Attila Vértes

Handbook of nuclear chemistry

Volume 1: Basics of Nuclear Science.Series Editors: A. Vertes, S. Nagy, Z. Klencsar. Volume Editor: R.G. Lovas. Appendix Editor: G.L. Molnar. Foreword (E. Teller).- Preface (A. Vertes, S. Nagy, Z. Klencsar).- 1. History of Nuclear and Radiochemistry (G. Friedlander, G. Herrmann).- 2. Basic Properties of the Atomic Nucleus (T. Fenyes).- 3. Nuclear Reactions (V.E. Viola).- 4. Nuclear Fission (J.O. Denschlag).- 5. Kinetics of Radioactive Decay (S. Nagy).- 6. Interaction of Radiation with Matter (D. Horvath, A. Vertes).- 7. Statistical Aspects of Nuclear Measurements (S. Nagy).- 8. The Standard Model of Elementary Particles (D. Horvath).- Appendix: Reference Data (R.B. Firestone, G.L. Molnar). Volume 2: Elements and Isotopes - Formation, Transformation, Distribution.Series Editors: A. Vertes, S. Nagy, Z. Klencsar. Appendix Editor: G.L. Molnar. 1. The Origin of the Chemical Elements (H. Oberhummer, A. Patkos, T. Rauscher).- 2. Natural Radioactive Decay Chains (H.C. Griffin).- 3. Radioelements (H.C. Griffin).- 4. Isotope Effects (G. Jancso).- 5. Isotopic Paleoclimatology (R. Bowen).- 6. Radioactive Dating Methods (R. Bowen).- 7. Production and Chemistry of Transuranium Elements (Y. Nagame, M. Hirata, H. Nakahara).- 8. Production and Identification of Transactinide Elements (G. Munzenberg).- 9. Chemistry of Transactinides (J.V. Kratz).- 10. Superheavy Elements (D.C. Hoffman, D.M. Lee).- Appendix: Table of the Nuclides (R.B. Firestone). Volume 3: Chemical Applications of Nuclear Reactions and Radiations.Series Editors: A. Vertes, S. Nagy, Z. Klencsar. Appendix Editor: G.L. Molnar. 1. Radiation Chemistry (L. Wojnarovits).- 2. Hot Atom Chemistry (H.K. Yoshihara, T. Sekine).- 3. Mossbauer Spectroscopy (E. Kuzmann, Z. Homonnay, S. Nagy, K. Nomura).- 4. Mossbauer Excitation by Synchrotron Radiation (M. Seto).- 5. Positron Annihilation Spectroscopies (K. Suvegh, T. Marek).- 6. Exotic Atoms and Muonium (D. Horvath).- 7. Neutron Scattering Methods in Chemistry (L. Pusztai).- 8. Activation Analysis (R. Zeisler, N. Vajda, G. Lamaze, G.L. Molnar).- 9. Applications of Neutron Generators (J. Csikai, R. Doczi).- 10. Chemical Applications of Accelerators (E. Koltay, F. Paszti, . Z. Kiss, L. Vincze, F. Adams).- 11. Tracer Technique (F. Ambe, S. Ambe, S. Enomoto).- Appendix: Reference Data (J. Csikai, R. Doczi, R.B. Firestone, Z. Homonnay, G.L. Molnar, R. Zeisler). Volume 4: Radiochemistry and Radiopharmaceutical Chemistry in Life Sciences.Series Editors: A. Vertes, S. Nagy, Z. Klencsar. Volume Editor: F. Rosch. Preface (F. Rosch).- In Memoriam Gerhard Stocklin (F. Rosch, H.-J. Wester, S.M. Qaim).- 1. Reactor-Produced Medical Radionuclides (S. Mirzadeh, L.F. Mausner, M.A. Garland).- 2. Cyclotron Production of Medical Radionuclides (S.M. Qaim).- 3. Radionuclide Generators (F. Rosch, F.F. Knapp).- 4. 11C: Labeling Chemistry and Labeled Compounds (G. Antoni, T. Kihlberg, B. Langstrom).- 5. 18F: Labeling Chemistry and Labeled Compounds (H.-J. Wester). 6. 99mTc: Labeling Chemistry and Labeled Compounds (R. Alberto, U. Abram).- 7. Radioiodination Chemistry and Radioiodinated Compounds (M. Eisenhut, W. Mier).- 8. Radiometals (non-Tc, non-Re) and Bifunctional Labeling Chemistry (H.R. Macke, S. Good).- 9. Radionuclide Therapy (M.R. Zalutsky).- 10. Dosimetry and Biological Effects of Ionizing Radiation (B. Kanyar, G.J. Koteles). Volume 5: Instrumentation, Separation Techniques, Environmental Issues.Series Editors: A. Vertes, S. Nagy, Z. Klencsar. Appendix Editor: G.L. Molnar. 1. Radiation Detection (H.C. Griffin).- 2. Dosimetry Methods (W.L. McLaughlin, A. Miller, A. Kovacs).- 3. Particle Accelerators (S. Biri, E. Koltay, A. Valek).- 4. Technical Application of Nuclear Fission (J.O. Denschlag).- 5. Isotope Separation (W.A. Van Hook).- 6. Solvent Extraction and Ion Exchange in Radiochemistry (G. Skarnemark). 7. Radiochemical Separations by Thermochromatography (A.F. Novgorodov, F. Rosch, N.A. Korolev).- 8. Environmental Radiation Protection (Y. Maeda, S. Osaki).- 9. Radioactive Waste Management (P.A. Baisden, C.E. Atkins-Duffin).- Appendix: Reference Data (R.B. Firestone, G.L. Molnar).

