Investigation of colourless complexes of thorium, hafnium and zirconium. The investigations conducted in the Institute of General Chemistry of Poznan Technical University in partial cooperation with Kharkhof Technical University related with thorium, hafnium and zirconium complexes are reviewed. Preparation of complexes of zirconium and hafnium tetrachlorides with phosphorus oxychloride. This patent describes an improvement in a method for separating hafnium tetrachloride from zirconium tetrachloride where a complex of zirconium- hafnium tetrachlorides and phosphorus oxychloride is prepared from zirconium- hafnium tetrachlorides and the complex of zirconium- hafnium tetrachlorides and phosphorus oxychloride is introduced into a distillation column, which distillation column has a reboiler connected at the bottom and a reflux condenser connected at the top and where a hafnium tetrachloride enriched stream is taken from the top of the column and a zirconium enriched tetrachloride stream is taken from the bottom of the column. The improvement comprising: prepurifying the zirconium- hafnium tetrachlorides, prior to preparation of the complex and introduction of the complex into a distillation column, to substantially eliminate iron chloride from the zirconium hafnium tetrachlorides, whereby buildup or iron chloride in the distillation column and in the reboiler is substantially eliminated and the column can be operated in a continuous, stable and efficient manner.
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Investigation of colourless complexes of thorium, hafnium and zirconium. The investigations conducted in the Institute of General Chemistry of Poznan Technical University in partial cooperation with Kharkhof Technical University related with thorium, hafnium and zirconium complexes are reviewed.
Preparation of complexes of zirconium and hafnium tetrachlorides with phosphorus oxychloride. This patent describes an improvement in a method for separating hafnium tetrachloride from zirconium tetrachloride where a complex of zirconium- hafnium tetrachlorides and phosphorus oxychloride is prepared from zirconium- hafnium tetrachlorides and the complex of zirconium- hafnium tetrachlorides and phosphorus oxychloride is introduced into a distillation column, which distillation column has a reboiler connected at the bottom and a reflux condenser connected at the top and where a hafnium tetrachloride enriched stream is taken from the top of the column and a zirconium enriched tetrachloride stream is taken from the bottom of the column.
The improvement comprising: prepurifying the zirconium- hafnium tetrachlorides, prior to preparation of the complex and introduction of the complex into a distillation column, to substantially eliminate iron chloride from the zirconium hafnium tetrachlorides, whereby buildup or iron chloride in the distillation column and in the reboiler is substantially eliminated and the column can be operated in a continuous, stable and efficient manner.
Complexing of zirconium and hafnium with ortho-aminobenzoic acid and paraaminobenzoic acid. Formation of complexes between zirconium and hafnium and ortho- and para-aminobenzoic acids has been studied by the kinetic method.
Stepwise constants and overall effective constants of complex formation have been calculated. Commercial production of metal hafnium and hafnium -based products. Hafnium possesses a unique complex of physical and chemical properties which allow the application of products on its basis in various industries.
Joint Stock Company 'Chepetsky Mechanical Plant' is the single enterprise which produces hafnium on the territory of Russia. The weight of melted hafnium ingots is up to 1 ton. Manufacture of wide range of products from hafnium is implemented. The plates from a hafnium with thickness of 0. It is shown that ingots and products obtained from metal hafnium correspond to the Russian and international standards for reactor materials in chemical composition, mechanical and corrosion properties.
Hafnium IV complexation with oxalate at variable temperatures. Friend, Mitchell T. Appropriate management of fission products in the reprocessing of spent nuclear fuel SNF is crucial in developing advanced reprocessing schemes. The addition of aqueous phase complexing agents can prevent the co-extraction of these fission products.
The addition of oxalate to the aqueous phase decreased the distribution ratio, indicating aqueous Hf IV -oxalate complex formation. Stability constants were observed to increase at higher temperature, an indication that Hf IV -oxalate complexation is endothermic and driven by entropy. Differential perturbed angular correlation: use of physico-chemical study of some hafnium complexes derivates of hydroxy acids and EDTA.
Measures of quadrupolar interaction to nucleus level of the metal, in some hafnium complexes are presented, including the analysis by combustion, microanalysis, infrared spectroscopy and thermogravimetry.
