Showing papers in "Journal of Inorganic and Nuclear Chemistry in 1979"

Abstract: The intercalation of n -propylamine, n -butylamine and ethylenediamine by the layered compound α-zirconium phosphate has been examined. Each of the amines forms a number of phases whose interlayer spacings are indicative of the orientation of the amines within the layers. At low uptakes of the n -alkyl amines, they appear to lie parallel to the layers. At higher contents a double layer forms with the carbon chain backbone roughly inclined at a 60° angle to the plane of the layer. A maximum of one n -alkyl amine molecule per phosphate group is intercalated. Half as much ethylenediamine is intercalated which constitutes the same number of amine-groups. The interlayer spacings indicate, however, that the ethylenediamine chain always lies parallel to the layer but in at least four different orientations, giving rise to as many phases.

Abstract: Formation region of γ-zirconium phosphate (γ-ZrP) is determined by using zirconium phosphate gels heated in phosphate solutions with various pH values. Sodium ions in the phosphate solutions play an important role in the formation of γ-ZrP. It is formed in the pH region where the protons of zirconium phosphate gels are partly exchanged with sodium ions. The crystal lattice parameters of γ-ZrP are determined to be a = 5.376±0.002 A . b = 6.636 ± 0.004 A , c = 24.56 ± 0.01 A and s = 93.94 ± 0.05° . A possible structural model for the crystal is proposed, in which ZrO6 octahedra and PO3(OH) tetrahedra are more densely linked by corners than in the known structure of α-ZrP.

Abstract: The crystal structure of tetrameric Al(OPr-iso) 3 has been determined by single crystal X-ray diffraction. The results obtained confirm the structure suggested by Bradley. A strucrural model of the polymerization equilibrium is suggested. A strict correlation between melting point values and degrees of association (or sample “age”) is established and an attempt is made to treat the physico-chemical properties of Al(OPr-iso) 3 in terms of a pseudo-binary trimer/tetramer system. The interaction between Al(OPr-iso) 3 and iso-PrOH has been studied with consideration of the interconversion equilibrium.

Abstract: Monodispersed cubic crystals (∼0.1 μm in edge length) of cobalt(II,III) oxide, Co3O4, have been obtained by heating cobalt acetate solutions (10−3–10−2 M) at ∼100°C for a few hours. Bubbling of oxygen prior to aging was found to greatly increase the yield in Co3O4. No precipitates have been obtained from other cobalt salt solutions (CoSO4, Co(NO3)2 and CoCl2) when these were treated in a similar manner. When sodium persulfate was used instead of oxygen as an oxidizing agent, the particles obtained on aging the cobalt(II) salt solutions at 100°C had a composition of CoO(OH) and were irregular in shape. Heating cobalt(II) salt solutions at 300°C in an autoclave yielded Co23O4 in all cases; in the presence of acetate ions the resulting particles were of cubic morphology but polydispersed, whereas other cobalt salts yielded irregularly shaped solids.

Abstract: Several complexes of palladium and nickel have been synthesized and subjected to a variety of in vitro/in vivo screens. Of the complexes submitted the most positive antibacterial was (πC 3 H 5 PdCl) 2 , antrivirals were cis Pd(NH 3 ) 2 Cl 2 and (NH 4 ) 2 PdCl 4 , anticancers were cis and trans Pd(NH 3 ) 2 Cl 2 , cis Pd(NH 3 ) 2 Cl 4 , Na 2 PdCl 6 , (NH 4 ) 2 PdCl 4 , ethylenediamineH 2 ·PdCl 4 , Pd(NH 3 ) 4 ·PdCl 4 , (πC 3 H 5 PdCl) 2 , Pd(cyclopentylamine) 2 Cl 2 , Pd(cyclohexylamine) 2 Cl 2 , and some palladium asparaginate complexes, and the most toxic complexes were (πC 3 H 5 PdCl) 2 and Ni(py) 4 (NCO) 2 . There appears to be different structural criteria which are necessary for active anticancer Pd complexes as compared to active Pt complexes. The advantages of introducing Pd into drugs are discussed.

