From Gas Phase Observations to Solid State Reality: The Identification and Isolation of Trinuclear Salicylaldoximato Copper Complexes.

Conditions have been identified in which phenolic aldoximes and ketoximes of the types used in commercial solvent extraction processes can be doubly deprotonated and generate polynuclear Cu complexes with lower extractant:Cu molar ratios than those found in commercial operations. Electrospray mass spectrometry has provided an insight into the solution speciation in extraction experiments and has identified conditions to allow isolation and characterization of polynuclear Cu-complexes. Elevation of pH is effective in enhancing the formation of trinuclear complexes containing planar {Cu-μ-O} or {Cu-μ-OH} units.

Direct isotopic analysis of solid uranium particulates on cotton swipes by microextraction-ICP-MS.

Direct isotope ratio analysis of solid uranium particulates on cotton swipes was achieved using a solution-based microextraction technique, coupled to a quadrupole inductively coupled plasma - mass spectrometer (ICP-MS). This microextraction-ICP-MS methodology provides rapid isotopic analysis which could be applicable to nuclear safeguards measurements. Particulates of uranyl nitrate hexahydrate (UO(NO)·6HO) and uranyl fluoride (UOF) ranging from 6 μm to 40 μm in length were transferred to cotton swipes with a particle manipulator.

Direct Uranium Isotopic Analysis of Swipe Surfaces by Microextraction-ICP-MS.

The ability to directly measure uranium isotope ratios on environmental swipes has been achieved through a solution-based microextraction process and represents a significant advancement toward the development of a rapid method to analyze international nuclear safeguard samples. Here, a microextraction probe is lowered and sealed onto the swipe surface, and analytes within the sampling site (∼8 mm) are dissolved and extracted into a flowing solvent of 2% nitric acid (HNO). The mobilized species are subsequently directed into an inductively coupled plasma-mass spectrometer (ICP-MS) for accurate and precise isotope ratio determination.

Trace Elemental Analysis of Bulk Thorium Using an Automated Separation-Inductively Coupled Plasma Optical Emission Spectroscopy Methodology.

Presented here is a novel automated method for determining the trace element composition of bulk thorium by inductively coupled plasma-optical emission spectroscopy (ICP-OES). ICP-OES is a universal approach for measuring the trace elemental impurities present in actinide-rich materials; however, due to the emission rich spectrum of the actinide, a separation from the trace elements is warranted for spectrochemical analysis. Here, AG MP-1 ion exchange resin was utilized for retention of the Th matrix, while allowing the trace element impurities to be separated prior to subsequent analysis using ICP-OES.

Rapid concentration and isotopic measurements of ultra-trace U fission products with comparison to an ORIGEN isotope depletion model.

This article presents the application of an automated online separation-direct analysis method, RAPID (Rapid Analysis of Post-Irradiation Debris), for the simultaneous measurement of both radioactive and stable fission isotopes from an irradiated highly-enriched uranium target. Developed for the measurement of the concentration and isotopic composition of over 40 elements down to the femtogram level, the RAPID method possesses the sensitivity, stability, and precision required to achieve accurate, low-level analyses of elements of non-natural origin. The isotopic compositions and concentrations of key fission elements cesium, strontium, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, and samarium have been measured repeatedly over a six-week period.

Development of a fast and efficient analytical technique for the isotopic analysis of fission and actinide elements in environmental matrices.

An automated separation-direct analysis scheme has been developed to determine both the concentration and isotopic composition of a suite of elements down to the low picogram level in a complex silicon-based matrix. With the ultimate goal of performing rapid analysis of materials with non-natural isotopic compositions, RAPID (Rapid Analysis of Post-Irradiation Debris) consists of a high-pressure ion chromatography system directly coupled to an inductively coupled plasma mass spectrometer. The RAPID method achieves matrix exclusion and direct online analysis of the elementally separated components, yielding precise isotopic compositions for up to 40 elements in less than one hour per sample.

Ion-pair triple helicates and mesocates self-assembled from ditopic 2,2'-bipyridine-bis(urea) ligands and Ni(II) or Fe(II) sulfate salts.

NiSO(4) and FeSO(4) self-assemble with heteroditopic ligands (L) comprising 2,2'-bipyridine and o-phenylene-(bis)urea cation- and anion-binding sites, respectively, into [ML(3)SO(4)] (M = Ni(2+), Fe(2+)) triple-stranded ion-pair helicates and mesocates.

Structural, magnetic, and electronic properties of phenolic oxime complexes of Cu and Ni.

Square planar complexes of the type Ni(L(1))(2), Ni(L(2))(2), Cu(L(1))(2), and Cu(L(2))(2), where L(1)H = 2-hydroxy-5-t-octylacetophenone oxime and L(2)H = 2-hydroxy-5-n-propylacetophenone oxime, have been prepared and characterized by single-crystal X-ray diffraction, cyclic voltammetry, UV/vis spectroscopy, field-effect-transistor measurements, density functional theory (DFT) and time-dependent DFT (TDDFT) calculations, and, in the case of the paramagnetic species, electron paramagnetic resonance (EPR) and magnetic susceptibility. Variation of alkyl groups on the ligand from t-octyl to n-propyl enabled electronic isolation of the complexes in the crystal structures of M(L(1))(2) contrasting with π-stacking interactions for M(L(2))(2) (M = Ni, Cu). This was evidenced by a one-dimensional antiferromagnetic chain for Cu(L(2))(2) but ideal paramagnetic behavior for Cu(L(1))(2) down to 1.

Using the outer coordination sphere to tune the strength of metal extractants.

A series of 3-substituted salicylaldoximes has been used to demonstrate the importance of outer-sphere interactions on the efficacy of solvent extractants that are used to produce approximately one-quarter of the world's copper. The distribution coefficient for extraction of copper by 5-tert-butyl-3-X-salicylaldoximes (X = H, Me, (t)Bu, NO(2), Cl, Br, OMe) varies by more than two orders of magnitude. X-ray structure determinations of preorganized free ligand dimers (10 new structures are reported) indicate that substituents with a hydrogen-bond acceptor atom attached to the 3-carbon atom, ortho to the phenolic oxygen, buttress the intermolecular hydrogen bond from the oximic proton.

Collision induced dissociation (CID) to probe the outer sphere coordination chemistry of bis-salicylaldoximate complexes.

Ligand-ligand interactions in the outer coordination sphere make an important contribution to the effects of 3-substituents on the stabilities of anionic Cu(II) salicylaldoximato complexes [CuL(L-H)](-). When substituents contain a different number of bonds the interpretation of CID tandem mass spectrometry must take into account the ability of ions to redistribute energy acquired in collisions within different numbers of vibrational modes.