Chie Miyake

Co-ordination compounds of actinides—I: The determination of the stability constants of uranyl complexes with anions of carboxylic acids

Abstract The consecutive and gross stability constants of a number of mononuclear uranyl complexes with anions of common carboxylic acids have been determined spectrophotometrically at an ionic strength of 1·0 in aqueous solutions. Great care was exercised to avoid uncontrolled hydrolytic action on the complexes by the solvent. The data show that the maximum ligand number for anions of normal fatty acids increase in parallel with the length of the carbon chain. Further general relations appear between the stability of the uranyl complex and the dissociation constant of the carboxylic acid corresponding to the respective ligand anion. The results for oxalate and lactate furnish experimental proof for the fact that the maximum co-ordination number of the uranyl ion equals 6.

Spectroscopic studies on the uranyl complexes with 1,2-disubstituted benzenes

Abstract Uranyl complexes with a series of 1,2-disubstituted benzenes, such as phthalic acid (H 2 ph), salicylic acid (Hsal), pyrocatechol (H 2 pc), anthranilic acid (Hant), o -aminophenol (amph), and o -phenyleneediamine (phen), have been prepared and studied by i.r., electronic and NMR spectroscopy. Characteristic i.r. stretching frequencing (4000-200 cm −1 ) are reported for each complex. One or two new strong bands are observed in the region of 340–500 nm in all the complexes except uranyl phthalate, which are considered to be due to the charge transfer transition from the pπ orbital of the donor atoms to 5 f - and/or 6 d -orbitals of uranium. Characteristic proton magnetic resonance spectra of the complexes are also reported and discussed in relation to the magnetic anisotropy of the uranyl ion and to the drainage of electron density from the donor atom to the metal.

Direct evidence of uranium(V) intermediates by electron spin resonance in photo- and electrolytic reduction processes of uranyl complexes in organic solutions

Abstract ESR and optical spectra of pentavalent uranium have been observed in both processes of photo- and electrolytic reduction of UO2(dimethylsulphoxide)5(ClO4)2, UO2(NO3)2 · 5dimethylsulphoxide and UO2(NO3)2 · 2triethylphosphate in each corresponding organic ligand solution. The optical spectra measured in both reductions of these complexes indicate the formation of uranium(V) (λmax; 770, 970 and 1400 nm). Uranyl perchlorate shows a nearly symmetric ESR signal with g1 = 2.5 and the linewidth of 150 mT (type 1) in both photo- and electrolytic reduction processes. Nitrates show the type 1 signal in electrolytic reduction but an asymmetric signal with g1 = 1.97 (type 2) in photoreduction. These results reflect the difference in the first coordination spheres of perchlorate and nitrate complexes.

Electron spin resonance spectra and magnetic susceptibilities of mixed oxides, MUO3 (M; Li, Na, K, and Rb), of pentavalent uranium

Abstract In all magnetic susceptibility versus temperature curves for MUO 3 (M; Li, Na, K and Rb) a sharp spike appeared at 16–32 K. Magnetic susceptibilities are one order smaller than those of normal U(V) complexes. ESR spectra are very broad and have g -values of 2–4.

Photoelectron spectra of uranium(IV), (V) and (VI) complexes

Abstract Satellites were observed on 4f photoelectron spectra of uranium (IV) complexes, while none was seen for diamagnetic uranyl complexes. Photoelectron lines of oxygen 1s coordinated to the uranium ion were broad for NaUO 3 and uranyl complexes.

«The third phase» of extraction processes in fuel reprocessing. I, Formation conditions, compositions and structures of precipitates in Zr-degradation products of TBP systems

Formation conditions, compositions and structures of precipitates or “the third phase” were systematically examined in the systems of Zr and radiation depleted products of TBP, such as HDBP, H2MBP, H3PO4, by means of elemental analysis, X-ray diffraction, infrared spectra and 1H-NMR. It was confirmed that one of the most important origins for the third phase is a complexation between Zr ion and the depleted products of TBP. Followings were also elucidated: (1) When the depleted products co-exist with each other, the cooperative effects on the precipitate formation appear in low acid solutions. (2) Precipitate formation depends on the mole ratio of HDBP/Zr. The amount of precipitate reaches the maximum at the mole ratio of approximately 2 and decreases with increasing concentration of HDBP and finally disappears at approximately 10. (3) Precipitate formed at the mole ratio of approximately 2 has the chemical formula, Zr (NO3)2 (HDBP)2 (OH)2. (4) Precipitates of the Zr-H2MBP system begin to appear at the co...

An anomaly in the magnetic susceptibility of NaUO3

Abstract A sharp spike in the magnetic susceptibility—temperature curve at 32 K has been observed on NaUO 3 with a rhombohedral perovskite structure. The anomally corresponds exactly to the lambda-type anomally observed in the heat capacity—temperature curve by Lyon et al.

