given. (author)

  11. Null current hysteresis for acetylacetonate electron extraction layer in perovskite solar cells

    Mohd Yusoff, Abd. Rashid Bin; Mat Teridi, Mohd Asri; Jang, Jin

    2016-03-01

    Solution processed zirconium acetylacetonate (Zr(acac)) is successfully employed as an electron extraction layer, replacing conventional titanium oxide, in planar CH3NH3PbI3 perovskite solar cells. The as-prepared Zr(acac) film possesses high transparency, high conductivity, a smooth morphology, high wettability, compatibility with PbI2 DMF solution, and an energy level matching that of CH3NH3PbI3 perovskite material. An average power conversion efficiency of about 11.93%, along with a high fill factor of 74.36%, an open circuit voltage of 1.03 V, and a short-circuit current density of 15.58 mA cm-2 is achieved. The overall performance of the devices is slight better than that of cells using ruthenium acetylacetonate (Ru(acac)). The differences between solar cells with different electron extraction layers in charge recombination, charge transport and transfer and lifetime are further explored and it is demonstrate that Zr(acac) is a more effective and promising electron extraction layer. This work provides a simple, and cost effective route for the preparation of an effective hole extraction layer.

  12. The development of radiogallium-acetylacetonate bis(thiosemicarbazone) complex for tumour imaging

    Background: Various radiometal complexes have been developed for tumour imaging, especially Ga-68 tracer. In this work, the development of a radiogallium bis(thiosemicarbazone) complex has been reported. Material and method: [67Ga]acetylacetonate bis(thio-semicarbazone) complex ([67Ga]AATS) was prepared starting with [67Ga]Gallium acetate and freshly prepared acetylacetonate bis(thiosemicarbazone) (AATS) for 30 min at 90oC. The partition co-efficient and stability of the tracer was determined in final solution (25oC) and the presence of human serum (37oC) for up to 24 hours. The biodistribution of the labelled compound in wild-type and fibrosarcoma-bearing rodents were determined for up to 72 hours. Results: The radiolabelled Ga complex was prepared to a high radiochemical purity (> 97%, HPLC) followed by initial biodistribution data with the significant tumour accumulation of the tracer at two hours, which is far higher than free Ga-67 cation, while the compound wash-out is significantly faster. Conclusion: The above-mentioned pharmacokinetic properties suggest an interesting radiogallium complex prepared by the PET Ga radioisotope, 68Ga, in accordance with the physical half life, for use in fibrosarcoma tumours and possibly in other malignancies. (authors)

  13. A New Homogeneous Catalyst for the Dehydrogenation of Dimethylamine Borane Starting with Ruthenium(III Acetylacetonate

    Ebru Ünel Barın

    2015-06-01

    Full Text Available The catalytic activity of ruthenium(III acetylacetonate was investigated for the first time in the dehydrogenation of dimethylamine borane. During catalytic reaction, a new ruthenium(II species is formed in situ from the reduction of ruthenium(III and characterized using UV-Visible, Fourier transform infrared (FTIR, 1H NMR, and mass spectroscopy. The most likely structure suggested for the ruthenium(II species is mer-[Ru(N2Me43(acacH]. Mercury poisoning experiment indicates that the catalytic dehydrogenation of dimethylamine-borane is homogeneous catalysis. The kinetics of the catalytic dehydrogenation of dimethylamine borane starting with Ru(acac3 were studied depending on the catalyst concentration, substrate concentration and temperature. The hydrogen generation was found to be first-order with respect to catalyst concentration and zero-order regarding the substrate concentration. Evaluation of the kinetic data provides the activation parameters for the dehydrogenation reaction: the activation energy Ea = 85 ± 2 kJ·mol−1, the enthalpy of activation ∆H# = 82 ± 2 kJ·mol−1 and the entropy of activation; ∆S# = −85 ± 5 J·mol−1·K−1. The ruthenium(II catalyst formed from the reduction of ruthenium(III acetylacetonate provides 1700 turnovers over 100 hours in hydrogen generation from the dehydrogenation of dimethylamine borane before deactivation at 60 °C.

  14. Structure of neodymium tris-acetylacetonate with dimethylsulfoxide [NdA3Dmso(H2O)]·Dmso

    Crystal structure of adduct of neodymium tris-acetylacetonate with dimethylsulfoxide was investigated. The adduct [NdA3Dmso(H2O)]. Dmso is crystallized in monclinic syngony. One of two Dmso molecules and water molecule enter the inner coordination sphere of the complex

  15. Ruthenium complexes with coordinated hydroxyiminoacetylacetonato or bridging nitrosyl groups formed by the reactions of nitrosylruthenium(III with acetylacetone

    Complexes formed by the reactions of nitrosylruthenium (III) with acetylacetone were investigated. The following products: [Ru(acac)2(hia)], 1; cis-[RuCl(NO)(acac)2], 2; and [(Ru(NO)(acac)2)4] 3; (acac=C5H7O2- and hia=C5H6NO3-), were isolated as crystals and were characterized. On the basis of chemical and thermal analyses, and on the basis of observations of the magnetic properties, the conductivities, the molecular weights, the infrared spectra, and the NMR spectra, it was concluded that 1 contains the hydroxyiminoacetyl acetonato ligand, which is formed by the reaction of the coordinated nitrosyl group with acetylacetone, and that 2 contains a terminal nitrosyl group, and 3, bridging nitrosyl groups. (auth.)

  16. Synthesis and spectroscopic studies of some chromium and molybdenum derivatives of bis-(acetylacetone)ethylenediimine ligand

    Ramadan, Ramadan M.; Abdel-Rahman, Laila H.; Ismael, Mohamed; Youssef, Teraze A.; Ali, Saadia A.

    2013-10-01

    Interaction of [Cr(CO)6] with bis-(acetylacetone)ethylenediimine Schiff base, H2acacen, under reduced pressure resulted in the formation of [Cr(CO)3(H2acacen)] derivative. The Schiff base acted as a tridentate and coordinated the metal through the nitrogen of the azomethine groups and one hydroxyl group. Reaction of [Mo(CO)6] with H2acacen under sunlight irradiation in presence of air gave the oxo derivative [Mo2O6(H2acacen)2]. The ligand acted as a bidentate and coordinated the metal through the two imine groups. In presence of 2,2'-bipyridine (bpy), the reaction of [Mo(CO)6] with H2acacen gave [Mo2O6(bpy)(H2acacec)]. The structures of the reported complexes were proposed on the basis of spectroscopic studies. The proposed structures were also verified by theoretical calculations based on accurate DFT approximations. Moreover, the relative reactivity was estimated using chemical descriptors analysis.

  17. Highly selective and sensitive monohydrogen phosphate membrane sensor based on molybdenum acetylacetonate

    Ganjali, Mohammad Reza [Center of Excellence in Electrochemistry, Department of Chemisrtry, Tehran University, Tehran (Iran, Islamic Republic of)]. E-mail: Ganjali@khayam.ut.ac.ir; Norouzi, Parviz [Center of Excellence in Electrochemistry, Department of Chemisrtry, Tehran University, Tehran (Iran, Islamic Republic of); Ghomi, Mahnaz [Department of Chemistry, Azad University, North of branch, Tehran (Iran, Islamic Republic of); Salavati-Niasari, Masoud [Department of Chemistry, Kashan University, Kashan (Iran, Islamic Republic of)

    2006-05-17

    In this work, a highly selective and sensitive monohydrogen phosphate membrane sensor based on a molybdenum bis(2-hydroxyanil) acetylacetonate complex (MAA) is reported. The sensor shows a linear dynamic range between 1.0 x 10{sup -1} and 1.0 x 10{sup -7} M, with a nice Nernstian behavior (-29.5 {+-} 0.3 mV decade{sup -1}) in pH of 8.2. The detection limit of the electrode is 6.0 x 10{sup -8} M ({approx}6 ppb). The best performance was obtained with a membrane composition of 32% poly(vinyl chloride), 58% benzyl acetate, 2% hexadecyltrimethylammonium bromide and 8% MAA. The sensor possesses the advantages of short response time, low detection limit and especially, very good selectivity towards a large number of organic and inorganic anions including salicylate, citrate, tartarate, acetate, oxalate, fluoride, chloride, bromide, iodide, sulfite, sulfate, nitrate, nitrite, cyanide, thiocyanate, perchlorate, metavanadate, and bicarbonate ions. The electrode can be used for at least 10 weeks without any considerable divergence in its slope and detection limit. It was used as an indicator electrode in potentiometric titration of monohydrogenphosphate ion with barium chloride. The proposed sensor was successfully applied to direct determination of monohydrogenphosphate in two fertilizer samples (NPK)

  18. Vanadium oxide thin films and fibers obtained by acetylacetonate sol–gel method

    Berezina, O.; Kirienko, D. [Department of Physical Engineering, Petrozavodsk State University, 185910 Petrozavodsk (Russian Federation); Pergament, A., E-mail: aperg@psu.karelia.ru [Department of Physical Engineering, Petrozavodsk State University, 185910 Petrozavodsk (Russian Federation); Stefanovich, G.; Velichko, A. [Department of Physical Engineering, Petrozavodsk State University, 185910 Petrozavodsk (Russian Federation); Zlomanov, V. [Department of Chemistry, Moscow State University, 119991 Moscow (Russian Federation)

    2015-01-01

    Vanadium oxide films and fibers have been fabricated by the acetylacetonate sol–gel method followed by annealing in wet nitrogen. The samples are characterized by X-ray diffraction and electrical conductivity measurements. The effects of a sol aging, the precursor decomposition and the gas atmosphere composition on the annealing process, structure and properties of the films are discussed. The two-stage temperature regime of annealing of amorphous films in wet nitrogen for formation of the well crystallized VO{sub 2} phase is chosen: 1) 25–550 °C and 2) 550–600 °C. The obtained films demonstrate the metal–insulator transition and electrical switching. Also, the effect of the polyvinylpyrrolidone additive concentration and electrospinning parameters on qualitative (absence of defects and gel drops) and quantitative (length and diameter) characteristics of vanadium oxide fibers is studied. - Highlights: • Vanadium oxide thin films and fibers are synthesized by sol–gel method. • The effect of annealing, atmosphere, time and electrospinning parameters is studied. • Produced VO{sub 2} structures exhibit metal–insulator transition and electrical switching.

  19. Keto-Enol Tautomeric Equilibrium of Acetylacetone Solution Confined in Extended Nanospaces.

    Tsukahara, Takehiko; Nagaoka, Kyosuke; Morikawa, Kyojiro; Mawatari, Kazuma; Kitamori, Takehiko

    2015-11-19

    We aim to clarify the effects of size confinement, solvent, and deuterium substitution on keto-enol tautomerization of acetylacetone (AcAc) in solutions confined in 10-100 nm spaces (i.e., extended nanospaces) using (1)H NMR spectroscopy. The keto-enol equilibrium constants of AcAc (K(EQ) = [keto]/[enol]) in various solvents confined in extended nanospaces of 200-3000 nm were examined using the area ratios of -CH3 peaks in keto to enol forms. The results showed that the keto form of AcAc in hydrogen-bonded solvents such as water and ethanol increased drastically with decreasing space sizes below about 500 nm, but the size confinement did not induce equilibrium shifts in aprotic solvents such as DMSO. The magnitudes of K(EQ) enhancement were well correlated with solvent proton donicity. It followed from the determination of thermodynamic parameters that the stabilization of intermolecular interactions between protons in water and carbonyl oxygen (C═O) in the keto form of AcAc were promoted by size-confinement, and that the keto form could be energetically and structurally favored in extended nanospaces vis-à-vis the bulk space. Furthermore, the measurements of deuterium dependence of the K(EQ) values verified that the nanoconfinement-induced shifts of keto-enol tautomerization of AcAc are attributable to high proton mobility via a proton hopping mechanism of the confined water. PMID:26503906

  20. Photo-and radiation chemical properties of manganese (3) acetylacetonates and structurization of polymeric compositions

    Methods of electron, EPR- and IR-spectroscopy have been used to study photochemical and radiation chemical behaviour of manganese (3) acetylacetonates. Effect of manganese chelates on structurization of polymeric compositions (the first composition - on the basis of saponified copolymer of vinyl chloride with vinyl acetate and the second composition on the basis of cellulose derivatives) linked (1) or destructed (2) under γ-radiation is considered. Maximum degree of structurization for the composition 1 at the absence of the complex made up 64%, at the presence of Mn(AA)Λ3 - 88%, at the presence of Mn(AA)Λ2(OCOCFΛ3) - 94% (at equal radiation doses). Adding the complexes amplifies the process of structurization, Mn(AA)Λ2 (OCOCFΛ3) amplifying the process to a larger extent than Mn(AA)Λ3. The degree of destruction of the composition 2 at the presence of the complex is essentially lower than at its absence. The mechanism of chelate effect on polymers comprises the stage of associate formation: metal complex - free radical

  1. L-Lactide Ring-Opening Polymerization with Tris(acetylacetonate)Titanium(IV) for Renewable Material.

    Kim, Da Hee; Yoo, Ji Yun; Ko, Young Soo

    2016-05-01

    A new Ti-type of catalyst for L-lactide polymerization was synthesized by reaction of titanium(IV) isopropoxide (TTIP) with acetylacetone (AA). Moreover, PLA was prepared by the bulk ring-opening polymerization using synthesized Ti catalyst. Polymerization behaviors were examined depending on monomer/catalyst molar ratio, polymerization temperature and time. The structure of synthesized catalysts was verified with FT-IR and 1H NMR and the properties of poly(L-lactide) (PLLA) were examined by GPC, DSC and FT-IR. There existed about 30 minutes of induction time at the monomer/catalyst molar ratio of 300. The molecular weight (MW) increased as monomer/catalyst molar ratio increased. The MW increased almost linearly as polymerization progressed. Increasing polymerization temperature increased the molecular weight of PLLA as well as monomer/catalyst molar ratio. The melting point (T(m)) of polymers was in the range of 142 to 167 degrees C. Lower T(m) was expected to be resulted from relatively lower molecular weight. PMID:27483787

  2. Vanadium oxide thin films and fibers obtained by acetylacetonate sol–gel method

    Vanadium oxide films and fibers have been fabricated by the acetylacetonate sol–gel method followed by annealing in wet nitrogen. The samples are characterized by X-ray diffraction and electrical conductivity measurements. The effects of a sol aging, the precursor decomposition and the gas atmosphere composition on the annealing process, structure and properties of the films are discussed. The two-stage temperature regime of annealing of amorphous films in wet nitrogen for formation of the well crystallized VO2 phase is chosen: 1) 25–550 °C and 2) 550–600 °C. The obtained films demonstrate the metal–insulator transition and electrical switching. Also, the effect of the polyvinylpyrrolidone additive concentration and electrospinning parameters on qualitative (absence of defects and gel drops) and quantitative (length and diameter) characteristics of vanadium oxide fibers is studied. - Highlights: • Vanadium oxide thin films and fibers are synthesized by sol–gel method. • The effect of annealing, atmosphere, time and electrospinning parameters is studied. • Produced VO2 structures exhibit metal–insulator transition and electrical switching

  3. Positron decay in benzene solutions of 3d transition metal acetylacetonates and dipivaloylmethanates

    The lifetime spectra of positrons and positronium were measured in benzene solutions containing metal acetylacetonates and dipivaloylmethanates. The lifetime of orthopositronium (o-Ps) observed in pure benzene, 3.20 ns, was not significantly affected by the diamagnetic aluminum, nickel(II), and zinc complexes dissolved in benzene, whereas the lifetime was reduced by the paramagnetic manganese(III), iron(III), chromium(III), cobalt(II), and diamagnetic cobalt(III) complexes with the increase in their concentration, e.g., down to 1.60 ns in the case of 0.20 M Mn(acac)3. The intensity (I2) of o-Ps decreased rapidly with an increase in the solute concentration and became saturated at about 0.05 M. The rate constants of the o-Ps annihilation were correlated with polarographic apparent half-wave potentials of the complexes. The large reaction rate constants for Mn(acac)3 and Fe(acac)3 were attributed to the oxidation of o-Ps by the complexes, which show the potentials less negative than -0.5 V vs. mercury pool in benzene--methanol

  4. Spectral studies on the interaction of acetylacetone with aluminum-containing MCM-41 mesoporous materials

    Diffuse reflectance spectroscopy (DRS) was used to study the interaction of acetylacetone (acac) with the mesoporous aluminum-containing MCM-41 materials. A room temperature synthesis method was used for preparation of purely siliceous MCM-41 and for aluminum-containing MCM-41 materials. Samples with Si/Al ratios of 50, 20, 10 and 5 were synthesized. The synthesized mesoporous materials possess highly ordered structure and high surface area as evidenced from X-ray diffraction and nitrogen physisorption measurements, respectively. The treatment of the as-synthesized aluminum-containing MCM-41 samples with acac shows a distinct band at ∼290 nm. This band is assigned to six coordinated aluminum atoms in the structure which is produced by diffusion of acac molecules through surfactant micelles and their interaction with aluminum atoms. The 290-nm band disappears upon several successive washing of the sample with ethanol. The treatment of the calcined aluminum-containing MCM-41 sample with acac produces the same 290-nm band where its intensity increases with the aluminum content of the sample. The intensity of this band is reduced upon successive ethanol washing, but remains nearly constant after three times washing. This irremovable aluminum species can be assigned to framework aluminum. The measured acidity for our aluminum-containing MCM-41 samples correlates linearly with the intensity of 290-nm band for the ethanol treated samples. This supports the idea that the Bronsted acidity in aluminum-modified MCM-41 samples is a function of the amount of tetrahedral framework aluminum in the structure

  5. Copper and Copper Oxide Nanoparticle Formation by Chemical Vapor Nucleation From Copper (II) Acetylacetonate

    Crystalline nanometer-size copper and copper (I) oxide particle formation was studied by thermal decomposition of copper acetylacetonate Cu(acac)2 vapor using a vertical flow reactor at ambient nitrogen pressure. The experiments were performed in the precursor vapor pressure range of Pprec = 0.06 to 44 Pa at furnace temperatures of 431.5 deg. C, 596.0 deg. C, and 705.0 deg. C. Agglomerates of primary particles were formed at Pprec0.1 Pa at all temperatures. At 431.5 deg. C the number mean size of the primary particles increased from Dp = 3.7 nm (with geometric standard deviation σg = 1.42) to Dp = 7.2 nm (σg = 1.33) with the increasing precursor vapor particle pressure from 1.8 to 16 Pa. At 705.0 deg. C the primary particle size decreased from Dp = 24.0 nm (σg=1.57) to Dp = 7.6 nm (σg = 1.54), respectively.At furnace temperatures of 431.5 deg. C and 596.0 deg. C only crystalline copper particles were produced. At 705.0 deg. C the crystalline product of the decomposition depended on the precursor vapor pressure: copper particles were formed at Pprec>10 Pa, copper (I) oxide at Pprecleq 1 Pa, and a mixture of the metal and its oxide at intermediate vapor pressures. A kinetic restriction on copper particle growth was shown, which leads to the main role of Cu2 molecule participation in the particle formation. The formation of copper (I) oxide particles occurs due to the surface reaction of the decomposition products (mainly carbon dioxide). For the explanation of the experimental results, a model is proposed to build a semiempirical phase diagram of the precursor decomposition products

  6. Indium Doped Zinc Oxide Thin Films Deposited by Ultrasonic Chemical Spray Technique, Starting from Zinc Acetylacetonate and Indium Chloride

    Rajesh Biswal; Arturo Maldonado; Jaime Vega-Pérez; Dwight Roberto Acosta; María De La Luz Olvera

    2014-01-01

    The physical characteristics of ultrasonically sprayed indium-doped zinc oxide (ZnO:In) thin films, with electrical resistivity as low as 3.42 × 10−3 Ω·cm and high optical transmittance, in the visible range, of 50%–70% is presented. Zinc acetylacetonate and indium chloride were used as the organometallic zinc precursor and the doping source, respectively, achieving ZnO:In thin films with growth rate in the order of 100 nm/min. The effects of both indium concentration and the substrate tempe...

  7. Solvatochromism Study on the Copper(II Complexes Containing 3–Substituted Derivatives of Acetylacetonate Ligands

    Hamid Golchoubian

    2012-01-01

    Full Text Available Solvatochromic properties of a series of bis(3–substituted derivatives of acetylacetone copper(II (X-acacH , X = Cl, H. CH3 complexes were studied. All the complexes demonstrated negative solvatochromism. Among the complexes the Cu(Cl-acac2, demonstrated the most solvatochromism. A multi-parametric equation has been utilized to explain the solvent effect on the d-d transition of the complexes using SPSS/PC software. The stepwise multiple linear regression (SMLR method demonstrated that the donor power of the solvent plays the most important role in the solvatochromism of the compounds.

  8. Solvatochromism Study on the Copper(II) Complexes Containing 3–Substituted Derivatives of Acetylacetonate Ligands

    Hamid Golchoubian; Fariba Khoshsiar

    2012-01-01

    Solvatochromic properties of a series of bis(3–substituted derivatives of acetylacetone) copper(II) (X-acacH , X = Cl, H. CH3) complexes were studied. All the complexes demonstrated negative solvatochromism. Among the complexes the Cu(Cl-acac)2, demonstrated the most solvatochromism. A multi-parametric equation has been utilized to explain the solvent effect on the d-d transition of the complexes using SPSS/PC software. The stepwise multiple linear regression (SMLR) method demonstrated th...

  9. Regiospecific tritium labeling of aromatic acids, amides, amines and heterocyclics using homogeneous rhodium trichloride and ruthenium acetylacetonate catalysts

    Homogeneous rhodium trichloride has been found to promote ortho-tritiation with high regioselectivity in a wide range of aromatic carboxylic acids, amides and aralkylamines. Less successful results were obtained using o-chlorobenzoic and o-anisic acids where some decomposition was seen, and in acids and amides of the phenolic type, where a degree of electrophilic exchange accompanies the ortho-exchange. The same catalyst has also been used to regiospecifically label a number of heterocyclics. In the course of investigations with other metal complexes ruthenium acetylacetonate has been identified as an excellent promoter of ortho-exchange in benzoic acids. (author)

  10. Host--guest complexation. 15. Macrocyclic acetylacetone ligands for metal cations

    Five macrocycles containing 1,5-disubstituted acetylacetone units (AcAc) have been synthesized. Their abilities to complex metal cations in water--dioxane have been compared to those of noncyclic model compounds. The AcAc units were bound together through bridges composed of the following groups: oxa (O), ethylene (E), and 1,3-disubstituted benzene (B). Cycles O(AcAcOEOE)(EOEOE)O(7), (OEOAcAcOE)2 (8), and (OEOAcAcOE)3 (9) were prepared by hydrolysis of rings closed by the reactions of CH2[HOCH2C(SCH2)2CH2]2 (2) and appropriate polyethylene glycol ditosylates. Ligand systems O(EAcAcE)2O (12) and B(CH2AcAcCH2)2B (14) were synthesized in Ca2+ or Mg2+ templated, two-step sequences involving reactions of HAcAcH dianions with either diethylene glycol ditosylate of m-xylyl dibromide, respectively. The preparation of (CH2IsCH2O)3 (17) is also described, in which Is is the 3,5-disubstituted isoxazole unit. Also described are the preparations of O(EAcAcH)2 (11), B(CH2AcAcH)2 (13), and P(CH2AcAcH)2 (15), in which P is 2,6-disubstituted pyridine. The logarithms of the formation constants (log K/sup f//sub av/) of the salts of (OEOAcAcOE)2 with 11 divalent metal cations and of (OEOAcAcOE)3 with 3 trivalent cations were 1.8 to 6.3 units higher valued than for CH3OAcAcOCH3. The log K/sup f//sub av/values for salt formation of O(EAcAcE)2O and B(CH2AcAcCH2)2B with 10 divalent cations were compared with those of O(EAcAcH)2 and B(CH2AcAcH)2, respectively, and with HAcAcH itself. Without exception, O(EAcAcE)2O > O(EAcAcH)2 > HAcAcH in values of log k/sup f//sub av/, the maximum difference being 4.3 for Ca2+

  11. Preparation and Biodistribution Studies of a Radiogallium-Acetylacetonate Bis (Thiosemicarbazone) Complex in Tumor-Bearing Rodents

    Jalilian, Amir Reza; Yousefnia, Hassan; Shafaii, Kamaleddin; Novinrouz, Aytak; Rajamand, Amir Abbas

    2012-01-01

    Various radiometal complexes have been developed for tumor imaging, especially Ga-68 tracer. In the present study, the development of a radiogallium bis-thiosemicarbazone complex has been reported. [67Ga] acetylacetonate bis(thiosemicarbazone) complex ([67Ga] AATS) was prepared starting [67Ga]Gallium acetate and freshly prepared acetylacetonate bis (thiosemicarbazone) (AATS) in 30 min at 90°C. The partition co-efficient and the stability of the tracer were determined in final solution (25°C) and the presence of human serum (37°C) up to 24 h. The biodistribution of the labeled compound in wild-type and fibrosarcoma-bearing rodents were determined up to 72 h. The radiolabled Ga complex was prepared in high radiochemical purity (> 97%, HPLC) followed by initial biodistribution data with the significant tumor accumulation of the tracer in 2 h which is far higher than free Ga-67 cation while the compound wash-out is significantly faster. Above-mentioned pharmacokinetic properties suggest an interesting radiogallium complex while prepared by the PET Ga radioisotope, 68Ga, in accordance with the physical half life, for use in fibrosarcoma tumors, and possibly other malignancies. PMID:24250475

  12. Investigation of the weak basic butyltriethylammonium acetylacetonate and polyethylene glycol mixture as a new efficient CO2 absorption solvent

    Highlights: • The absorption of CO2 in butyltriethylammonium acetylacetonate and polyethylene glycol 200 mixtures has been reported. • The absorption enthalpy and absorption entropy were calculated. • The absorption process is efficient and reversible. • The mixtures showed low absorption enthalpy for CO2 capture. • The addition of PEG-200 can accelerate absorption process. - Abstract: Efficient and reversible absorption of CO2 was investigated by weak basic ionic liquid of butyltriethylammonium acetylacetonate ([N2224][acac]) and polyethylene glycol 200 (PEG-200) mixtures with different mass ratios. The results showed that [N2224][acac]/PEG-200 mixtures possessed a maximum absorption capacity of 0.9 mol CO2 per mole [N2224][acac] at T = 298.15 K under ambient pressure. The mixtures used could be easily regenerated by bubbling N2 through the solutions without obvious loss of absorption performance. Furthermore, the solubility data of CO2 in the mixtures at T = (303.15, 318.15, and 333.15) K under different pressures were measured. The thermodynamic parameters of absorption enthalpy and absorption entropy were calculated with resulting negative values at each condition. The mixtures showed low absorption enthalpy for CO2 capture. The addition of PEG-200 can accelerate absorption process. The CO2 capture process described using [N2224][acac]/PEG-200 mixtures is a promising method for CO2 absorption with both good reversibility and high absorption capacity

  13. Effect of magnesium acetylacetonate on the signal of organic forms of vanadium in graphite furnace atomic absorption spectrometry.

    Kowalewska, Zofia; Welz, Bernhard; Castilho, Ivan N B; Carasek, Eduardo

    2013-01-15

    The aim of this work was to investigate the influence of magnesium acetylacetonate (MgA) on the signal of organic forms of vanadium in xylene solution by graphite furnace atomic absorption spectrometry. MgA alone or mixed with palladium acetylacetonate (PdA) was considered as a chemical modifier. It has been found that MgA does not improve, but decreases significantly the integrated absorbance of V in the form of alkyl-aryl sulfonates, acetylacetonates, porphyrins and in lubricating oils, while its effect is negligible in the case of "dark products" from petroleum distillation, i.e., heavy oil fractions and residues. The decrease is also observed in the presence of Pd. The MgA (or MgA+PdA) effect on the integrated absorbance of V has been studied using the following variants: different ways of modifier application, various pyrolysis temperature, additional application of air ashing, preliminary pretreatment with iodine and methyltrioctylammonium chloride, application of various graphite furnace heating systems (longitudinal or transverse) and various optical and background correction systems (medium-resolution line source spectrometer with deuterium background correction or high-resolution continuum source spectrometer). The experiments indicate formation of more refractory compounds as a possible reason for the decrease of the integrated absorbance for some forms of V in the presence of MgA. The application of MgA as a chemical modifier in V determination is not recommended. Results of this work have general importance as, apart from the intentional use of MgA as a modifier, organic Mg compounds, present in petroleum products for other reason (e.g. as an additive), can influence the signal of V compounds and hence the accuracy in V determination. Generally, petroleum products with known amount of V are recommended as standards; however, lubricating oils can be inadequate for "dark products" from petroleum distillation. In the case of unknown samples it is

  14. An extractive spectrophotometry method for the determination of vanadium as V(II)-8-hydroxyquinoline complex into acetylacetone-chloroform

    A simple and rapid extractive spectrophotometric method of determination of vanadium is developed by reduction of the metal ion with Zn/Hg in presence of 8-hydroxyquinoline under acidic conditions employing acetylacetone-chloroform as extractant. No interference is shown by W(VI), Cr(VI, III), U(VI), Mo(VI), Fe(II), Co(II), Ni(II), Cu(II) and several other elements of interest. The applicability of the method is tested by analysis of a large number of different samples. The method is highly reproducible with a standard deviation of 0.0065 and Sandell's sensitivity 8.6956x10-2 μg V/cm2. Stoichiometry of the complex is also studied. (author). 1 tab., 17 refs

  15. Heat capacity and thermodynamic functions of ruthenium tris-acetylacetonate from 0 K up to the melting point

    Highlights: • The heat capacity for Ru(AA)3 for the entire range of solid phase existence. • Density of phonon states calculated from the low-temperature heat capacity • Thermodynamic functions in the range (0–505) K. - Abstract: In the present work, the vibrational spectrum of the ruthenium tris-acetylacetonate crystal, Ru(C5H7O2)3, was reconstructed and its heat capacity was calculated for the entire range of solid phase existence (5–505 K) based on the experimental data on heat capacity obtained by adiabatic method within the range of 6–310 K. The Cp−Cv difference was estimated at the temperatures above 310 K. Based on the heat capacity obtained from the vibrational spectrum, integral thermodynamic functions (entropy, internal energy, and Helmholtz energy) were calculated up to the melting point

  16. Heat capacity and thermodynamic functions of ruthenium tris-acetylacetonate from 0 K up to the melting point

    Kuzin, Timofei M., E-mail: kuzin@niic.nsc.ru; Bespyatov, Michael A.; Naumov, Victor N.; Musikhin, Anatoly E.; Gelfond, Nikolay V.