Abstract: The influence of sulfate ions on the formation of an iron(III) oxide phase of colloidal size was studied by homogeneous titration of acidified iron(III) solutions with varying SO4/Fe ratios (0–2.4). During titration the optical density of the solution was continuously recorded. Solid phase analysis was performed by means of X-ray and Mossbauer spectroscopy. An analysis of the experimental results shows that the role of the sulfate ion is rather complex. The process of the nucleation and growth of the iron oxyhydroxides is described and the influence of sulfate on the various stages in that process is discussed. Certain stages are catalyzed by the sulfate ions, whereas other stages are suppressed.

Abstract: Reactions of powdered samples of the iron monosulfide phases mackinawite (tetragonal FeS1−x troilite (hexagonal FeS) and a hexagonal pyrrhotite (Fe0.9S), and of single crystals of troilite, with aqueous H2S at a total pressure of 1.8 MPa and temperatures up to 160°C have been investigated. The reaction sequences mackinawite → (greigite) → pyrrhotite → pyrite, and troilite → pyrrhotite → pyrite have been established by X-ray powder diffractometry. Morphological examination by scanning electron microscopy has permitted a distinction to be made between solid state and solution pathways for most of the transformations and factors which affect the rate of crystallization of pyrite have been identified.

Abstract: Distribution ratios for nitric acid, actinides, fission products and corrosion products between PUREX HLW-solution and 50% tributylphosphate in an aliphatic diluent have been investigated in the range 0.1–6 M nitric acid. Comparable measurements for some of the elements have been made in pure HNO3 in the range 0.05–11 M. Empirical equations have been derived for elements with distribution ratios above 0.01 in the investigated acidity range.

Abstract: Crystalline Ti(HPO4)2·2H2O has been obtained by slow decomposition of titanium fluoro-complexes in the presence of phosphoric acid. From the formation of intercalation compounds, X-ray powder patterns and density measurements, as well as from comparison with several acid salts of tetravalent metals, the following conclusions were derived: 1. (1) The crystal structure of Ti(HPO4)2·2H2O is built up of polymeric macro-anions, Tin(PO4)2n2n−, having negative fixed charges neutralized by protons (which can be easily exchanged by other cations), while the water is placed between the layers of these macro-anions. Polar organic molecules can also be intercalated between the macro-anions. 2. (2) The crystal structure of Ti(HPO4)2·2H2O in analogous to that of γ-Zr(HPO4)2·2H2O. 3. (3) The structural differences between the α and γ-phases are not due, as previously reported in the literature, to differences in the inter-layer structural arrangement of the same type of macro-anions but to a different structure of the macro-anions itself. From the conditions of the formation of the γ-Ti(HPO4)2·2H2O and γ-Zr(HPO4)2·2H2O it is concluded that the formation of the γ-phases is favoured by a high mole ratio [H2XO4−]/[M(IV)] in the solution. Some suggestion on the nomenclature for insoluble acid salts are proposed.

Abstract: Several new compounds, EuB4O7, EuB2O4 and Eu2B2O5 were synthesized. EuB4O7 and EuB2O4 crystallized in the orthorhombic, space group C2v7-Pnm21 with cell dimensions: a = 4.435(1), b = 10.731(1), c = 4.240(1) A and Z = 2 , and space group D2h14-Pnca with cell dimensions: a = 6.593(1), b = 12.063(2), c = 4.343(1) A and Z = 4 , respectively. Eu2B2O5 is monoclinic, space group C 2h 5 - P2 1 a with cell dimensions: a = 11.91(1), b = 5.36(1), c = 7.74(1) A , β = 92.7(1)° and Z = 4 . The IR patterns of EuB4O7, EuB2O4 and Eu2B2O5 were able to be ascribed to a three-dimensional network of BO4-tetrahedra, an endless chain of BO3 groups, (BO2)∞, and a B2O54− ion, respectively. The magnetic susceptibilities of these compounds were measured. EuB4O7 and Eu2B2O5 were paramagnetic in the ranges of measured temperature, and EuB2O4 was an antiferromagnet with the Neel temperature TN = 3 K. Their magnetic properties were understood by considering the relationship between their structures and the magnetic interactions.

