ABSTRACT Raman spectroscopy is an ideal tool in the characterization of materials including PuO 2 . The wavelength‐dependent absorptivity material defines light penetration depth and relative scattering contribution from bulk surface. surface to total was investigated for calcined at various temperatures recorded with laser wavelengths 355, 325, 244 nm. These experiments provided first glimpse disappearance emergence new phonons electronic bands layers. indication wavelength transition...

Microparticle compositional characterization for nuclear forensics has traditionally been achieved by "gold-standard" destructive analytical techniques such as large geometry-secondary ion mass spectrometry and fission track-thermal ionization spectrometry, but long processing times total sample consumption eliminate the option of subsequent analysis other methods. Electron probe microanalysis widely employed rapid, nondestructive, micrometer-scale measurements imaging in fields material...

Preparation and characterization of a series pincer-type [P2Si]Co complexes are reported, including crystal structure the first base-free cobalt silylene complex. The cationic complex is strongly Lewis acidic oxophilic, readily coordinating bases such as triflate pyridine heterolytically cleaving O–H bonds in ethanol water.

Iridium complexes supported by four different diarylamido/bis(phosphine) PNP ligands have been studied as catalysts for the dehydrogenative borylation of terminal alkynes (DHBTA). Experimental mechanistic investigations on a representative ligand system established that reaction rate is zeroth order in concentration borylating agent HBpin, first [alkyne] and [Ir], inverse [H2]. These findings are understood arising from formation saturated, 18-electron resting state (PNP)IrH3Bpin (5a), which...

Anhydrous UF₄ stirred in water for 1–6 days forms UF₄(H₂O)_2.5 and a minor amount of uranyl fluoride. This hydrolysis results morphological spectroscopic changes.

Diffuse reflectance spectroscopy measurements in the shortwave infrared (930-1600 nm) spectral region were acquired for Pu2(C2O4)3•9H2O and its thermal decomposition product, PuO2. We analyzed a total of eight PuO2 samples that produced at different calcination temperatures (300, 350, 450, 525, 600, 675, 750, 900 °C). Our goal was to identify spectroscopic fingerprints could be used gain retrospective information regarding production parameters these important nuclear compounds. The diffuse...

A series of square-planar, low-spin Co(II) and Co(III) complexes supported by the POCOP pincer ligand have been prepared for purpose exploring reactions potentially involved in aryl halide coupling catalysis (POCOP = 2,6-diisopropylphosphinoxyphenyl). The investigations determined that Co(III)–aryl intermediates envisioned catalytic cycle are accessible, but desired is derailed a C–C reductive elimination reaction involves ligand. Metalation parent (POCOP)H with CoCl2 DMAP led to formation...

Actinium-225 (225Ac) can be produced with a linear accelerator by proton irradiation of thorium (Th) target, but the Th also underdoes fission and produces 400 other radioisotopes. No research exists on optimization cation step for purification. The herein examines exchange purification 225Ac. following variables were tested: pH load solution (1.5-4.6); rinse steps various concentrations HCl, HNO3, H2SO4, combinations HCl HNO3; chelators to block retention; MP50 AG50 resins; retention 20-45...

The effect of γ-irradiation on physico-chemical properties International Simple Glass (ISG) nuclear waste glass simulants with low iron impurities was investigated. study performed glasses produced by Corning Inc. (named ISG-1, ISG-2) following a 0.95 MGy dose. Fourier-transform infrared and Raman spectroscopy, chemical durability tests, dilatometry, differential scanning calorimetry, electron paramagnetic resonance (EPR), optical absorption, photoluminescence (PL) spectroscopy appraisals...

Plutonium research has been stifled by the significant number of administrative controls and safety procedures, space instrumentation limitations in radiological gloveboxes, potential for personnel equipment contamination. To address limited spectroscopic studies Pu-bearing compounds current scientific literature, this work presents use double-walled cells (DWCs) “clean” buildings/laboratories as an alternative to gloveboxes. This study reports first laser-induced breakdown spectroscopy...