    2015-02-20

    Highlights: • The heat capacity for Ru(AA){sub 3} for the entire range of solid phase existence. • Density of phonon states calculated from the low-temperature heat capacity • Thermodynamic functions in the range (0–505) K. - Abstract: In the present work, the vibrational spectrum of the ruthenium tris-acetylacetonate crystal, Ru(C{sub 5}H{sub 7}O{sub 2}){sub 3}, was reconstructed and its heat capacity was calculated for the entire range of solid phase existence (5–505 K) based on the experimental data on heat capacity obtained by adiabatic method within the range of 6–310 K. The C{sub p}−C{sub v} difference was estimated at the temperatures above 310 K. Based on the heat capacity obtained from the vibrational spectrum, integral thermodynamic functions (entropy, internal energy, and Helmholtz energy) were calculated up to the melting point.

  17. Effect of chelating agent acetylacetone on corrosion protection properties of silane-zirconium sol-gel coatings

    Yu, Mei; Liang, Min; Liu, Jianhua; Li, Songmei; Xue, Bing; Zhao, Hao

    2016-02-01

    The hybrid sol-gel coatings on AA2024-T3 were prepared with a silane coupling agent 3-glycidoxypropyltrimethoxysilane (GPTMS) and a metal alkoxide tetra-n-propoxyzirconium (TPOZ) as precursors. The effect of acetylacetone (AcAc) as a chelating agent on the corrosion protection properties of sol-gel coatings were evaluated and the optimal AcAc/TPOZ molar ratio was obtained. The sol-gel coatings were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The corrosion protection properties of the coatings were evaluated by means of potentiodynamic polarization study (PDS) and electrochemical impedance spectroscopy (EIS). It is demonstrated that AcAc avoids fast hydrolysis of TPOZ and benefits to form stable sols. The coating with AcAc/TPOZ molar ratio of 3 shows the best corrosion protection performance in 0.05 M NaCl solution.

  18. Detection limits in the chromatographic element trace analysis - quantitative TLC, HPLC and GC with the example of beryllium acetylacetonate

    Chromatographic analyses of beryllium acetylacetonate are carried out in synthetic solutions within the nano- and picogram range of beryllium. For thin-layer chromatography (TLC) normal and silanized silica gel is used, for high-performance liquid chromatography (HPLC) silica gel of 7 μm particles, for gas chromatography (GC) silicone SE-30 as stationary phase. Visual evaluation and remission measurements in TLC, UV-254 nm absorption measurements in HPLC and measurements with a FID in GC are employed for the determination of the calibration curves. A calibration curve through the origin and a detection limit of 150 pg Be determinable form are received by HPLC only. For trace analyses by GC a new definition of a detection limit for the evaluation of substance peaks on a solvent tailing is suggested. (orig.)

  19. Contribution to the study of the chemical consequences of the (n, γ) reaction in solid Co(3) tris-acetylacetone

    The fragmentation and annealing of thermal neutron irradiated Co(III) tris-acetylacetone was investigated using the thin layer chromatographic technique (silica-gel 1 mm thickness). Low temperature irradiations (0 C - -72 C and -180 C) lead to 60Co retentions as low as (1,1 ± 0,2) per cent. Annealing by linear temperature programming at different heating rates has shown the existence of eight reactions. The influences of pile dose and of gases (air and helium) as well as of thermal decomposition on the annealing processes were confirmed. A temperature and dose dependent effect was found out for the retentions of the 60mCo - 60Co isomers. (author)

  20. Transport of Indium, Gallium and Thallium Metal Ions Through Chromatographic Fiber Supported Solid Membrane in Acetylacetone Containing Mixed Solvents

    Abaji Gaikwad

    2011-01-01

    The transport of metal ions of indium, gallium and thallium from source solution to receiving phase through the chromatographic fiber supported solid membrane in the acetylacetone (HAA) containing mixed solvent system has been explored. The fibers supported solid membranes were prepared with chemical synthesis from cellulose fibers and citric acid with the carboxylic acid ion exchange groups introduced. The experimental variables, such as concentration of metal ions (10^-2 to 10^-4 mol.L^-1) in the source solution, mixed solvent composition [for exampl, e, acetylacetone, (2,4-pentanedione), (HAA) 20% (by volume), 1,4-dioxane 10% to 60% and HC1 0.25 to 2 mol.L^-1] in the receiving phase and stirring speed (50-130 r.min ) of the bulk source and receiving phase, were explored. The efficiency of mixed solvents for the transport of metal ions from the source to receiving phase through the fiber supported solid membrane was evaluated. The combined ion exchange solvent extraction (CIESE) was observed effective for the selective transport of thallium, indium and gallium metal ions through fiber supported solid membrane in mixed solvents. The oxonium salt formation in the receiving phase enhances thallium, indium and gallium metal ion transport through solid membrane phase. The selective transport of thallium metal ions from source phase was observed from indium and gallium metal ions in the presence of hydrochloric acid in organic solvents in receiving phase. The separation of thallium metal ions from the binary mixtures of Be(II), Ti(IV), AI(III) Ca(II), Mg(II), K (I), La(III) and Y(III) was carried out in the mixed solvent system using cellulose fiber supported solid membrane.

  1. Calculating the thermodynamic characteristics of hydrophobic hydration of chromium(III) and cobalt(III) tris-acetylacetonates in water and regularities of their solvation in aqueous alcoholic solvents

    Vologdin, N. V.; Fabinskii, P. V.; Fedorov, V. A.

    2016-06-01

    Based on the scaled-particle theory, the Gibbs energy of the formation of cavities in the structure of water and some alcohols are calculated for the processes of dissolution of cobalt(III) and chromium(III) tris-acetylacetonates. The contribution from the hydrophobic hydration of the tris-acetylacetonate molecules in water is calculated. The location of the inversion area is clarified for a number of aqueous alcoholic solvents, and the effect the solvent's macrophysical parameters have on the patterns of tris-acetylacetonate solvation is analyzed.

  2. The chemistry and mechanism of thermal degradation reactions of lanthanum(III) and praseodymium(III) complexes of acetylacetone-bis(thiosemicarbazones)

    The reactions of acetylacetone with 4-phenyl, 4-(2-chlorophenyl), 4-(4-nitrophenyl) and 4-(2-methylphenyl) thiosemicarbazide yields acetylacetone-bis(thiosemicarbazone) ligands (H2L). Lanthanum(III) and praseodymium(III) complexes with these ligands of the type (Ln(L)Cl(H2O)) have been prepared. The thermal behaviour of these compounds in non-isothermal conditions was investigated using TG, DTG and DSC techniques. The intermediates obtained at the end of various thermal decomposition steps were identified from elemental analyses and infrared spectral studies. The graphical method of Coats and Redfern was employed to evaluate the kinetic parameters such as apparent activation energy and order of reaction. The heats of reaction for the different decomposition steps were calculated from DSC curves. (author)

  3. Formation of TiO/Al2O3/C Composite in Thermal Co-decomposition of Aluminium(III) Acetylacetonate and Titanium(IV) Oxyacetylacetonate.

    Kovářík, T.; Pokorná, Dana; Urbanová, Markéta; Bezdička, Petr; Bastl, Zdeněk; Kupčík, Jaroslav; Křenek, T.; Pola, M.; Kullová, L.; Pola, Josef

    2016-01-01

    Roč. 117, JAN 2016 (2016), s. 182-190. ISSN 0165-2370 R&D Projects: GA TA ČR TA04020860 Institutional support: RVO:67985858 ; RVO:61388980 ; RVO:61388955 Keywords : thermal co-decomposition * aluminium(III) acetylacetonate * titanium(IV) oxyacetylacetonate * titanium monoxide * alumina * Carbona Subject RIV: CF - Physical ; Theoretical Chemistry; CA - Inorganic Chemistry (UACH-T) Impact factor: 3.564, year: 2014

  4. Indium Doped Zinc Oxide Thin Films Deposited by Ultrasonic Chemical Spray Technique, Starting from Zinc Acetylacetonate and Indium Chloride

    Rajesh Biswal

    2014-07-01

    Full Text Available The physical characteristics of ultrasonically sprayed indium-doped zinc oxide (ZnO:In thin films, with electrical resistivity as low as 3.42 × 10−3 Ω·cm and high optical transmittance, in the visible range, of 50%–70% is presented. Zinc acetylacetonate and indium chloride were used as the organometallic zinc precursor and the doping source, respectively, achieving ZnO:In thin films with growth rate in the order of 100 nm/min. The effects of both indium concentration and the substrate temperature on the structural, morphological, optical, and electrical characteristics were measured. All the films were polycrystalline, fitting well with hexagonal wurtzite type ZnO. A switching in preferential growth, from (002 to (101 planes for indium doped samples were observed. The surface morphology of the films showed a change from hexagonal slices to triangle shaped grains as the indium concentration increases. Potential applications as transparent conductive electrodes based on the resulting low electrical resistance and high optical transparency of the studied samples are considered.

  5. Synthesis, structure, theoretical studies and luminescent properties of a ternary erbium(III) complex with acetylacetone and bathophenanthroline ligands

    A novel erbium(III) complex with acetylacetone (Hacac) and bathophenanthroline (4,7-diphenyl-1,10-phenanthroline, bath) ligands, formulated as [Er(acac)3(bath)], has been characterized by elemental analysis, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, Raman spectroscopy, absorption and emission spectroscopies. In the theoretical part of this study, semi-empirical quantum chemistry methods using AM1, PM3, PM6 and PM7 models have been employed to predict the structure of the complex, calculate the geometric and crystallographic parameters, and make comparisons with spectroscopic data using INDO/S-CI calculations. Real-time time-dependent density-functional theory (TDDFT) has also been used to calculate the optical absorption spectrum of the complex in the gas phase. - Highlights: • Synthesis and structure of a new erbium(III) β-diketonate complex. • TDDFT used for the first time to calculate the optical absorption spectrum. • Complex show strong near-infrared luminescence at 1.53 µm due to antenna effect

  6. Phosphorescence quantum yield determination with time-gated fluorimeter and Tb(III)-acetylacetonate as luminescence reference

    Penzkofer, A., E-mail: alfons.penzkofer@physik.uni-regensburg.de [Fakultät für Physik, Universität Regensburg, Universitätsstrasse 31, D-93053 Regensburg (Germany)

    2013-03-29

    Highlights: ► Procedure for absolute phosphorescence quantum yield measurement is described. ► Experimental setup for absolute luminescence quantum yield standard calibration. ► Tb(acac){sub 3} proposed as phosphorescence quantum yield reference standard. ► Luminescence quantum yield of Tb(acac){sub 3} in cyclohexane measured. ► Luminescence lifetime of Tb(acac){sub 3} in cyclohexane measured. - Abstract: Phosphorescence quantum yield measurements of fluorescent and phosphorescent samples require the use of time-gated fluorimeters in order to discriminate against the fluorescence contribution. As reference standard a non-fluorescent luminescent compound is needed for absolute phosphorescence quantum yield determination. For this purpose the luminescence behavior of the rare earth chelate terbium(III)-acetylacetonate (Tb(acac){sub 3}) was studied (determination of luminescence quantum yield and luminescence lifetime). The luminescence quantum yield of Tb(acac){sub 3} was determined by using an external light source and operating the fluorimeter in chemo/bioluminescence mode with a fluorescent dye (rhodamine 6G in methanol) as reference standard. A procedure is developed for absolute luminescence (phosphorescence) quantum yield determination of samples under investigation with a time-gated fluorimeter using a non-fluorescent luminescent compound of known luminescence quantum yield and luminescence lifetime.

  7. Efficient alkene epoxidation catalyzed by molybdenyl acetylacetonate supported on aminated UiO-66 metal−organic framework

    Kardanpour, Reihaneh [Department of Chemistry, Catalysis Division, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Tangestaninejad, Shahram, E-mail: stanges@sci.ui.ac.ir [Department of Chemistry, Catalysis Division, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Mirkhani, Valiollah, E-mail: mirkhani@sci.ui.ac.ir [Department of Chemistry, Catalysis Division, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Moghadam, Majid, E-mail: moghadamm@sci.ui.ac.ir [Department of Chemistry, Catalysis Division, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Mohammadpoor-Baltork, Iraj; Zadehahmadi, Farnaz [Department of Chemistry, Catalysis Division, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of)

    2015-03-15

    Metal–organic frameworks (MOFs) containing Mo Schiff base complexes were prepared by post-synthesis method and applied as efficient catalysts in the epoxidation of alkenes with tert-BuOOH. In this manner, UiO-66-NH{sub 2} (UiO=University of Oslo) MOF was reacted with salicylaldehyde and thiophene-2-carbaldehyde to produce bidentate Schiff bases. Then, the Schiff base ligands were used for immobilization of molybdenyl acetylacetonate. These new catalysts were characterized by FT-IR, UV–vis spectroscopic techniques, X-ray diffraction (XRD), BET, inductively coupled plasma atomic emission spectroscopy (ICP-AES) and field emission scanning electron microscopy (FE-SEM). These catalytic systems showed excellent activity in the epoxidation of alkenes such as cyclic and linear ones with tert-butyl hydroperoxide (TBHP) in 1,2-dichloroethane, and reused several times without any appreciable loss of their activity. - Graphical abstract: Efficient alkene epoxidation with TBHP catalyzed by heterogeneous and reusable molybdenum base catalysts is reported. - Highlights: • UiO-66-NH{sub 2} was modified with salicylaldehyde and thiophene-2-carbaldehyde. • The Schiff base groups were used for immobilization of MoO{sub 2}(acac){sub 2}. • The heterogeneous catalysts were prepared. • The prepared catalysts were used for epoxidation of alkenes. • Compared to other catalyst, our catalysts were more efficient and forceful.

  8. Efficient alkene epoxidation catalyzed by molybdenyl acetylacetonate supported on aminated UiO-66 metal−organic framework

    Metal–organic frameworks (MOFs) containing Mo Schiff base complexes were prepared by post-synthesis method and applied as efficient catalysts in the epoxidation of alkenes with tert-BuOOH. In this manner, UiO-66-NH2 (UiO=University of Oslo) MOF was reacted with salicylaldehyde and thiophene-2-carbaldehyde to produce bidentate Schiff bases. Then, the Schiff base ligands were used for immobilization of molybdenyl acetylacetonate. These new catalysts were characterized by FT-IR, UV–vis spectroscopic techniques, X-ray diffraction (XRD), BET, inductively coupled plasma atomic emission spectroscopy (ICP-AES) and field emission scanning electron microscopy (FE-SEM). These catalytic systems showed excellent activity in the epoxidation of alkenes such as cyclic and linear ones with tert-butyl hydroperoxide (TBHP) in 1,2-dichloroethane, and reused several times without any appreciable loss of their activity. - Graphical abstract: Efficient alkene epoxidation with TBHP catalyzed by heterogeneous and reusable molybdenum base catalysts is reported. - Highlights: • UiO-66-NH2 was modified with salicylaldehyde and thiophene-2-carbaldehyde. • The Schiff base groups were used for immobilization of MoO2(acac)2. • The heterogeneous catalysts were prepared. • The prepared catalysts were used for epoxidation of alkenes. • Compared to other catalyst, our catalysts were more efficient and forceful

  9. Iron-Mediated Homogeneous ICAR ATRP of Methyl Methacrylate under ppm Level Organometallic Catalyst Iron(III Acetylacetonate

    Jian Wu

    2016-01-01

    Full Text Available Atom Transfer Radical Polymerization (ATRP is an important polymerization process in polymer synthesis. However, a typical ATRP system has some drawbacks. For example, it needs a large amount of transition metal catalyst, and it is difficult or expensive to remove the metal catalyst residue in products. In order to reduce the amount of catalyst and considering good biocompatibility and low toxicity of the iron catalyst, in this work, we developed a homogeneous polymerization system of initiators for continuous activator regeneration ATRP (ICAR ATRP with just a ppm level of iron catalyst. Herein, we used oil-soluble iron (III acetylacetonate (Fe(acac3 as the organometallic catalyst, 1,1′-azobis (cyclohexanecarbonitrile (ACHN with longer half-life period as the thermal initiator, ethyl 2-bromophenylacetate (EBPA as the initiator, triphenylphosphine (PPh3 as the ligand, toluene as the solvent and methyl methacrylate (MMA as the model monomer. The factors related with the polymerization system, such as concentration of Fe(acac3 and ACHN and polymerization kinetics, were investigated in detail at 90 °C. It was found that a polymer with an acceptable molecular weight distribution (Mw/Mn = 1.43 at 45.9% of monomer conversion could be obtained even with 1 ppm of Fe(acac3, making it needless to remove the residual metal in the resultant polymers, which makes such an ICAR ATRP process much more industrially attractive. The “living” features of this polymerization system were further confirmed by chain-extension experiment.

  10. Effect of some d-transition metal complexes of salen-type ligands and acetylacetone on fluorescence of europium(III) and terbium(III)

    Fluorescence spectra of europium(III) and terbium(III) have been measured in methanolic solutions containing various amounts of [M(salen)] (M=Cu(II), Ni(II)), [Cr(salen)(H2O)2]Cl, [M(saltn)] (M=Cu(II), Ni(II)), [Cu(acacen)], [M(acac)2] (M=Cu(II), VIVO), [M(acac)3] (M=Cr(III), Co(III)), or [Ni(acac)2(H2O)2]. Our purpose was to investigate the influence of these metal complexes on the fluorescence of Eu(III) and Tb(III), where H2salen, H2saltn, H2acacen, and Hacac stand for N,N'-bis(salicylidene)ethylenediamine, N,N'-bis(salicylidene)-1,3-propanediamine, N,N'-bis(1-methyl-3-oxobutylidene)ethylenediamine, and acetylacetone, respectively. The fluorescence intensities of both Eu(III) and Tb(III) decreased with increasing the concentration of [M(salen)] (M=Cu, Ni), [Cr(salen)(H2O)2]Cl, [M(saltn)] (M=Cu, Ni), [Cu(acacen)], and [M(acac)3] (M=Cr, Co), whereas it was little affected by simple metal salts. The intensity of Tb(III) increased up to the addition of a given amount of [M(acac)2] (M=Cu, VO) or [Ni(acac)2(H2O)2] and then decreased on further addition, whereas the intensity of Eu(III) decreased gradually by the addition of these acetylacetonate complexes. These results are explained by the formation of heteronuclear complex species and by the stabilities of acetylacetonate complexes. (author)

  11. The comparison of 8-hydroxyquinoline, tropolone, and acetylaceton as mediators in the labelling of polymorphonuclear leucocytes with indium-111: A functional study

    Tropolone forms a lipophilic complex with indium-111 which is capable of mediating the labelling of polymorphonuclear leucocytes (PMNs) by this isotope; labelling efficiencies are comparable with the best achieved using 8-hydroxyquinoline and acetylacetone. However, in terms of PMN chemotaxis and phagocytosis, tropolone is significantly less toxic than either of the other ligands. 8-hydroxyquinoline was found to reduce PMN chemotaxis and phagocytosis to approximately 70% of the control values at a concentration of 20 μM. Tropolone may prove a superior labelling reagent. (orig.)

  12. Determination of Chromium(III), Chromium(VI), and Chromium(III) acetylacetonate in water by ion-exchange disk extraction/metal furnace atomic absorption spectrometry

    Kamakura, Nao, E-mail: minnie04_tb@yahoo.co.jp; Inui, Tetsuo; Kitano, Masaru; Nakamura, Toshihiro

    2014-03-01

    A new method for the separate determination of Chromium(III) (Cr(III)), Chromium(VI) (Cr(VI)), and Cr(III) acetylacetonate (Cr(acac){sub 3}) in water was developed using a cation-exchange extraction disk (CED) and an anion-exchange extraction disk (AED) combined with metal furnace atomic absorption spectrometry (MFAAS). A 100-mL water sample was adjusted to pH 5.6 and passed through the CED placed on the AED. Cr(acac){sub 3} and Cr(III) were adsorbed on the CED, and Cr(VI) was adsorbed on the AED. The adsorbed Cr(acac){sub 3} was eluted with 50 mL of carbon tetrachloride, followed by the elution of Cr(III) with 50 mL of 3 mol L{sup −1} nitric acid. Cr(VI) was eluted with 50 mL of 3 mol L{sup −1} nitric acid. The chemical species of Cr eluted from the CED with carbon tetrachloride was identified as Cr(acac){sub 3} using infrared spectroscopy. The eluate of Cr(acac){sub 3} was diluted to 100 mL with carbon tetrachloride, and those of Cr(III) and Cr(VI) were diluted to 100 mL with deionized water. All of the solutions were subsequently analyzed by MFAAS. The calibration curve for the Cr(acac){sub 3} aqueous solutions exhibited good linearity in the range of 0.1 to 1 ng. The detection limit of Cr, which corresponded to three times the standard deviation (n = 10) of the blank values, was 20 pg. The recovery test for Cr(III), Cr(VI), and Cr(acac){sub 3} exhibited desirable results (96.0%–107%) when 5 μg of each species (50 μg L{sup −1}) was added to 100 mL water samples (i.e., tap water, rainwater, and bottled drinking water). In a humic acid solution, Cr(acac){sub 3} was quantitatively recovered (103%), but Cr(III) and Cr(VI) exhibited poor recoveries (i.e., 84.8% and 78.4%, respectively). - Highlights: • A determination method of Cr(III), Cr(VI), and Cr(III) acetylacetonate in water was developed. • The combination of ion-exchange resin disks with metal furnace AAS was used. • No effect of humic acid on the recovery of Cr(III) acetylacetonate was

  13. Determination of Chromium(III), Chromium(VI), and Chromium(III) acetylacetonate in water by ion-exchange disk extraction/metal furnace atomic absorption spectrometry

    A new method for the separate determination of Chromium(III) (Cr(III)), Chromium(VI) (Cr(VI)), and Cr(III) acetylacetonate (Cr(acac)3) in water was developed using a cation-exchange extraction disk (CED) and an anion-exchange extraction disk (AED) combined with metal furnace atomic absorption spectrometry (MFAAS). A 100-mL water sample was adjusted to pH 5.6 and passed through the CED placed on the AED. Cr(acac)3 and Cr(III) were adsorbed on the CED, and Cr(VI) was adsorbed on the AED. The adsorbed Cr(acac)3 was eluted with 50 mL of carbon tetrachloride, followed by the elution of Cr(III) with 50 mL of 3 mol L−1 nitric acid. Cr(VI) was eluted with 50 mL of 3 mol L−1 nitric acid. The chemical species of Cr eluted from the CED with carbon tetrachloride was identified as Cr(acac)3 using infrared spectroscopy. The eluate of Cr(acac)3 was diluted to 100 mL with carbon tetrachloride, and those of Cr(III) and Cr(VI) were diluted to 100 mL with deionized water. All of the solutions were subsequently analyzed by MFAAS. The calibration curve for the Cr(acac)3 aqueous solutions exhibited good linearity in the range of 0.1 to 1 ng. The detection limit of Cr, which corresponded to three times the standard deviation (n = 10) of the blank values, was 20 pg. The recovery test for Cr(III), Cr(VI), and Cr(acac)3 exhibited desirable results (96.0%–107%) when 5 μg of each species (50 μg L−1) was added to 100 mL water samples (i.e., tap water, rainwater, and bottled drinking water). In a humic acid solution, Cr(acac)3 was quantitatively recovered (103%), but Cr(III) and Cr(VI) exhibited poor recoveries (i.e., 84.8% and 78.4%, respectively). - Highlights: • A determination method of Cr(III), Cr(VI), and Cr(III) acetylacetonate in water was developed. • The combination of ion-exchange resin disks with metal furnace AAS was used. • No effect of humic acid on the recovery of Cr(III) acetylacetonate was observed. • The proposed method enabled the determination of three Cr

  14. A non-empirical LCAO MO SCF and experimental investigation on the core-ionized states of acetylacetone and some of its enol tautomers

    Non-empirical LCAO MO SCF calculations have been performed on the ground and core-hole states of acetylacetone for a range of geometries. The theoretical studies have been complemented by gas-phase ESCA studies of both the O 1s and C 1s core levels. A comparison of the theoretical and experimental data shows excellent agreement for an unsymmetrical Csub(s) enol structure and a discussion is given of the low-energy shake-up satellites accompanying both C 1s and O 1s core ionization. Consideration is also given to the relative energies of the various tautomeric model systems as a function of the hole states. (orig.)

  15. Molybdenum oxide catalysts for metathesis of higher 1-alkenes via supporting MoO2(acetylacetonate)2 and MoO2(glycolate)2 on SBA-15 mesoporous molecular sieves

    Balcar, Hynek; Mishra, D.; Marceau, E.; Carrier, X.; Žilková, Naděžda; Bastl, Zdeněk

    2009-01-01

    Roč. 359, 1-2 (2009), s. 129-135. ISSN 0926-860X R&D Projects: GA MŠk MEB020723; GA AV ČR IAA400400805; GA AV ČR KAN100400701 Institutional research plan: CEZ:AV0Z40400503 Keywords : 1-alkene metathesis * Mo heterogeneous catalysts * Molybdenum dioxide bis(acetylacetonate) * Molybdenum dioxide bis(glycolate) Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.564, year: 2009

  16. Thermal co-decomposition of silver acetylacetonate and tin(II) hexafluoroacetylacetonate: Formation of carbonaceous Ag/AgxSn(x = 4 and 6.7)/SnO2 composites

    Highlights: • Ag acetylacetonate increases thermal stability by mixing with Sn hexafluoroacetylacetonate. • Heated mixture of chelates yields a residue containing Ag, Sn, O and C elements. • Residues obtained at higher temperature contain Ag–Sn intermetallic compounds. - Abstract: Thermal co-decomposition of silver(I) acetylacetonate and tin(II) hexafluoroacetylacetonate has been examined by using thermal gravimetry, differential scanning calorimetry and complementary analyses of gaseous products and solid residues by Fourier transform infrared and Raman spectroscopy, X-ray diffraction and scanning electron microscopy. It is revealed that poorly stable silver(I) acetylacetonate mixed with tin(II) hexafluoroacetylacetonate does not undergo thermal decomposition at around 120 °C, but takes part in a room-temperature solid-state interaction with the Sn counterpart, which is ensued by an exothermal process at 109 °C and subsequent co-decomposition involving a pronounced stage at around 275 °C. All steps lead to carbonaceous Ag/SnO2 composites containing crystalline Ag at 200 °C, Ag and SnO2 at 400 °C, and Ag, SnO2, Ag4Sn and Ag6.7Sn at 600 °C. The intermetallic Ag6.7Sn compound is judged to arise from nanostructured environment of alloying Ag and Sn

  17. Optimization of the Energy Level Alignment between the Photoactive Layer and the Cathode Contact Utilizing Solution-Processed Hafnium Acetylacetonate as Buffer Layer for Efficient Polymer Solar Cells.