Mössbauer spectroscopic study of the formation of Fe(III) oxyhydroxides and oxides by hydrolysis of aqueous Fe(III) salt solutions

Abstract Mossbauer spectroscopy has been used to investigate the precipitates formed by hydrolysis of 0.1 M solutions of Fe(NO 3 ) 3 , FeCl 3 , Fe 2 SO 4 ) 3 , and NH 4 Fe(SO) 2 at 90°C. The isomer shifts, electric quadrupole splittings, and nuclear magnetic splittings were used for the qualitative and quantitative identification of the hydrolysis products. Proposals were made concerning the mechanism of formation of the oxides and hydroxyoxides of iron. Hydrolysis in the nitrate and chloride solutions proceeds by the formation of monomers and dimers of iron III) ions, followed by the formation of polymeric species. The polymers formed in the nitrate solution are not presumed to include the nitrate ion in the polymer chain, whereas the polymers formed in the chloride solution contain some chloride ions in place of the hydroxyl ion. The next step in the precipitation process is the formation of oxybridges and the development of α-FeOOH and β-FeOOH structures. This step is followed by loss of water and internal crystallization of α-FeOOH to α-Fe 2 O 3 in nitrate solution or by dissolution of β-FeOOH and growth of α-FeOOH in chloride solution. In sulfate solutions the formation of an FeSO 4 + complex suppresses the polymerization process and the formation of oxyhydroxides and oxides. Basic Fe(III) sulfates are formed instead.

Mössbauer spectroscopy and its application to corrosion studies

Abstract The principles and the experimental methods of Mossbauer spectroscopy are briefly summarized. The application of the Mossbauer technique in studies of metal corrosion—especially of iron—is presented.

Unusual coordination behavior of D-fructose towards dimethyltin(IV): metal-promoted deprotonation of alcoholic OH groups in aqueous solutions of low pH

Abstract To study the effect of the conformation of sugar hydroxy groups on metal complexation processes, complex formation of eight saccharides (D-fructose, L-sorbose, L-arabinose, D-arabinose, D-glucose, D-sorbitol, 2-deoxy-D-glucose and D-saccharose) with dimethyltin(IV) cations was investigated in aqueous solution by potentiometric equilibrium measurements, 13 C NMR, polarimetric and Mossbauer spectroscopic methods. The experimental results proved that deprotonation of D-fructose and L-sorbose is caused by the coordination of dimethyltin(IV) in the unusual low pH interval 4–6 in contrast to the other saccharides deprotonated in analogous way at pH > 8. Increasing the pH of the solution resulted in the formation of further complexes. Stability and composition of the species was determined by potentiometric studies. 13 C NMR measurements led to the assignment of the sugar OH groups participating in the processes. Mossbauer investigations in the quick-frozen solutions permitted the determination of the stereochemistry of tin(IV) in the complexes.

Electrochemical and in situ mössbauer studies of tin passivation

Abstract The tin passivation in borate buffer was studied using potentiodynamic curves recorded at high scanning rate (9 V min −1 , 3.6 V min −1 ). The most important feature of these curves is the presence of a current peak at around — 1180 mV ( vs sce ) which had not been previously observed. The nature of the passive film formed in the vicinity of this potential was characterized using in situ Mossbauer measurements. On the basis of these results it was concluded that in borate buffer solution: (a) the passive film formed at more negative range of potentials (− 1180 to − 780 mV) is duplex, consisting of highly amorphous Sn(OH) 2 or hydrated stannous oxide and SnO 2 or Sn(OH) 4 ; (b) at more positive potentials, the passive layer consists only of Sn(IV) hydroxide or oxide which ensures a more efficient passivation.