Spectroscopic analysis of radiological materials has been historically limited to labs with older or less advanced scientific instrumentation. The development double-walled cells (DWCs) at the Savannah River National Laboratory (SRNL) enabled Pu-bearing compounds be removed from laboratories and studied in our radiologically clean spectroscopy laboratory state-of-the-art In this manuscript, we discuss contributions DWCs that have allowed application Raman spectroscopy, diffuse reflectance...

This work discloses the facile synthesis and efficacy of (PNP)IrH(OAc), a precatalyst for dehydrogenative borylation terminal alkynes (DHBTA). Unlike previously reported precatalysts in (PNP)Ir system (PNP = diarylamido/bis(phosphine) pincer), it is air-stable solid state. Upon exposure to air solution, possesses useful half-life on order 1–100 h, depending intensity mixing. Air-degraded solutions (PNP)IrH(OAc) retain DHBTA catalytic activity selectivity upon mixture alkyne HBpin. It also...

This manuscript describes the chemical transformations that occur during hydrolysis of uranium tetrafluoride (UF4) due to its storage in humid air (85% and 50% relative humidity) at ambient temperatures. was previously reported proceed slowly or not all (depending on percent humidity); however, previous reports relied primarily X-ray diffraction methods probe speciation. In our report, we employ a battery physiochemical probing techniques explore potential hydrolysis, including Raman...

This report discloses a combined experimental and computational study aimed at understanding C–S reductive elimination from Co(<sc>iii</sc>) supported by diarylamido/bis(phosphine) PNP pincer ligand.

Abstract The Raman spectrum of PuO 2 was measured up to 13,000 cm −1 with three different laser excitation wavelengths spanning the resonance (405 nm), near‐resonance (457 and preresonance (514 nm) energy range. Approximately 26 never‐before‐seen bands were observed between 3500 . Given very high shifts these relative insensitivity their spectral position interrogating wavelength, they are believed arise from an electronic origin. These present in both freshly calcined radiolytically aged ,...

Abstract Plutonium dioxide (PuO 2 ) is an important compound used in nuclear fuel, irradiation targets, and heat sources. As such, improved understanding of its structural spectroscopic properties has numerous applications. Alpha particle‐induced damage a PuO crystal lattice modifies several Raman spectrum, including band intensities, positions, widths. The decay also induces growth new bands creates electron‐trapped defects with luminescent properties. Herein, we show for the first time...

A method is described for using custom snap-on lids to protect chemicals in microtiter plates from evaporation and contamination. The contain apertures (diameter 1.5, 1.0, or 0.5 mm) through which the chemical building blocks can be transferred. lid with mm was tested a noncontact acoustic liquid handler; 1.0 1.5 were two tip-based handlers. All of reduced rate at solvents evaporated room air, greatly contamination by water oxygen air. In steady-state measurements, methanol, 1-hexene, 33%...

Uranium tetrafluoride is an important intermediate in the nuclear fuel cycle. Facile synthesis of its hydrate, uranium hydrate (UF4·2.5H2O), has recently been reported. The forms by contacting anhydrous UF4 with neat H2O at room temperature for 24 h or exposing to high relative humidity (>90%) conditions several weeks. These pathways are clear environmental relevance. Further understanding structure and optical spectra UF4·2.5H2O, especially water molecules, therefore necessary. Herein,...

The Savannah River National Laboratory (SRNL) has been developing advanced spectroscopic tools for the characterization of plutonium-bearing compounds with intent to develop material and process signatures nuclear forensics. Plutonium in a production, refining, or finishing facility will exist many forms including oxide precursors (PuF₄, PuF₃, Pu oxalate, etc.), oxide, metal. ability identify plutonium each these chemical determine their processing history is crucial...

This manuscript describes the synthesis of Os complexes supported by diarylamido/bis(phosphine) PNP pincer ligand. Compound (PNP)OsH(CO) (3-Os) was prepared analogy with previously reported 3-Ru. However, attempts to make (PNP)OsH3 (4-Os) analogously 4-Ru resulted in formation an unexpected compound (5-Os) that is a product addition BH3 unit across Os-N bond 4-Os. Nonetheless, 4-Os via alternative route. Unlike 4-Ru, appears be classical trihydride. Compounds 3-Ru, 3-Os, 4-Os, and 5-Os were...