Coordination structures of lanthanide(III) and uranyl(VI) nitrato complexes with N,N′-dimethyl-N,N′-dibutylmalonamide. Part II

Abstract The coordination structures of lanthanide(III) and uranyl(VI) nitrato complexes with N,N ′-dimethyl- N,N ′-dibutylmalonamide (DMDBMA) were investigated in terms of 1 H, 13 C and 14 N NMR measurements, infrared spectrum, molar conductivity measurement, absorption spectrum, fluorescence spectrum, magnetic susceptibility measurement and thermal analysis. The chemical formulae of the isolated lanthanide(III) and uranyl(VI) nitrato-DMDBMA complexes are Ln(NO 3 ) 3 · 2DMDBMA and UO 2 (NO 3 ) 2 · DMDBMA, respectively. The DMDBMA coordinates to the lanthanide(III) and uranyl(VI) ions, with the oxygen atoms of carbonyl group and nitrate ions coordinate to the central metal ions in a bidentate manner. For the lanthanide(III) nitrato complexes, the coordination number is ten, and a change of the coordination structure occurs between the lighter and heavier complexes. The uranyl(VI) nitrato-DMDBMA complex has an eight-coordinated structure with the uranyl group surrounded by six oxygen atoms, four from the bidentate nitrate groups and two from the bidentate DMDBMA, lying in the plane perpendicular to the axial uranyl group.

Thin-section CT findings in peripheral lung cancer of 3 cm or smaller: are there any characteristic features for predicting tumor histology or do they depend only on tumor size?

Background Ground-glass opacity (GGO) is reported to be characteristic to lepidic growth of neoplasm in subsolid nodules. In solid nodules of lung cancer, however, there is no characteristic feature to be reported. Purpose To study if there are any thin-section CT findings characteristic to tumor histology or if they are only related to tumor size in solid nodules of the lung cancer. Material and Methods This study included 106 solid peripheral lung cancers of 3 cm or smaller (56 adenocarcinomas, 33 squamous cell carcinomas, and 17 small cell carcinomas) in which 16-slice CT with 1 mm collimation was performed before surgery. Six morphologic findings (presence or absence of lobulation, coarse spiculation, air bronchogram, cavity, pleural tag, and pleural-based lesion) and four measurements (ratio of the greatest transverse and vertical diameter to the shortest transverse diameter and density of lobulation and coarse spiculation) on thin-section CT images were evaluated. Density of lobulation (coarse spiculation) was defined as the ratio of lobulation (coarse spiculation) number to the greatest transverse diameter of a nodule. Results Air bronchogram (P < 0.01) was the only significant factor for predicting lung adenocarcinoma. The prevalence of air bronchogram was significantly greater in adenocarcinoma than in squamous cell carcinoma (P < 0.01) or small cell carcinoma (P < 0.01). As the tumor size advanced, significantly positive linear trends were seen in the prevalence of lobulation (P < 0.01), coarse spiculation (P < 0.01), and pleural tag (P < 0.01), and the mean values of density of lobulation (P < 0.01) and coarse spiculation (P < 0.01), while the significant negative linear trend was seen in the ratio of vertical diameter to the shortest transverse (P = 0.02). Conclusion Air bronchogram on thin-section CT is characteristic feature of solid adenocarcinoma of the lung. However, other thin-section CT findings are irrelevant to tumor histology and related only to tumor size.

Mutual oxidation states of uranium and molybdenum in UMoO ternary oxides

UMoO6, UMoO5, U2MoO8 and UMo2O8 have been prepared and identified by powder X-ray diffraction analysis. Mutual oxidation states of uranium and molybdenum in these ternary mixed oxides were determined by X-ray photoelectron spectroscopy (XPS), magnetic susceptibility measurement and electron spin resonance (ESR) absorption. All of the magnetic susceptibility vs. temperature curves for the oxides, except for UMoO6, have broad peaks around 50 K, suggesting a magnetic exchange interaction between paramagnetic ions through oxygen atoms. For UMo2O8, an ESR signal with g = 1.94 and a linewidth of 0.0057 T was observed with a small anisotropy. This signal is attributed to pentavalent molybdenum. From the XPS spectra, the oxidation states of uranium and molybdenum in U2MoO8 are found to be pentavalent and hexavalent respectively. However, in UMo2O8 both uranium and molybdenum are in mixed pentavalent and hexavalent states. In UMoO5, uranium is hexavalent with a shoulder corresponding to the pentavalent state, whereas molybdenum is pentavalent with a shoulder corresponding to the tetravalent state. In UMoO6, both uranium and molybdenum show the hexavalent state, as seen from the chemical formula. Alternations of oxidation states between uranium and molybdenum, according to the kind of ternary mixed oxides, were observed.