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Abstract  

Synergistic extraction of tetravalent actinides, using mixtures of a β-diketone and several neutral organophosphorous extractants, was recently demonstrated. In this work the extraction of the ions Th(IV), Np(IV) and Pu(IV), from perchloric acid medium, by benzene solutions of a β-diketone, thenoyltrifluoroacetone (HTTA), in combination with a neutral organosulfoxide donor, di-n-octyl sulfoxide (DOSO), has been investigated. Two methods viz. the slope analysis method and JOB's method have been employed for the study. The species mainly responsible for the observed synergism, with the M(IV) ions studied, was found to be M(TTA)4·DOSO. The extraction and adduct formation equilibrium constants are given.

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Abstract  

The equilibrium constants for coordination of methyl substituted pyridine N-oxides with plutonium(VI) thenoyl trifluoroacetonate in chloroform (Ks) follow an order similar to those of the analogous uranium(VI) complexes indicating steric hindrance to bonding in the case of ortho substituted pyridine N-oxides. The extraction constants (k) of Pu(VI) chelates with various β-diketones are found to be only marginally higher than the values for the corresponding uranium(VI) chelates which is in conformity with the close similarity of the ionic radii of PuO 2 2+ and UO 2 2+ .

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Abstract  

Preparation of lanthanide fluoride and chloride films has been studied by chemical vapor deposition (CVD) using Ln(thd)3 (Ln=lanthanide(III); thd=2,2,6,6-tetramethyl-3,5-heptanedionato ligand) and Y(thd)3 with gas mixture systems of CF2Cl2 (difluorodichloromethane)/O2 and CF2Cl2/H2. Two kinds of fluorides, LnOF oxyfluoride and LnF3 triffluoride, were obtained separately along a CVD tube at atmospheric pressure and temperature as low as 300–600°C by the reaction of Ln(thd)3 chelates with CF2Cl2/O2 gas system. The chemical characteristics of the CVD products were considered from the thermochemical point of view.

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Abstract  

This work presents preparation and thermal characterization of three novel organomercurials: Hg2(CF3COCHCOCF3)22-(CF3COCCOCF32(CF3C(OH)2CH2C(OH)2CF3) (I), Hg2(CF3COCHCOCF3)22-(CF3COCCOCF3) (II) and Hg2(CH3COCHCOCF3)22-(CH3COCCOCF3) (III) which means that they contain at least one direct mercury-to-carbon bond among the carbonyl groups of β-diketone molecules which are capable for chelating of metal ions. IR-spectra support the conclusion that mercury is most probably bound to the γ-carbon of fluorinated derivatives of acetylacetone and is not chelated through oxygen in any of the isolated compounds. The thermal decomposition of mercurated hexafluoro- and trifluoroacetylacetone in nitrogen occurs in a few steps. Each step was identified and studied by simultaneous DTA/TG analyzer. On the basis of dynamic heating experiments by TG applying Flynn-Wall method the activation energy for each of them was determined.

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Abstract  

Several adducts of U(IV) and Th(IV) with 1,1,1,2,2,3,3-heptafluoro-7,7-dimethyl-4,6-octanedione (FOD) as -diketone and a variety of neutral oxodonors were synthesized and characterized by visible spectral, proton magnetic resonance as well as thermogravimetric studies. Adducts with dimethylformamide (DMF) were found to be most volatile, whereas with trioctylphosphine oxide (TOPO) were quite susceptible towards decomposition.

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Abstract  

Preparation of thin films of lanthanide (Ln) sulfides has been studied by the chemical vapor deposition (CVD) method, using metal -diketonato chelates with 2,2,6,6-tetramethyl-3,5-heptanedione and reactant H2S gas as starting materials. Two kinds of sulfides, Ln2O2S oxysulfides and EuS monosulfide, were obtained as thin films at temperatures as low as 390–570 °C. The CVD method was confirmed to be suited for the above purpose.

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Abstract  

Preparation of thin film deposits of lanthanide, thorium and uranium oxides has been studied by chemical vapor deposition (CVD) method using -diketonate metal chelates with 2,2,6,6-tetramethyl-3,5-heptanedione and some reactant gases as starting materials. The deposition process was carried out using a special apparatus designed for the CVD method at atmospheric pressure and temperatures as low as 400–600°C.As a result, it was demonstrated that each chelate used was well suited for the above purpose by its high volatility and reactivity with the reactant, especially with water vapor.

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Abstract  

A novel double -diketone 1,6-bis(1-phenyl-3-methyl-5-oxo-pyrazol-4-yl) hexanedione-[1,6] (BPMOPH) was further studied on its coordination compounds with uranium and thorium, respectively. The IR, UV, and1H-NMR spectra were examined, and the proposed structure is discussed.

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Abstract  

The rate of copper extraction with individual 4-acyl-5-pyrazolones and the stability of various enolic and keto forms and their monohydrates were studied. The rate of extraction depends mainly upon the structure of substituent at position 4 and falls when the substituent becomes spacy. The effect of the substituent at position 1 is rather low. The enolic form with intramolecular hydrogen bonding is the most stable. It can form hydrates with water molecules without intramolecular hydrogen bond breaking.

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Abstract  

The present article describes the synthesis, spectral, coordination and thermal aspects of N,N′-polymethylene bis(1-phenyl-3-methyl-4-trifluoroacetylimino-2-pyrazoline-5-ol)oxovanadium(IV) or copper(II) Schiff base complexes with alkyl backbones ranging from two to four carbons have been characterized on the basis of elemental analysis, magnetic moments, molar conductivity measurements, spectra (FTIR, ESR, UV-Visible, MS), VPO and thermal studies. The vapour pressure osmometry (VPO) and mass spectral studies indicate that the complexes are monomeric. An ESR study of all these complexes of VO(IV) and Cu(II) are consistent with the square pyramidal and square planar geometries of these metal ions, respectively. In addition, the kinetics and thermodynamic parameters for the different thermal decomposition steps of the complexes have been studied employing Horowitz-Metzger and Freemen-Carroll methods.

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