Scanning Transmission X-ray Spectromicroscopy of Actinide Complexes

AbstractThe fundamental characterization and understanding of 5f electron behavior in actinide complexes is imperative to provide an enhanced basis for the rational and accelerated development of improved processes relevant to nuclear energy. Soft x-ray absorption spectroscopy utilizing the scanning transmission x-ray microscope (STXM) at the Advanced Light Source-Molecular Environmental Science (ALS-MES) Beamline 11.0.2 has been used to probe the electronic characteristics of a nitrogen donor ligand 2,6-Bis(2-benzimidazyl)pyridine (BBP) and its resulting U(IV) complex. The nitrogen K- and carbon K-edges have been collected from both ligand and uranium complex, as well as the uranium 4d-edge from the complex. Upon complexation, the light element absorption spectra change markedly and the uranium spectra from the complex is compared to the reference spectrum obtained from U(IV)Cl4. The evolution of the spectral features are described and interpreted within a simple conceptual framework. Based on spectral evidence alone, the uranium is bound through the pyridine-like nitrogens and the oxidation state of the uranium is consistent with a U(IV) species.

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Actinide Science with a Soft X-ray Scanning Transmission X-ray Microscope (STXM)

MRS Proceedings ◽

10.1557/proc-1264-z01-01 ◽

2010 ◽

Vol 1264 ◽

Cited By ~ 1

Author(s):

Per-Anders Glans ◽

Geza Szigethy ◽

Dustin Demoin ◽

Tolek Tyliszczak ◽

Jide Xu ◽

...

Keyword(s):

Environmental Science ◽

Materials Science ◽

Light Element ◽

Radioactive Materials ◽

Basic Approach ◽

X Ray ◽

Actinide Chemistry ◽

Scanning Transmission ◽

Uranium Nitride ◽

X Ray Absorption

AbstractSoft x-ray scanning transmission x-ray microscope (STXM) spectromicroscopy has been developed and employed to investigate several aspects of actinide chemistry and materials science at the Advanced Light Source Molecular Environmental Science (ALS-MES) Beamline 11.0.2 STXM end station. The basic approach and fundamentals of STXM experiments for radioactive materials systems is discussed. Representative results from STXM spectromicroscopy investigations of a mixed phase uranium nitride, single crystals of Eu(III)[TREN(Me-3,2-HOPO)]3 2H2O and hydrated Pu2(III)(C2O4)3(6H2O) 3H2O complexes are presented. The STXM images and soft x-ray absorption spectra illustrate the capabilities and utility of soft x-ray STXM for providing information about actinide materials, especially the light element constituents. Lastly, new and future opportunities for actinide science utilizing soft x-ray STXM are discussed in light of the planned upgrades for the STXM end stations at the ALS.

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Synthesis, characterization and single crystal X-ray structure determination of three cadmium(II) complexes derived from picric acid and p-nitrobenzoic acid in the presence and absence of nitrogen donor ligand N-(hydroxyethyl)ethylenediamine

Polyhedron ◽

10.1016/j.poly.2017.09.053 ◽

2018 ◽

Vol 139 ◽

pp. 178-188 ◽

Cited By ~ 3

Author(s):

Santosh Kumar ◽

Raj Pal Sharma ◽

Paloth Venugopalan ◽

Thammarat Aree

Keyword(s):

Single Crystal ◽

Structure Determination ◽

Picric Acid ◽

Donor Ligand ◽

X Ray ◽

Nitrobenzoic Acid ◽

Nitrogen Donor Ligand ◽

Nitrogen Donor ◽

Presence And Absence

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Chemical and orientational imaging of polymeric samples

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100168074 ◽

1994 ◽

Vol 52 ◽

pp. 68-69

Author(s):

H. Ade ◽

B. Hsiao ◽

G. Mitchell ◽

E. Rightor ◽

A. P. Smith ◽

...