    Yu, Lu; Li, Qiuxiang; Shi, Zhenzhen; Liu, Hao; Wang, Yaping; Wang, Fuzhi; Zhang, Bing; Dai, Songyuan; Lin, Jun; Tan, Zhan'ao

    2016-01-13

    The insertion of an appropriate interfacial buffer layer between the photoactive layer and the contact electrodes makes a great impact on the performance of polymer solar cells (PSCs). Ideal interfacial buffer layers could minimize the interfacial traps and the interfacial barriers caused by the incompatibility between the photoactive layer and the electrodes. In this work, we utilized solution-processed hafnium(IV) acetylacetonate (Hf(acac)4) as an effective cathode buffer layer (CBL) in PSCs to optimize the energy level alignment between the photoactive layer and the cathode contact, with the short-circuit current density (Jsc), open-circuit voltage (Voc), and fill factor (FF) all simultaneously improved with Hf(acac)4 CBL, leading to enhanced power conversion efficiencies (PCEs). Ultraviolet photoemission spectroscopy (UPS) and scanning Kelvin probe microscopy (SKPM) were performed to confirm that the interfacial dipoles were formed with the same orientation direction as the built-in potential between the photoactive layer and Hf(acac)4 CBL, benefiting the exciton separation and electron transport/extraction. In addition, the optical characteristics and surface morphology of the Hf(acac)4 CBL were also investigated. PMID:26684416

  18. Growth behavior and properties of atomic layer deposited tin oxide on silicon from novel tin(II)acetylacetonate precursor and ozone

    In this work, a novel liquid tin(II) precursor, tin(II)acetylacetonate [Sn(acac)2], was used to deposit tin oxide films on Si(100) substrate, using a custom-built hot wall atomic layer deposition (ALD) reactor. Three different oxidizers, water, oxygen, and ozone, were tried. Resulting growth rates were studied as a function of precursor dosage, oxidizer dosage, reactor temperature, and number of ALD cycles. The film growth rate was found to be 0.1 ± 0.01 nm/cycle within the wide ALD temperature window of 175–300 °C using ozone; no film growth was observed with water or oxygen. Characterization methods were used to study the composition, interface quality, crystallinity, microstructure, refractive index, surface morphology, and resistivity of the resulting films. X-ray photoelectron spectra showed the formation of a clean SnOx–Si interface. The resistivity of the SnOx films was calculated to be 0.3 Ω cm. Results of this work demonstrate the possibility of introducing Sn(acac)2 as tin precursor to deposit conducting ALD SnOx thin films on a silicon surface, with clean interface and no formation of undesired SiO2 or other interfacial reaction products, for transparent conducting oxide applications

  19. Surface chemistry of copper metal and copper oxide atomic layer deposition from copper(ii) acetylacetonate: a combined first-principles and reactive molecular dynamics study.

    Hu, Xiao; Schuster, Jörg; Schulz, Stefan E; Gessner, Thomas

    2015-10-28

    Atomistic mechanisms for the atomic layer deposition using the Cu(acac)2 (acac = acetylacetonate) precursor are studied using first-principles calculations and reactive molecular dynamics simulations. The results show that Cu(acac)2 chemisorbs on the hollow site of the Cu(110) surface and decomposes easily into a Cu atom and the acac-ligands. A sequential dissociation and reduction of the Cu precursor [Cu(acac)2 → Cu(acac) → Cu] are observed. Further decomposition of the acac-ligand is unfavorable on the Cu surface. Thus additional adsorption of the precursors may be blocked by adsorbed ligands. Molecular hydrogen is found to be nonreactive towards Cu(acac)2 on Cu(110), whereas individual H atoms easily lead to bond breaking in the Cu precursor upon impact, and thus release the surface ligands into the gas-phase. On the other hand, water reacts with Cu(acac)2 on a Cu2O substrate through a ligand-exchange reaction, which produces gaseous H(acac) and surface OH species. Combustion reactions with the main by-products CO2 and H2O are observed during the reaction between Cu(acac)2 and ozone on the CuO surface. The reactivity of different co-reactants toward Cu(acac)2 follows the order H > O3 > H2O. PMID:26399423

  20. Determination of formaldehyde in vegetables by acetylacetone spectrophotometry%测定蔬菜中的甲醛的乙酰丙酮分光光度法

    张以春

    2012-01-01

    目的 优化测定蔬菜中甲醛含量的实验条件.方法 采用浸泡法对蔬菜样品中的甲醛进行提取,利用甲醛与乙酰丙酮及氨反应生成黄色化合物通过分光光度法检测甲醛浓度.结果 方法线性范围为0.2~3.2 mg/L,线性方程为y =0.011x+0.018,相关系数为0.999 8,对4种蔬菜样品进行6次平行测定,RSD为2.37%~ 8.22%,对豇豆测定回收率为90% ~ 96%.结论 该法快速、准确、重现性好,适用于蔬菜样品中的甲醛检测.%[ Objective ] To optimize experimental conditions for the analysis of the formaldehyde content in the vegetables. [ Methods ] Formaldehyde was extracted by soaking the vegetable samples. The yellow compound which was generated by formaldehyde and acetylacetone with ammonia was detected by spectrophotometry. [ Results] The linear range was 0. 2-3. 2 mg/L. The linear equation was y = 0. 011 x + 0. 018 , and the correlation coefficient was 0. 999 8. Four kinds of vegetable samples were determined for 6 times. The RSD was 2. 37%-78. 22% . The recovery of cowpea was 90%-96%. [Conclusion]This method is rapid, accurate, reproducible, and suitable for detection of formaldehyde in vegetable samples.

  1. Synthesis, interactions, molecular structure, biological properties and molecular docking studies on Mn, Co, Zn complexes containing acetylacetone and pyridine ligands with DNA duplex.

    Thamilarasan, V; Sengottuvelan, N; Stalin, N; Srinivasan, P; Chakkaravarthi, G

    2016-07-01

    Three metal complexes (1-3) of the type [Mn(acac)2(py)·H2O] (1), [Co(acac)2(py)·H2O] (2) and [Zn(acac)2(py)·H2O] (3), [Where acac=acetylacetone, py=pyridine] were synthesized and characterized by spectral (UV-vis, FT-IR, ESI-mass) analysis. The structure of complex 2 has been determined by single crystal X-ray diffraction studies and the configuration of ligand-coordinated to metal(II) ion was well described as distorted octahedral coordination geometry. The interaction of the complexes with CT-DNA has been explored by absorption, fluorescence, circular dichromism spectroscopy, viscosity measurements and molecular docking studies. The intrinsic binding constant Kb of complexes 1-3 with CT-DNA obtained from UV-vis absorption spectral studies were 2.1×10(4), 2.1×10(5) and 1.98×10(4)M(-1), respectively, which revealed that the complexes could interact with CT-DNA through groove binding. The results indicated that the complexes (1-3) were able to bind to DNA with different binding affinity, in the order: 2>1>3. The interaction of the compounds with bovine serum albumins were also investigated using fluorescence methods and the gel electrophoresis assay demonstrates weak cleavage ability of the pBR322 plasmid DNA in the presence of the metal complexes (1-3) with various activators. Further, the in vitro cytotoxic effect of the complexes were examined on cancerous cell line, with human breast cancer cells MCF-7. PMID:27104666

  2. Determination of Chromium(III), Chromium(VI), and Chromium(III) acetylacetonate in water by ion-exchange disk extraction/metal furnace atomic absorption spectrometry

    Kamakura, Nao; Inui, Tetsuo; Kitano, Masaru; Nakamura, Toshihiro

    A new method for the separate determination of Chromium(III) (Cr(III)), Chromium(VI) (Cr(VI)), and Cr(III) acetylacetonate (Cr(acac)3) in water was developed using a cation-exchange extraction disk (CED) and an anion-exchange extraction disk (AED) combined with metal furnace atomic absorption spectrometry (MFAAS). A 100-mL water sample was adjusted to pH 5.6 and passed through the CED placed on the AED. Cr(acac)3 and Cr(III) were adsorbed on the CED, and Cr(VI) was adsorbed on the AED. The adsorbed Cr(acac)3 was eluted with 50 mL of carbon tetrachloride, followed by the elution of Cr(III) with 50 mL of 3 mol L- 1 nitric acid. Cr(VI) was eluted with 50 mL of 3 mol L- 1 nitric acid. The chemical species of Cr eluted from the CED with carbon tetrachloride was identified as Cr(acac)3 using infrared spectroscopy. The eluate of Cr(acac)3 was diluted to 100 mL with carbon tetrachloride, and those of Cr(III) and Cr(VI) were diluted to 100 mL with deionized water. All of the solutions were subsequently analyzed by MFAAS. The calibration curve for the Cr(acac)3 aqueous solutions exhibited good linearity in the range of 0.1 to 1 ng. The detection limit of Cr, which corresponded to three times the standard deviation (n = 10) of the blank values, was 20 pg. The recovery test for Cr(III), Cr(VI), and Cr(acac)3 exhibited desirable results (96.0%-107%) when 5 μg of each species (50 μg L- 1) was added to 100 mL water samples (i.e., tap water, rainwater, and bottled drinking water). In a humic acid solution, Cr(acac)3 was quantitatively recovered (103%), but Cr(III) and Cr(VI) exhibited poor recoveries (i.e., 84.8% and 78.4%, respectively).

  3. Continuous extraction of vanadium(V) and iron(III) with acetylacetone under high-speed stirring with Teflon phase separator

    A continuous extraction system consisting of a distillation flask, an extraction flask (Morton flask) containing a high speed stirrer and a Teflon phase separator was investigated. The utility of the system was examined by the separation and concentration of V(V) and Fe(III) with acetylacetone(AA). m-Xylene was selected as the extraction solvent because distillation took place at about 140degC. Fe(III) was easily extracted into the organic solvent with AA. On the other hand, V(V) was not extracted with AA without adding pentyl alcohol. Therefore, V(V) was extracted by the synergism between AA and pentyl alcohol. The effect of stirring speed was examined on the extractions of V(V) and Fe(III). The recommended procedure for the stepwise determination of V(V) and Fe(III) was as follows: A solvent mixture of m-xylene (15cm3) and AA (1cm3) was added to the sample solution (50cm3, pH 4) containing Fe(III) and V(V) in the Morton flask (200cm3) containing a stirring rod and a Teflon phase separator. The stirring speed was kept at 1800rpm. The rate of solvent-transport by the Peristaltic pump was regulated at 1.6cm3/min. The extraction was stopped after 30min and the distillation flask containing the concentrate for Fe(III) analysis was removed. The distillation flask in the extraction-apparatus was then exchanged and 1cm3 of pentyl alcohol and 0.5cm3 of AA were added to the extraction solvent in the Morton flask. Subsequently, 1cm3 of 8 mol dm-3 HCl solution was added in order to adjust the pH to 2.5. The extraction was then performed again. After 60min, the absorbance of the concentrated extract was measured at 449nm after dilution to 10cm3 with m-xylene. Similarly, the amount of Fe(III) in the previous flask was determined at 437nm. The metal ions were quantitatively extracted by the proposed method. The extractability of V(V) by this batch method was 63%. The determination ranges of V(V) and Fe(III) were 20-100 μg and 10-80 μg, respectively. (author)

  4. Nanoparticle Synthesis from Cobalt Acetylacetonate

    Moravec, Pavel; Smolík, Jiří; Levdansky, V.V.; Bakardjieva, Snejana

    Helsinki : -, 2010, P2J35. ISBN N. [International Aerosol Conference IAC 2010. Helsinki (FI), 29.08.2010-03.09.2010] R&D Projects: GA ČR GA104/07/1093 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z40320502 Keywords : hot wall reactor * nanoparticle generation * mocvd Subject RIV: CF - Physical ; Theoretical Chemistry www.iac2010.fi

  5. Synthesis, characterisation and electrochemical behaviour of Cu(II), Co(II), Ni(II) and Zn(II) complexes derived from acetylacetone and p-anisidine and their antimicrobial activity

    N Raman; V Muthuraj; S Ravichandran; A Kulandaisamy

    2003-06-01

    Neutral tetradentate N2O2 type complexes of Cu(II), Ni(II), Co(II) and Zn(II) have been synthesised using the Schiff base formed by the condensation of acetylacetone and p-anisidine. Microanalysis, molar conductance, magnetic susceptibility, IR, UV-Vis, 1H NMR, CV and EPR studies have been carried out to determine the structure of the complexes. From the data, it is found that all the complexes possess square-planar geometry. The EPR spectrum of the copper complex in DMSO at 300 K and 77 K was recorded and its salient features are reported. All the title complexes were screened for antimicrobial activity by the well diffusion technique using DMSO as solvent. The minimum inhibitory concentration (MIC) values were calculated at 37°C for a period of 24 h. It has been found that all the complexes are antimicrobially active and show higher activity than the free ligand.

  6. Efeito da concentração do catalisador acetilacetonato férrico na cura de poliuretano à base de polibutadieno líquido hidroxilado (PBLH) e diisocianato de isoforona (IPDI) Effect of ferric acetylacetonate catalyst concentration on the cure of polyurethane based on hydroxy terminated polybutadiene and isophorone diisocyanate

    Willian César Paterlini; Edson Cocchieri Botelho; Luís Cláudio Rezende; Vera Lucia Lourenço; Mirabel Cerqueira Rezende

    2002-01-01

    The reaction between hydroxy-terminated polybutadiene and isophorone diisocyanate constitutes the base of the curing process of the most composite solid propellant used in the propulsion of solid rocket propellant. In this work, differential scanning calorimetry and viscosity measurements were used to evaluate the effect of the ferric acetylacetonate catalyst concentration on the reaction between HTBR and IPDI. These analyses show one exotherm, which shifts to lower temperatures as the cataly...

  7. Radiation induced synthesis of In{sub 2}O{sub 3} nanoparticles - Part II: Synthesis of In{sub 2}O{sub 3} nanoparticles by thermal decomposition of un-irradiated and γ-irradiated indium acetylacetonate

    Al-Resheedi, Ajayb Saud; Alhokbany, Norah Saad [Department of Chemistry, College of Science, King Saud University, KSU, (Saudi Arabia); Mahfouz, Refaat Mohammed, E-mail: rmhfouz@science.au.edu.eg [Chemistry Department, Faculty of Science, Assiut University, AUN, (Egypt)

    2015-09-15

    Pure cubic phase, In{sub 2}O{sub 3} nanoparticles with porous structure were synthesized by solid state thermal oxidation of un-irradiated and γ-irradiated indium acetyl acetonate in presence and absence of sodium dodecyl sulphate as surfactant. The as- synthesized In{sub 2}O{sub 3} nanoparticles were characterized by X-ray diffraction (XRD), fourier transformation infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transition electron microscopy (TEM) and thermogravimetry (TG). The shapes and morphologies of as- synthesized In{sub 2}O{sub 3} nanoparticles were highly affected by γ-irradiation of indium acetyl acetonate precursor and by addition of sodium dodecyl sulphate as surfactant. Calcination of un-irradiated indium acetyl acetonate precursor to 4 hours of 600 °C leads to the formation of spherical- shaped accumulative and merged In{sub 2}O{sub 3} nanoparticles with porous structure, whereas irregular porous architectures composed of pure In{sub 2}O{sub 3} nanoparticles were obtained by using γ-irradiated indium acetylacetonate precursor. The as- prepared In{sub 2}O{sub 3} nano products exhibit photoluminescence emission (PL) property and display thermal stability in a wide range of temperature (25-800 °C) which suggest possible applications in nanoscale optoelectronic devices. (author)

  8. Efeito da concentração do catalisador acetilacetonato férrico na cura de poliuretano à base de polibutadieno líquido hidroxilado (PBLH e diisocianato de isoforona (IPDI Effect of ferric acetylacetonate catalyst concentration on the cure of polyurethane based on hydroxy terminated polybutadiene and isophorone diisocyanate

    Willian César Paterlini

    2002-05-01

    Full Text Available The reaction between hydroxy-terminated polybutadiene and isophorone diisocyanate constitutes the base of the curing process of the most composite solid propellant used in the propulsion of solid rocket propellant. In this work, differential scanning calorimetry and viscosity measurements were used to evaluate the effect of the ferric acetylacetonate catalyst concentration on the reaction between HTBR and IPDI. These analyses show one exotherm, which shifts to lower temperatures as the catalyst concentration increases. The viscosity analyses show that the increase of temperature causes, at first, a reduction in the mixture viscosity, reaching a minimum range called gelification region (increasing the crosslinking density.

  9. Nanoparticle Synthesis from Manganese(II) Acetylacetonate

    Moravec, Pavel; Smolík, Jiří; Bakardjieva, Snejana; Levdansky, V.V.

    - : -, 2012, P281. [European Aerosol Confrernce EAC 2012. Granada (ES), 02.09.2012-07.09.2012] R&D Projects: GA ČR GA104/07/1093; GA ČR(CZ) GAP503/11/2315; GA ČR(CZ) GBP503/12/G147 Institutional support: RVO:67985858 Keywords : nanoparticle generation * metal organic CVD * hot wall tube reactor Subject RIV: CI - Industrial Chemistry, Chemical Engineering http://www.eac2012.com/EAC2012Book/3.html

  10. Synthesis and characterization of tetraphenylporphyrinate of dysprosium route dysprosium acetylacetonate

    Dysprosium bis (tetraphenylporphyrinate) and bis (dysprosium) Tris (tetraphenylporphyrinate) were synthesized from dysprosium tetraphenylporphyrinate prepared in situ, and characterized by IR, UV-vis, TGA, DTA, EPR and magnetic susceptibility measurements. The double decker compound was obtained by direct oxidation of the HDy(TPP)2 intermediate. The existence of the radical anion, (TPP)- , in the double decker product was conformed by EPR spectrometry. Dysprosium monoporphyrinate was isolated and characterized by the same techniques. (Author)

  11. Metal-Acetylacetonate Synthesis Experiments: Which Is Greener?

    Ribeiro, M. Gabriela T. C.; Machado, Adlio A. S. C.

    2011-01-01

    A procedure for teaching green chemistry through laboratory experiments is presented in which students are challenged to use the 12 principles of green chemistry to review and modify synthesis protocols to improve greenness. A global metric, green star, is used in parallel with green chemistry mass metrics to evaluate the improvement in greenness.…

  12. Influence of Acetylacetone on Photocatalytic Properties of TiO2 Thin Films Deposited on PMMA Substrates%乙酰丙酮对PMMA负载锐钛矿型TiO2薄膜及其光催化性能影响

    张志清; 黄剑锋; 曹丽云; 吴建鹏

    2011-01-01

    The nanociystalline TiO2 solution was prepared using a microwave hydrotheimal process to treat precursor liquid which was obtained by control the hydrolysis of titanium-n-butoxide in the presence of excessive water and acetylacetone (AcAcH). Then nanociystalline TiO2 thin films were deposited on polymethylmethacrylate (PMMA) substrates by dip-coating process from TiO2 colloidal solution. The phase composition of TiO2 nanoparticles, morphologies and optical properties of TiO2 thin films deposited on PMMA substrates were characterized by X-ray diffraction (XRD), fourier transform infrared spectrometer (FTTR), transmission electron microscope (TEM), atomic force microscopy (AFM) and UV-vis spectroscopy. Meanwhile photocatalytic properties of TiO2 films were investigated by degradation of Rhodamine B ( RhB) under ultraviolet radiation. Trie results indicate that anatase TiO2 colloidal solution modified by AcAcH is disperse, uniform, deposit-free and the deposited TiO2 thin films are transparent, homogeneous and compact, and show high efficiency of photocatalysis. Rhodamine B has been degradated over 90% at 180 min%以钛酸丁酯作为钛源,水为溶剂,乙酰丙酮(AcAcH)为表面修饰剂,采用微波水热辅助溶胶-凝胶法制备了纳米晶二氧化钛水溶液,利用提拉镀膜法在聚合物聚甲基丙烯酸甲酯(PMMA)基板上沉积得到了透明TiO2纳米晶薄膜.通过X射线衍射(XRD)、红外光谱(FTIR)、透射电子显微镜(TEM)、原子力显微镜(AFM)和紫外-可见光吸收光谱(UV-Vis)等对TiO2纳米颗粒和薄膜的晶相组成、表面形貌及光学性能进行表征.同时通过紫外光光催化降解罗丹明B研究了TiO2薄膜的光催化性能.结果表明:通过引入乙酰丙酮,可以得到高度分散、晶相为锐钛矿型的TiO2水溶胶,在PMMA基板上沉积得到的薄膜表面平整、致密,具有良好的透光率,经过180 min紫外光照射,对罗丹明B的降解率达到90%以上.

  13. NiOx Nanoparticle Synthesis by Chemical Vapor Deposition from Nickel Acetylacetonate

    Moravec, Pavel; Smolík, Jiří; Keskinen, H.; Mäkelä, J.M.; Bakardjieva, Snejana; Levdansky, V.V.

    2011-01-01

    Roč. 2, č. 4 (2011), s. 258-264. ISSN 2153-117X R&D Projects: GA ČR GA104/07/1093 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z40320502 Keywords : electron diffraction * nickel nanostructures * hot wall tube reactor Subject RIV: CF - Physical ; Theoretical Chemistry http://www.scirp.org/journal/msa/

  14. Nanoparticle Formation by Thermal Decomposition and Oxidation of Manganese(II) Acetylacetonate

    Moravec, Pavel; Smolík, Jiří; Bakardjieva, Snejana; Levdansky, V.V.

    Praha : Česká aerosolová společnost, 2012 - (Vodička, P.; Zíková, N.), s. 39-42 ISBN 978-80-86186-40-5. [Výroční konference České aerosolové společnosti /13./. Třeboň (CZ), 25.10.2012-26.10.2012] R&D Projects: GA ČR GA104/07/1093; GA ČR(CZ) GAP503/11/2315; GA ČR(CZ) GBP503/12/G147 Institutional support: RVO:67985858 ; RVO:61388980 Keywords : nanoparticle generation * metal organic cvd * hot wall tube reactor Subject RIV: CF - Physical ; Theoretical Chemistry; DN - Health Impact of the Environment Quality (UACH-T)

  15. Effect of polyethylene glycol and crown ether additives on the decomposition of cyclohexenyl hydroperoxide in the presence of vanadyl acetylacetonate

    This paper investigates the kinetic characteristics of the VO (AcAc)2catalyzed liquid-phase decomposition of cyclohexenyl hydroperoxide in the presence of additives (A), such as polyethylene glycol (PEG) and a crown ether. The reaction occurs via the formation of a complex of the type (A...VO(AcAc)2). The rate constants for complex formation, as well as for hydroperoxide decomposition in the presence of this complex, have been determined. The differences in the calculated values of these constants have been attributed to contributions of the energy of nonequilibrium conformations of the PEG polymer chain to the rates of catalysis

  16. Studies in technetium chemistry, Project 1: Evaluation of technetium acetylacetonates as potential cerebral blood flow agents, Project 2

    Although the emphasis in our original submission was on N2S2 and N3S coordinating ligands in technetium(V), we have now broadened the chemistry studies into areas that encompass new systems that allow the generation of neutral complexes. This change was based upon developments that have taken place in our basic chemistry studies that could bear on one of the original aims of this work, i.e., the design of complexes designed to penetrate cellular membranes and to remain trapped in target tissues. Among these topics are oxotechnetium(V) complexes containing amine and alcoholate ligands, coordination compounds containing the alternative technetium(V) nitrido core and the synthesis at macroscopic levels of a tetradentate ''umbrella'' ligand that successfully binds the metal. Basic studies with the original bisamide-bisthiol ligand system have continued with the identification of the products formed when aqueous solutions of the complex [TcO(ema)]- are acidified. This material is isolatable as yellow/brown crystals when HCl is added to the tetraphenylarsonium salt of the complex synthesized according to published procedures. Elemental analysis, FAB(+) mass spectrometry and 1H NMR results were consistent with the formulation TcO(ema)H. Infrared spectra showed a dramatic shift in the Tc = O stretch to 966 cm-1, as distinct from 945 cm-1 in the original complex

  17. Corrigendum to "Electronic structure and photoelectron spectra of nickel (II) acetylacetonate and its thio- and amino-substituted analogues" [J. Mol. Struct. 1099 (2015) 579-587

    Vovna, Vitaliy I.; Korochentsev, Vladimir V.; Komissarov, Alexander A.; L'vov, Igor B.; Myshakina, Nataliya S.

    2016-01-01

    The authors regret to inform that it was given erroneous spelling of Vitaliy I. Vovna author name in the published version of the article. It was written "Vitaliy V. Vovna" instead of "Vitaliy I. Vovna".

  18. The Triruthenium Complex [{(acac)(2)Ru-II}(3)(L)] Containing a Conjugated Diquinoxaline[2,3-a : 2 '',3 ''-c]phenazine (L) Bridge and Acetylacetonate (acac) as Ancillary Ligands. Synthesis, Spectroelectrochemical and EPR Investigation

    Patra, S.; Sarkar, B.; Ghumaan, S.; Fiedler, Jan; Kaim, W.; Lahiri, G. K.

    -, č. 5 (2004), s. 754-758. ISSN 1477-9226 R&D Projects: GA MŠk OC D14.20; GA MŠk OC D15.10 Institutional research plan: CEZ:AV0Z4040901 Keywords : nonlinear-optical properties * electrochemical properties * spectroelectrochemistry Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.926, year: 2004

  19. Thermal Co-Decomposition of Silver Acetylacetonate and Tin (II) Hexafluoroacetylacetonate: Formation of Carbonaceous Ag/AgxSn(x=4 and 6.7)/SnO2 Composites

    Křenek, T.; Duchek, P.; Urbanová, Markéta; Pokorná, Dana; Bezdička, Petr; Jakubec, Ivo; Pola, M.; Čerstvý, R.; Kovářík, T.; Galíková, Anna; Pola, Josef

    2013-01-01

    Roč. 566, AUG 20 (2013), s. 92-99. ISSN 0040-6031 Grant ostatní: GA MŠK(CZ) CZ1.05/2.1.00/03.0088 Institutional support: RVO:67985858 ; RVO:61388980 Keywords : co-decomposition * thermal gravimetric analysis * Ag-Sn intermetallic compounds Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.105, year: 2013

  20. Preparation and characterization of technetium complexes with Schiff base and phosphine coordination. 1. complexes of technetium-99g and -99m with substituted acac2en and trialkyl phosphines (where acac2en N,N'-ethylenebis[acetylacetone iminato])

    A series of 23 technetium(III) complexes of the type [TcL(PR3)2]+, where L represents a tetradentate Schiff base ligand in the equatorial plane and PR3 represents the axial phosphine ligands, are reported. Full ligand syntheses and characterizations are included. The technetium complexes were prepared with 99mTc to study the organ distribution in guinea pigs at 5 and 60 min postinjection. Four prototypical complexes of the series were also prepared with either 99gTc or 99gTc/99mTc (designated as carrier-added) to allow macroscopic characterization. Equivalence of the 99gTc and 99mTc complexes was demonstrated by dual detection high performance liquid chromatography (HPLC) techniques. The development of a one-step preparation from the standard two-step method is discussed for some complexes. Biodistribution data are related to structure and lipophilicity. None of the complexes in the series exhibited a tendency for in vivo reduction. Myocardial uptake was favorable for a number of complexes. The optimal agent from this series for further imaging development was chosen based on myocardial uptake, rapid blood and liver clearance, and ability to be formulated as a one-step kit

  1. Narrow bandgap host material for high quantum efficiency yellow phosphorescent organic light-emitting diodes doped with iridium(III) bis(4-phenylthieno[3,2-c]pyridine)acetylacetonate

    Yook, Kyoung Soo; Lee, Jun Yeob, E-mail: leej17@skku.edu

    2015-05-15

    A narrow bandgap host material, 4,5-di(9H-carbazol-9-yl)phthalonitrile (2CzPN), was used as a bipolar host material to improve the device performances of yellow phosphorescent organic light-emitting diodes(PHOLEDs). The device performances of the yellow PHOLEDs were optimized at a low doping concentration of 1%. A low turn-on voltage of 3.0 V and high quantum efficiency of 19.3% were achieved using the 2CzPN host material and no efficiency roll-off of the device was observed up to 1000 cd/m{sup 2} compared with 25% of reference device. - Highlights: • High quantum efficiency in yellow phosphorescent organic light-emitting diodes. • Narrow bandgap host material with donor–acceptor structure for low driving voltage. • Low optimum doping concentration of 1% for high quantum efficiency and power efficiency.

  2. An investigation of tautomeric equilibria by means of mass spectrometry

    Zamir, Lolita; Jensen, Bror Skytte; Larsen, Elfinn

    1969-01-01

    Changes in the mass spectra with inlet temperature were used in this work to demonstrate the dependence of keto-enol tautomerism of acetylacetone, 3-methyl acetylacetone and 3-allyl acetylacetone on temperature. The largest dependence of temperature were shown by the ion [M 42]+. arising from a M...

  3. Ultrasound-assisted dealumination of zeolite Y

    M Hosseini; M A Zanjanchi; B Ghalami-Choobar; H Golmojdeh

    2015-01-01

    We demonstrate a new procedure for dealumination of zeolite Y. The method employs a 28 KHz ultrasound bath and an ethanolic acetylacetone solution. Acetylacetone was used as chelating agent and ultrasound irradiation was used as extraction intensifier. Four types of samples, as-synthesized, ammoniumexchanged, acidic and neutralized zeolite were used for dealumination. Parts of the framework aluminumatoms are removed from their sites in the structure of zeolite Y upon the use of either acetylacetone on its own or simultaneous use of acetylacetone and ultrasound waves. Higher dealumination was observed for those samples subjected to both ultrasound irradiation and acetylacetone extraction.

  4. Structure of alumina supported vanadia catalysts for oxidative dehydrogenation of propane prepared by flame spray pyrolysis

    Høj, Martin; Jensen, Anker Degn; Grunwaldt, Jan-Dierk

    2013-01-01

    A series of five vanadia on alumina catalysts for oxidative dehydrogenation of propane to propene were synthesized by flame spray pyrolysis (FSP) using vanadium(III)acetylacetonate and aluminium(III)acetylacetonate dissolved in toluene as precursors. The vanadium loading was 2, 3, 5, 7.5 and 10wt...