Abstract: The extraction of titanium(IV), iron(III) and iron(II) by di-2-ethyl hexyl phosphoric acid in benzene has been studied as a function of contact time, the concentration of the extractant in the organic phase, the temperature, etc. The study has been performed at different titanium and iron concentration ratios. It was observed that at around 0.35 M of sulfuric acid in the aqueous phase, the extraction of titanium is at a maximum. The three metal ions are extracted in the order: Ti(IV) > Fe(III) > Fe(II) with 0.2 M extractant and 0.35 M sulfuric acid solution, the separation factors β1 and β2 for Ti(IV)Fe(III) and TI(IV)Fe(II) respectively are found to be: β 1 = D Ti(IV) D Fe(III) ≈60; β 2 = D Ti(IV) D Fe(II) ≈500 . As β2 is much greater than β1, the separation of titanium is facilitated if all the iron present is in the ferrous state. It has been observed that the separation of the metal ions is dependent on temperature of extraction, concentration of the extractant and acidity of the aqueous solution. Maximum extraction is shown at 50°C for Ti(IV) and Fe(II) and 40°C for Fe(III).

Abstract: The reactions of Cysteine hydrochloride (CysHCl) and Cysteinemethylester hydrochloride (OMeCysHCl) with K 2 MX 4 or PdCl 2 , where M:Pd(II), Pt(II) and X:Cl, Br have been studied in acidic, neutral and alkaline aqueous solutions. The isolated complexes are of 1:1 and 1:2 metal to ligand ratio as their elemental analyses show. They correspond to the formulae: M(Cy − ) 2 , M(Cys) 2 X 2 , (MCys − X) 2 , M(OMeCy − ) 2 , M(OMeCys) 2 X 2 , [M(OMeCys − )X] 2 and (MCys 2− ) n . Possible structures of the isolated complexes are suggested and discussed with respect to their IR spectra. The results indicate that the coordination sites strongly depend upon the pH of the solutions and the stoichiometry of the metal to ligand ratio.

Abstract: Exchange isotherms for hydrogen ion/alkali metal ions have been measured at 20 and 40°C, with a solution ionic strength of 0.1, in crystalline antimonic(V) acid as a cation-exchanger. The isotherms showed S-shaped curves for the systems of H + Na + , H + K + , H + Rb + and H + Cs + , but not for H + Li + exchange. The selectivity coefficients (logarithm scale) vs equivalent fraction ( X M + ) of alkali metal ions in the exchanger give linear functions for all systems studied. The selectivity sequences as a function of X M + decrease in the order; Na+>Rb+>Cs+>K+ for 0.0 – 0.1 of X M + , Na+>Rb+>K+>Cs+ for 0.1 – 0.32 and Na+>K+>Rb+>Cs+ for 0.32 – 1.0. Overall and hypothetical (zero loading) thermodynamic equilibrium constants were evaluated for these ion-exchange reactions.

Abstract: “Cation-cation” complexes Np(V)-Np(VI) and Np(V)-U(VI) have been studied in aqueous nitric and perchloric solutions by spectrophotometry and EPR. The formation of these complexes obeys the law of mass action, contrary to previous interpretations. These complexes are weak ( K = 3.0 , σ K % 5 for Np(V)-Np9VI); K = 3.7 ; σ K % = 3 for Np(V)-U(VI) inperchloric medium) and slightly more stable in perchloric than in nitric media. These complexes are of the outer-sphere type. A critical discussion of the different interpretations is proposed.

Abstract: The structure of the title compound, UO2(CH2COO)2·H2O, has been determined from three-dimensional X-ray data The crystals are orthorhombic, space group Pbcn with four formula units in a cell of dimensions a = 7583(2), b = 9491(3) and c = 10890(3) A Least-squares refinement has led to a value of the conventional R index of 0039 for the 418 unique reflections having I⩾3σ(I) The coordination geometry about the uranium atom is pentagonal bipyramidal The uranyl ions are equatorially surrounded by one water oxygen and by four carboxylate oxygen atoms of different succinic ligands Each ligand is shared by four uranyl units giving rise to a polymeric-like structure

Abstract: Tris(indole 3-acetates) and tris(indole 3-butyrates) of lanthanum, praseodymium, neodymium and samarium were prepared and characterized by elemental analysis, electronic and IR measurements. The f ↔ f spectra of the complexes show low intensity transitions, and positive values of bonding parameters δ(%) and b 1 2 , computed from the nephelauxetic ratio, indicated covalency.