Keyword(s):

Ethylene Terephthalate ◽

National Laboratory ◽

Brookhaven National Laboratory ◽

Carbonyl Groups ◽

Aromatic Rings ◽

Edge Structure ◽

X Ray ◽

Scanning Transmission ◽

Polymeric Samples ◽

X Ray Absorption

We have used the Scanning Transmission X-ray Microscope at beamline X1A (X1-STXM) at Brookhaven National Laboratory (BNL) to acquire high resolution, chemical and orientation sensitive images of polymeric samples as well as point spectra from 0.1 μm areas. This sensitivity is achieved by exploiting the X-ray Absorption Near Edge Structure (XANES) of the carbon K edge. One of the most illustrative example of the chemical sensitivity achievable is provided by images of a polycarbonate/pol(ethylene terephthalate) (70/30 PC/PET) blend. Contrast reversal at high overall contrast is observed between images acquired at 285.36 and 285.69 eV (Fig. 1). Contrast in these images is achieved by exploring subtle differences between resonances associated with the π bonds (sp hybridization) of the aromatic groups of each polymer. PET has a split peak associated with these aromatic groups, due to the proximity of its carbonyl groups to its aromatic rings, whereas PC has only a single peak.

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Spatially Resolved Characterization of Biogenic Manganese Oxide Production within a Bacterial Biofilm

Applied and Environmental Microbiology ◽

10.1128/aem.71.3.1300-1310.2005 ◽

2005 ◽

Vol 71 (3) ◽

pp. 1300-1310 ◽

Cited By ~ 94

Author(s):

Brandy Toner ◽

Sirine Fakra ◽

Mario Villalobos ◽

Tony Warwick ◽

Garrison Sposito

Keyword(s):

Careful Consideration ◽

Bacterial Biofilm ◽

Bacterial Cells ◽

X Ray ◽

Spatially Resolved ◽

Nexafs Spectroscopy ◽

Promising Tool ◽

Scanning Transmission ◽

X Ray Absorption

ABSTRACT Pseudomonas putida strain MnB1, a biofilm-forming bacterial culture, was used as a model for the study of bacterial Mn oxidation in freshwater and soil environments. The oxidation of aqueous Mn+2 [Mn+2 (aq)] by P. putida was characterized by spatially and temporally resolving the oxidation state of Mn in the presence of a bacterial biofilm, using scanning transmission X-ray microscopy (STXM) combined with near-edge X-ray absorption fine structure (NEXAFS) spectroscopy at the Mn L2,3 absorption edges. Subsamples were collected from growth flasks containing 0.1 and 1 mM total Mn at 16, 24, 36, and 48 h after inoculation. Immediately after collection, the unprocessed hydrated subsamples were imaged at a 40-nm resolution. Manganese NEXAFS spectra were extracted from X-ray energy sequences of STXM images (stacks) and fit with linear combinations of well-characterized reference spectra to obtain quantitative relative abundances of Mn(II), Mn(III), and Mn(IV). Careful consideration was given to uncertainty in the normalization of the reference spectra, choice of reference compounds, and chemical changes due to radiation damage. The STXM results confirm that Mn+2 (aq) was removed from solution by P. putida and was concentrated as Mn(III) and Mn(IV) immediately adjacent to the bacterial cells. The Mn precipitates were completely enveloped by bacterial biofilm material. The distribution of Mn oxidation states was spatially heterogeneous within and between the clusters of bacterial cells. Scanning transmission X-ray microscopy is a promising tool for advancing the study of hydrated interfaces between minerals and bacteria, particularly in cases where the structure of bacterial biofilms needs to be maintained.

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ChemInform Abstract: COMPLEXES WITH LIGANDS CONTAINING NITRILE GROUPS. PART XVIII HYDROGEN CYANIDE, A NEUTRAL NITROGEN DONOR LIGAND TO DIVALENT METAL IONS

Chemischer Informationsdienst ◽

10.1002/chin.197614324 ◽

1976 ◽

Vol 7 (14) ◽

pp. no-no

Author(s):

P. L. A. EVERSTEIN ◽

A. P. ZUUR ◽

W. L. DRIESSEN

Keyword(s):

Metal Ions ◽

Hydrogen Cyanide ◽

Divalent Metal ◽

Divalent Metal Ions ◽

Donor Ligand ◽

Nitrogen Donor Ligand ◽

Nitrogen Donor

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Diverse Chemical Mixing States of Aerosol Particles in the Southeastern United States

10.5194/acp-2017-1222 ◽

2018 ◽

Cited By ~ 1

Author(s):

Amy L. Bondy ◽

Daniel Bonanno ◽

Ryan C. Moffet ◽

Bingbing Wang ◽

Alexander Laskin ◽

...

