Journal article
Uranyl Speciation on the Surface of Amidoximated Polyacrylonitrile Mats
Inorganic chemistry, Vol.59(12), pp.8134-8145
06/15/2020
DOI: 10.1021/acs.inorgchem.0c00440
PMCID: PMC7718723
PMID: 32437172
Abstract
Naturally occurring uranium is a widespread contaminant present in the water resources around the abandoned uranium mines in the southwest United States. A novel method for rapid uranium detection has been recently developed that relies on the sequestering of uranium by amidoximated polyacrylonitrile (AO-PAN) polymer mats and uses the Raman-active (ν
) symmetric stretch as the signal. The Raman signals obtained from uranium bearing AO-PAN were challenging to interpret due to an unknown uranyl speciation on the surface of the mats. Herein, we provide the synthesis and structural characterization of six model coordination compounds that contain acetamidoxime/benzamidoxime (AAO/BAO) coordinated to the uranyl cation: [UO
(η
-AAO)(NO
)
(H
O)] (
), [UO
(η
-AAO)
(NO
)
] (
), [UO
(η
-BAO)
(CH
OH)
] (
), [(UO
)
(η
-BAO)
(μ
-NO
)
] (
), [(UO
)
(μ
-O)
(μ
-BAO)
(η
-BAO)
(H
O)
](NO
)
(
), and [(UO
)
(μ
-O)
(μ
-BAO)
(η
-BAO)
Na(NO
)
](NO
)
(
). Solid-state Raman spectra of
-
showed dramatic differences in the uranyl ν
symmetric stretch depending on the coordination of the amidoxime functional group. The assignments made from the solid-state Raman spectra were used to deconvolute the solution-state Raman spectra of uranyl-acetamidoxime/benzamidoxime methanol solutions at different metal to ligand molar ratios. At low molar ratios (1 U:1 AAO/BAO and 1 U:2 AAO/BAO) the dominant species is the uranyl coordinated via the η
-oxygen atom of the oxime group, while at high molar ratios (1 U:3 AAO/BAO and 1 U:4 AAO/BAO) the dominant species are a tetrameric uranyl-μ
-O-η
-amidoxime complex similar to compounds
and
and a uranyl-η
-amidoxime complex similar to compounds
and
. Solid-state Raman spectra showed good agreement with Raman signals obtained from the uranyl-AO-PAN mats, demonstrating that binding motifs between uranyl and amidoxime in compounds
and
are the most representative of the uranyl species on the surface of the AO-PAN mats.
Details
- Title: Subtitle
- Uranyl Speciation on the Surface of Amidoximated Polyacrylonitrile Mats
- Creators
- Dmytro V Kravchuk - University of IowaAnamar Blanes Diaz - University of IowaMargaret E Carolan - University of IowaElias A Mpundu - University of IowaDavid M Cwiertny - University of IowaTori Z Forbes - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Inorganic chemistry, Vol.59(12), pp.8134-8145
- DOI
- 10.1021/acs.inorgchem.0c00440
- PMID
- 32437172
- PMCID
- PMC7718723
- NLM abbreviation
- Inorg Chem
- ISSN
- 0020-1669
- eISSN
- 1520-510X
- Grant note
- P30 ES005605 / NIEHS NIH HHS R01 ES027145 / NIEHS NIH HHS
- Language
- English
- Date published
- 06/15/2020
- Academic Unit
- Center for Health Effects of Environmental Contamination; Civil and Environmental Engineering; Core Research Facilities; Public Policy Center (Archive); Chemistry; Chemical and Biochemical Engineering
- Record Identifier
- 9984197087202771
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