  5. Asymmetric Synthesis of ( - ) -(2R, 3R, 6S ) -Irnigaine

    MA, Nan; MA, Da-Wei

    2003-01-01

    Asymmetric synthesis of irnigaine was achieved starting from an enantiopure β-amino ester 5 using the condensation of amino alcohol 2 with acetylacetone and the subsequent intramolecular cyclization as the key steps.

  6. Characterization of tetraketone ligands for active materials of all-uranium redox flow battery

    For active materials of the all-uranium redox flow battery for power storage, two tetraketone ligands, which possess two monomer acetylacetone moieties, were investigated in terms of the complexation with uranium. Detailed NMR measurements were conducted to reveal the keto-enol tautomerism of the tetraketones in CDCl3 and titration measurements were carried out in water-dioxane (1:1 (v/v)) solutions to evaluate formation constants with metal ions at III-VI valences. Although the first acid dissociation constants for tetraketones are close to that for the acetylacetone, the formation constants of tetraketones at large coordination numbers are larger than those of acetylacetone. On the basis of these formation constants, the thermodynamic distributions of tetraketone complexes are evaluated in the solution to demonstrate that the change in the coordination number is not expected during the redox reactions contrary to the case of the acetylacetone

  7. Synchrotron X-Ray Absorption Spectroscopy Study of Self-Assembled Nanoparticles Synthesized from Fe(acac)3 and Pt(acac)2

    Chokprasombat, K.; Sirisathitkul, C; Harding, P.; S. Chandarak; R. Yimnirun

    2012-01-01

    The synchrotron X-ray absorption technique was used to complement electron microscopy in the investigation of nanoparticles synthesized from the coreduction of iron acetylacetonate, Fe(acac)3 and platinum acetylacetonate, Pt(acac)2. A much higher Pt composition than Fe leads to an extended X-ray absorption fine structure (EXAFS) spectrum for the sample that differs from that of fcc FePt nanoparticles. Most importantly, X-ray absorption near-edge structure (XANES) spectra clearly indicate the ...

  8. Laboratory animals pulmonary clearance study with chromium 51 labelled polystyrene spherical particles: investigations for clinical application

    Polystyrene spherical particles labelled with chromium 51, retaining a small amount of chromium acetylacetonate, were administered through different ways to laboratory animals, mice, rats, dogs and monkeys, in order to work out a suitable technique for clinical investigations. The following results were obtained: radioactive labelling may be considered as stable because in vivo chromium elution from the particles does not exceed 0.1% daily. No short-term toxicity has been found for any of the ways of administration due to acetylacetonate or the particles themselves. Long-term pulmonary clearance of inhaled polystyrene particles is close to that of metallic oxides, and no detectable nuisance was observed

  9. Селективное определение оксида свинца(II) во фториде свинца(II)

    Гайдук, О. В.

    2014-01-01

    The possibility of use of acetylacetone to selective separation the lead(II) oxide from lead(II) fluoride was investigated. Were рroposed to use mixture of acetone, acetylacetone and Triton X-100 for dissolving PbO. Were chosen the optimum concentration of the reactants and selective dissolution conditions allowing quantitatively retrieve lead(II) oxide at minimum solubility of lead(II) fluoride. A complexonometric techniques for determining 0.3-3% PbO in the mixture ...

  10. Hydrothermal Synthesis of Indium Tin Oxide Nanoparticles without Chlorine Contamination

    Indium tin oxide (In2Sn1-xO5-y) nanoparticles were synthesized by hydrothermal method from stable indium tin acetylacetone complexes and post annealing at 600 .deg. C. The absence of chlorine ions shortened the synthesis process, decreased the particle agglomeration and improved the particle purity. The introduced complexing ligand acetylacetone decreased the obtained nanoparticle size. The improved powder properties accelerated the sintering of the In2Sn1-xO5-y nanoparticles and reached a relative density of 96.4% when pressureless sintered at 1400 .deg. C

  11. A facile route to inverted polymer solar cells using a precursor based zinc oxide electron transport layer

    de Bruyn, P.; Moet, D. J. D.; Blom, P. W. M.

    2010-01-01

    Inverted polymer: fullerene solar cells with ZnO and MoO(3) transport layers are demonstrated. ZnO films are prepared through spin casting of a zinc acetylacetonate hydrate solution, followed by low temperature annealing under ambient conditions. The performance of solar cells with an inverted struc

  12. Coordination Complexes as Catalysts: The Oxidation of Anthracene by Hydrogen Peroxide in the Presence of VO(acac)[subscript 2

    Charleton, Kimberly D. M.; Prokopchuk, Ernest M.

    2011-01-01

    A laboratory experiment aimed at students who are studying coordination chemistry of transition-metal complexes is described. A simple vanadyl acetylacetonate complex can be used as a catalyst in the hydrogen peroxide oxidation of anthracene to produce anthraquinone. The reaction can be performed under a variety of reaction conditions, ideally by…

  13. Ni/NiO Nanoparticle Synthesis by MOCVD

    Moravec, Pavel; Smolík, Jiří; Keskinen, H.; Mäkelä, J.M.; Levdansky, V.V.

    - : -, 2007. T09A029. [European Aerosol Conference. 09.09.2007-14.09.2007, Salzburg] R&D Projects: GA ČR(CZ) GA104/07/1093 Institutional research plan: CEZ:AV0Z40720504 Keywords : CVD * generation of nanoparticles * nickel acetylacetonate Subject RIV: CF - Physical ; Theoretical Chemistry

  14. Quenching of the triplet state of benzophenone by lanthanide 1,3-diketonate chelates in solutions

    The phosphorescence of benzophenone in benzene and acetonitrile was quenched by several lanthanide (Sm, Eu, Gd, Tb and Dy) acetylacetonate chelates. The results of Stern-Volmer analysis including the quenching of benzophenone triplet and sensitization of lanthanide emission indicate that the quenching process occurs by the energy transfer mechanism via the excited triplet state of the ligand. (Author)

  15. Influence of metal β-diketonates on processes of radiation-chemical cross-linking of polymeric compositions

    The effect of copper (2) and manganese (3) acetylacetonates on the cross-linking and destruction of polymer compositions on the basis of sapon ficated copolymer of vinyl chloride and vinyl acetate, cellulose nitrate and acetobutyrate under the effect of γ-radiation, is studied using the EPR method

  16. Substituent effects of iridium (III) complexes with 2,4-diphenylquinoline for efficient red organic light-emitting diodes

    We demonstrate efficient red electrophosphorescence using bis[2-(5-methoxyphenyl)-4-phenylquinolinato-N,C2] iridium(III)(acetylacetonate) [Ir(dpq-5OCH3)2(acac)], bis[2-(5-methylphenyl)-4-phenylquinolinato-N,C2] iridium(III)(acetylacetonate)[Ir(dpq-5CH3)2(acac)] and bis[2-(5-fluorophenyl)-4-phenylquinolinato-N,C2] iridium(III) (acetylacetonate) [Ir(dpq-5F)2(acac)] in compared with bis[2,4-diphenylquinolinato-N,C2] iridium(III)(acetylacetonate) [Ir(dpq)2(acac)]. The -CH3, -OCH3 and -F group substituted on the 5'-position of phenyl ring strongly affected the energy level of molecule. The organic light-emitting diodes (OLEDs) with Ir(dpq-5OCH3)2(acac), Ir(dpq-5CH3)2(acac), Ir(dpq-5F)2(acac) and Ir(dpq)2(acac) have a maximum luminous efficiency of 8.20 cd/A, 10.20 cd/A, 15.80 cd/A and 11.60 cd/A, respectively. Also, their electroluminescent emission appeared at 605, 617, 610 and 617 nm, respectively

  17. A facile route to inverted polymer solar cells using a precursor based zinc oxide electron transport layer

    Bruyn, P. de; Moet, D.J.D.; Blom, P.W.M.

    2010-01-01

    Inverted polymer:fullerene solar cells with ZnO and MoO3 transport layers are demonstrated. ZnO films are prepared through spin casting of a zinc acetylacetonate hydrate solution, followed by low temperature annealing under ambient conditions. The performance of solar cells with an inverted structur

  18. Preparation of ZnO-Al2O3 Particles in a Premixed Flame

    Jensen, Joakim Reimer; Johannessen, Tue; Wedel, Stig;

    2000-01-01

    Zinc oxide (ZnO) and alumina (Al2O3) particles are synthesized by the combustion of their volatilized acetylacetonate precursors in a premixed air-methane flame reactor. The particles are characterized by XRD, transmission electron microscopy, scanning mobility particle sizing and by measurement of...

  19. Preparation and characterization of nanometer-scale powders ceria by electrochemical deposition method

    Ceria (CeO2) nanoparticles of 10-30 nm in average particle size have been synthesized via electrochemical deposition method in cerium(III) chloride solution with an undivided cell as electrochemical cell and ethanol-acetylacetone as additives. X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transformation infrared spectroscopy (FT-IR) and thermal analysis (TG-DTA) are introduced to characterize the samples. The results indicate that the as-prepared powders after being treated at 650 deg. C are nanocrystalline with the cubic fluorite structure and the sphericity in shape. It is revealed that the size of ceria nanoparticles can be decreased effectively by adding the ethanol-acetylacetone solution. In addition, the possible formed mechanism of CeO2 nanometer-scale powder. The role of additive is also investigated in this paper

  20. One-pot synthesis of amphiphilic superparamagnetic FePt nanoparticles and magnetic resonance imaging in vitro

    Yang Hong; Zhang Jingjing; Tian Qiwei; Hu He [Department of Chemistry, Shanghai Normal University, 100 Guilin Road, Shanghai 200234 (China); Fang Yong [No.3 People' s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (China); Wu Huixia [Department of Chemistry, Shanghai Normal University, 100 Guilin Road, Shanghai 200234 (China); Yang Shiping, E-mail: shipingy@shnu.edu.c [Department of Chemistry, Shanghai Normal University, 100 Guilin Road, Shanghai 200234 (China)

    2010-04-15

    Monodispersed amphiphilic FePt nanoparticles with the diameter of about 4 nm were synthesized by high temperature pyrolysis of iron(III) acetylacetonate and platinum(II) acetylacetonate. Their amphiphilicity is contributed to the tetraethylene glycol (TEG) and oleic acid (OA) on the surface, which is confirmed by FTIR and XPS spectra. They provide a superparamagnetic property with the saturation magnetization (Ms) of about 25 emu/g and the transverse relaxivity (r{sub 2}) of about 122.6 mM{sup -1} s{sup -1} in aqueous solutions. Furthermore, FePt nanoparticles show low cytotoxicity in living cells. They can be uptaken by HeLa cells effectively and result in the obvious decrease of T{sub 2} relaxation time after internalization.

  1. Synthesis of Pt{sub 3}Sn alloy nanoparticles and their catalysis for electro-oxidation of CO and methanol.

    Liu, Y.; Li, D.; Stamenkovic, V. R.; Soled, S.; Henao, J. D.; Sun, S. (Materials Science Division); (Brown Univ.); (Exxon Mobil Res. Eng. Co.)

    2011-11-04

    Monodisperse Pt{sub 3}Sn alloy nanoparticles (NPs) were synthesized by a controlled coreduction of Pt(II) acetylacetonate and Sn(II) acetylacetonate at 180-280 C in 1-octadecene. In the synthesis, oleylamine was used as a reducing agent, and oleylamine/oleic acid served as surfactants. The sizes of the Pt{sub 3}Sn NPs were tuned from 4 to 7 nm by controlling the metal salt injection temperatures from 180 to 240 C. These monodisperse Pt3Sn NPs were highly active for CO and methanol oxidation in 0.1 M HClO{sub 4} solutions, and their activity and stability could be further improved by a postsynthesis thermal treatment at 400 C in Ar + 5% H{sub 2} for 1 h. They are promising as a practical catalyst for CO and methanol oxidation reactions in polymer electrolyte membrane fuel cell conditions.

  2. Revisiting curcumin chemistry part I: A new strategy for the synthesis of curcuminoids

    E Venkata Rao

    2011-01-01

    Full Text Available A new strategy for the synthesis of curcuminoids is described involving the reaction of acetylacetone difluroboronite with an aromatic aldehyde in the presence of n-butylamine as catalyst. The new intermediate products, curcuminoid difluroboronites, of symmetrically substituted curcuminoids like curcumin and bisdemethoxycurcumin are stable, can be isolated and hydrolysed with aq. methanol at pH 5.8 to get the curcuminoids of high purity. The method is applicable for unsymmetrical curcuminoids like demethoxycurcumin also with some modification involving column chromatography. The intermediate curcuminoid difluroboronites, as also the natural β-diketone pongamol difluroboronite, prepared for the first time were characterized on the basis of physical and chemical properties and spectroscopic data. The advantage of using borontrifluoride to protect the enol group in acetylacetone over the generally used boric oxide is brought out. The importance of conducting biological activity studies using pure curcuminoids is explained.

  3. Chemical modification of chitosan in the absence of solvent for diclofenac sodium removal: pH and kinetics studies

    Pereira, Kerlaine Alexandre Araujo; Osorio, Luizangela Reis; Silva, Marcos Pereira; Silva Filho, Edson Cavalcanti da, E-mail: edsonfilho@ufpi.edu.br [Universidade Federal do Piaui (UFPI/CCN), Teresina, PI (Brazil). Centro de Ciencias da Natureza. Lab. Interdisciplinar de Materiais Avancados; Sousa, Kaline Soares [Universidade Federal da Paraiba (UFPB/CCEN), Joao Pessoa, PB (Brazil). Centro de Ciencias Exatas e da Natureza. Dept. de Quimica

    2014-08-15

    Chitosan was modified with acetylacetone and ethylenediamine in the absence of solvent. The new biopolymer obtained from the modification was characterized by elemental analysis and NMR 13C and applied in the removal of diclofenac sodium aqueous solution varying the pH and time. Through elemental analysis was possible to verify a decreasing in C/N relation after reaction with acetylacetone and an increasing after modification with ethylenediamine. From NMR analysis was verified the appearance of peaks around 160-210 ppm in both materials due to free carbonyl groups in the first step of the modification, besides the formation of imine bonds. The adsorption tests showed that the highest value occurred at pH 4 and from the results of the kinetic study was found that maximum adsorption occurred within 45 minutes and experimental data adjusted better to linear adjustment, following pseudo second-order model. The results show a material efficient in the removal of emerging pollutants. (author)

  4. Bis(acetylacetonato-κ2O,O′(pyridine-κN(thiocyanato-κNmanganese(III: a redetermination using data from a single crystal

    Christian Näther

    2013-12-01

    Full Text Available In the crystal structure of the title compound, [Mn(C5H7O22(NCS(C5H5N], the Mn3+ cation is coordinated by two acetylacetonate anions, one terminal thiocyanate anion and one pyridine ligand within a slightly distorted octahedron. The asymmetric unit consists of half a complex molecule with the Mn3+ cation, the thiocyanate anion and the pyridine ligand located on a mirror plane. The acetylacetonate anion is in a general position. The title compound was previously described [Stults et al. (1975. Inorg. Chem. 14, 722–730] but could only be obtained as a powder. Suitable crystals have now been obtained for a high-precision single-crystal structure determination.

  5. Effects of chromium and cobalt compounds on burning rate of ammonium nitrate/hydroxyl-terminated polybutadiene composite propellants. Shosan ammonium/HTPB kei composite suishin'yaku no nensho sokudo ni oyobosu chromium to cobalt kagobutsu no eikyo

    Hagihara, Y.; Ichikawa, T.; Shinpo, H.; Suzuki, M. (The National Defense Academy, Yokosuka (Japan))

    1991-12-31

    Study was made on the effects of chromium and cobalt compounds on burning rate of AN/HTPB composite propellants by using 14 types of chromium and cobalt compounds as catalysts and it was clear that burning rate of composite propellants increases with all catalysts and increase in burning rate by ammonium dichromate and chromium (III) acetylacetone is significantly large. Pressure exponent for cobalt(II) oxide and cobalt(II) benzoate has decreased but it has increased with other catalysts. Pressure exponent has significantly increased in the case of cobalt 2-ethylhexanoate and cobalt(II) acetylacetone. Effect of compounds on slurry viscosity also has shown the decrease in the viscosity except chromium(III) oxide and cobalt(II,III) oxide, and in the case of cobalt 2-ethylhexanoate the viscosity is significantly low. Drophammer sensitivity of AN is not affected with the added compounds. 4 refs., 3 figs., 4 tabs.

  6. Combustion deposition of MoO3 films: from fundamentals to OPV applications

    MARCHAL, Wouter; De Dobbelaere, Christopher; KESTERS, Jurgen; Bonneux, Gilles; Vandenbergh, Joke; DAMM, Hanne; Junkers, Thomas; Maes, Wouter; D'Haen, Jan; Van Bael, Marlies K; Hardy, An

    2015-01-01

    A systematic study of a combustion precursor's thermal decomposition pathway is undertaken, in both powders and thin films, to obtain insights in the various parameters influencing the combustion process. The study focuses on MoO3 as a hole transporting layer (HTL) for applications in organic photovoltaics (OPV). Via evolved gas analysis, it was found that fuel volatility occurs prior to the actual combustion reaction of the acetylacetonate based precursor, affecting the optimal oxidizer to f...

  7. Reaction of cycloheptatriene derivatives with 1,3-diketones in the presence of Mn(OAc)3

    SÜDEMEN, Mahir Burak; ZENGİN, Mustafa; and, Hayriye GENÇ

    2011-01-01

    The reactions of some 1,3-dicarbonyl compounds with cycloheptatriene derivatives in the presence of Mn(OAc)3 were examined. Cycloheptatriene forms mainly [2+3] and [6+3] dihydrofuran addition products derived from cycloheptatriene. However, the reaction of acetylacetone with cycloheptatriene substituted with an electron withdrawing group exclusively gave products derived from the norcaradiene structure. The formation mechanism of the products as well as the role of the substituent a...

  8. Structural study of Ni- or Mg-based complexes incorporated within UiO-66-NH2 framework and their impact on hydrogen sorption properties

    Nickel and magnesium acetylacetonate molecular complexes were post-synthetically incorporated into microporous zirconium-based MOF (UiO-66-NH2) in order to introduce active open-metal sites for hydrogen sorption. Elemental analysis, nitrogen physisorption and DFT calculations revealed that 5 molecules of Ni(acac)2 or 2 molecules of Mg(acac)2 were incorporated into one unit cell of UiO-66-NH2. 1H–13C CPMAS and 1H MAS NMR spectroscopy showed that, although embedded within the pores, both Ni- and Mg-complexes interacted with the UiO-66-NH2 framework only through weak van der Waals bonds. Inclusion of metal complexes led to the decrease of hydrogen sorption capacities in Ni-modified as well as in Mg-modified samples in comparison with the parent UiO-66-NH2. The isosteric hydrogen adsorption enthalpy slightly increased in the case of Ni-modified material, but not in the case of Mg-modified analogue. - Graphical abstract: A post-synthesis impregnation of Mg- and Ni-acetylacetonate complexes performed on zirconium-based MOF UiO-66-NH2 does influence the hydrogen sorption performance with respect to the parent matrix. The structural study revealed that Mg- and Ni-acetylacetonate molecules interact with zirconium-terephthalate framework only by weak interactions and they are not covalently bonded to aminoterephthalate ligand. Still, they remain confined into the pores even after hydrogen sorption experiments. - Highlights: • Mg- and Ni-acetylacetonate molecules embedded in the pores of UiO-66-NH2 by PSM. • Molecules of complexes interact with framework only by van der Waals interactions. • Type/structure of deposited metal-complex impact hydrogen enthalpy of adsorption

  9. Synthese und Charakterisierung neuer Phthalocyanine für eine mögliche industrielle Anwendung

    Moustafa, Tamer Ezzat Youssef

    2004-01-01

    Zusammenfassung: Das Ziel dieser Arbeit war die Synthese und die Charakterisierung sowie das Studium der nichtlinear optischen Eigenschaften der löslichen monomeren und binuclear phthalocyanine 10 und 11 und der trinuclear Verbindung 13 und 20. Eingeschlossen, ist auch die strukturelle Modifikationen der Pc-Systeme mit (2-ethylhexyloxy) als peripheren Substituenten und Indium-acetylacetonate (Inacac) als axialen Liganden Weiterhin werden asymmetrisches Pc-Systeme mit stickstoff Heterocyclisch...

  10. VO(acac)2 catalyzed condensation of o-phenylenediamine with aromatic carboxylic acids/aldehydes under microwave radiation affording benzimidazoles

    Madhudeepa Dey; Krishnajyoti Deb; Siddhartha Sankar Dhar

    2011-01-01

    Vanadyl acetylacetonate, VO(acac)2, has been found to be very effective catalyst for synthesis of a variety of benzimidazoles under solvent-free condition. The methodology involves the exposure of a mixture of o-phenylenediamine and a selected aromatic carboxylic acid/aldehyde to microwave radiation without the use of any solvent or supporting agents. The benzimidazoles were obtained in quick time with high yields.

  11. Synthesis and Characterization of Biodegradable Polyurethane for Hypopharyngeal Tissue Engineering

    Shen, Zhisen; Lu, Dakai; Li, Qun; Zhang, Zongyong; Zhu, Yabin

    2015-01-01

    Biodegradable crosslinked polyurethane (cPU) was synthesized using polyethylene glycol (PEG), L-lactide (L-LA), and hexamethylene diisocyanate (HDI), with iron acetylacetonate (Fe(acac)3) as the catalyst and PEG as the extender. Chemical components of the obtained polymers were characterized by FTIR spectroscopy, 1H NMR spectra, and Gel Permeation Chromatography (GPC). The thermodynamic properties, mechanical behaviors, surface hydrophilicity, degradability, and cytotoxicity were tested via d...

  12. Mesoporous TiO2 Yolk-Shell Microspheres for Dye-sensitized Solar Cells with a High Efficiency Exceeding 11%

    Li, Zhao-Qian; Chen, Wang-Chao; Guo, Fu-Ling; Mo, Li-E.; Hu, Lin-Hua; Dai, Song-Yuan

    2015-09-01

    Yolk-shell TiO2 microspheres were synthesized via a one-pot template-free solvothermal method building on the aldol condensation reaction of acetylacetone. This unique structure shows superior light scattering ability resulting in power conversion efficiency as high as 11%. This work provided a new synthesis system for TiO2 microspheres from solid to hollow and a novel material platform for high performance solar cells.

  13. Synthesis of Polyfunctionalized 4H-Pyrans

    Manisha Bihani

    2013-01-01

    Full Text Available Amberlyst A21 catalyzed one-pot three-component coupling of aldehyde and malononitrile with active methylene compounds such as acetylacetone and ethyl acetoacetate for the synthesis of pharmaceutically important polyfunctionalized 4H-pyrans has been reported. Simple experimental procedure, no chromatographic purification, no hazardous organic solvents, easy recovery and reusability of the catalyst, and room temperature reaction conditions are some of the highlights of this protocol for the synthesis of pharmaceutically relevant focused libraries.

  14. Designer synthesis of monodisperse heterodimer and ferrite nanoparticles

    Nakhjavan, Bahar

    2011-01-01

    The work presented in this doctoral thesis is a facile procedure, thermal decomposition, forrnthe synthesis of different types of monodisperse heterodimer M@iron oxide (M= Cu, Co, Nirnand Pt) and single ferrites, MFe2O4 (M= Cu and Co), nanoparticles. In the following chapter,rnwe study the synthesis of these monodiperse nanoparticles with the similar iron precursorrn(iron pentacarbonyl) and different transition metal precursors such as metalrnacetate/acetylacetonate/formate precursors in the ...

  15. Copper(II) complex of 3-cinnamalideneacetylacetone: Synthesis and characterisation

    A Veeraraj; P Sami; N Raman

    2000-10-01

    A bidentate ligand derived from cinnamaldehyde and acetylacetone and its copper(II) complex have been synthesized and characterized by elemental analysis, UV-Vis, IR, ESR and magnetic susceptibility measurements. Magnetic susceptibility measurements, ESR and electronic spectral data indicate the presence of six coordinated Cu(II) ion. The ligand and complex are tested for antibacterial activity against Pseudomonas aeroginosa. They are found to show the antibacterial activity

  16. Oxidative coupling polymerization of p-alkoxyphenols with Mn(acac)2-ethylenediamine catalysts

    Hideyuki Higashimura; Shigeki Habaue; Osamu Haba; Soichiro Murakami; Yuuta Akutsu

    2010-01-01

    The oxidative coupling polymerization of p alkoxyphenols with Mn(acac)2ethylenediamine catalysts was carried out. The polymerization of pmethoxyphenol with the manganese(II) acetylacetonate [Mn(acac)2]N,N’diethylethylene diamine catalyst in CH2Cl2 at room temperature under an O2 atmosphere afforded a polymer, which mainly consists of the mphenylene unit, whereas the polymer obtained with Mn(acac)2 was rich in the oxyphenylene structure. The polymer yield and regioselectivity were significantl...

  17. sup(1)H, sup(13)C and sup(17)O NMR studies of cumene hydroperoxide coordination to Cr(AA)sub(3)

    The mechanism of the catalytic decomposition of hydroperoxides by tris-chelates of transition metals was studied by means of NMR. It was established that the outer sphere coordination of cumene hydroperoxide to tris-acetylacetonate of Cr(III) (Cr(AA)sub(3)) is due to both the formation of hydrogen bonds between hydroxyl proton and chelate oxygen atoms and the π-π-interactions between the aromatic ring and chelate π-system. (author)

  18. Epoxidación de aceite de soja refinado mediante oxígeno molecular. Influencia de las variables. Estudio cinético

    Martínez de la Cuesta, P. J.; Rus Martínez, E.; Román Cortés, V.

    1991-01-01

    The influences of temperature, concentration of catalyst and initial concentration of unsaturation on epoxide formation and esters from oleic and linoleic acids disappearance in liquid phase epoxidation reaction by molecular oxygen of soy-bean oil using molibdenyl-acetylacetonate as catalyst, has been studied. From experimental data obtained by a complex factorial design, an equation for epoxide formation reaction rate as a function of temperature, catalyst concentration and unsaturation...

  19. Synthesis and Properties of MPEG-Coated Superparamagnetic Magnetite Nanoparticles

    Xueli Cao; Baolin Zhang; Fangyuan Zhao; Lingyun Feng

    2012-01-01

    The magnetite nanoparticles were synthesized by the thermal decomposition of iron(III) acetylacetonate in methoxy polyethylene glycol, which was used as solvent, reducing agent, and modifying agent in the reaction. The morphologies and phase compositions of the nanoparticles were determined by transmission electron microscopy and X-ray diffraction, respectively. The surface coating of the nanoparticles was recognized using Fourier transform infrared spectroscopy. Magnetic properties were meas...

  20. Synthesis, characterization, and reactivity of pentamethylcyclopentadienyl complexes of divalent cobalt and nickel

    Smith, M.E.

    1993-10-01

    The thesis is divided into the following 4 chapters: synthesis, characterization, and reactivity of trinuclear pentamethylcyclopentadienyl cobalt and nickel clusters with triply-bridging methylidyne groups; chemical and physical properties of pentamethylcyclopentadienyl acetylacetonate complexes of Co(II) and Ni(II); synthesis, characterization, and reactivity of pentamethylcyclopentadienyl halide complexes of Co and Ni; and crystallographic studies of distortions in metallocenes with C{sub 5}-symmetrical cyclopentadienyl rings.

  1. Diastereoselective metal-catalyzed synthesis of C-aryl and C-vinyl glycosides.

    Nicolas, Lionel; Angibaud, Patrick; Stansfield, Ian; Bonnet, Pascal; Meerpoel, Lieven; Reymond, Sébastien; Cossy, Janine

    2012-10-29

    Cobalt, the catalyst of choice: The diastereoselective cobalt-catalyzed cross-coupling of 1-bromo glycosides and aryl or vinyl Grignard reagents is described. A convenient and inexpensive catalyst, [Co(acac)(3)]/tmeda (acac = acetylacetonate, tmeda = N,N'-tetramethylethylenediamine), gives full α selectivity in the mannose and galactose series, and an α selectivity in the glucose series with α/β ratios of 1.3:1-3:1. PMID:23023954

  2. Laser-induced chemical liquid deposition of discontinuous and continuous copper films

    Ouchi, A.; Bastl, Zdeněk; Boháček, Jaroslav; Šubrt, Jan; Pola, Josef

    2007-01-01

    Roč. 201, č. 8 (2007), s. 4728-4733. ISSN 0257-8972 R&D Projects: GA AV ČR 1ET400400413 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z40320502; CEZ:AV0Z40720504 Keywords : copper films * laser photolysis * Cu(II) acetylacetonate * chemical liquid deposition Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.678, year: 2007

  3. UV Laser Photolytic Solution Deposition of α-Fe/Polyoxocarbosilane/Carbon Nanocomposite and Evolution to α-Fe2O3/Polyoxocarbosilane/Carbon Nanocomposite

    Pola, Josef; Maryško, Miroslav; Vorlíček, Vladimír; Bakardjieva, Snejana; Šubrt, Jan; Bastl, Zdeněk; Ouchi, A.