This patent describes an improvement in a method for separating hafnium chloride from zirconium chloride using a distillation column, with a hafnium chloride enriched vapor stream taken from the top of the column and a zirconium enriched chloride stream taken from the bottom of the column.
The improvement comprising: purifying the zirconium- hafnium chloride in a molten salt purification vessel prior to or after introduction into the distillation column to substantially eliminate iron chloride from the zirconium- hafnium chloride by at least periodically removing iron chloride from the molten salt purification vessel by electrochemically plating iron onto an electrode in the molten salt purification vessel. The molten salt in the molten salt purification vessel consisting essentially of a mixture of chlorides selected from the group consisting of alkali metals, alkaline earth metals, zirconium, hafnium , aluminum, manganese, and zinc.
Complexation of di- amides of dipicolinic acid with neodymium. Lapka, J. Di- amides have undergone significant studies as possible ligands for use in the partitioning of trivalent minor actinides and lanthanides.
The binding affinities of three isomeric ligands with neodymium in acetonitrile solution have been investigated. The stability constants of the metal-ligand complexes formed between different isomers of N,N'-diethyl-N,N'- ditolyl-di-picolinamide EtTDPA and trivalent neodymium in acetonitrile have been determined by spectrophotometric and calorimetric methods.
Values from spectrophotometric and calorimetric titrations are within reasonable agreement with each other. The obtained values are comparable to other di- amidic ligands obtained under similar system conditions and mirror previously obtained solvent extraction data for EtTDPA at low ionic strengths.
This research thesis addressed the study of complex carbonates of cations of metals belonging to the IV A column, i. The author first presents methods used in this study, discusses their precision and scope of validity.
She reports the study of the formation of different complex ions which have been highlighted in solution, and the determination of their formation constants. She reports the preparation and study of the stability domain of solid complexes. The next part reports the use of thermogravimetric analysis, IR spectrometry, and crystallography for the structural study of these compounds.
Study of hafnium IV oxide nanoparticles synthesized by polymerized complex and polymer precursor derived sol-gel methods. This work reports the preparation and characterization of hafnium IV oxide HfO2 nanoparticles grown by derived sol-gel routes that involves the formation of an organic polymeric network.
A comparison between polymerized complex PC and polymer precursor PP methods is presented. For the PC method, citric acid CA and ethylene glycol EG are used as the chelating and polymerizable reagents, respectively. In both cases, different precursor gels were prepared and the hafnium IV chloride HfCl4 molar ratio was varied from 0. The thermal characterization of the precursor gels was carried out by thermogravimetric analysis TGA and the structural and morphological characterization by X-ray diffraction XRD and transmission electron microscopy TEM.
The PC method exhibited also the cubic phase. Actinides complexes in solvent extraction. The amide type of extractants. The N,N-dialkylamides and the N,N'-tetraalkyl. The main advantages of the amides lie in their complete incinerability and the small interference of their radiolytic and hydrolytic degradation products for the processes.
The actinide extraction chemistry with various amides is reviewed in this paper. Chemometric characterization of the hydrogen bonding complexes of secondary amides and aromatic hydrocarbons.
The paper reports the results of the study of hydrogen bonding complexes between secondary amides and various aromatic hydrocarbons. Hierarchical clustering and Principal Component Analysis PCA have been applied on infrared spectroscopic and Taft parameters of 43 N-substituted amide complexes with different aromatic hydrocarbons.
Results obtained in this report are Magnetic-superexchange interactions of uranium IV chloride-addition complexes with amides , 2. The magnetic susceptibilities of five cyclic amide lactam -addition complexes of uranium IV chloride were measured between room temperature and 2 K.
Magnetic-exchange interaction was found only for N-methyl-substituted amide complexes , and a dimer structure was assumed for them on the basis of their chemical properties. Treating interdimer interaction with a molecular-field approximation, the magnetic susceptibilities were calculated to be in good agreement with the experimental results in the temperature region of the maxima in chi sub A. Directory of Open Access Journals Sweden. Full Text Available The paper reports the results of the study of hydrogen bonding complexes between secondary amides and various aromatic hydrocarbons.