Abstract: With regard to the assumption that thermodynamic processes such as complex formation and distribution equilibria of the rare earth elements (REE) are responsible for their fractionation during the mineralization of fluorites, the formation of the fluoro complexes of the REE has been studied. The investigation was carried out in 1 M NaCl-aqueous medium at 25°C and pH-rang ⩽ 5. From all the ligands to be considered at this pH-range only SO42− participate to the complex formation. Within the REE-series the stability constant of the monofluoro complexes has a maximum at Tb and the decrease Tb to La is more than its decrease Tb to Lu. The stability constant of difluoro complexes, on the contrary, increases gradually from La to Lu.

Abstract: Single crystals of indium trihydroxide were obtained by hydrothermal methods at varied concentrations and temperatures. The cubic form of indium trihydroxide crystallizes in space group Im , 3( T 5 h ), with a lattice constant of 7.9743(6) A. The expermental and calculated densities are 4.38 g cm −3 and 4.344 g cm −3 , respectively. An analysis of indium trihydroxide has been carried out by single crystal X-ray diffraction methods. The final refinement based on 106 independent reflections yields a conventional R value of 1.48%. Six oxygen atoms are octahedrally coordinated about each indium atom, and each oxygen atom is coordinated by two indium atoms. A neutron diffraction investigation verifies the conclusions obtained from the X-ray study and additionally shows the hydrogen atoms to be disordered. The 157 observed independent reflections obtained on a computer-controlled four-circle diffractometer yield a final R value of 3.09%. Indium trideuteroxide has been prepared in order to compare the IR spectra of In(OH) 3 and In(OD) 3 . Two different strengths of hydrogen-bonding are noted for the disordered hydrogens. The study of indium trihydroxide is part of a research program investigation the structure and morphology of M(OH) 3 compounds, which include the lanthanide trihydroxides. Indium trihydroxide is isomorphous with scandium trihydroxide and a newly-found cubic lutetium trihydroxide.

Abstract: The synthesis, thermal behaviour and crystal structure of lithium glutaratehydrogenglutaratedioxouranate(VI) tetrahydrate is described. The compound crystallizes in the monoclinic system, space group P21/n with a = 9.143(3), b = 26.825(11), c = 7.776(2) A, β = 101.2°(2) and Z = 4. The two glutarato ligands behave differently; one is bridging the uranyl groups in infinite chains running approximately in the a axis direction, the second is bridging the uranyl and the lithium ions. The carboxylic groups are chelated on the uranium and monodentate on the lithium. The structure is linked through a network of hydrogen bonding involving water molecules and oxygen atoms from the carboxylato groups. The geometry around the uranium is approximately hexagonal bipyramidal while the lithium is tetrahedrally coordinated with one glutarate oxygen and 3 water oxygens.

Abstract: Excitation functions and isomer ratios for 93 Tc 96 Tc from the reactions 93 Nb( α , xn ) have been measured between 16 and 72 MeV. The excitation functions cannot be satisfactorily explained with a model assuming only a statistically-equilibrated compound nucleus, but the inclusion of pre-equilibrium processes produces a much better fit. The isomer ratio data (expressed as high spin/low spin) show a characteristic increase followed by a decrease in the tail of the excitation function. This is explained by taking explicit account of the distribution in spin arising from the initial interaction. When combined with hybrid (compound nucleus plus pre-equilibrium) model calculations, this provides a satisfactory explanation of the observed isomer ratios. The fall in isomer ratio arises from the increasing importance of pre-equilibrium processes in the tail of the excitation function, since these processes appear to produce residual nuclei with lower average spins than those formed by compound nucleus decay.

Abstract: The equilibria of dioxouranium (VI) and carbonate ions in acid solution (log [H+] > −5) have been studied at 25°C by measuring, with a glass electrode, the hydrogen ion concentration of a series of UO2−2+ perchlorate solutions, saturated with CO2(g) at known partial pressure. The investigation covers the [U(VI)] values from 2.5 × 10−4 to 0.01 M, and the partial pressure of carbon dioxide from 0.2 to 0.97 atm. For each [U(VI)] level the hydrogen ion concentration was decreased from a value, corresponding to negligible complex formation, until solid U(VI) carbonates start to form. All the solutions contained 3 MClO4 added as NaClO4. The e.m.f. data may be explained by assuming, in addition to the hydrolysis complexes[24], the formation of UO2(OH)2CO2(=UO2CO3), (UO2)3(OH)5CO2+(=(UO2)3(OH)3CO3+) and a large species of probable composition (UO2)11(OH)24(CO2)62−, with the equilibrium constants given in Table 3.