    2008-01-01

    Roč. 199, 2-3 (2008), s. 156-164. ISSN 1010-6030 R&D Projects: GA AV ČR IAA400720619 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z10100521; CEZ:AV0Z40320502; CEZ:AV0Z40400503 Keywords : Fe(II) acetylacetonate * Fe composite * laser solution deposition Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.362, year: 2008

  4. Fuel cell electrodes from organometallic Pt precursors: an easy atmospheric plasma approach

    Merche, Delphine; Dufour, Thierry; Baneton, Joffrey; Caldarella, Giuseppe; Debaille, Vinciane; Job, Nathalie; Reniers, François

    2016-01-01

    An organometallic powder (platinum (II) acetylacetonate) is decomposed in the post-discharge of an atmospheric RF plasma torch to deposit Pt nanoparticles on carbon black supports. The resulting nanohybrid materials are characterized by FEG-SEM and XPS techniques to highlight their high content in Pt, their oxidation degree, and the dispersion of the Pt nanoparticles on the substrate. ICP-MS and electrochemical characterizations in a single fuel cell (cyclic voltammetry, dynamic polarization ...

  5. Fabrication of Size-Tunable Metallic Nanoparticles Using Plasmid DNA as a Biomolecular Reactor

    Charles Michael Drain; Raihan Saleh; Amit Aggarwal; Andrea Parpas; Patrick Nahirney; Alex Yampolski; Jacopo Samson; Irene Piscopo

    2011-01-01

    Plasmid DNA can be used as a template to yield gold, palladium, silver, and chromium nanoparticles of different sizes based on variations in incubation time at 70 °C with gold phosphine complexes, with the acetates of silver or palladium, or chromium acetylacetonate. The employment of mild synthetic conditions, minimal procedural steps, and aqueous solvents makes this method environmentally greener and ensures general feasibility. The use of plasmids exploits the capabilities of the biotechno...

  6. Structural study of Ni- or Mg-based complexes incorporated within UiO-66-NH{sub 2} framework and their impact on hydrogen sorption properties

    Žunkovič, E.; Mazaj, M. [Laboratory for Inorganic Chemistry and Technology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); Mali, G. [Laboratory for Inorganic Chemistry and Technology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); EN-FIST Centre of Excellence, Dunajska 156, 1000 Ljubljana (Slovenia); Rangus, M. [Laboratory for Inorganic Chemistry and Technology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); Devic, T.; Serre, C. [Institut Lavoisier, UMR CNRS 8180, Université de Versailles Saint-Quentin-en-Yvelines, 78035 Versailles (France); Logar, N. Zabukovec, E-mail: natasa.zabukovec@ki.si [Laboratory for Inorganic Chemistry and Technology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); CO-NOT Centre of Excellence, Hajdrihova 19, 1000 Ljubljana (Slovenia); University of Nova Gorica, Vipavska 13, 5000 Nova Gorica (Slovenia)

    2015-05-15

    Nickel and magnesium acetylacetonate molecular complexes were post-synthetically incorporated into microporous zirconium-based MOF (UiO-66-NH{sub 2}) in order to introduce active open-metal sites for hydrogen sorption. Elemental analysis, nitrogen physisorption and DFT calculations revealed that 5 molecules of Ni(acac){sub 2} or 2 molecules of Mg(acac){sub 2} were incorporated into one unit cell of UiO-66-NH{sub 2}. {sup 1}H–{sup 13}C CPMAS and {sup 1}H MAS NMR spectroscopy showed that, although embedded within the pores, both Ni- and Mg-complexes interacted with the UiO-66-NH{sub 2} framework only through weak van der Waals bonds. Inclusion of metal complexes led to the decrease of hydrogen sorption capacities in Ni-modified as well as in Mg-modified samples in comparison with the parent UiO-66-NH{sub 2}. The isosteric hydrogen adsorption enthalpy slightly increased in the case of Ni-modified material, but not in the case of Mg-modified analogue. - Graphical abstract: A post-synthesis impregnation of Mg- and Ni-acetylacetonate complexes performed on zirconium-based MOF UiO-66-NH{sub 2} does influence the hydrogen sorption performance with respect to the parent matrix. The structural study revealed that Mg- and Ni-acetylacetonate molecules interact with zirconium-terephthalate framework only by weak interactions and they are not covalently bonded to aminoterephthalate ligand. Still, they remain confined into the pores even after hydrogen sorption experiments. - Highlights: • Mg- and Ni-acetylacetonate molecules embedded in the pores of UiO-66-NH{sub 2} by PSM. • Molecules of complexes interact with framework only by van der Waals interactions. • Type/structure of deposited metal-complex impact hydrogen enthalpy of adsorption.

  7. Synthesis, structural characterization, and antimicrobial efficiency of sulfadiazine azo-azomethine dyes and their bi-homonuclear uranyl complexes for chemotherapeutic use

    Khedr, Abdalla M.; SAAD, FAWAZ A.

    2015-01-01

    Two sulfadiazine azo-azomethine dyes containing two active coordination centers and their bi-homonuclear UO_2(II)-complexes were synthesized for potential chemotherapeutic use. The ligands were prepared, starting from the coupling of sulfadiazine dizonium salt with acetylacetone, followed by condensation with ethylenediamine and 1,6-hexanediamine (HL^I and HL^{II}) using a modified literature procedure. The structures of the ligands and their UO_2(II)-complexes were elucidated by conve...

  8. Angularly and spectrally resolved light scattering from lead zirconate titanate thin films

    The results of light-scattering measurements for a series of Pb(Zr,Ti)O3 thin films prepared by a sol-gel method are presented and analyzed. The films differed due to the addition of different concentrations of acetylacetone to the precursor solution immediately prior to film fabrication. Visual inspection of the films indicated improvements in optical quality with the addition of acetylacetone. To quantify these improvements, two types of light-scattering measurements were performed: angularly resolved light scattering and spectrally resolved light scattering. Surprisingly, only slight differences between the films were observed using angularly resolved light scattering at 633 nm. In contrast, the spectrally resolved scattering revealed large differences between the films, with the films prepared using the largest concentrations of acetylacetone exhibiting the lowest scattering. The apparent contradiction between these findings is resolved using a theoretical model for light scattering due to fluctuations in the dielectric constant occurring within the volume of the thin film and by noting that slight thickness differences exist between the films in the series. Analysis of the light scattering from the best sample yields estimates for the amplitude (ξ0 = 0.08) and the characteristic size (τ0 = 110 nm) of the dielectric constant fluctuations. These estimates are consistent with the variations of the dielectric constant expected due to the birefringent, polycrystalline nature of these films

  9. Preparation of molybdenum oxide thin films by MOCVD

    In this study, molybdenum oxide films were prepared in a horizontal hot-wall MOCVD apparatus using molybdenum dioxide acetylacetonate as precursor. The molybdenum precursor was synthesized from acetylacetone and molybdenum oxide powder. Thermal gravimetric (TG) and differential thermal analyses (DTA) of the precursor suggested the formation of molybdenum oxides around 430 oC (703 K). Thus, a range of deposition temperatures varying from 350 to 630 oC (623-903 K) was explored to investigate the effects on the nature of the molybdenum oxide films. X-ray diffraction (XRD) results showed that the films consisted of α-MoO3 phase at deposition temperatures ranging from 400 to 560 oC (673-833 K). Crystalline α-MoO3 films can be obtained from molybdenum dioxide acetylacetonate precursor, without need of a post-annealing treatment. The best crystalline quality was found in films having needle-like crystallites grown at deposition temperature of about 560 oC (833 K), which exhibit a strong (0 1 0) preferred orientation and a transparent visual appearance

  10. Characterization of microstructure and catalytic of cerium oxide obtained by colloidal solution

    This study investigated to obtain particles of cerium oxide, for use as catalysts for the combustion of methane using the technique of through polymeric colloidal solution. Obtaining the colloidal system is based on hydrolysis of salts such as cerium acetylacetonate, cerium nitrate in the presence of additives such as polyvinylbutyral (PVB), polyvinylpyrrolidone (PVP) and polyvinyl acetate (PVA), at concentrations of 5, 10 and 15% in aqueous or alcoholic medium. These solutions containing ions of interest were subjected to a heat treatment at 650° C for 30 minutes, with heating rate of 2 ° C/ min. After heat treatment, the fibers were characterized according to their morphology, surface area, crystallinity, weight loss and catalytic activity. Samples obtained from cerium acetylacetonate were more reactive than the cerium nitrate to the combustion of methane, as showed greater conversions and higher temperatures reached during the process, which is of utmost importance since the combustion catalytic methane is used for generating thermal energy. After the reaction with methane, the samples underwent significant change in surface area, probably due to the intensity of combustion reactions of the nitrate and the generation of heat involved in this reaction, which gave rise to coarse particles. During the combustion process using the obtained from particles of cerium acetylacetonate, there was the release of large quantities of nitrogen compared to the results of assays with the particles obtained with cerium nitrate. (author)

  11. Characterization of microstructure and catalytic of cerium oxide obtained by colloidal solution; Caracterizacao da microestrutura e da atividade catalitica de oxido de cerio obtido por solucao coloidal

    Senisse, C.A.L.; Bergmann, C.P.; Alves, A.K., E-mail: carolinasenisse@hotmail.com [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alege, RS (Brazil). Lab. de Materiais Ceramicos

    2012-07-01

    This study investigated to obtain particles of cerium oxide, for use as catalysts for the combustion of methane using the technique of through polymeric colloidal solution. Obtaining the colloidal system is based on hydrolysis of salts such as cerium acetylacetonate, cerium nitrate in the presence of additives such as polyvinylbutyral (PVB), polyvinylpyrrolidone (PVP) and polyvinyl acetate (PVA), at concentrations of 5, 10 and 15% in aqueous or alcoholic medium. These solutions containing ions of interest were subjected to a heat treatment at 650° C for 30 minutes, with heating rate of 2 ° C/ min. After heat treatment, the fibers were characterized according to their morphology, surface area, crystallinity, weight loss and catalytic activity. Samples obtained from cerium acetylacetonate were more reactive than the cerium nitrate to the combustion of methane, as showed greater conversions and higher temperatures reached during the process, which is of utmost importance since the combustion catalytic methane is used for generating thermal energy. After the reaction with methane, the samples underwent significant change in surface area, probably due to the intensity of combustion reactions of the nitrate and the generation of heat involved in this reaction, which gave rise to coarse particles. During the combustion process using the obtained from particles of cerium acetylacetonate, there was the release of large quantities of nitrogen compared to the results of assays with the particles obtained with cerium nitrate. (author)

  12. Synthesis of oxide and spinel nanocrystals for use in solid state lighting

    Foley, Megan Elizabeth

    In this dissertation, microwave chemistry is employed to synthesize a variety of different crystalline nanoparticles (NPs). This introduction will describe the structures, properties and applications of the NPs studied within the dissertation, with a main focus being on ligand sensitization for the goal of enhanced luminescence. The use of metal acetylacetonate complexes to make Europium (III) doped Ytrrium (Y2O3) NPs is explored, where the acetylacetonate acts both as a source of oxygen for the synthesis of Y2O3, as well as an organic chromophore acting as an "antenna" for the absorption of light and subsequent excitation transfer to the incorporated Europium (III) (Chapter 2). Other host materials are investigated by method of metal acetylacetonate decomposition to synthesize a variety of different nanospinels, having the general formula AB2X4, with sulfide variants made by decomposition of diethyldithiocarbamate, (Chapter 3). The antenna ligand thenoyltrifluoroacetone (tta), which is known to undergo a Dexter energy transfer (DET) mechanism to efficiently sensitize Europium (III) emission, is used to determine the distance of energy transfer in Europium (III) doped nanospinels by passivating the surface of the nanospinel with a tta (Chapter 4). A variety of ligands are explored in order to optimize the sensitization efficiency in relation to the difference in energy between the singlet and triplet levels of the ligands versus the 5D0 and 5D4 energy levels of Europium (III) and Terbium (III) respectively (Chapter 5).

  13. Electrochemical decontamination in easily processed electrolytes

    Metallic surfaces can be reduced to very low levels of residual activity by electrochemical decontamination, thus reducing decommissioning and disposal costs. Two electrolyte systems have been developed which minimize the volume for disposal of secondary waste containing the bulk of the activity. Kraftanlagen, Heidelberg has developed a system for use in an immersion tank based on a KBr solution of acetylacetone. This leads to a continuous precipitation of the insoluble acetylacetonates of ferrous substrates together with such active species as 60Co. The bath performance can be maintained by continuous acetylacetone addition. From pilot scale trials, a solids waste volume of 1.1 dm3/m2 of surface decontaminated has been determined. Harwell has developed both immersion and in-situ processes based on nitric acid, as the spent electrolyte is compatible with existing UK waste treatment philosophy - potentially yielding an immobilized product volume of 0.6 dm3/m2 area treated. Nitric acid has the additional advantage of suppressing any hydrogen production. Both processes have been developed from laboratory to microprocessor controlled pilot scale units which have been demonstrated successfully for the treatment of genuine waste. The immersion tank process uses electroetching at low current densities for the treatment of extended areas, while the in-situ technique uses electropolishing in 6M HNO3 in an engineered head connected to a service trolley by an umbilical. This has also shown potential for incorporation in an integrated monitoring/decontamination system under robotic control. (abstract)

  14. Studies of solution deposited cerium oxide thin films on textured Ni-alloy substrates for YBCO superconductor

    Cerium oxide (CeO2) buffer layers play an important role for the development of YBa2Cu3O7-x (YBCO) based superconducting tapes using the rolling assisted biaxially textured substrates (RABiTS) approach. The chemical solution deposition (CSD) approach has been used to grow epitaxial CeO2 films on textured Ni-3 at.% W alloy substrates with various starting precursors of ceria. Precursors such as cerium acetate, cerium acetylacetonate, cerium 2-ethylhexanoate, cerium nitrate, and cerium trifluoroacetate were prepared in suitable solvents. The optimum growth conditions for these cerium precursors were Ar-4% H2 gas processing atmosphere, solution concentration levels of 0.2-0.5 M, a dwell time of 15 min, and a process temperature range of 1050-1150 deg. C. X-ray diffraction, AFM, SEM, and optical microscopy were used to characterize the CeO2 films. Highly textured CeO2 layers were obtained on Ni-W substrates with both cerium acetate and cerium acetylacetonate as starting precursors. YBCO films with a J c of 1.5 MA/cm2 were obtained on cerium acetylacetonate-based CeO2 films with sputtered YSZ and CeO2 cap layers

  15. Comparative evaluation of red cell-labelling parameters of three lipid-soluble 111-In-chelates: Effect of lipid solubility on membrane incorporation and stability constant on transchelation

    A rabbit red cell model was used to determined the cell labeling properties of three lipid-soluble 111In-complexes: 111In-oxine, 111In-acetylacetone, and 111In-tropolone. Partition coefficients (olive oil/buffer) were measured to determine the lipid solubility and were 3.54, 7.93, and 18.18 for 111In-oxine, 111In-acetylacetone, and 111In-tropolone respectively. The effect of the concentration of these three chelating agents on labeling efficiencies was studied. The factors influencing the labeling efficiencies of these complexes such as cell density, time of incubation, influence of temperature, pH, effect of plasma proteins, and citrate ion concentration in the cell-labeling medium were studied. Labeling yields as high as 95.15 +- 4.15% were achieved with 111In-tropolone after a 10-min incubation at 370C. The optimum pH for cell labeling was 6.5 Excess critrate ion (> 3.02 mg/ml) and small amounts of plasma proteins (> 10 μl/ml) decreased the labeling efficiencies in all three cases. Distribution of these 111In-complexes in membrane, membrane frgments, and hemoglobin was studied after hemolysis. In spite of the higher lipid solubility of 111In-tropolone, the transchelation capacity appears to be similar to that of 111In-oxine. 111In-acetylacetone had the highest transchelation capacity. (orig.)

  16. Study of the Gelling Process for the Preparation of Tin Oxide Materials Based on Tin Tetrabutoxide%Sn(OBun)4为前驱体制备SnO2材料中的溶胶-凝胶过程

    黄瑞安; 侯立松; 赵启涛; 任叔华

    2005-01-01

    The gelling process in the preparation of tin oxide materials based on tin tetrabutoxide is studied. Sn(OBun)4 modified by two moles of acetylacetone (AcAc) has a stable six-member ring structure and is less susceptive to water. In a system with a lower molar ratio of acetylacetone to Sn(OBun)4 ([AcAc]/[Sn(OBun)4]<2.0) or a larger portion of water ([H2O]/[Sn(OBun)4]>2.5), colloidal suspension or white precipitation will take place. A system with molar ratios of both acetylacetone to Sn(OBun)4 and water to Sn(OBun)4 at 2.0 is transparent and olivaceous sol. As catalysts, hydrofluoric,hydrochloric, hydrobromic and acetic acids, and ammonia all accelerate the hydrolysis and condensation of Sn(OBun)4 during the sol-gel process. Light scattering measurement indicates that cluster size distribution in the sol system undergoes gradual broadening during the sol-gel transition.

  17. ET-AAS determination of aluminium in dialysis concentrates after continuous flow solvent extraction.

    Komárek, J; Cervenka, R; Růzicka, T; Kubán, V

    2007-11-01

    Conditions of a continuous flow extraction (CFE) of aluminium acetylacetonate in acetylacetone and aluminium 8-hydroxyquinolinate into methylisobutylketone (lengths of reaction and extraction coils, flow rates of aqueous and organic phases and their flow rate ratio, pH of aqueous phase, lengths of coils for transport of aqueous and organic phases and effect of salts) were studied. The analytical signal of the aluminium chelates present in the organic phase was measured at 309.3 nm using atomic absorption spectrometry with electrothermal atomization (ET-AAS) at the flow rate ratio F aq/F org=3 for aqueous and organic phases. The five points calibration curves were linear (R2 0.9973 and 0.9987) up to 21 microgl(-1) Al with the limits of detection of 0.3 microgl(-1) and the recovery 100+/-2% and precision of 3% at 2-10-fold dilution of the dialysis concentrates. The acetylacetonate method was applied to the determination of aluminium in real dialysis concentrates. Aluminium in concentrations 5-6 microgl(-1) (R.S.D.s 5-10% in real samples) were found and the results were in the very good agreement with those obtained by an ET-AAS using preconcentration of Al(III) on a Spheron-Salicyl chelating sorbent (absolute and relative differences were under 0.4 microgl(-1) and 8.2%, respectively). PMID:17897803

  18. Ruthenium based redox flow battery for solar energy storage

    Research highlights: → Undivided redox flow battery employing porous graphite felt electrodes was used. → Ruthenium acetylacetonate dissolved in acetonitrile was the electrolyte. → Charge/discharge conditions were determined for both 0.02 M and 0.1 M electrolytes. → Optimum power output of 0.180 W was also determined for 0.1 M electrolyte. → 55% voltage efficiency was obtained when battery was full of electrolytes. -- Abstract: The technical performance for the operation of a stand alone redox flow battery system for solar energy storage is presented. An undivided reactor configuration has been employed along with porous graphite felt electrodes and ruthenium acetylacetonate as electrolyte in acetonitrile solvent. Limiting current densities are determined for concentrations of 0.02 M and 0.1 M ruthenium acetylacetonate. Based on these, operating conditions for 0.02 M ruthenium acetylacetonate are determined as charging current density of 7 mA/cm2, charge electrolyte superficial velocity of 0.0072 cm/s (through the porous electrodes), discharge current density of 2 mA/cm2 and discharge electrolyte superficial velocity of 0.0045 cm/s. An optimum power output of 35 mW is also obtained upon discharge at 2.1 mA/cm2. With an increase in the concentration of ruthenium species from 0.02 M to 0.1 M, the current densities and power output are higher by a factor of five approximately (at same superficial velocities) due to higher mass transport phenomenon. Moreover at 0.02 M concentration the voltage efficiency is better for battery full of electrolytes prior to charging (52.1%) in comparison to an empty battery (40.5%) due to better mass transport phenomenon. Voltage efficiencies are higher as expected at concentrations of 0.1 M ruthenium acetylacetonate (55% when battery is full of electrolytes and 48% when empty) showing that the all-ruthenium redox flow battery has some promise for future applications in solar energy storage. Some improvements for the system are

  19. Synthesis and characterization of potential iron–platinum drugs and supplements by laser liquid photolysis

    Forbes A

    2012-06-01

    Full Text Available Steven S Nkosi,1,2 Bonex W Mwakikunga,4 Elias Sideras-Haddad,2 Andrew Forbes1,31CSIR National Laser Centre, Pretoria, South Africa; 2DST/NRF Centre for Excellence in Strong Materials and School of Physics, University of the Witwatersrand, Johannesburg, 3School of Physics, University of KwaZulu-Natal, Durban, South Africa; 4DST/CSIR National Centre for Nano-Structured Materials, Pretoria, South AfricaAbstract: Highly crystalline nanospherical iron–platinum systems were produced by 248 nm laser irradiation of a liquid precursor at different laser fluences, ranging from 100–375 mJ/cm2. The influence of laser intensity on particle size, iron composition, and structure was systematically investigated. Different nanostructures of iron–platinum alloy and chemically disordered iron–platinum L10 phase were obtained without annealing. The prepared precursor solution underwent deep photolysis to polycrystalline iron–platinum nanoalloys through Fe(III acetylacetonate and Pt(II acetylacetonate. Fe(II and Pt(I acetylacetone decomposed into Fe0 and Pt0 nanoparticles. We found that the (001 diffraction peak shifted linearly to a lower angle, with the last peak shifting in opposition to the others. This caused the face-centered cubic L10 structure to change its composition according to laser fluence. The nanostructures were shown to contain iron and platinum only by energy-dispersive spectroscopy at several spots. The response of these iron–platinum nanoparticles to infrared depends on their stoichiometric composition, which is controlled by laser fluence.Keywords: nanostructures, iron, platinum, nanoparticles, laser liquid photolysis, composition

  20. Study on Progress in Synthesis of Natural Product Curcumin%天然产物姜黄素合成工艺研究

    邹春阳; 王凤秋; 田家明

    2011-01-01

    Curcumin was prepared by a modified method in this paper. Meanwhile, the optimum condition was also established. The mixture of acetylacetone and boric anhydride in ethyl acetate was stirred under reflux temperature for 30 minutes and gived a boron complex of acetylacetone. N - Butylamine was added dropwise to a solution of vanillin, tributyl borate and boron complex of acetylacetone in DMF (N, N -dimethylformamide) at 80X1. After stirred for 3 hours, crude curcumin was obtained by use 5% acetic acid to destroy the boron complex of curcumin. It was furtherly purified by re-crystallization from chloroform methanol. The overyield reaches 70% under the condition of inventory rating reaching one hundred grams - level. This method provides a reference for the large scale preparation of curcumin.%采用了一种改良的合成方法制备姜黄素,并确定了最优工艺条件.即:先将乙酰丙酮与硼酸酐于乙酸乙酯内回流反应30min,制得乙酰丙酮的硼络合物;然后在DMF(N,N-二甲基甲酰胺)中,将香兰素、三丁基硼酸酯及新制的乙酰丙酮的硼络合物于80℃,以正丁胺为催化剂反应3h;最后向其中加入5%的醋酸破坏络合物得到姜黄素粗品,以氯仿-甲醇重结晶得到姜黄素纯品.在投料量为百克级情况下,总收率达到了70%.这也为大量制备提供参考.

  1. A dual chelating sol–gel synthesis of BaTiO{sub 3} nanoparticles with effective photocatalytic activity for removing humic acid from water

    Wang, Peigong [College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Fan, Caimei, E-mail: fancm@163.com [College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Wang, Yawen; Ding, Guangyue; Yuan, Peihong [College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China)

    2013-02-15

    Graphical abstract: The cubic phase BaTiO{sub 3} nanoparticles can be obtained at 600 °C and changed into tetragonal phase at 900 °C by a dual chelating sol–gel method, and the photocatalytic activities of the photocatalysts calcined at different temperatures were investigated by the removal of humic acid (HA) from water under UV light irradiation. Highlights: ► The humic acid in water was firstly degradated by BaTiO{sub 3} photocatalyst. ► The cubic BaTiO{sub 3} was obtained and changed into tetragonal phase at lower temperature. ► The chelating agents had an important influence on the phase formation of BaTiO{sub 3}. ► The tetragonal phase BaTiO{sub 3} calcined at 900 °C exhibited higher photocatalytic activity under UV irradiation. -- Abstract: In this paper, a dual chelating sol–gel method was used to synthesize BaTiO{sub 3} nanoparticles by using acetylacetone and citric acid as chelating agents. The samples calcined at different temperatures were analyzed by thermogravimetric and differential thermal analysis (TG-DTA), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), scanning electron microscope (SEM) and UV–vis diffuse reflectance spectra (UV–vis). The results indicated that cubic phase BaTiO{sub 3} nanoparticles about 19.6 nm can be obtained at 600 °C and changed into tetragonal phase at 900 °C about 97.1 nm. All the BaTiO{sub 3} nanoparticles showed effective photocatalytic activities on the removal of humic acid (HA) under UV light irradiation. A comparison of single (acetylacetone or citric acid) and dual chelating (acetylacetone and citric acid) synthetic processes was also studied and the results demonstrated that the dual chelating agents indeed reduced phase transformation temperature from cubic to tetragonal BaTiO{sub 3}.

  2. Sol-gel synthesis of Pt-Ru-Os-Ir based anode electro-catalysts for direct methanol fuel cells

    Research highlights: → Complex sol-gel synthesis (CSG) of high specific surface area Pt-Ru-Os-Ir catalysts. → Catalysts exhibit specific surface area of ∼95 m2/g. → Electrocatalytic activity is 35-40% higher than CSG derived Pt0.5Ru0.5 and commercially obtained JM catalyst. - Abstract: A high specific surface area (∼95 m2/g) Pt44Ru41Os10Ir5 based anode electro-catalysts for direct methanol fuel cell, synthesized by a novel complexed sol-gel (CSG) process, shows better catalytic activity in comparison to pure equi-atomic compositions of Pt-50 at.% Ru anode catalysts synthesized by similar sol-gel processes. A homogeneous amorphous gel was successfully synthesized by complexing platinum(II) acetylacetonate, ruthenium(III) acetylacetonate, iridium(III) acetylacetonate and osmium(III) chloride with tetramethylammonium hydroxide (TMAH) used as a complexing agent. Phase-pure Pt(Ru,Os,Ir) and Pt(Ru) solid solutions possessing high specific surface area (SSA) (∼90-120 m2/g) were successfully synthesized by thermal decomposition of the amorphous gel followed by controlled removal of carbonaceous species present in the thermally treated powders. The controlled removal of carbon, present in the thermally treated Pt-Ru-Os-Ir powder, has been successfully achieved by conducting precise thermal treatments of the thermally treated powders using controlled oxidizing atmospheres. Results indicate that the nano-crystalline pure Pt(Ru,Os,Ir) solid solution of nominal composition Pt-41 at.%Ru-10 at.%Os-5 at.% Ir possessing good chemical homogeneity exhibit excellent catalytic activity, demonstrating the potential of the novel complexed sol-gel process for synthesizing high-performance Pt-Ru-Os-Ir based catalysts for direct methanol fuel cells.

  3. Sol-gel synthesis of Pt-Ru-Os-Ir based anode electro-catalysts for direct methanol fuel cells

    Alyousef, Yousef M. [Energy Research Institute, King Abdulaziz City for Science and Technology, Riyadh 11442 (Saudi Arabia); Datta, Moni Kanchan [Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Kadakia, Karan [Chemical and Petroleum Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Yao, S.C. [Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Kumta, Prashant N., E-mail: pkumta@pitt.ed [Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Chemical and Petroleum Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Mechanical Engineering and Materials Science, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States)

    2010-09-17

    Research highlights: {yields} Complex sol-gel synthesis (CSG) of high specific surface area Pt-Ru-Os-Ir catalysts. {yields} Catalysts exhibit specific surface area of {approx}95 m{sup 2}/g. {yields} Electrocatalytic activity is 35-40% higher than CSG derived Pt{sub 0.5}Ru{sub 0.5} and commercially obtained JM catalyst. - Abstract: A high specific surface area ({approx}95 m{sup 2}/g) Pt{sub 44}Ru{sub 41}Os{sub 10}Ir{sub 5} based anode electro-catalysts for direct methanol fuel cell, synthesized by a novel complexed sol-gel (CSG) process, shows better catalytic activity in comparison to pure equi-atomic compositions of Pt-50 at.% Ru anode catalysts synthesized by similar sol-gel processes. A homogeneous amorphous gel was successfully synthesized by complexing platinum(II) acetylacetonate, ruthenium(III) acetylacetonate, iridium(III) acetylacetonate and osmium(III) chloride with tetramethylammonium hydroxide (TMAH) used as a complexing agent. Phase-pure Pt(Ru,Os,Ir) and Pt(Ru) solid solutions possessing high specific surface area (SSA) ({approx}90-120 m{sup 2}/g) were successfully synthesized by thermal decomposition of the amorphous gel followed by controlled removal of carbonaceous species present in the thermally treated powders. The controlled removal of carbon, present in the thermally treated Pt-Ru-Os-Ir powder, has been successfully achieved by conducting precise thermal treatments of the thermally treated powders using controlled oxidizing atmospheres. Results indicate that the nano-crystalline pure Pt(Ru,Os,Ir) solid solution of nominal composition Pt-41 at.%Ru-10 at.%Os-5 at.% Ir possessing good chemical homogeneity exhibit excellent catalytic activity, demonstrating the potential of the novel complexed sol-gel process for synthesizing high-performance Pt-Ru-Os-Ir based catalysts for direct methanol fuel cells.