Results obtained in this report are in good agreement with conclusions of other spectroscopic and thermodynamic analysis. A molecular mechanics MM3 96 force field for metal- amide complexes. A molecular mechanics MM3 96 force field is reported for modeling metal complexes of amides in which the amide is coordinated through oxygen.
Relationships between force field parameters and metal ion properties charge, ionic radius, and electronegativity are presented that allow the application of this model to a wide range of metal ions. The model satisfactorily reproduces the structures of over fifty amide complexes with the alkaline earths, transition metals, lanthanides, and actinides.
Zinc II complexes with intramolecular amide oxygen coordination as models of metalloamidases. Thus, the reaction of Zn ClO4 2. L and undergo cleavage of the tert-butylamide upon addition of Me4NOH. The extent by which the amide cleavage reaction is accelerated in relative to the free ligands, L, is correlated with the strength of amide oxygen binding and Lewis acidity of the zinc II centre in deduced from the X-ray, NMR and IR studies.
Flotation separation of hafnium IV from aqueous solutions. Cationic hafnium complex ions were floated from dilute acid solutions with sodium lauryl sulfate SLS and anionic hafnium complexes were floated from basic and oxalic acid solutions with hexadecyltrimethyl ammonium bromide HTMAB.
The conditions necessary for quantitative recovery of the metal and mechanisms of flotation are described. The direct synthesis of amides from alcohols and amines is described with the simultaneous liberation of dihydrogen.
The reaction does not require any stoichiometric additives or hydrogen acceptors and is catalyzed by ruthenium N-heterocyclic carbene complexes. Three different catalyst systems In addition, potassium tert-butoxide and a tricycloalkylphosphine are required for the amidation to proceed. A range of different primary alcohols and amines have been coupled in the presence of the three catalyst systems to afford the corresponding amides in moderate to excellent yields.
The best results are obtained with sterically unhindered alcohols and amines. The three catalyst systems do Complexes of vanadium V oxotrichloride with amides and tertiary amines.
Vanadium V oxotrichloride forms dark brown hygroscopic solid complexes of the composition VOCl 3. These complexes have been characterized on the basis of their analytical and IR spectral data. Investigation of the complex reaction coordinate of acid catalyzed amide hydrolysis from molecular dynamics simulations. The rate-determining step of acid catalyzed peptide hydrolysis is the nucleophilic attack of a water molecule to the carbon atom of the amide group.
Therein the addition of the hydroxyl group to the amide carbon atom involves the association of a water molecule transferring one of its protons to an adjacent water molecule. The protonation of the amide nitrogen atom follows as a separate reaction step.
Since the nucleophilic attack involves the breaking and formation of several bonds, the underlying reaction coordinate is rather complex. We investigate this reaction step from path sampling Car-Parrinello molecular dynamics simulations.
This approach does not require the predefinition of reaction coordinates and is thus particularly suited for investigating reaction mechanisms. From our simulations the most relevant components of the reaction coordinate are elaborated. Moreover, the proton transfer is found to depend on favorable solvent configurations.
Thus, also the arrangement of non-reacting, i. Complexing properties of amide oxime of picolinic acid APA. Experiments in vivo were carried out on 10 Swiss mice with implanted Ehrlich tumor.
The ADF ratio tumor:blood was 2. Renoscintigraphy showed that the decline of renal activity in the stage when excretion prevailed phase III was slow and of the cumulative nature. Simple synthesis, labelling and low toxity of APA are the factors that advocate further experiments in investigating its usefulness for diagnostics.
Structural motifs of diiodine complexes with amides and thioamides. The crystal structure of 1 was also determined by X-ray diffraction at 1 K.
Polakowski, Benon (1927-2008)
Metallothionein in Hermetia illucens Linnaeus , larvae Diptera: Stratiomyidae , a potential biomarker for organic waste system. Black soldier fly, Hermetia illucens Linnaeus , , is an important economic fly as its larvae can be used for recycling organic waste, such as food waste and manure. Metallothionein MT usually serve as biomarker because of its role in metal homeostasis, detoxification, and dose response of heavy metals. Therefore, a MT gene was cloned from H.