Keyword(s):

Chemical Species ◽

Accumulation Mode ◽

X Ray ◽

Internal Mixing ◽

Scanning Transmission ◽

Sea Spray Aerosol ◽

Cloud Activation ◽

Mixing States ◽

X Ray Absorption ◽

Individual Particles

Abstract. Aerosols in the atmosphere are chemically complex with thousands or more chemical species distributed in different proportions across individual particles in an aerosol population. An internal mixing assumption, with species present in the same proportions across all aerosols, is used in many models and calculations of secondary organic aerosol (SOA) formation, cloud activation, and aerosol optical properties. However, many of these effects depend on the distribution of species within individual particles, and important information can be lost when internal mixtures are assumed. Herein, we show that during the Southern Oxidant and Aerosol Study (SOAS) in Centreville, Alabama, at a rural, forested location, that aerosols frequently are not purely internally mixed, even in the accumulation mode (0.2–1.0 µm). A range of aerosol sources and mixing states were obtained using computer controlled scanning electron microscopy with energy dispersive X-ray spectroscopy (CCSEM-EDX) and scanning transmission X-ray microscopy-near-edge X-ray absorption fine structure spectroscopy (STXM-NEXAFS). Particles that were dominated by SOA and inorganic salts were the majority of particles by number fraction from 0.2–5 microns with an average of 78 % SOA in the accumulation mode. However, during certain periods contributions by sea spray aerosol (SSA) and mineral dust were significant to accumulation (22 % SSA and 26 % dust) and coarse mode number concentrations (38 % SSA and 63 % dust). The fraction of particles containing key elements (Na, Mg, K, Ca, and Fe) were determined as a function of size for specific classes of particles. Within internally mixed SOA/sulfate particles

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Nitrogen donor ligand for capping ZnS quantum dots: a quantum chemical and toxicological insight

RSC Advances ◽

10.1039/c9ra05651c ◽

2019 ◽

Vol 9 (49) ◽

pp. 28510-28524 ◽

Cited By ~ 2

Author(s):

Vivek Pandey ◽

Vinay Kumar Tripathi ◽

Keshav Kumar Singh ◽

Tejasvi Bhatia ◽

Nitesh Kumar Upadhyay ◽

...

Keyword(s):

Quantum Dots ◽

Electronic Properties ◽

Quantum Chemical ◽

Donor Ligand ◽

Sensor Development ◽

Nitrogen Donor Ligand ◽

Optical And Electronic Properties ◽

Nitrogen Donor

Nanoparticles having strong optical and electronic properties are the most widely used materials in sensor development.

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Solution X-Ray Absorption Spectroscopy (XAS) for Analysis of Catalytically Active Species in Reactions with Ethylene by Homogeneous (Imido)vanadium(V) Complexes—Al Cocatalyst Systems

Catalysts ◽

10.3390/catal9121016 ◽

2019 ◽

Vol 9 (12) ◽

pp. 1016 ◽

Cited By ~ 6

Author(s):

Kotohiro Nomura

Keyword(s):

Active Species ◽

Oxidation States ◽

Donor Ligands ◽

Ethylene Dimerization ◽

Edge Structure ◽

Donor Ligand ◽

X Ray ◽

Catalytically Active ◽

Type V ◽

X Ray Absorption

Solution V K-edge XANES (X-ray absorption near edge structure) and EXAFS (extended X-ray absorption fine structure) analysis of vanadium(V) complexes containing both imido ligands and anionic ancillary donor ligands (L) of type, V(NR)(L)X2 (R = Ar, Ad (1-adamantyl); Ar = 2,6-Me2C6H3; X = Cl, Me, L = 2-(ArNCH2)C5H4N, OAr, WCA-NHC, and 2-(2’-benzimidazolyl)pyridine; WCA-NHC = anionic NHCs containing weak coordinating B(C6F5)3), which catalyze ethylene dimerization and/or polymerization in the presence of Al cocatalysts, has been explored. Different catalytically actives species with different oxidation states were formed depending upon the Al cocatalyst (MAO, Me2AlCl, AliBu3, etc.) and the anionic ancillary donor ligand employed. The method is useful for obtainment of the direct information of the active species (oxidation state, basic framework around the centered metal) in solution, and for better understanding in catalysis mechanism and organometallic as well as coordination chemistry.

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