  4. Microspheres with an ultra high holmium content for brachytherapy of malignancies

    Lira, Raphael A.; Myamoto, Douglas M.; Souza, Jaime R.; Nascimento, Nanci; Azevedo, Mariangela de Burgos M. de [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Biotecnologia; Osso Junior, Joao A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Radiofarmacia; Martinelli, Jose R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencias e Tecnologia de Materiais

    2011-07-01

    The overall objective of this work is to develop biodegradable microspheres intended for internal radiation therapy which provides an improved treatment for hepatic carcinomas. The most studied brachytherapy system employing microspheres made of holmium-biopolymer system is composed by poly(L-lactic acid) (PLLA) and holmium acetylacetonate (HoAcAc). The importance of the holmium high content in the microspheres can be interpreted as follow from a therapeutic standpoint, to achieve an effective use of microspheres loaded with HoAcAc, a high content of holmium is required to yield enough radioactivity with a relatively low amount of microspheres.The usual amounts of holmium that are incorporated in the microspheres composed by poly(L-lactic acid) and HoAcAc are 17.0 {+-} 0.5% (w/w) of holmium, which corresponds to a loading of about 50% of HoAcAc. Different approaches have been investigated to increase that value. One updated approach towards this direction is the production of microspheres with ultrahigh holmium as matrix using HoAcAc crystals as the sole starting material without the use of biopolymer. Likewise, in the search of microspheres with increased holmium content , it has been demonstrated that by changing the HoAcAc crystal structure by its recrystallization from crystal phase to the amorphous there is lost of acetylacetonate and water molecules causing the increasing of the holmium content. Microspheres were prepared by solvent evaporation, using holmium acetylacetonate (HoAcAc) crystals as the sole ingredient. Microspheres were characterized by using light and scanning electron microscopy, infrared and Raman spectroscopy, differential scanning calorimetry, X-rays diffraction, and confocal laser scanning microscopy. (author)

  5. Binary heterocyclic systems containing the ethylideneamino linkage: synthesis of some new heterocyclic compounds bearing the naphtho-[2,1-b]furan moiety

    A. H. BEDAIR

    2006-05-01

    Full Text Available Ethylidene hydrazine (4a,b and thiazolidin-4-one (5 derivatives were synthesized by the reaction of ethylidenethiosemicarbazide derivative (3a with a-haloketone/ethyl bromoacetate, respectively. Hetrocyclization of ethylideneacetohydrazide derivative (7 with o-phenolic aldehydes gave the corresponding coumarin derivatives (8,9. The interaction of 7 with acetylacetone afforded the corresponding pyridine derivative (10. Treatment of the arylidene derivative 11b with malononitrile afforded the corresponding pyran derivative (12. The new products 3-12 were subjected to IR, 1H NMR and mass spectra studies.

  6. Influence of liquid-phase synthesis parameters on particle sizes and structural properties of nanocrystalline ZnO powders

    Chory, Christine; Mueller, Gerd [Lehrstuhl fuer Silicatchemie, Julius-Maximilians-Universitaet Wuerzburg, Roentgenring 11, 97070 Wuerzburg (Germany); Neder, Reinhard B.; Korsunskiy, Vladimir I. [Institut fuer Mineralogie, Julius-Maximilians-Universitaet Wuerzburg, Am Hubland, 97074 Wuerzburg (Germany); Niederdraenk, Franziska; Kumpf, Christian; Umbach, Eberhard [Lehrstuhl fuer Experimentelle Physik II, Physikalisches Institut, Julius-Maximilians-Universitaet Wuerzburg, Am Hubland, 97074 Wuerzburg (Germany); Schumm, Marcel; Lentze, Michael; Geurts, Jean; Astakhov, Georgy; Ossau, Wolfgang [Lehrstuhl fuer Experimentelle Physik III, Physikalisches Institut, Julius-Maximilians-Universitaet Wuerzburg, Am Hubland, 97074 Wuerzburg (Germany)

    2007-07-01

    In order to obtain well-controlled size and optimized structural properties, ZnO nanoparticles were grown from ethanolic solutions using acetate, acetylacetonate and dimethylpropylendiamine as stabilizer molecules. The low-temperature syntheses yield considerably large amounts of pure, nanocrystalline powder. Structural properties like particle size, crystal structure and quality were investigated by x-ray diffractometry, photoluminescence, and Raman spectroscopy. Particle sizes down to 4 nm and a size dependent anisotropic shape are observed. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Bis(acetylacetonato-κ2O,O′(2-amino-1-methyl-1H-benzimidazole-κN3oxidovanadium(IV

    Zukhra Ch. Kadirova

    2009-07-01

    Full Text Available The title mixed-ligand oxidovanadium(IV compound, [VO(C5H7O22(C8H9N3], contains a VIV atom in a distorted octahedral coordination, which is typical for such complexes. The vanadyl group and the N-heterocyclic ligand are cis to each other. The coordination bond is located at the endocyclic N atom of the benzimidazole ligand. Intramolecular hydrogen bonds between the exo-NH2 group H atoms and acetylacetonate O atoms stabilize the crystal structure.

  8. 1. Mono([8]annulene)Uranium(4) half-sandwich complexes, 2. Novel syntheses of symmetrically substituted cyclooctatetetraenes

    A reproducible, high-yield synthesis of mono([8]annulene)uranium(4)dichloride (1) is reported, along with the X-ray crystal structural of the bis(pyridine) adduct. Metathesis reactions of the half-sandwich complex 1 with a variety of simple alkyl and alkoxy reagents failed to generate any isolable mono-ring complexes. Reactions of 1 with polydentate, delocalized anions did produce stable derivatives, including mono([8]annulene)uranium(4)bis(acetylacetonate) (4). An X-ray crystal structure of 4 is reported

  9. Effect of O2 flow rate on the thermochromic performance of VO2 coatings grown by atmospheric pressure CVD

    This paper reports the atmospheric pressure chemical vapor deposition of vanadium oxide coatings using vanadyl (IV) acetylacetonate at 500 oC. The as-grown samples for 0.8 L min-1 O2 flow rate showed an (022)-oriented single vanadium dioxide monoclinic phase of low crystallinity. The narrowest hysteresis width is observed for the particular flow rate indicating a dependency on the shape of the grown crystallites. Regarding the difference in transmittance is determined by the enhanced presence of short- and long-range bond ordering of the samples. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Perspectives of applications of alkoxide sol-gel process in heterogeneous catalysis

    Basic principles, specific features, advantages and drawbacks of alkoxide technology application for the preparation of oxide heterogeneous catalysts and carriers (RuO, V2O5, ZrO2, B2O3) have been considered. Application of acetylacetonates E(acac)n is considered alongside with mixed alkoxyacetylacetonates E(OR)x(acac)n-1. The lack of extensive commercial production of Al and Zr alkoxides in Russia rather than their high cost, is a real obstacle for alkoxide technology introduction. 293 refs., 2 figs., 2 tabs

  11. Complexometric titration of zirconium and yttrium in the same solution for its application in zirconia-yttria ceramics

    A simple stepwise complexometric method with EDTA has been developed for the determination of zirconium and yttrium in a single aliquot solution involving direct titration of zirconium at 1N HNO3 and 90 degC and of yttrium at pH 5.3 using methyl thymol blue as indicator. Interferences due to Fe, Ti, Al and Cu have been eliminated by masking with acetylacetone. The method has been standardised against synthetic solutions and applied to various zirconia-yttria ceramics and other yttria bearing materials. (author). 7 refs., 4 tabs

  12. Investigation into kinetics of redox interaction in the system Ce(4) β-diketonate-additional ligand

    The rate of reduction of β-diketonate complexes of Ce(4) to Ce(3) β-diketonates in benzene solution in the presence and in the absence of additional ligands is studied using spectrophotometry. The rate of reduction of Ce(4) β-diketonates increases in the series Ce(TTFA)44444 (TTFA - thenoyltrifluoroacetone, DPM- --dipivaloylmethane, DBM - dibenzoylemethane, BA benzoylacetone, AA - acetylaceton). The studied phosphorus-containing additional ligands as to their effect on the rate of Ce (4) reduction can be arranged in the following order: trioctylphosphine oxide>triphenylphosphine oxide>tributyl phosphate

  13. Near-Monodisperse Ni-Cu Bimetallic Nanocrystals of Variable Composition: Controlled Synthesis and Catalytic Activity for H2 Generation

    Zhang, Yawen; Huang, Wenyu; Habas, Susan E.; Kuhn, John N.; Grass, Michael E.; Yamada, Yusuke; Yang, Peidong; Somorjai, Gabor A.

    2008-07-22

    Near-monodisperse Ni{sub 1-x}Cu{sub x} (x = 0.2-0.8) bimetallic nanocrystals were synthesized by a one-pot thermolysis approach in oleylamine/1-octadecene, using metal acetylacetonates as precursors. The nanocrystals form large-area 2D superlattices, and display a catalytic synergistic effect in the hydrolysis of NaBH{sub 4} to generate H{sub 2} at x = 0.5 in a strongly basic medium. The Ni{sub 0.5}Cu{sub 0.5} nanocrystals show the lowest activation energy, and also exhibit the highest H{sub 2} generation rate at 298 K.

  14. Enhancement of Nitrite Reduction Kinetics on Electrospun Pd-Carbon Nanomaterial Catalysts for Water Purification.

    Ye, Tao; Durkin, David P; Hu, Maocong; Wang, Xianqin; Banek, Nathan A; Wagner, Michael J; Shuai, Danmeng

    2016-07-20

    We report a facile synthesis method for carbon nanofiber (CNF) supported Pd catalysts via one-pot electrospinning and their application for nitrite hydrogenation. A mixture of Pd acetylacetonate (Pd(acac)2), polyacrylonitrile (PAN), and nonfunctionalized multiwalled carbon nanotubes (MWCNTs) was electrospun and thermally treated to produce Pd/CNF-MWCNT catalysts. The addition of MWCNTs with a mass loading of 1.0-2.5 wt % (to PAN) significantly improved nitrite reduction activity compared to the catalyst without MWCNT addition. The results of CO chemisorption confirmed that the addition of MWCNTs increased Pd exposure on CNFs and hence improved catalytic activity. PMID:27387354

  15. Epoxidation of Alkenes with Molecular Oxygen Catalyzed by Immobilized Co(acac)2 and Co(bpy)2Cl2 Complexes within Nanoreactors of Al-MCM-41

    Farzaneh, F; Jalalian, M; Tayebi, L.

    2012-01-01

    Cobalt complexes with different ligands such as bipyridine, and acetylacetonate were immobilized within nanoreactors of Al-MCM-41, designated as Co(acac)2/Al-MCM-41 and Co(bipy)22+/Al-MCM41. The immobilized complexes were characterized by XRD, N2-adsorption desorption, FT-IR and UV-Vis techniques. It was found that Co(bipy)22+/Al-MCM41 and Co(acac)2/Al-MCM-41 successfully catalyze the oxidation of norbornene, styrene, cis-stilbene, trans-stilbene, and cyclohexene with 68% to 100% conversion a...

  16. Fluorine doped vanadium dioxide thin films for smart windows

    Kiri, Pragna [Department of Chemistry, University College London, Christopher Ingold Laboratories, 20 Gordon Street, London, WC1H 0AJ (United Kingdom); Warwick, Michael E.A. [UCL Energy Institute, Central House, 14 Upper Woburn Place, London, WC1H 0HY (United Kingdom); Ridley, Ian [Bartlett School of Graduate Studies, University College London, Wates House, 22 Gordon Street, WC1H 0QB, London (United Kingdom); Binions, Russell, E-mail: r.binions@ucl.ac.uk [Department of Chemistry, University College London, Christopher Ingold Laboratories, 20 Gordon Street, London, WC1H 0AJ (United Kingdom)

    2011-12-01

    Thermochromic fluorine doped thin films of vanadium dioxide were deposited from the aerosol assisted chemical vapour deposition reaction of vanadyl acetylacetonate, ethanol and trifluoroacetic acid on glass substrates. The films were characterised with scanning electron microscopy, variable temperature Raman spectroscopy and variable temperature UV/Vis spectroscopy. The incorporation of fluorine in the films led to an increase in the visible transmittance of the films whilst retaining the thermochromic properties. This approach shows promise for improving the aesthetic properties of vanadium dioxide thin films.

  17. Effect of O{sub 2} flow rate on the thermochromic performance of VO{sub 2} coatings grown by atmospheric pressure CVD

    Louloudakis, Dimitris [Center of Materials Technology and Photonics, School of Applied Technology, Technological Educational Institute of Crete, 710 04 Heraklion, Crete (Greece); Department of Physics, University of Crete, 711 00 Heraklion, Crete (Greece); Vernardou, Dimitra; Dokianakis, Spyros [Center of Materials Technology and Photonics, School of Applied Technology, Technological Educational Institute of Crete, 710 04 Heraklion, Crete (Greece); Spanakis, Emmanouel [Department of Materials Science and Technology, University of Crete, 711 00 Heraklion, Crete (Greece); Panagopoulou, Marianthi; Raptis, Giannis [School of Applied Mathematical and Physical Sciences, National Technical University of Athens, Zografou Campus, 157 80 Athens (Greece); Aperathitis, Elias [Department of Physics, University of Crete, 711 00 Heraklion, Crete (Greece); Kiriakidis, George [Department of Physics, University of Crete, 711 00 Heraklion, Crete (Greece); Institute of Electronic Structure and Laser, Foundation for Research and Technology- Hellas, P.O. Box 1527, 711 10 Heraklion, Crete (Greece); Katsarakis, Nikolaos [Center of Materials Technology and Photonics, School of Applied Technology, Technological Educational Institute of Crete, 710 04 Heraklion, Crete (Greece); Department of Electrical Engineering, School of Applied Technology, Technological Educational Institute of Crete, 710 04 Heraklion, Crete (Greece); Institute of Electronic Structure and Laser, Foundation for Research and Technology- Hellas, P.O. Box 1527, 711 10 Heraklion, Crete (Greece); Koudoumas, Emmanouel [Center of Materials Technology and Photonics, School of Applied Technology, Technological Educational Institute of Crete, 710 04 Heraklion, Crete (Greece); Department of Electrical Engineering, School of Applied Technology, Technological Educational Institute of Crete, 710 04 Heraklion, Crete (Greece)

    2015-07-15

    This paper reports the atmospheric pressure chemical vapor deposition of vanadium oxide coatings using vanadyl (IV) acetylacetonate at 500 {sup o}C. The as-grown samples for 0.8 L min{sup -1} O{sub 2} flow rate showed an (022)-oriented single vanadium dioxide monoclinic phase of low crystallinity. The narrowest hysteresis width is observed for the particular flow rate indicating a dependency on the shape of the grown crystallites. Regarding the difference in transmittance is determined by the enhanced presence of short- and long-range bond ordering of the samples. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. The role of detergent in labeling of Erysipelothrix rhusiopathiae bacteria

    The chelating agents oxine, acetylacetone, tropolone, and 2-mercaptopyridine 1-oxide were analysed for their suitability in labelling the bacterium Erysipelothrix rhusiopathiae (E.r.), strain B10, with 111In and 67Ga. The labelling conditions were improved. The bactericidal activity of the labeling process was investigated. The different chelates did not result in a significant difference in labelling yield. The addition of 0.01% detergent to the labelling buffer doubled the labelling yield up to 45%. Labelled bacteria were injected intravenously into rats. The percentage organ distribution was determined and compared with a control group. (author)

  19. The isolation of beryllium and mercury from lithium chloride solution by means of gas extraction

    The possibility and optimal conditions of beryllium and mercury extraction using acetylacetone (HAA) from lithium chloride solution by argon blowing through the solution are determined. Dependences of extraction degrees and distribution coefficients on different parameters of liquid phase: initial pH value, lithium chloride concentration and initial content of HAA, are presented. The degree of beryllium extraction reaches the maximum at liquid phase pH of 4.4-5.25 and concentration of lithium chloride of 8.5 mol/l. Distribution coefficient changes in inverse proportion to the extraction degree

  20. NOVEL SYNTHESIS OF POLYARYLENESULFONIUM CATIONS THROUGH A MULTI-ELECTRON TRANSFER PROCESS

    1998-01-01

    The oxidative polymerization of aryl sulfoxides provides a novel polysulfonium compound, poly(methylsulfonio-1,4-phenylenethio-1,4-phenylene cation) in quantitative yield. The polymerization proceeds efficiently in an acidic solution under atmospheric conditions. Oxygen, chemical and electrochemical oxidations are available. Vanadyl acetylacetonate and cerium ammonium nitrate act as an effective catalyst for the oxygen oxidative polymerization. The polymerization mechanism involves multielectron oxidation of the sulfides followed by successive electrophilic substitution. The resulting polyarylenesulfonium cations are useful as a soluble precursor for the synthesis of high molecular weight (Mw>105) poly(thio arylne)s.

  1. Multiferroic PbFe12O19 Ceramics

    Tan, Guo-Long; Wang, Min

    2011-01-01

    PbFe12O19 (PFO) powders in hexagonal structure have been synthesized by sol-gel process using lead acetate, glycerin and ferric acetylacetonate as the precursor. PbFe12O19 ceramics were obtained by sintering the PbFe12O19 powders at 1000\\degree C for 1 hour. Distorted flaky hexahedron grains are frequently observed in the SEM images of sintered PbFe12O19 ceramics. Large spontaneous polarization was observed in PbFe12O19 ceramic at room temperature, exhibiting a clear ferroelectric hysteresis ...

  2. Metalorganic chemical vapor deposition of highly oriented thin film composites of V2O5 and V6O13: Suppression of the metal–semiconductor transition in V6O13

    Sahana, MB; Shivashankar, SA

    2004-01-01

    Thin films of vanadium oxides were grown on fused quartz by metalorganic chemical vapor deposition using vanadyl acetylacetonate as the precursor. Growth at temperatures \\geq560 °C results in composites of strongly (00l)-oriented $V_{2}O_{5}$ and $V_{6}O_{13}$. The dominant phase of the film changes from $V_{2}O_{5}$ to $V_{6}O_{13}$, and back to $V_{2}O_{5}$, as the growth temperature is raised from 560 to 570 °C, then to 580 °C, as evidenced by x-ray diffraction and Rutherford backscatterin...

  3. Syntheses, magnetic and spectral studies on polystyrene supported coordination compounds of bidentate and tetradentate Schiff bases

    D Kumar; P K Gupta; A Syamal

    2005-05-01

    The reaction of aminomethylated polystyrene (PSCH2-NH2) and 2-hydroxyacetanilide in DMF results in the formation of polystyrene-anchored monobasic bidentate Schiff base, PSCH2-LH (I). On the other hand, the reaction of chloromethylated polystyrene (PSCH2-Cl), 3-formylsalicylic acid, ethylenediamine and acetylacetone in DMF in presence of ethyl acetate (EA) and triethylamine (TEA) produces another polystyrene-anchored dibasic tetradentate Schiff base, PSCH2-L'H2 (II). Both I and II react with a number of di-, tri- and hexavalent metal ions like Co, Ni, Cu, Zn and Cd to form polystyreneanchored coordination compounds, and these have been characterized and discussed.

  4. Preparation and Characterization of TiO2/CdS Layers as Potential Photoelectrocatalytic Materials

    Teofil-Danut Silipas; Ioan Bratu; Simina-Virginia Dreve; Ramona-Crina Suciu; Marcela-Corina Rosu; Emil Indrea

    2011-01-01

    The TiO2/CdS semiconductor composites were prepared on
    indium tin oxide (ITO) substrates in di®erent mass proportions via wet-chemical techniques using bi-distilled water, acetyl-acetone, poly-propylene-glycol and Triton X-100 as additives. The composite layers were annealed in normal conditions at the temperature of 450±C, 120 min. with a rate of temperature increasing of 5±C/min. The structural and optical properties of all the TiO2/CdS ayers were ch...

  5. Facile synthesis of deuterated and [14C]labeled analogues of vanillin and curcumin for use as mechanistic and analytical tools

    Gordon, Odaine N.; Graham, Leigh A.; Schneider, Claus

    2013-01-01

    Curcumin is a dietary diphenol with antioxidant, antinflammatory and antitumor activity. We describe facile procedures for the synthesis of [14C2]curcumin (4 mCi/mmol), [d6]curcumin, [d3]curcumin, [13C5]curcumin, and [d6]bicyclopentadione, the major oxidative metabolite of curcumin. We also describe synthesis of the labeled building blocks [14C]vanillin, [d3]vanillin, and [13C5]acetylacetone. The overall molar yields of the labeled products were 52% ([14C]) and 47% ([d3]) for vanillin and 25%...

  6. An Sn-Fe/carbon nanocomposite as an alternative anode material for rechargeable lithium batteries

    Sn-Fe/carbon nanocomposites were synthesized by the mechanochemical treatment of Sn with various amounts of an Fe/C composite through the pyrolysis of Fe(III) acetylacetonate. The composites were then evaluated as alternative anode materials for rechargeable lithium batteries. Based on the obtained ex situ X-ray diffraction (XRD) data, X-ray absorption spectroscopy (XAS) results, and differential capacity plots (DCPs), a reaction mechanism was suggested. It was found that increasing the amounts of the SnFe phase and pyrolyzed carbon in the composite improved its electrochemical characteristics in terms of its capacity retention

  7. Ferrocene and cobaltocene derivatives for non-aqueous redox flow batteries.

    Hwang, Byunghyun; Park, Min-Sik; Kim, Ketack

    2015-01-01

    Ferrocene and cobaltocene and their derivatives are studied as new redox materials for redox flow cells. Their high reaction rates and moderate solubility are attractive properties for their use as active materials. The cyclability experiments are carried out in a static cell; the results showed that these materials exhibit stable capacity retention and predictable discharge potentials, which agree with the potential values from the cyclic voltammograms. The diffusion coefficients of these materials are 2 to 7 times higher than those of other non-aqueous materials such as vanadium acetylacetonate, iron tris(2,2'-bipyridine) complexes, and an organic benzene derivative. PMID:25428116

  8. Fabrication of supported Ca-doped lanthanum niobate electrolyte layer and NiO containing anode functional layer by electrophoretic deposition

    Bozza, Francesco; Bonanos, Nikolaos

    2012-01-01

    The technique of electrophoretic deposition (EPD) has been applied for the preparation of a dense calcium-doped lanthanum niobate electrolyte film. La0.995Ca0.005NbO4 (LCN) powder was suspended in a solution of acetylacetone, iodine and water. The effects of suspension composition and deposition...... conditions were analyzed in order to identify a suitable set of EPD process parameters. The powders were deposited on a composite substrate of LCN, NiO, binder and graphite. A dense 8 μm film of lanthanum niobate supported on a porous substrate was obtained after sintering at 1200 °C. The technique was found...

  9. I- V characteristics of vanadium-flavonoid complexes based Schottky diodes

    Karimov, Khasan S.; Mahroof-Tahir, Mohammad; Saleem, Muhammad; Ahmad, Zubair

    2011-08-01

    In this study, we have investigated the current-voltage characteristics of the Schottky diodes of two vanadium complexes, VO 2(3-fl) ( 1) (3-fl=3-hydroxyflavone) and VO(acac) 2 ( 2), (acac=acetylacetonate), and their composites with TiO 2. Thin films of vanadium complexes and their composites were deposited by the centrifugation method. Current-voltage characteristics of the samples were processed by the modified Shockley equation, Cheung functions and space-charge limited currents (SCLC) approaches. Different junction parameters, such as series resistances, reverse saturation currents, ideality factors and barrier height of the samples, were determined.

  10. AVALIAÇÃO DE DIFERENTES REAGENTES COLORIMÉTRICOS PARA A DETERMINAÇÃO DE FORMALDEÍDO EM AMOSTRAS DE AR EM AMBIENTES INTERNOS

    Darllene Silveira

    2015-07-01

    Full Text Available Different colorimetric reagents, the Nash reagent (acetylacetone/ammonia solution, Purpald (4-amino- 3-hydrazino-5-mercapto-1,2,4-triazole/sodium hydroxide solution and 3-methyl-2-benzothiazolinone hydrazone (MBTH, were evaluated for the determination of formaldehyde in indoor air samples. Analytical parameters such as color stability of the product formed, sampling efficiency and reaction conditions were compared for the methodologies. Several method validation parameters were determined for the three colorimetric methods. The MBTH method showed better results and was used for the determination of formaldehydes in indoor environments.

  11. Structural and Luminescence Properties of Lu2O3:Eu3+ F127 Tri-Block Copolymer Modified Thin Films Prepared by Sol-Gel Method

    María Luz Carrera Jota; Dulce Yolotzin Medina Velazquez; Joel Moreno Palmerin; Antonieta García Murillo; Felipe de Jesús Carrillo Romo; Margarita García Hernández; Angel de Jesus Morales Ramírez

    2013-01-01

    Lu2O3:Eu3+ transparent, high density, and optical quality thin films were prepared using the sol-gel dip-coating technique, starting with lutetium and europium nitrates as precursors and followed by hydrolysis in an ethanol-ethylene glycol solution. Acetic acid and acetylacetonate were incorporated in order to adjust pH and as a sol stabilizer. In order to increment the thickness of the films and orient the structure, F127 Pluronic acid was incorporated during the sol formation. Structural, m...

  12. Avaliação da "microverdura" de sínteses com a estrela verde

    Rita C. C. Duarte

    2014-07-01

    Full Text Available This article reports a study to increase the overall greenness of chemical syntheses for first-year university laboratories. The separate evaluation of the micro-greenness of the three stages of synthesis (reaction, isolation and purification using the Green Star (GS was implemented and their respective contribution to overall greenness was investigated for two examples: syntheses of cobalt (III tris(acetylacetonate and potassium nitrilosulfonate. Results showed that the post-reaction (work-up steps are the most problematic for overall greenness. Greenness optimization can be achieved by combining the greenest procedures for each step obtained from different protocols available in the literature.

  13. 1. Mono([8]annulene)Uranium(4) half-sandwich complexes, 2. Novel syntheses of symmetrically substituted cyclooctatetetraenes

    Boussie, T.R.

    1991-10-01

    A reproducible, high-yield synthesis of mono([8]annulene)uranium(4)dichloride (1) is reported, along with the X-ray crystal structural of the bis(pyridine) adduct. Metathesis reactions of the half-sandwich complex 1 with a variety of simple alkyl and alkoxy reagents failed to generate any isolable mono-ring complexes. Reactions of 1 with polydentate, delocalized anions did produce stable derivatives, including mono([8]annulene)uranium(4)bis(acetylacetonate) (4). An X-ray crystal structure of 4 is reported.

  14. 1. Mono((8)annulene)Uranium(4) half-sandwich complexes, 2. Novel syntheses of symmetrically substituted cyclooctatetetraenes

    Boussie, T.R.

    1991-10-01

    A reproducible, high-yield synthesis of mono((8)annulene)uranium(4)dichloride (1) is reported, along with the X-ray crystal structural of the bis(pyridine) adduct. Metathesis reactions of the half-sandwich complex 1 with a variety of simple alkyl and alkoxy reagents failed to generate any isolable mono-ring complexes. Reactions of 1 with polydentate, delocalized anions did produce stable derivatives, including mono((8)annulene)uranium(4)bis(acetylacetonate) (4). An X-ray crystal structure of 4 is reported.

  15. Fabrication of Size-Tunable Metallic Nanoparticles Using Plasmid DNA as a Biomolecular Reactor

    Charles Michael Drain

    2011-10-01

    Full Text Available Plasmid DNA can be used as a template to yield gold, palladium, silver, and chromium nanoparticles of different sizes based on variations in incubation time at 70 °C with gold phosphine complexes, with the acetates of silver or palladium, or chromium acetylacetonate. The employment of mild synthetic conditions, minimal procedural steps, and aqueous solvents makes this method environmentally greener and ensures general feasibility. The use of plasmids exploits the capabilities of the biotechnology industry as a source of nanoreactor materials.

