David C. Moody

The chemistry of trivalent uranium: The synthesis and reaction chemistry of the tetrahydrofuran adduct of uranium trichloride, UCl3(THF)x☆

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.

Crystal and molecular structure of tricyclopentadienyltetrahydrofuranuranium(III), (η5-C5H5)3U·OC4H8

Abstract Tricyclopentadienyltetrahydrofuranuranium(III), (η 5 -C 5 H 5 ) 3 U·OC 4 H 8 , crystallizes in the centrosymmetric monoclinic space group P2 1 / n with a 8.248(3), b 24.322(17), c 8.357(4) A, β 101.29(5)°, V 1644.0 A 3 and ρ(calc) 2.04 g cm −1 for Z = 4 and mol.wt. 595.0. Diffraction data (Mo-K α , 2θ(max) 45°) were collected on an Enraf-Nonius CAD4 diffractometer and the structure was refined to R w (F) 4.7% for those 1530 reflections having I > 2σ( I ). The molecule consists of a distorted tetrahedral arrangement of THF and (η 5 -C 5 H 5 ) ligands with CpUCp angles in the range 110.4–122.4° and CpUO angles between 90.2 and 106.0°. Individual uranium-carbon distances range from 2.76(2) to 2.82(2) A and average 2.79[1] A. The uranium-oxygen distance of 2.551(10) A suggests a 10-coordinate U 3+ radius of 1.20 A in this class of compounds.

Platinum(0) complexes with bulky phosphines: Trinuclear SO2 and CS2 complexes

Abstract The synthesis and reaction chemistry of series of trinuclear SO 2 and CS 2 complexes containing the bulky phosphines PCy 3 and P(t-Bu) 3 are reported.

Catalytic reduction of sulfur dioxide

Many processes have been utilized with varying degrees of success for removal of sulfur dioxide from flue gases. Quite a few more have been proposed. One type of process that would appear quite attractive is the reduction of the SO/sub 2/ to sulfur. The present work was undertaken to examine the effect of using an extremely active hydrogenation catalyst to promote the reduction of SO/sub 2/ with H/sub 2/ at low enough temperatures such that H/sub 2/S formation could be minimized. Ruthenium on ..gamma..-alumina was examined and found to be quite active at temperatures as low as 150/sup 0/C. These results are discussed in this paper.

Raman study of SO2 at high pressure: aggregation, phase transformations, and photochemistry

Abstract We report Raman measurements made on SO2 in a diamond cell up to 75 kbar showing two new phases, solid II and solid III, which differ from known, zero-pressure solid I. Spectra indicate that SO2 molecules aggregate in solid III to possibly form a cyclical trimer; solid III is shown to be photochemically active to blue radiation.

Novel reactivity and low temperature (–60 °C)X-ray crystal structure determination of Ru(CO)2(η2-SO2·SO2)(PPh3)2

Crystals of the title complex have been obtained from SO2 saturated benzene–heptane solutions of Ru(CO)3(PPh3)2, and an X-ray crystal structure determination at –60 °C has shown not only η2-SO2 co-ordination to the ruthenium, but also a second molecule of SO2 co-ordinated to the terminal oxygen of the η2-SO2; reaction with excess of SO2 and PPh3 under anaerobic conditions results in stoicheiometric production of Ru(SO4)(CO)2(PPh3)2 plus PPh3S.

Electrolytic separation of selenium isotopes from proton irradiated RbBr targets

Abstract An electrochemical method has been developed to separate selenium isotopes from the spallation products induced in RbBr targets by 800-MeV protons. The selenium isotopes were electrolytically deposited as copper(I) selenide at the surface of a platinum gauze electrode. The copper(I) selenide was then chemically stripped from the electrode in an oxidizing acid environment. This solution was evaporated to soft dryness. The condensate was brought up in 0.1 F HCl and passed through a cation exchange column. Recoveries of better than 80% were obtained.

Production of mono-isotopic 88Y from the decay of 88Zr

Abstract Mono-isotopic 88 Y was recovered from the decay of 88 Zr. The 88 Zr was produced with other spallation products, by irradiating natural molybdenum metal with 800-MeV protons at the Los Alamos Meson Physics Facility. The 88 Zr was separated from the molybdenum target material and other spallation produced-isotopes by ion-exchange procedures. After the 88 Zr had decayed to 88 Y, a second ion-exchange separation was performed to isolate the 88 Y.

Alumina-catalyzed isotope exchange in CO☆

Abstract Catalytic isotope exchange in carbon monoxide has been found to occur over λ-alumina, 0.5% ruthenium/alumina, and molecular sieves. The exchange occurs readily at 400–500 °C with little or no carbon dioxide formation.

Low valent actinides as hydrogenation catalysts

The preparation of an olefin hydrogenation catalyst containing uranium is described. Reduction of UCl/sub 4/ with lithium aluminum hydride in tetrahydrofuran (THF) produces UCI/sub 3/THF as a transient species which ultimately precipitates as a black pyrophoric solid. Adsorption of the UCI/sub 3/THF onto ..gamma..-alumina prior to reduction with LiAlF/sub 4/ yields a reproducible catalyst. Characterization of the uranium-containing catalyst is almost impossible because of its reactivity. Data are presented to demonstrate a moderate activity of the catalyst with ethylene and cyclohexene hydrogenation at room temperature to ethane and cyclohexane, respectively.