Abstract: Kinetics of the reaction between Zn(II) ion and the peripherally positively charged tetra-(p-trimethylammoniumphenyl)porphyrin (H2TAPP) were investigated at 30°C and 0.5°F ionic strength (NaNO3). The reaction was found to be first order in Zn(II) ion and porphyrin concentration. The specific rate constant for the reaction, if the reacting species were [Zn(OH)+], is 210±30M −1 sec−1 in comparison with 1.50±0.10 M−1 sec−1 determined for the reaction of Zn2+. Both these rates are faster than the corresponding rates for the reaction of a negatively charged tetra-(p-sulfophenyl)porphyrin (H2TPPS). But the demetallation reaction of Zn(II)TAPP is about eight times slower than that of Zn(II)TPPS. No unusual anion dependence of the reaction is observed. Isotope effect and activation parameters of these reactions are presented.

Abstract: Uranium tetrachloride in THF solution has been found to react with NaH to yield UCl3(THF)x. From this solution the 1:1 adduct UCl3(THF) has been isolated. Unlike the parent UCl3, this material is soluble in THF enabling the study of a variety of reactions. The reactions of UCl3(THF)x with 4-picoline-N-oxide, TICp, NaCp and NaBH4 have been studied as well as the decomposition of UCl3(THF) at elevated temperatures.

Abstract: Optical absorption and electron spin resonance (ESR) spectral studies have been carried out for the complexes formed in the extractions of vanadium(IV) by tricaprylmethylammonium chloride (R 3 R′NCl; Aliquat-336), tri- n -octylamine (R 3 N; TOA), tri- n -octylphosphine oxide (R 3 PO; TOPO) and tri- n -butylphosphate ((RO) 3 PO: TBP) in benzene from hydrochloric acid solutions or mixed solutions of hydrochloric acid and lithium chloride. As a result, it is found that the species VOCl 2 · n L, VO(OH)Cl· n L and VO 2 Cl· n L (L = R 3 R′NCl, R 3 NHCl, R 3 PO, (RO) 3 PO; n = 1 for R 3 R′NCl and R 3 NHCl, n = 2 for R 3 PO and (RO) 3 PO) are formed in the organic phase.

Abstract: The oxovanadium(IV) complexes of the hydrazones derived from benzoylhydrazine and salicylaldehyde (BSH), o-hydroxyacetophenone (BAH), o-hydroxypropiophenone (BPH), o-hydroxybutyrophenone (BBH) and 2-hydroxy-1-naphthaldehyde (BNH) have been described. These complexes have been characterised by elemental analyses and by molecular weight, conductance, magnetic, IR and electronic spectral measurements. The IR spectra suggest the presence of phenoxide bridging and thus the complexes are formulated as dimers, each unit having 5-coordinate distorted square-pyramidal geometry. The low μeff values (1.02 – 1.26 B.M.) have been attributed to antiferromagnetic exchange coupling and the principal path for spin coupling is direct σ-metal-metal interaction. The electronic spectra have been interpreted in terms of energy level scheme delineated for distorted square-pyramidal geometry. Various ligand field parameters Dq, Ds, Dt along with NSH parameters DQ, DS and DT have been evaluated and the degree of distortion (DT/DQ) lies in the range 0.169 – 0.233.

Abstract: The crystal structures of Pr(OH)3, Eu(OH)3 and Tm(OH)3 have been determined from single-crystal, X-ray diffraction data. The hexagonal form of these lanthanide trihydroxides crystallizes in the space group P63/m(C6h2) with two formula units per unit cell. The respective lattice constants for the trihydroxides of Pr, Er and Tm are a 0 = 6.456(1), 6.352(1), and 6.221(1) A and c 0 = 3.769(1), 3.653(1), and 3.503(2) A . The metal atom of each is 9-coordinate with two unique MO bond distances and three independent OO bond distances. These isotypic compounds have been refined to conventional residual index values of 0.0320, 0.0280 and 0.0199, respectively. Fluorescence and IR data were collected on each of the isomorphous compounds. Refined parameters from this investigation have been added to earlier studies on structural trends in the lanthanide trihydroxides.