  16. Complete removal of uranyl nitrate from tissue matrix using supercritical fluid extraction

    The removal of uranyl nitrate from tissue matrix has been studied with supercritical carbon dioxide modified with methanol alone as well as complexing reagents dissolved in methanol. A systematic study of various complexing agents led to the development of an extraction procedure for the quantitative recovery of uranium from tissue matrix with supercritical carbon dioxide modified with methanol containing small quantities of acetylacetone. The drying time and temperature employed in loading of uranyl nitrate onto tissue paper were found to influence the extraction efficiency significantly

  17. Determination of the Hydrogenation Degree of Telechelic Polybutadiene by {sup 1}H NMR

    Lira, C.H.; Nicolini, L.F.; Dolinsky, M.C.B. [Petroflex Industria e Comercio S.A., Duque de Caxias, RJ (Brazil)]. E-mail: clira@petroflex.com.br; Oliveira, C.M.F.; Gomes, A.S. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Macromoleculas Professora Eloisa Mano

    2006-07-01

    The liquid hydroxyl terminated polybutadiene (HTPB) was hydrogenated to improve its thermal and oxidative resistance. Hydrogenation was carried out using cyclohexane as solvent and a soluble catalyst system consisting of diisobutyl aluminum hydride (DIBAL-H) and Co{sup III} acetylacetonate, at a molar ratio of 6:1. Hydrogenation was only possible after esterification of hydroxyl groups due to interactions with the catalyst system. {sup 1}H NMR technique was used to confirm the esterification and hydrogenation of the polymeric material. This method can be also used to determine the degree of hydrogenation in different reaction times. (author)

  18. Fabrication and performance of silver coated copper powder

    Cao, Xiao Guo; Zhang, Hai Yan

    2012-08-01

    Electroless silver coating on copper powder and its effects on oxidation resistance were investigated by varying the fabrication parameters. Using acetylacetone (C5H8O2) as chelating reagent, silver-coated copper powder was fabricated by displacement reaction method. In the process, acetylacetone forms chelating compound with Cu 2+, which prevent the formation of [Cu (NH3)4]2+. Therefore, Ag + can be reduced continully and deposited on the surface of copper particles. As-coated copper particles were characterized using x-ray diffraction (XRD), scanning electron microscopy (SEM) and x-ray energy dispersive spectroscopy (EDS). The oxidation resistance of silver coated copper powder was investigated by gravimetric method. It was found that a fairly continuous silver layer was formed on the surface of copper powder by the electroless type of substitution plating. When the silver content reached 10 wt. %, silver was homogeneously distributed around the copper particles and few free silver particles were detected. The results showed that the silver coated copper powder with the best oxidation resistance was prepared at 40°C and the C5H8O2/AgNO3 molar ratio was 1:1.

  19. Simple one-pot synthesis of platinum-palladium nanoflowers with enhanced catalytic activity and methanol-tolerance for oxygen reduction in acid media

    Graphical abstract: PtPd nanoflowers were fabricated by one-pot solvothermal co-reduction method in oleylamine system, which exhibited the improved electrocatalytic activity and higher methanol tolerance for oxygen reduction, compared with commercial Pt and Pd black catalysts. - Highlights: • Bimetallic alloyed PtPd nanoflowers are prepared by a simple one-pot solvothermal co-reduction method. • PtPd nanoflowers display high catalytic performance for ORR dominated by a four-electron pathway. • PtPd nanoflowers show good methanol tolerance for ORR. - Abstract: In this work, bimetallic alloyed platinum-palladium (PtPd) nanoflowers are fabricated by one-pot solvothermal co-reduction of Pt (II) acetylacetonate and Pd (II) acetylacetonate in oleylamine system. The as-prepared nanostructures show the enhanced electrocatalytic activity for oxygen reduction reaction (ORR), dominated by a four-electron pathway based on the Koutecky-Levich plots, mainly owing to the inhibition of the formation of Pt–OHad via the downshift of d-band center for Pt. Meanwhile, PtPd nanoflowers display good methanol tolerance and improved stability for ORR. The chronoamperometry test reveals that the current of PtPd nanoflowers remains 45.9% of its original value within 6000 s, much higher than those of commercial Pt (36.7%) and Pd (32.2%) black catalysts. Therefore, PtPd nanoflowers with unique interconnected structures can be used as a promising cathode catalyst in direct methanol fuel cells

  20. Nano-sized, quaternary titanium(IV) metal-organic frameworks with multidentate ligands

    Baranwal, Balram Prasad; Singh, Alok Kumar

    2010-12-01

    Some mononuclear nano-sized, quaternary titanium(IV) complexes having the general formula [Ti(acac)(OOCR) 2(SB)] (where Hacac = acetylacetone, R = C 15H 31 or C 17H 35, HSB = Schiff bases) have been synthesized using different multidentate ligands. These were characterized by elemental analyses, molecular weight determinations and spectral (FTIR, 1H NMR and powder XRD) studies. Conductance measurement indicated their non-conducting nature which may behave like insulators. Structural parameters like the values of limiting indices h, k, l, cell constants a, b, c, angles α, β, γ and particle size are calculated from powder XRD data for complex 1 which indicated nano-sized triclinic system in them. Bidentate chelating nature of acetylacetone, carboxylate and Schiff base anions in the complexes was established by their infrared spectra. Molecular weight determinations confirmed mononuclear nature of the complexes. On the basis of physico-chemical studies, coordination number 8 was assigned for titanium(IV) in the complexes. Transmission electron microscopy (TEM) and the selected area electron diffraction (SAED) studies indicated spherical particles with poor crystallinity.

  1. Optimization of process conditions for the production of TiO2–N film by sol–gel process using response surface methodology

    Rui Liu; Ching-Shieh Hsieh; Wein-Duo Yang; Hui-Yi Tsai

    2014-10-01

    TiO2–N film has been synthesized successfully through the sol–gel method. It is found that the anatase phase is formed at 400 °C and converted to rutile phase at 600 °C. The response surface methodology (RSM) and Box–Behnken design were employed to optimize the process conditions of sol–gel process. Based on the results in preliminary experiments, we selected molar ratio of surfactant to Ti, molar ratio of acetylacetone to Ti, molar ratio of water to Ti and calcination temperature as the key process factors affecting the roughness of TiO2–N film. The adjusted determination coefficient ($R^{2}_{\\text{Adj}}$) of the regression model was 0.9651, which indicated that the regression model is significant. By analysing the contour plots of response surface as well as solving the regression model, the optimized conditions were obtained as: 0.19 for molar ratio of surfactant to Ti, 2.01 for molar ratio of acetylacetone to Ti, 1.38 for molar ratio of water to Ti and 500 °C for calcination temperature. The predicted roughness of TiO2–N film for the optimized condition was calculated to be 41 nm. Confirmation experiments using the optimized conditions were performed, and a value about 43 nm was obtained. The experimental results are in good agreement with the predicted results.

  2. Long-chain amine-templated synthesis of gallium sulfide and gallium selenide nanotubes

    Seral-Ascaso, A.; Metel, S.; Pokle, A.; Backes, C.; Zhang, C. J.; Nerl, H. C.; Rode, K.; Berner, N. C.; Downing, C.; McEvoy, N.; Muñoz, E.; Harvey, A.; Gholamvand, Z.; Duesberg, G. S.; Coleman, J. N.; Nicolosi, V.

    2016-06-01

    We describe the soft chemistry synthesis of amine-templated gallium chalcogenide nanotubes through the reaction of gallium(iii) acetylacetonate and the chalcogen (sulfur, selenium) using a mixture of long-chain amines (hexadecylamine and dodecylamine) as a solvent. Beyond their role as solvent, the amines also act as a template, directing the growth of discrete units with a one-dimensional multilayer tubular nanostructure. These new materials, which broaden the family of amine-stabilized gallium chalcogenides, can be tentatively classified as direct large band gap semiconductors. Their preliminary performance as active material for electrodes in lithium ion batteries has also been tested, demonstrating great potential in energy storage field even without optimization.We describe the soft chemistry synthesis of amine-templated gallium chalcogenide nanotubes through the reaction of gallium(iii) acetylacetonate and the chalcogen (sulfur, selenium) using a mixture of long-chain amines (hexadecylamine and dodecylamine) as a solvent. Beyond their role as solvent, the amines also act as a template, directing the growth of discrete units with a one-dimensional multilayer tubular nanostructure. These new materials, which broaden the family of amine-stabilized gallium chalcogenides, can be tentatively classified as direct large band gap semiconductors. Their preliminary performance as active material for electrodes in lithium ion batteries has also been tested, demonstrating great potential in energy storage field even without optimization. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01663d

  3. Mesoporous Titania Powders: The Role of Precursors, Ligand Addition and Calcination Rate on Their Morphology, Crystalline Structure and Photocatalytic Activity

    Elisabetta Masolo

    2014-07-01

    Full Text Available We evaluate the influence of the use of different titania precursors, calcination rate, and ligand addition on the morphology, texture and phase content of synthesized mesoporous titania samples, parameters which, in turn, can play a key role in titania photocatalytic performances. The powders, obtained through the evaporation-induced self-assembly method, are characterized by means of ex situ X-Ray Powder Diffraction (XRPD measurements, N2 physisorption isotherms and transmission electron microscopy. The precursors are selected basing on two different approaches: the acid-base pair, using TiCl4 and Ti(OBu4, and a more classic route with Ti(OiPr4 and HCl. For both precursors, different specimens were prepared by resorting to different calcination rates and with and without the addition of acetylacetone, that creates coordinated species with lower hydrolysis rates, and with different calcination rates. Each sample was employed as photoanode and tested in the water splitting reaction by recording I-V curves and comparing the results with commercial P25 powders. The complex data framework suggests that a narrow pore size distribution, due to the use of acetylacetone, plays a major role in the photoactivity, leading to a current density value higher than that of P25.

  4. Density Functional Theory Study of Atomic Layer Deposition of Zinc Oxide on Graphene

    Ali, Amgad Ahmed; Hashim, Abdul Manaf

    2015-07-01

    The dissociation of zinc ions (Zn2+) from vapor-phase zinc acetylacetonate, Zn(C5H7O2)2, or Zn(acac)2 and its adsorption onto graphene oxide via atomic layer deposition (ALD) were studied using a quantum mechanics approach. Density functional theory (DFT) was used to obtain an approximate solution to the Schrödinger equation. The graphene oxide cluster model was used to represent the surface of the graphene film after pre-oxidation. In this study, the geometries of reactants, transition states, and products were optimized using the B3LYB/6-31G** level of theory or higher. Furthermore, the relative energies of the various intermediates and products in the gas-phase radical mechanism were calculated at the B3LYP/6-311++G** and MP2/6-311 + G(2df,2p) levels of theory. Additionally, a molecular orbital (MO) analysis was performed for the products of the decomposition of the Zn(acac)2 complex to investigate the dissociation of Zn2+ and the subsequent adsorption of H atoms on the C5H7O2 cluster to form acetylacetonate enol. The reaction energies were calculated, and the reaction mechanism was accordingly proposed. A simulation of infrared (IR) properties was performed using the same approach to support the proposed mechanism via a complete explanation of bond forming and breaking during each reaction step.

  5. 黄铁矿和黄铜矿中铁铜钴镍的纸层析及定量测定

    中国科学院贵阳地球化学研究所中心分析室

    1973-01-01

    The method of paper chromatography for the separation and quantitative determination of iron, copper, cobalt and nickel in pyrite and chalcopyrite is described.The three systems of ehromtograpbie solvents for the separation of iron, copper, cobalt and nickel on the 8×25 or 15×26 cm Whatman No. 3, involving acetone-hydrochloric acid-water, butanone-hydrochloric acid-water and acetone-acetylacetone-hydrochloric acid-water have been tested. As a developing system for the separation of this four elements in samples, the mixture of aoetone-acetylacetone-hydroehlorio acid-water is considered to be the best. After developing in a 30×40 cm glass dryer, the paper is dried in air and rendered the zone visible by treatment with 0.1% (W/V) rubeanic acid solution. The R1 values, colour reactions with this spray reagent and the eolour are given. A good paper chromatography of elements has been obtained. The elements are determined by colorimetrie method, with 1-nitroso-2-naphthol for cobalt,1-(2-pyridylozo)-2-naphthol for nickel, oxalic acid bis-cyelohexylidene hydrozide for copper, and sulfosalicylic acid for iron. In addition, iron and copper can also be determined by titration with potassium dichromate solution and iodimetry respectively.

  6. Graphene oxide/manganese ferrite nanohybrids for magnetic resonance imaging, photothermal therapy and drug delivery.

    Yang, Yan; Shi, Haili; Wang, Yapei; Shi, Benzhao; Guo, Linlin; Wu, Dongmei; Yang, Shiping; Wu, Huixia

    2016-01-01

    Superparamagnetic manganese ferrite (MnFe2O4) nanoparticles have been deposited on graphene oxide (GO) by the thermal decomposition of manganese (II) acetylacetonate and iron (III) acetylacetonate precursors in triethylene glycol. The resulting GO/MnFe2O4 nanohybrids show very low cytotoxicity, negligible hemolytic activity, and imperceptible in vivo toxicity. In vitro and in vivo magnetic resonance imaging experiments demonstrate that GO/MnFe2O4 nanohybrids could be used as an effective T2 contrast agent. The strong optical absorbance in the near-infrared (NIR) region and good photothermal stability of GO/MnFe2O4 nanohybrids result in the highly efficient photothermal ablation of cancer cells. GO/MnFe2O4 nanohybrids can be further loaded with doxorubicin (DOX) by π-π conjugate effect for chemotherapy. DOX release from GO/MnFe2O4 is significantly influenced by pH and can be triggered by NIR laser. The enhanced cancer cell killing by GO/MnFe2O4/DOX composites has been achieved when irradiated with near-infrared light, suggesting that the nanohybrids could deliver both DOX chemotherapy and photothermal therapy with a synergistic effect. PMID:26296777

  7. Frequency-dependent conductivity in tris(acetylacetonato)manganese(III) thin films on Si(1 0 0) substrates

    Thin tris(acetylacetonate)manganese(III) films of amorphous structure were prepared by vacuum deposition on glass and Si (1 0 0) substrates. The as-deposited and annealed-in-vacuum films were characterised by X-ray fluorescence, X-ray diffraction and optical absorption spectroscopy. The prepared title-complex amorphous films were investigated as insulators for Al/insulator/Si(P) metal-insulator-semiconductor (MIS) structures, which were characterised by the measurement of their capacitance and AC-conductance as a function of gate voltage. From those measurements, State density D it at insulator/semiconductor interface and the density of the fixed charges in the complex insulator were determined. It was found that D it was in order of 1011 eV-1 cm-2 and the surface charge density in the insulator film was in order of 1011-1012 cm-2.The frequency dependence of the electrical conductivity and dielectric properties of MIS structures were studied at room temperature. The results follow the correlated barrier-hopping (CBH) model, from which the fundamental absorption bandgap, the minimum hopping distance and other parameters of the model were determined. This study shows that the tris(acetylacetonate)manganese(III) films grown on Si(1 0 0) is a promising candidate for high-ε dielectric applications. It displays sufficiently high-ε value in the range 30-40

  8. Synthesis and spectroscopic characterization of some lanthanide(III nitrate complexes of ethyl 2-[2-(1-acetyl-2-oxopropylazo]-4,5-dimethyl-3-thiophenecarboxyate

    CHEMPAKAM JANARDHANAN ATHIRA

    2011-02-01

    Full Text Available Ethyl 2-[2-(1-acetyl-2-oxopropylazo]-4,5-dimethyl-3-thiophenecarboxyate was synthesized by coupling diazotized ethyl 2-amino-4,5-dimethylthiophene-3-carboxylate with acetylacetone. Based on various spectral studies and elemental analysis, an intramolecularly hydrogen-bonded azo-enol structural form was assigned for the ligand. This ligand is versatile in forming a series of lanthanide(III complexes, viz., lanthanum(III, cerium(III, praseodymium(III, neodymium(III, samarium(III and gadolinium(III, which were characterized through various spectral studies, elemental analysis, magnetic susceptibility measurements, molar conductance and thermal analysis. The spectral data revealed that the ligand acted as a neutral tridentate, coordinating to the metal ion through one of the azo nitrogen atoms, the ester carbonyl and the enolic oxygen of the acetylacetone moiety, without deprotonation. Molar conductance values adequately supported their non-electrolytic nature. The ligand and lanthanum(III complex were subjected to X-ray diffraction studies. In addition, the lanthanum(III complex underwent a facile transesterification reaction on refluxing with methanol for a long period. The thermal behaviour of the lanthanum(III complex was also examined

  9. Ion-molecule interactions of biological importance. A vibrational spectroscopic study of magnesium complexes with hydroxylated quinones

    Luteoskyrin and rugulosin are two naturally occurring yellow pigments with hydroxylated bis-anthraquinonic structures. They cause serious liver disorders in man due to the formation of complexes of the type pigment-Mg2+-DNA. In order to elucidate the structure of these complexes we have studied the vibrational spectra of some model systems, namely 1-hydroxy- and 1,4-dihydroxyanthraquinone, their magnesium chelate complexes, and a series of simpler complexes as the acetylacetonates of some divalent metals. Complete vibrational assignment are proposed for anthraquinone-9,10, the two hydroxylated and deureroxylated derivatives and their magnesium complexes. The substitution of 26Mg in place of 24Mg in these complexes enabled us to assign the Mg-O vibrations; their number corresponds to a hexa-coordinated metal in the acetylacetonate case and to a tetra-coordinated structure in the anthraquinone-olates complexes. The position of the ν C=0 and ν C-0 vibrations bands in the complexes shows that the bonds in the chelated ring of Mg(1-O-AQ)2 retains their single and double bond characteristic whereas in the CMg(1,4-O2,-AQ)n a resonating structure appears in the ring. The study of the IR and R spectra of the complexes enabled a tetrahedral structure to be proposed for the oxygens around the magnesium. Finally it was noted that the Mg-O bonds possessed a high degree of covalent character. (author)

  10. Influences of alcoholic solvents on spray pyrolysis deposition of TiO2 blocking layer films for solid-state dye-sensitized solar cells

    Influences of alcoholic solvents for titanium diisopropoxide bis(acetylacetonate) (TPA) precursor solutions on the spray pyrolysis deposited TiO2 films and the photovoltaic performance of the solid-state dye-sensitized solar cells (SDSCs) using these TiO2 films as the blocking layers were investigated. Smooth TiO2 films were obtained by spray pyrolysis deposition of a TPA solution in isopropanol (IPA) at a relatively low temperature of 260 °C. On the other hand, when ethanol was used as solvent, the TiO2 films fabricated at the same temperature showed much rougher surfaces with many pinholes. Our results showed that ethanol reacts with TPA to form titanium diethoxide bis(acetylacetonate) (TEA), which requires a higher thermal decomposition temperature than that of TPA. SDSCs with TiO2 blocking layer films fabricated using a TPA solution in IPA showed higher power conversion efficiencies with smaller variations. - Graphical abstract: Alcoholic solvents used for the TiO2 precursor play a critical role in determining the surface morphology of blocking layers and thus the photovoltaic performance of the SDSCs. Highlights: ► Solvent influences morphology of spray pyrolysis deposited TiO2 blocking layer. ► Ethanol reacts with TPA, resulting poor quality of blocking layer. ► Isopropanol is better than ethanol for obtaining smooth blocking layer. ► SDSC with blocking layer made with isopropanol showed better performance.

  11. A selective nanocatalyst for an efficient Ugi reaction: Magnetically recoverable Cu(acac)2/NH2-T/SiO2@Fe3O4 nanoparticles

    Monireh Ghavami; Maryam Koohi; Mohammad Zaman Kassaee

    2013-11-01

    A novel, magnetically recoverable nanocatalyst is fabricated through simple immobilization of copper(II) acetylacetonate on the surface of amine-terminated silica-coated Fe3O4 nanoparticles: Cu(acac)2/NH2-T/SiO2@Fe3O4NPs. Unambiguous bonding of Cu to the terminal amine is indicated by Xray photoelectron spectroscopy (XPS). Further characterizations are carried out by different techniques. Selectivity of this catalyst is demonstrated through one-pot synthesis of fourteen α-aminoacyl amides using Ugi four-component reaction of cyclohexyl isocyanide, acetic acid, amines and various aldehydes. Interestingly, all aromatic aldehydes react with short reaction times and high yields, but heteroaromatic aldehydes do not yield any product. Catalyst efficiency remains unaltered through three consecutive experiments.

  12. Schiff bases of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and its silatranes: Synthesis and characterization

    Gurjaspreet Singh; Amandeep Saroa; Sadhika Khullar; Sanjay K Mandal

    2015-04-01

    This paper aims at the introduction of azomethine group by the condensation reaction of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane with different compounds containing carbonyl group such as 2’-hydroxyacetophenone, salicylaldehyde, pyrrole-2-carboxaldehyde, acetylacetone and ethyl acetoacetate. Further, transesterification reaction of these Schiff base modified silanes with triethanolamine as a tripodal ligand leads to the synthesis of corresponding silatranes 1–5 bearing Schiff base functionalized long chain in the axial position. All the synthesized compounds are characterized by spectroscopic methods, elemental analysis and mass spectrometry. The authentication of Schiff base modified silatranes is scrutinized by single X-ray crystal structure of silatrane 1. The thermal stability of the five silatranes is studied by thermo-gravimetric analysis (TGA).

  13. Shape control of the magnetic iron oxide nanoparticles under different chain length of reducing agents

    We report on the effect of using reducing agents with different chain-length on the synthesis of iron oxide nanoparticles by thermal decomposition of iron (III) acetylacetonate in 1-octadecene. This modification allows us to control the shape of nanoparticles into spherical and cubic iron oxide nanoparticles. The highly monodisperse 14 nm spherical nanoparticles are obtained under 1,2-dodecanediol and average 14 nm edge-length cubic iron oxide nanoparticles are obtained under 1,2-tetradecanediol. The structural characterization such as transmission electron microscope (TEM) and X-ray diffraction (XRD) shows similar properties between two particles with different shapes. The vibrating sample magnetometer (VSM) shows no significant difference between spherical and cubic nanoparticles, which are 36 emu/g and 37 emu/g respectively and superparamagnetic in nature

  14. Polyesters from 1,4 cyclohexanediol: kinetics aspects in protic and non protic catalysis

    Continuing with the kinetic studies in polycondensation, it has been choosen the 1,4 cyclohexane diol as a monomer to polyesterify with acid and succinic anhydride, using p.toluen sulphonic acid as protic external catalyst and cooper (II) acetylacetonate as non protic catalyst. The reactions were carried out in bulk and the acid number followed for kinetical approaches. The structure of the polyester was characterized by means of IR, NMR and the thermal properties were studied by TGA and DSC. The molecular weight were measured by GPC and end group analysis. The kinetics is accomplish and the properties of the resulting material is compared to those of the polymer prepared from 1,4 cyclohexane dimethanol, in order to explore its probable liquid crystal behaviour

  15. Development of multicomponent hybrid density functional theory with polarizable continuum model for the analysis of nuclear quantum effect and solvent effect on NMR chemical shift

    We have developed the multicomponent hybrid density functional theory [MC-(HF+DFT)] method with polarizable continuum model (PCM) for the analysis of molecular properties including both nuclear quantum effect and solvent effect. The chemical shifts and H/D isotope shifts of the picolinic acid N-oxide (PANO) molecule in chloroform and acetonitrile solvents are applied by B3LYP electron exchange-correlation functional for our MC-(HF+DFT) method with PCM (MC-B3LYP/PCM). Our MC-B3LYP/PCM results for PANO are in reasonable agreement with the corresponding experimental chemical shifts and isotope shifts. We further investigated the applicability of our method for acetylacetone in several solvents

  16. Epoxidation of soybean oil with [MoO{sub 2}(acac){sub 2}]/TBHP Catalytic system in [bmim][PF{sub 6}]; Epoxidacao do oleo de soja com o sistema catalitico [MoO{sub 2}(acac){sub 2}]/TBHP em [bmim][PF{sub 6}

    Farias, Maritana [Instituto Federal de Educacao, Ciencia e Tecnologia Sul-rio-grandense, Pelotas, RS (Brazil); Martinelli, Marcia, E-mail: maritana@pelotas.ifsul.edu.br [Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil). Inst. de Quimica. Dept. de Quimica Inorganica

    2012-07-01

    Epoxidation of soybean oil was investigated using 1-n-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF{sub 6}] ionic liquid as biphasic medium with molybdenum(VI) acetylacetonate complex and tert-butyl hydroperoxide TBHP as oxidizing agent. Reaction conditions were molar ratio TBHP:number of double bonds of oil:catalyst of 100:100:1, reaction temperature of 60 deg C and reaction time between 2 and 24 h. The proposed system showed catalytic activity for epoxidation reactions under tested conditions. Reuse of ionic liquid/catalyst system for epoxidation reactions was also investigated. Evaluation of epoxidation observed in this catalytic system was done by quantitative {sup 1}H NMR data. (author)

  17. Heteroleptic protonated bis(phthalocyaninato) rare earth compounds containing 1,4,8,11,15,18,22,25-octa(butyloxy)-phthalocyanine ligand

    Condensation between M(Pc)(acac) (M = Sm, Eu, Gd; Pc = phthalocyaninate; acac = acetylacetonate) and metal-free 1,4,8,11,15,18,22,25-octa(butyloxy)phthalocyanine in n-octanol afforded heteroleptic double-deckers H{M(Pc)[Pc(α-OC4H9)8]} [Pc(α-OC4H9)8 1,4,8,11,15,18,22,25-octa(butyloxy)phthalocyaninate]. The series of double-decker complexes were characterized by elemental analysis, mass spectra, electronic absorption spectra, and IR spectra. The molecular structure of the compound of Gd was determined by single-crystal X-ray diffraction analysis. It was found that it exists as a pair of enantiomers in the unit cell of the crystals. Furthermore, the complex of Sm reacted with NaOH producing a supramolecule in which two Na+ ions connect two double-deckers together

  18. High mass-resolution electron-ion-ion coincidence measurements on core-excited organic molecules

    Tokushima, T; Senba, Y; Yoshida, H; Hiraya, A

    2001-01-01

    Total electron-ion-ion coincidence measurements on core excited organic molecules have been carried out with high mass resolution by using multimode (reflectron/linear) time-of-flight mass analyzer. From the ion correlation spectra of core excited CH sub 3 OH and CD sub 3 OH, the reaction pathway to form H sub 3 sup + (D sub 3 sup +) is identified as the elimination of three H (D) atoms from the methyl group, not as the inter-group (-CH sub 3 and -OH) interactions. In a PEPIPICO spectrum of acetylacetone (CH sub 3 COCH sub 2 COCH sub 3) measured by using a reflectron TOF, correlations between ions up to mass number 70 with one-mass resolution was recorded.

  19. (Acetylacetonato-κ2O,O′(phthalocyaninato-κ4N(phenanthroline-κ2N,N′erbium(III

    Hong-Feng Li

    2012-03-01

    Full Text Available The title complex, [Er(C32H16N8(C5H7O2(C12H8N2], possesses a mirror plane and the asymmetric unit is half of the molecule. The ErIII cation, lying on the mirror plane, is eight-coordinated by two O atoms from acetylacetone, two N (Nphen atoms from 1,10-phenanthroline and four isoindole N (Niso atoms from the phthalocyanine ligand in an antiprismatic geometry. The Er—N distances are in the range 2.376 (5–2.529 (4 Å and the Er—O distance is 2.272 (3 Å. Notably, the Er—Niso bonds are shorter than the Er—Nphen bonds, but longer than the Er—O bonds.

  20. Epoxidação do óleo de soja com o sistema catalítico [MoO2(acac2]/TBHP EM [bmim][PF6

    Maritana Farias

    2012-01-01

    Full Text Available Epoxidation of soybean oil was investigated using 1-n-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF6] ionic liquid as biphasic medium with molybdenum(VI acetylacetonate complex and tert-butyl hydroperoxide TBHP as oxidizing agent. Reaction conditions were molar ratio TBHP:number of double bonds of oil:catalyst of 100:100:1, reaction temperature of 60 ºC and reaction time between 2 and 24 h. The proposed system showed catalytic activity for epoxidation reactions under tested conditions. Reuse of ionic liquid/catalyst system for epoxidation reactions was also investigated. Evaluation of epoxidation observed in this catalytic system was done by quantitative ¹H NMR data.

  1. Quantum molecular dynamics and molecular interactions studied by NMR and INS Nuclear magnetic resonance; Proton tunnelling; Hydrogen bond

    Jones, N

    2002-01-01

    The wavefunction of a particle extends into the classically forbidden barrier region of the potential energy surface. The consequence of this partial delocalisation is the phenomenon of quantum tunnelling, an effect which enables a particle to penetrate a potential barrier of magnitude greater than the energy of the particle. The tunnelling probability is an exponential function of the particle mass. The effect is therefore an important contribution to the behaviour of light atoms, in particular the proton. The hydrogen bond has long been appreciated to be an essential component of many biological and chemical systems, and the proton transfer reaction in the hydrogen bond is fundamental to many of these processes. The proton behaviour in the hydrogen bonds of benzoic acid, acetylacetone and calix-4-arene has been studied. A variety of techniques, both experimental and computational, were adopted for the study of the three hydrogen bonded systems. The complementary spectroscopic techniques of inelastic neutron...

  2. Convenient preparation of ITO nanoparticles inks for transparent conductive thin films

    Tin-doped indium oxide (ITO) nanoparticles are useful precursors to transparent electrodes in a variety of technologically important applications. We synthesized ITO nanoparticles from indium and tin acetylacetonates in oleyl alcohol using a novel temperature ramp profile. The monodispersed ITO nanoparticles have an average diameter of 8.6 nm and form dense, flat films by simple spin coating. The thickness of the film can be controlled by varying the number of additional depositions. The resulting ITO film is transparent and has a resistivity of 7 × 10−3 Ω cm after sintering at 300 °C. Using a suitable solvent, it is possible to coat high-aspect-ratio structures with ITO nanoparticles. This approach to ITO coatings is greener and offers a number of advantages for transparent electrodes because it is highly versatile, easily scalable, and supports low-cost manufacturing.