One metal–two pathways to the carboxylate-enhanced, iron-containing quercetinase mimics

Mononuclear iron(iii) flavonolate was synthesized as synthetic enzyme-substrate complex, and its direct and carboxylate-enhanced dioxygenation as biomimetic functional models with relevance to flavonol 2,4-dioxygenase are briefly described.

Structural studies of electrodeposited tin—cobalt alloys

Abstract The cast tin—cobalt alloys γ′Co3Sn2 (hexagonal) and CoSn2 (tetragonal) were prepared and studied using Mossbauer and X-ray measurements. These results were used in the indentification of the components of electrodeposited tin—cobalt alloys obtained from mildly alkaline sulphate baths. γ′Co3Sn2 (hexagonal), CoSn (cubic) and metallic tin were detected as components of the electrodeposited alloys. The relative amounts of the components is highly dependent on the bath operation conditions, and no γ′Co3Sn2 was observed when the concentration of electroactive tin in the plating bath was high. The Mossbauer parameters of all the studied alloys are given and are well within the observed values for binary tin alloys.

Synthesis, magnetochemistry, and spectroscopy of heterometallic trinuclear basic trifluoroacetates [Fe2M(μ3-O)(CF3COO)6 (H2O)3]·H2O (M = Mn, Co, Ni)

Three new µ3-oxo(trifluoroacetato) complexes [FeIII2MII(μ3-O)(CF3COO)6(H2O)3]·H2O [M = Mn (1), Co (2), Ni (3)] have been prepared. Compounds 1 and 2 crystallize in the monoclinic space groups C2/c [a = 22.002(5), b = 13.647(3), c = 24.767(4) A, β = 98.23(3)°] and C2/m [a = 21.426(4), b = 15.100(2), c = 14.815(3) A, β = 117.99(2)°], respectively. The coordination spheres of the metal ions are essentially octahedral, with the Fe−O distances [1.870(5) A] falling in the usual range for these systems. Magnetochemical studies reveal the presence of antiferromagnetic exchange in the isosceles triangular skeletons of the polynuclear species. Application of the isotropic spin Hamiltonian H = −2JFeM[SFe1SM + SMSFe2] − 2JFeFe[SFe1SFe2] gives the fitting parameters: gFe = gMn = 2.00, JFe-Fe = −56.50(7) and JFe-Mn = −16.23(4) cm−1 (1), gmol = 2.09(1), JFe-Fe = −42.8(3.5) cm−1, JFe-Co = −17.8(1.4) cm−1 (2) and gFe = 2.00, gNi = 2.215(2), JFe-Fe = −45.60(1) and JFe-Ni = −16.96(2) cm−1 (3). A Mossbauer investigation confirms that no electron transfer from MnII or CoII to FeIII occurs during the syntheses of these complexes. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)

A Mössbauer study on the hydration of brownmillerite (4CaO.A12O3.Fe2O3)

Abstract The hydration of the iron-bearing phase of portland cement or brownmillerite, can be easily studied by Mossbauer-spectrometry, because a very significant difference exists between the spectra of anhydrous and hydrated brownmillerite. The Mossbauer spectrum of anhydrous brownmillerite shows a magnetic hyperfine structure and iron is present in a complex environment. During hydration the magnetic hyperfine structure disappears and only one sharp line remains showing that all iron atoms are surrounded by the same, very symmetric environment. The hydration is almost complete after 14 days. The hydration product is a solid solution of tricalcium aluminate hexahydrate and tricalcium ferrite hexahydrate (hydrogarnet). The full quantity of iron is bound in this hydrate and is present in an octahedral environment. Excess aluminum is present in the form of amorphous hydroxide.

COORDINATION PROPERTIES OF L-CYSTEINE AND ITS DERIVATIVES TOWARDS DIETETHYLTIN(IV) IN AQUEOUS SOLUTION

Complex formation equilibria of L-cysteine (LH3), S-methyl-L-cysteine (LH2) and N-acetyl-Lcysteine (LH2) with diethyltin(IV) were studied in aqueous solution (I = 0.1 Μ NaC104). The formation constants of the complexes were determined by Potentiometrie equilibrium measurements. Besides the carboxil-oxygen, thiol-sulphur of L-cysteine and of its N-acetyl derivative were shown to be deprotonated and coordinated to the metal in the acidic region. Due to the stabilizing effect of additional thioether coordination in case of S-methyl-L-cysteine the formation of an MLH complex was detected. In case of Lcysteine and its S-methyl derivative, amino nitrogen served as third donor atom at higher pH. N-acetyl-Lcysteine participated in the complex formation only by two donor atoms in the whole pH range studied (211). For the system containing L-cysteine as ligand, Mössbauer investigations in quick-frozen solutions based on the partial quadrupole splitting concept reflected the geometry of the species formed.