  3. Solvothermal synthesis and characterization of acicular -Fe2O3 nanoparticles

    S Basavaraja; D S Balaji; Mahesh D Bedre; D Raghunandan; P M Prithviraj Swamy; A Venkataraman

    2011-12-01

    Nanometer-sized -Fe2O3 particles have been prepared by a simple solvothermal method using ferric acetylacetonate as a precursor. The products were characterized by X-ray diffraction (XRD), energy dispersive X-ray microanalysis (EDAX), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transition electron microscopy (TEM), infrared spectroscopy (IR) and thermal analysis (TG–DTA). XRD indicates that the product is single-phase -Fe2O3 with rhombohedral structure. Bundles of acicular shaped nanoparticles are seen in TEM images with an aspect ratio ∼ 12; typically 8–12 nm wide and over 150 nm long. The -Fe2O3 nanoparticles posses a high thermal stability, as observed on thermal analysis traces.

  4. Continuous tubular nanofibers of vanadium pentoxide by electrospinning for energy storage devices

    Tubular nanofibers (TNFs) of vanadium pentoxide (V2O5) were synthesized by electrospinning technique using a single spinneret for the first time by controlling the properties of the precursor solution. A partially miscible polymeric solution of vanadium oxytrihydroxide [VO(OH)3] was produced by hydrolysis of vanadyl acetylacetonate in Poly(vinylpyrrolidone) (PVP). The phase-separated polymer solution formed the core of the electrospun fibers whereas the VO(OH)3 formed the shell; the core PVP has been removed by controlled heat treatment. The TNFs had an inner diameter ∼60 nm and wall thickness ∼±100 nm. The capacitive behavior of the V2O5 TNFs was studied using cyclic voltammetry and galvanostatic cycling techniques. The studies showed ideal stable supercapacitive characteristics in the electrospun V2O5 TNFs.

  5. Continuous tubular nanofibers of vanadium pentoxide by electrospinning for energy storage devices

    Lala, Neeta L., E-mail: neeta@ump.edu.my; Jose, Rajan, E-mail: rjose@ump.edu.my; Yusoff, Mashitah M. [Universiti Malaysia Pahang, Faculty of Industrial Sciences and Technology (FIST) (Malaysia); Ramakrishna, Seeram [NUS Center for Nanofibers and Nanotechnology (Singapore)

    2012-11-15

    Tubular nanofibers (TNFs) of vanadium pentoxide (V{sub 2}O{sub 5}) were synthesized by electrospinning technique using a single spinneret for the first time by controlling the properties of the precursor solution. A partially miscible polymeric solution of vanadium oxytrihydroxide [VO(OH){sub 3}] was produced by hydrolysis of vanadyl acetylacetonate in Poly(vinylpyrrolidone) (PVP). The phase-separated polymer solution formed the core of the electrospun fibers whereas the VO(OH){sub 3} formed the shell; the core PVP has been removed by controlled heat treatment. The TNFs had an inner diameter {approx}60 nm and wall thickness {approx}{+-}100 nm. The capacitive behavior of the V{sub 2}O{sub 5} TNFs was studied using cyclic voltammetry and galvanostatic cycling techniques. The studies showed ideal stable supercapacitive characteristics in the electrospun V{sub 2}O{sub 5} TNFs.

  6. Synthesis of thiophene-linked pyrimidopyrimidines as pharmaceutical leads

    M B Siddesh; Basavaraj Padmashali; K S Thriveni; C Sandeep

    2014-05-01

    Thiophene-substituted chalcones were cyclised with guanidine in the presence of potassium hydroxide to get 4-substituted-6-thiophenopyrimidines 2a-e which were then refluxed with acetylacetone to obtain pyrimidopyrimidines 3a-e. Compounds 2a-e were also refluxed with ethylacetoacetate to afford pyirmidopyirimidines 4a-e which on refluxing with POCl3 in presence of DMF produced compounds 5a-e. Nucleophilic substitution reactions on 5a-e were carried out with aniline to obtain 6a-e. The structures of the newly synthesised compounds have been confirmed by elemental analysis and spectral studies. Some selected compounds have been screened for antibacterial and analgesic activities.

  7. Lifetime enhanced phosphorescent organic light emitting diode using an electron scavenger layer

    We demonstrate a method to improve lifetime of a phosphorescent organic light emitting diode (OLED) using an electron scavenger layer (ESL) in a hole transporting layer (HTL) of the device. We use a bis(1-(phenyl)isoquinoline)iridium(III)acetylacetonate [Ir(piq)2(acac)] doped HTL to stimulate radiative decay, preventing thermal degradation in HTL. The ESL effectively prevented non-radiative decay of leakage electron in HTL by converting non-radiative decay to radiative decay via a phosphorescent red emitter, Ir(piq)2(acac). The lifetime of device (t95: time after 5% decrease of luminance) has been increased from 75 h to 120 h by using the ESL in a phosphorescent green-emitting OLED

  8. Blistering during the atomic layer deposition of iridium

    The authors report on the formation of blisters during the atomic layer deposition of iridium using iridium acetylacetonate and oxygen precursors. Films deposited on fused silica substrates led to sparsely distributed large blisters while in the case of silicon with native oxide additional small blisters with a high density was observed. It is found that the formation of blisters is favored by a higher deposition temperature and a larger layer thickness. Postdeposition annealing did not have a significant effect on the formation of blisters. Finally, changing purge duration during the film growth allowed us to avoid blistering and evidenced that impurities released from the film in gas phase were responsible for the formation of blisters

  9. Preparation of Sr1-xCaxRuO3 thin films

    The series Sr1-xCaxRuO3 displays a continuous evolution from itinerant electron magnetism with (Tc=160 K,x=0) towards a paramagnetic metallic state at x=1. Previous studies on polycrystalline bulk samples raise the question whether the series shows a quantum critical point or phase separation near x=0.7. Here, we report first results on thin films which have been grown epitaxially on SrTiO3 substrates by the metalorganic aerosol deposition technique. This technique is based on the use of a solution containing acetylacetonates of Sr2+, Ca2+ and Ru3+. Growth conditions have been optimized by the variation of the (Sr1-xCax) to Ru ratio, deposition rate, molarity of the solution and deposition temperature. X-ray diffraction as well as STM, electrical resistivity and magnetization measurements are reported

  10. Efficient solution route to transparent ZnO semiconductor films using colloidal nanocrystals

    Satoshi Suehiro

    2016-09-01

    Full Text Available ZnO nanocrystals (NCs were synthesized by heating Zn (II acetylacetonate in oleic acid/oleylamine in the presence of 1,2-hexadecanediol at 220 °C. Transmission electron microscopy (TEM and dynamic light scattering (DLS measurements revealed the formation of monodispersed ZnO NCs of ca. 7 nm. ZnO NC assembled films were fabricated on a glass substrate by deposition with the colloidal ZnO NCs dispersed in toluene. The film composed of the NCs showed good optical transparency in the visible to near-infrared region. A device coupling the ZnO NC film with a p-type Cu2ZnSnS4 (CZTS NC film exhibited an obvious diode-like current–voltage behavior. The results suggest that the transparent ZnO film has a potentiality to be used for an n-type window layer in some optoelectronic applications.

  11. Preparation and characterization of electroluminescent devices based on complexes of β-diketonates of Tb3+, Eu3+, Gd3+ ions with macrocyclic ligands and UO22+ films

    Complexes containing Rare Earth ions are of great interest in the manufacture of electro luminescent devices as organic light emitting devices (OLED). These devices, using rare earth trivalent ions (TR3+) as emitting centers, show high luminescence with extremely fine spectral bands due to the structure of their energy levels, long life time and high quantum efficiency. This work reports the preparation of Rare Earth β-diketonate complexes (Tb3+, Eu3+ and Gd3+) and (tta - thenoyltrifluoroacetonate and acac - acetylacetonate) containing a ligand macrocyclic crown ether (DB18C6 - dibenzo18coroa6) and polymer films of UO22+. The materials were characterized by complexometric titration with EDTA, CH elemental analysis, near infrared absorption spectroscopy, thermal analysis, X-ray diffraction (powder method) and luminescence spectroscopy. For manufacturing the OLED it was used the technique of deposition of thin films by physical vapor (PVD, Physical Vapor Deposition). (author)

  12. Some regularities of Ce(3) and Ce(4) stabilization in their compounds with β-diketones

    Adduct formation of cerium (3) and cerium (4) β-diketonates (acetylacetonate, benzoylacetonate, dibenzoylmethanate and thenoyltrifluoroacetonate) with oxygen- and nitrogen-donor ligands (Q-α, α'-dipyridyl, o-phenanthroline, trioctylphosphine oxide and triphenylphosphine oxide) is studied. The compounds obtained as a results of the reactions are studied by means of IR-spectroscopic, derivatographic and X-ray phase methods. It is concluded that composition and thermodynamic stability of adducts of Ce(3) tris-β-diketonates are determined by correlation of donor properties of the basis and additional ligand and stability of adducts to oxidation - as well as by their solubility. Introduction of the additional ligand to the system Ce(4)-β-diketones even in the presence of air oxygen stabilizes Ce(3) and destabilizes Ce(4)

  13. Luminescent properties of compounds of europium(III) with quinaldic acid and β-diketones

    Kalinovskaya, I. V.; Mirochnik, A. G.

    2015-12-01

    We have obtained luminescent complex compounds of europium(III) with quinaldic acid and β- diketones of composition Eu(Quin)2β-dic • H;2O, where Quin is the anion of quinaldic acid, and β-dic is the anion of acetylacetone (acac), benzoylacetone (bzac), or dibenzoylmethane (dbm). The spectral properties of the obtained compounds have been examined. The joint presence of quinaldic acid and β-diketone in the coordination sphere of europium(III) leads to a broadening of the absorption spectral range of the investigated complex compounds. We have found that the "anomalous" Stark structure of luminescence spectra and the luminescence quenching of complexes at 300 K are determined by the occurrence of a high-lying ligand-europium(III) charge-transfer state.

  14. Temperature and Exciton Concentration Induced Excimer Emission of 4,4'-Bis(4''-Triphenylsilyl) Phenyl-1,1'-Binaphthalene and Application for Sunlight-Like White Organic Light-Emitting Diodes.

    Xu, Tao; Li, Weiling; Gao, Xicun; Sun, Chang; Chen, Guo; Zhang, Xiaowen; Li, Chunya; Zhu, Wenqing; Wei, Bin

    2016-12-01

    This paper demonstrates the influence of temperature, exciton concentration, and electron transportation layers on the excimer emission of a novel deep-blue material: 4,4'-bis(4''-triphenylsilyl) phenyl-1,1'-binaphthalene (SiBN), by studying the photoluminescence and electroluminescence spectra of SiBN-based film. We have further developed sunlight-like and warm-light white organic light-emitting diodes (WOLEDs) with high efficiency and wide-range spectra, using SiBN and bis(2-phenylbenzothiozolato-N,C2')iridium(acetylacetonate) (bt2Ir(acac)) as the blue excimer and yellow materials, respectively. The resulting device exhibited an excellent spectra overlap ratio of 82.9 % with sunlight, while the device peak current efficiency, external quantum efficiency, and power efficiency were 18.5 cd/A, 6.34 %, and 11.68 lm/W, respectively, for sunlight-like WOLEDs. PMID:27562015

  15. Speciation of titanium in solvent refined coal using SESC - INAA

    The preasphaltenes (Pa) separated from solvent refined coal (SRC-I) were fractionated by sequential elution solvent chromatography (SESC) on silica column into 10 fractions. Titanium was determined by instrumental neutron activation analysis (INAA), and was found to be concentrated in fractions 7-10. The preasphaltenes form stable complexes with bis (cyclopentadienyl) titanium(IV) dichloride (BTD), cyclopentadienyl titanium(IV) trichloride (CTT) and titanium(IV) oxide bis (acetylacetone) (TOBA). Preasphaltene titanium complexes (Pa-BTD, Pa-CTT, and Pa-TOBA) were fractionated using the SESC scheme, and the concentration of titanium in each fraction was determined. The mechanism for the reaction between titanium complexes (BTD, CTT or TOBA) and Pa was studied, and the existence of titanium phenoxide type complexes in SRC-I was proposed

  16. Synthesis and functionalization of biocompatible Tb:CePO{sub 4} nanophosphors with spindle-like shape

    Rodriguez-Liviano, Sonia; Aparicio, Francisco J.; Becerro, Ana I. [Instituto de Ciencia de Materiales de Sevilla (CSIC-US) (Spain); Garcia-Sevillano, Jorge; Cantelar, Eugenio [C-04. Universidad Autonoma de Madrid, Dpto. Fisica de Materiales (Spain); Rivera, Sara; Hernandez, Yulan; Fuente, Jesus M. de la [Universidad de Zaragoza, Instituto de Nanociencia de Aragon (Spain); Ocana, Manuel, E-mail: mjurado@icmse.csic.es [Instituto de Ciencia de Materiales de Sevilla (CSIC-US) (Spain)

    2013-02-15

    Monoclinic Tb:CePO{sub 4} nanophosphors with a spindle-like morphology and tailored size (in the nanometer and micrometer range) have been prepared through a very simple procedure, which consists of aging, at low temperature (120 Degree-Sign C), ethylene glycol solutions containing only cerium and terbium acetylacetonates and phosphoric acid, not requiring the addition of surfactants or capping agents. The influence of the heating mode (conventional convection oven or microwave oven) and the Tb doping level on the luminescent, structural and morphological features of the precipitated nanoparticles have also been analyzed. This study showed that microwave-assisted heating resulted in an important beneficial effect on the luminescent properties of these nanophosphors. Finally, a procedure for the functionalization of the Tb:CePO{sub 4} nanoparticles with aspartic-dextran is also reported. The functionalized nanospindles presented negligible toxicity for Verocells, which along with theirs excellent luminescent properties, make them suitable for biomedical applications.

  17. Catalytic performance for CO{sub 2} conversion to methanol of gallium-promoted copper-based catalysts. Influence of metallic precursors

    Toyir, Jamil; Ramirez de la Piscina, Pilar; Homs, Narcis [Departament de Quimica Inorganica, Facultat de Quimica, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona (Spain); Fierro, Jose Luis G. [Instituto de Catalisis y Petroleoquimica, C.S.I.C., Cantoblanco, 28049 Madrid (Spain)

    2001-11-28

    This study reports new gallium-promoted copper-based catalysts prepared by co-impregnation of methoxide-acetylacetonate (acac) precursors from methanolic solutions onto silica and zinc oxide supports. Catalyst performance in the CO{sub 2} hydrogenation to methanol was investigated at 2MPa and temperatures between 523 and 543K. A high activity and selectivity for ZnO-supported catalysts was found, which also showed a high stability in terms of both activity and selectivity. The maximum value for the activity was 378gMeOH/kgcath at 543K, with a selectivity of 88% towards methanol production. The high performance of these materials in the CO{sub 2} hydrogenation is related to the presence of Ga{sub 2}O{sub 3} promoter and highly dispersed Cu{sup +} species on the surface, determined by XPS and Auger on used catalysts.

  18. Controlled Synthesis and Characterization of Monodisperse Fe3O4 Nanoparticles

    SHI,Rongrong; GAO,Guanhua; YI,Ran; ZHOU,Kechao; QIU,Guanzhou; LIU,Xiaohe

    2009-01-01

    Monodisperse Fe3O4 nanoparticles were successfully synthesized through the thermal decomposition of iron acetylacetonate in octadecene solvent in the presence of oleic acid and oleylamine.The influences of experimental parameters,such as reacting temperature,amounts and kinds of surfactants,solvents,oleic acid and oleylamine,on the size and shape of monodisperse Fe3O4 nanoparticles were discussed.The phase structures,morphology,and size of the as-prepared products were investigated in detail by X-ray diffraction (XRD),transmission electron microscopy (TEM),selected area electron diffraction (SAED) and high-resolution transmission electron microscopy (HRTEM).Magnetic property was measured using a vibrating sample magnetometer (VSM) at room temperature,which revealed that Fe3O4 nanoparticles were of ferromagnetism with a saturation magnetization (Ms) of 74.0 emu/g and coercivity (Hc) of 72.6 Oe.

  19. Shape control of the magnetic iron oxide nanoparticles under different chain length of reducing agents

    Ngoi, Kuan Hoon; Chia, Chin-Hua, E-mail: chia@ukm.edu.my; Zakaria, Sarani [School of Applied Physics, Faculty Science and Technology, University Kebangsaan Malaysia 43600 UKM Bangi, Selangor (Malaysia); Chiu, Wee Siong [Low Dimensional Materials Research Centre, Department of Physics, Faculty of Science, University of Malaya, 50603 Lembah Pantai, Kuala Lumpur (Malaysia)

    2015-09-25

    We report on the effect of using reducing agents with different chain-length on the synthesis of iron oxide nanoparticles by thermal decomposition of iron (III) acetylacetonate in 1-octadecene. This modification allows us to control the shape of nanoparticles into spherical and cubic iron oxide nanoparticles. The highly monodisperse 14 nm spherical nanoparticles are obtained under 1,2-dodecanediol and average 14 nm edge-length cubic iron oxide nanoparticles are obtained under 1,2-tetradecanediol. The structural characterization such as transmission electron microscope (TEM) and X-ray diffraction (XRD) shows similar properties between two particles with different shapes. The vibrating sample magnetometer (VSM) shows no significant difference between spherical and cubic nanoparticles, which are 36 emu/g and 37 emu/g respectively and superparamagnetic in nature.

  20. Total synthesis and absolute configuration assignment of MRSA active garcinol and isogarcinol.

    Socolsky, Cecilia; Plietker, Bernd

    2015-02-01

    A short total synthesis of (±)-garcinol and (±)-isogarcinol, two endo-type B PPAPs with reported activity against methiciline resistant Staphylococcus aureus (MRSA), is presented. The separation of framework-constructing from framework-decorating steps and the application of two highly regio- and stereoselective Pd-catalysed allylations, that is, the Pd-catalysed decarboxylative Tsuji-Trost allylation and the diastereoselective Pd-catalysed allyl-allyl cross-coupling, are key elements that allowed the total synthesis to be accomplished within 13 steps starting from acetylacetone. After separation of the enantiomers the absolute configurations of the four natural products (i.e., (-)-garcinol, (+)-guttiferone E (i.e., ent-garcinol), (-)-isogarcinol, and (+)-isoxanthochymol (i.e., ent-isogarcinol)) were assigned based on ECD spectroscopy. PMID:25537962

  1. Prospects for Thermal Atomic Layer Etching Using Sequential, Self-Limiting Fluorination and Ligand-Exchange Reactions.

    George, Steven M; Lee, Younghee

    2016-05-24

    Thermal atomic layer etching (ALE) of Al2O3 and HfO2 using sequential, self-limiting fluorination and ligand-exchange reactions was recently demonstrated using HF and tin acetylacetonate (Sn(acac)2) as the reactants. This new thermal pathway for ALE represents the reverse of atomic layer deposition (ALD) and should lead to isotropic etching. Atomic layer deposition and ALE can together define the atomic layer growth and removal steps required for advanced semiconductor fabrication. The thermal ALE of many materials should be possible using fluorination and ligand-exchange reactions. The chemical details of ligand-exchange can lead to selective ALE between various materials. Thermal ALE could produce conformal etching in high-aspect-ratio structures. Thermal ALE could also yield ultrasmooth thin films based on deposit/etch-back methods. Enhancement of ALE rates and possible anisotropic ALE could be achieved using radicals or ions together with thermal ALE. PMID:27216115

  2. Issues Affecting the Synthetic Scalability of Ternary Metal Ferrite Nanoparticles

    Lauren Morrow

    2015-01-01

    Full Text Available Ternary Mn-Zn ferrite (MnxZn1-xFe2O4 nanoparticles (NPs have been prepared by the thermal decomposition of an oleate complex, sodium dodecylbenzenesulfonate (SDBS mediated hydrazine decomposition of the chloride salts, and triethylene glycol (TREG mediated thermal decomposition of the metal acetylacetonates. Only the first method was found to facilitate the synthesis of uniform, isolable NPs with the correct Mn : Zn ratio (0.7 : 0.3 as characterized by small angle X-ray scattering (SAXS, transmission electron microscopy (TEM, and inductively coupled plasma-optical emission spectroscopy (ICP-OES. Scaling allowed for retention of the composition and size; however, attempts to prepare Zn-rich ferrites did not result in NP formation. Thermogravimetric analysis (TGA indicated that the incomplete decomposition of the metal-oleate complexes prior to NP nucleation for Zn-rich compositions is the cause.

  3. Effects of the addition of H2O and NH4OH in the optical and structural properties of the thin films of Y2O3 deposited by pyrolytic spray

    In this work we studied the optical and structural properties of yttrium oxide thin films deposited by spray pyrolysis. Yttrium acetylacetonate was used as raw material and N, N-DMF was used as solvent. The films were deposited on Si (100) and Si (111) substrates at temperatures of 400, 450, 500 and 550 C. The optical and structural characteristics of the films were dramatically improved when a mist of H2O and/or NH40H was simultaneously added during deposition of the films. A refraction index up to 1.88, and deposition rates lower than 10 A/sec were obtained in the films. Infrared spectroscopy measurements indicate that the films resulted free from -OH bonds. X-ray diffraction patterns reveal that the films were polycrystalline. In addition, the relative chemical composition of the films was determined by Energy Dispersive Spectroscopy and the surface morphology was analyzed in the Atomic Force Microscope. (Author)

  4. Electronic structure of planar-quasicycled organic molecules with intramolecular hydrogen bond

    ALEXEI N. PANKRATOV

    2007-03-01

    Full Text Available By means of the HF/6-311G(d,p method, the electronic structure of the series of organic molecules, among which are malonaldehyde, acetylacetone, thiomalonaldehyde,’the derivatives of aniline 2-XC6H4NH2, phenol 2-XC6H4OH, benzenethiol 2-XC6H4SH (X = CHO, COOH, COO-, NO, NO2, OH, OCH3, SH, SCH3, F, Cl, Br, 8-hydroxyquinoline, 8-mercaptoquinoline, tropolone, has been studied. The intramolecular hydrogen bond (IHB has been established to lead to a local electron redistribution in quasicycle, and primarily to the electron density transfer between the direct IHB participants – from the hydrogen atom toward the proton-aceptor atom. On forming the IHB of the S–H···O type, the electron density in general decreases on the sulphohydryl hydrogen atom and increases on the sulphur atom.

  5. Thermodynamic study of CVD-ZrO{sub 2} phase diagrams

    Torres-Huerta, A.M., E-mail: atorresh@ipn.m [Research Center for Applied Science and Advanced Technology, Altamira-IPN, Altamira C.P.89600 Tamaulipas (Mexico); Vargas-Garcia, J.R. [Dept of Metallurgical Eng., ESIQIE-IPN, Mexico 07300 D.F. (Mexico); Dominguez-Crespo, M.A. [Research Center for Applied Science and Advanced Technology, Altamira-IPN, Altamira C.P.89600 Tamaulipas (Mexico); Romero-Serrano, J.A. [Dept of Metallurgical Eng., ESIQIE-IPN, Mexico 07300 D.F. (Mexico)

    2009-08-26

    Chemical vapor deposition (CVD) of zirconium oxide (ZrO{sub 2}) from zirconium acetylacetonate Zr(acac){sub 4} has been thermodynamically investigated using the Gibbs' free energy minimization method and the FACTSAGE program. Thermodynamic data Cp{sup o}, DELTAH{sup o} and S{sup o} for Zr(acac){sub 4} have been estimated using the Meghreblian-Crawford-Parr and Benson methods because they are not available in the literature. The effect of deposition parameters, such as temperature and pressure, on the extension of the region where pure ZrO{sub 2} can be deposited was analyzed. The results are presented as calculated CVD stability diagrams. The phase diagrams showed two zones, one of them corresponds to pure monoclinic phase of ZrO{sub 2} and the other one corresponds to a mix of monoclinic phase of ZrO{sub 2} and graphite carbon.

  6. Thermodynamic study of CVD-ZrO2 phase diagrams

    Chemical vapor deposition (CVD) of zirconium oxide (ZrO2) from zirconium acetylacetonate Zr(acac)4 has been thermodynamically investigated using the Gibbs' free energy minimization method and the FACTSAGE program. Thermodynamic data Cpo, ΔHo and So for Zr(acac)4 have been estimated using the Meghreblian-Crawford-Parr and Benson methods because they are not available in the literature. The effect of deposition parameters, such as temperature and pressure, on the extension of the region where pure ZrO2 can be deposited was analyzed. The results are presented as calculated CVD stability diagrams. The phase diagrams showed two zones, one of them corresponds to pure monoclinic phase of ZrO2 and the other one corresponds to a mix of monoclinic phase of ZrO2 and graphite carbon.

  7. Conformational features of meso-tetrathienylporphyrins and photosensitising properties of their β-1-acetyl-2-oxopropyl derivatives

    Prasath, Rangaraj; Bhavana, Purushothaman

    2015-08-01

    The difference in the site of electrophilic nitration of meso-tetra-thien-2-yl- and thien-3-yl-porphyrins is explained based on the difference in extended conjugation between porphyrin core and meso-thienyl rings. The significance of resonance in dictating the site of substitution is also explained based on the behavior of tetrakis(5-bromothien-2-yl)porphyrin toward electrophilic nitration. Three new β-1-acetyl-2-oxopropyl-substituted porphyrins are synthesized by Michael addition of acetylacetone group on pyrrole β-nitroporphyrins. The photosensitizing properties of these porphyrins is investigated using porphyrin-TiO2 composites in the degradation of 4-nitrophenol. The results showed the importance of the effect of the position of sulfur on the thienyl ring and the orientation of meso-thienyl groups with the central macrocyclic ring of porphyrins in deciding its efficiency as photosensitiser.

  8. Phosphorescent Platinum(II) Complexes with Mesoionic 1H-1,2,3-Triazolylidene Ligands.

    Soellner, Johannes; Tenne, Mario; Wagenblast, Gerhard; Strassner, Thomas

    2016-07-11

    The synthesis and characterization of eight unprecedented phosphorescent C^C* cyclometalated mesoionic aryl-1,2,3-triazolylidene platinum(II) complexes with different β-diketonate ligands are reported. All compounds proved to be strongly emissive at room temperature in poly(methyl methacrylate) films with an emitter concentration of 2 wt %. The observed photoluminescence properties were strongly dependent on the substitution on the aryl system and the β-diketonate ligand. Compared to acetylacetonate, the β-diketonates with aromatic substituents (mesityl and duryl) were found to significantly enhance the quantum yield while simultaneously reducing the emission lifetimes. Characterization was carried out by standard techniques, as well as solid-state structure determination, which confirmed the binding mode of the carbene ligand. DFT calculations, carried out to predict the emission wavelength with maximum intensity, were in excellent agreement with the (later) obtained experimental data. PMID:27294887

  9. Novel magnetite-silica nanocomposite (Fe3O4-SBA-15) particles for DNA binding and gene delivery aided by a magnet array.

    Yiu, Humphrey H P; McBain, Stuart C; Lethbridge, Zoe A D; Lees, Martin R; Palona, Iryna; Olariu, Cristina I; Dobson, Jon

    2011-04-01

    Novel magnetite-silica nanocomposite particles were prepared using SBA-15 nanoporous silica as template. Magnetite nanoparticles were impregnated into the nanopore array of the silica template through thermal decomposition of iron(III) acetylacetonate, Fe(AcAc)3 at 200 degrees C. These composite particles were characterized using TEM, XRD and SQUID magnetometry. The TEM images showed that the size of composite particles was around 500 nm and the particles retained the nanoporous array of SBA-15. The formation of magnetite nanoparticles was confirmed by the powder XRD study. These composite particles also exhibited ferrimagnetic properties. By coating with short chain polyethyleneimine (PEI), these particles are capable of binding DNA molecules for gene delivery and transfection. With an external magnetic field, the transfection efficiency was shown to have an increase of around 15%. The results indicated that these composite nanoparticles may be further developed as a new tool for nanomagnetic gene transfection. PMID:21776740

  10. Solution processed nickel oxide anodes for organic photovoltaic devices

    Mustafa, Bestoon; Griffin, Jonathan; Alsulami, Abdullah S.; Lidzey, David G.; Buckley, Alastair R., E-mail: alastair.buckley@sheffield.ac.uk [Department of Physics and Astronomy, Hicks Building, Hounsfield Road, University of Sheffield, Sheffield S3 7RH (United Kingdom)

    2014-02-10

    Nickel oxide thin films have been prepared from a nickel acetylacetonate (Ni(acac)) precursor for use in bulk heterojunction organic photovoltaic devices. The conversion of Ni(acac) to NiO{sub x} has been investigated. Oxygen plasma treatment of the NiO layer after annealing at 400 °C affords solar cell efficiencies of 5.2%. Photoelectron spectroscopy shows that high temperature annealing converts the Ni(acac) to a reduced form of nickel oxide. Additional oxygen plasma treatment further oxidizes the surface layers and deepens the NiO work function from 4.7 eV for the annealed film, to 5.0 eV allowing for efficient hole extraction at the organic interface.